text:
The influence of soil remediation on lead in house dust.
Lead in house dust has long been recognized as a principal source of excess lead absorption among children at the Bunker Hill Superfund Site (BHSS) in northern Idaho. House dust lead concentration from homeowner's vacuum cleaner bags has been monitored since the epidemic of childhood lead poisoning in 1974. Geometric mean house dust lead concentrations decreased from >10000 mg/kg in 1974 to approximately 4000 mg/kg in 1975, in response to air pollution control initiatives at the defective primary lead smelter. After smelter closure, 1983 mean dust lead concentrations were near 3000 mg/kg and were most dependent on soil sources. Following emergency soil removals from public areas and roadsides and fugitive dust control efforts in the mid-1980s, house dust lead decreased by approximately 40-60% to 1200-1500 mg/kg. In 1992, a cleanup goal of 500 mg/kg dust lead community average, with no individual home exceeding 1000 mg/kg, was adopted. This goal was to be achieved by a combination of contaminated soil removals and fugitive dust control efforts throughout the 21 square mile BHSS. Continual reductions in house dust lead concentrations have been noted throughout the residential area soil cleanup. Geometric mean house dust lead concentrations averaged approximately 500-600 mg/kg from 1996 to 1999 and dropped below 500 mg/kg in 2000. Analysis of these data indicates that approximately 20% of the variance in dust lead concentrations is attributed to yard, neighborhood, and community soil lead concentrations. Since 1996, dust lead concentrations and dust and lead loading rates have also been measured by dust mats placed at entryways into the homes. Neighborhood soil lead concentrations, household hygiene, the number of adults living in the home, and the number of hours a child spends outdoors in summer explain approximately 26% of the variance in mat dust lead loading rates. It is estimated that post-remedial house dust lead concentrations will stabilize at 400-500 mg/kg, as compared to approximately 200 mg/kg in socio-economically similar background communities; the difference possibly attributed to residual soil concentrations (3-6 times background), recontamination of rights-of-way, tracking of non-residential mining district soils and dusts, fugitive dusts associated with the remediation, and residual structural or carpet dusts. PMID:12568765
von Lindern, Ian H; Spalinger, Susan M; Bero, Bridget N; Petrosyan, Varduhi; von Braun, Margrit C
Seasonal variations of lead concentration and loading rates in residential house dust in northern Idaho.
Although lead hazards to humans have been known since ancient times and many regulatory actions and lead risk reductions have been achieved over the past century, lead contamination and exposure remain significant problems worldwide. The focus of this study was to investigate whether residential house dust lead concentrations and lead and dust loading rates in non-contaminated or "background" communities in northern Idaho are significantly affected by seasonal variations. House dust samples were obtained from 34 houses in five towns of northern Idaho from March to November 1999. There was evidence of significant seasonality of lead concentration in house dust in some towns, but no evidence in other towns. Because of the high variability between the towns and small sample sizes, it was difficult to make firm conclusions about seasonal patterns observed in house dust lead levels. A linear relationship between precipitation rates and dust loading rates was detected. PMID:16442226
Petrosyan, Varduhi; von Braun, Margrit C; Spalinger, Susan M; von Lindern, Ian H
Northern Idaho house dust and soil lead levels compared to the Bunker Hill Superfund Site.
House dust has been identified as a major exposure medium for lead (Pb) in children. High levels of Pb in soil and house dust have been recorded at the Bunker Hill Superfund Site (BHSS) in northern Idaho, an historic mining and smelting district. Soil and dust remediation at the site was required; however, regional background soil and dust Pb levels had not been well characterized. The objective of this survey was to determine background house dust Pb levels and to compare those levels with concentrations, and dust and Pb loading rates measured at the BHSS. Soil and house dust samples were collected in five towns demographically similar to the BHSS but unaffected by the mining industry. The background concentrations and loading rates were significantly lower than those observed at the site. House age was a significant factor affecting background soil and house dust Pb concentrations and loading rates. PMID:17171279
Spalinger, Susan M; von Braun, Margrit C; Petrosyan, Varduhi; von Lindern, Ian H
Canadian House Dust Study: Lead Bioaccessibility and Speciation
Vacuum samples were collected from 1025 randomly selected urban Canadian homes to investigate bioaccessible Pb (Pb{sub S}) concentrations in settled house dust. Results indicate a polymodal frequency distribution, consisting of three lognormally distributed subpopulations defined as 'urban background' (geomean 58 μg g⁻¹), 'elevated' (geomean 447 μg g⁻¹), and 'anomalous' (geomean 1730 μg g⁻¹). Dust Pb{sub S} concentrations in 924 homes
P Rasmussen; S Beauchemin; M Chenier; C Levesque; L MacLean; L Marrow; H Jones-Otazo; S Petrovic; L McDonald; H Gardner
Evolution of efficient methods to sample lead sources, such as house dust and hand dust, in the homes of children
Efficient sampling methods to recover lead-containing house dust and hand dust have been evolved so that sufficient lead is collected for analysis and to ensure that correlational analyses linking these two parameters to blood lead are not dependent on the efficiency of sampling. Precise collection of loose house dust from a 1-unit area (484 cmS) with a Tygon or stainless
S. S. Que Hee; B. Peace; C. S. Clark; J. R. Boyle; R. L. Bornschein; P. B. Hammond
Canadian House Dust Study: Lead Bioaccessibility and Speciation
Vacuum samples were collected from 1025 randomly selected urban Canadian homes to investigate bioaccessible Pb (Pb{sub S}) concentrations in settled house dust. Results indicate a polymodal frequency distribution, consisting of three lognormally distributed subpopulations defined as 'urban background' (geomean 58 {micro}g g{sup -1}), 'elevated' (geomean 447 {micro}g g{sup -1}), and 'anomalous' (geomean 1730 {micro}g g{sup -1}). Dust Pb{sub S} concentrations in 924 homes (90%) fall into the 'urban background' category. The elevated and anomalous subpopulations predominantly consist of older homes located in central core areas of cities. The influence of house age is evidenced by a moderate correlation between house age and dust Pb{sub S} content (R{sup 2} = 0.34; n = 1025; p < 0.01), but it is notable that more than 10% of homes in the elevated/anomalous category were built after 1980. Conversely, the benefit of home remediation is evidenced by the large number of homes (33%) in the background category that were built before 1960. The dominant dust Pb species determined using X-ray Absorption Spectroscopy were as follows: Pb carbonate, Pb hydroxyl carbonate, Pb sulfate, Pb chromate, Pb oxide, Pb citrate, Pb metal, Pb adsorbed to Fe- and Al-oxyhydroxides, and Pb adsorbed to humate. Pb bioaccessibility estimated from solid phase speciation predicts Pb bioaccessibility measured using a simulated gastric extraction (R{sup 2} = 0.85; n = 12; p < 0.0001). The trend toward increased Pb bioaccessibility in the elevated and anomalous subpopulations (75% {+-} 18% and 81% {+-} 8%, respectively) compared to background (63% {+-} 18%) is explained by the higher proportion of bioaccessible compounds used as pigments in older paints (Pb carbonate and Pb hydroxyl carbonate). This population-based study provides a nationally representative urban baseline for applications in human health risk assessment and risk management.
P Rasmussen; S Beauchemin; M Chenier; C Levesque; L MacLean; L Marrow; H Jones-Otazo; S Petrovic; L McDonald; H Gardner
Canadian house dust study: lead bioaccessibility and speciation.
Vacuum samples were collected from 1025 randomly selected urban Canadian homes to investigate bioaccessible Pb (Pb(S)) concentrations in settled house dust. Results indicate a polymodal frequency distribution, consisting of three lognormally distributed subpopulations defined as "urban background" (geomean 58 ?g g(-1)), "elevated" (geomean 447 ?g g(-1)), and "anomalous" (geomean 1730 ?g g(-1)). Dust Pb(S) concentrations in 924 homes (90%) fall into the "urban background" category. The elevated and anomalous subpopulations predominantly consist of older homes located in central core areas of cities. The influence of house age is evidenced by a moderate correlation between house age and dust Pb(S) content (R(2) = 0.34; n = 1025; p < 0.01), but it is notable that more than 10% of homes in the elevated/anomalous category were built after 1980. Conversely, the benefit of home remediation is evidenced by the large number of homes (33%) in the background category that were built before 1960. The dominant dust Pb species determined using X-ray Absorption Spectroscopy were as follows: Pb carbonate, Pb hydroxyl carbonate, Pb sulfate, Pb chromate, Pb oxide, Pb citrate, Pb metal, Pb adsorbed to Fe- and Al-oxyhydroxides, and Pb adsorbed to humate. Pb bioaccessibility estimated from solid phase speciation predicts Pb bioaccessibility measured using a simulated gastric extraction (R(2) = 0.85; n = 12; p < 0.0001). The trend toward increased Pb bioaccessibility in the elevated and anomalous subpopulations (75% � 18% and 81% � 8%, respectively) compared to background (63% � 18%) is explained by the higher proportion of bioaccessible compounds used as pigments in older paints (Pb carbonate and Pb hydroxyl carbonate). This population-based study provides a nationally representative urban baseline for applications in human health risk assessment and risk management. PMID:21563758
Rasmussen, Pat E; Beauchemin, Suzanne; Ch�nier, Marc; Levesque, Christine; MacLean, Lachlan C W; Marro, Leonora; Jones-Otazo, Heather; Petrovic, Sanya; McDonald, Lauren T; Gardner, H David
Cadmium and Lead Levels in House Dust from Smokers' and Non-Smokers' Homes Related to Nicotine Levels
In children there is an association between environmental tobacco smoke exposure and blood lead levels. One possible explanation is a contamination of house dust by cigarette ash and smoke, since several studies have shown that house dust is a source of lead exposure. Thus, house dust samples from the vacuum cleaner sacks from 72 homes in the city of Copenhagen
Stefan Willers; Hans O. Hein; Andrejs Sch�tz; Poul Suadicani; Finn Gyntelberg
Dust Weight and Asthma Prevalence in the National Survey of Lead and Allergens in Housing (NSLAH)
Background Settled dust has been used in studies to assess exposures to allergens and other biologically active components, but it has not been considered in the aggregate in relation to respiratory health outcomes in the general population. Objective We addressed whether total house dust weight, an index of total dust exposure, was associated with respiratory health outcomes in the National Survey of Lead and Allergens in Housing (1998�1999) (NSLAH). Methods NSLAH was a cross-sectional survey designed to represent permanently occupied housing units in the United States. In each household, a questionnaire was administered and settled dust was vacuumed from five locations. Linear regression models were used to identify predictors of dust weight; logistic regression models were used to examine the relationship between dust weight and asthma and wheeze. Results Dust weight samples were available for 829 households, and survey information was available for 2,456 participants (children and adults). Lower income, older homes, household pets, having a smoker in the house, and less frequent cleaning predicted higher dust weight levels in U.S. households. Higher levels of dust weight were associated with greater odds of current asthma and wheeze. The strongest associations were seen for wheeze [adjusted odds ratio (OR) = 1.99; 95% confidence interval (CI), 1.21�3.28 for bedroom bed dust; OR = 2.81; 95% CI, 1.52�5.21 for upholstery dust). These associations persisted when adjusting for allergen and endotoxin exposures. Conclusions Dust weight, an index of total dust exposure in the home, may contribute to respiratory outcomes independently of the exposure to specific components.
Elliott, Leslie; Arbes, Samuel J.; Harvey, Eric S.; Lee, Robert C.; Salo, Paivi M.; Cohn, Richard D.; London, Stephanie J.; Zeldin, Darryl C.
A study of urban housing demolitions as sources of lead in ambient dust: demolition practices and exterior dust fall.
Demolition of older housing for urban redevelopment purposes benefits communities by removing housing with lead paint and dust hazards and by creating spaces for lead paint-free housing and other community resources. This study was conducted to assess changes, if any, in ambient dust lead levels associated with demolition of blocks of older lead-containing row houses in Baltimore, Maryland (USA). In this article we present results based on dust-fall samples collected from fixed locations within 10 m of three demolition sites. In subsequent reports we will describe dust lead changes on streets, sidewalks, and residential floors within 100 m of the demolition sites. Geometric mean (GM) lead dust-fall rate increased by > 40-fold during demolition to 410 micro g Pb/m2/hr (2,700 micro g Pb/m2 per typical work day) and by > 6-fold during debris removal to 61 micro g Pb/m2/hr (440 micro g Pb/m2 per typical work day). Lead concentrations in dust fall also increased during demolition (GM, 2,600 mg/kg) and debris removal (GM, 1,500 mg/kg) compared with baseline (GM, 950 mg/kg). In the absence of dust-fall standards, the results were compared with the U.S. Environmental Protection Agency's (U.S. EPA's) dust-lead surface loading standard for interior residential floors (40 micro g/ft2, equivalent to 431 micro g/m2); daily lead dust fall during demolition exceeded the U.S. EPA floor standard by 6-fold on average and as much as 81-fold on an individual sample basis. Dust fall is of public health concern because it settles on surfaces and becomes a pathway of ambient lead exposure and a potential pathway of residential exposure via tracking and blowing of exterior dust. The findings highlight the need to minimize demolition lead deposition and to educate urban planners, contractors, health agencies, and the public about lead and other community concerns so that society can maximize the benefits of future demolition activities nationwide.
Farfel, Mark R; Orlova, Anna O; Lees, Peter S J; Rohde, Charles; Ashley, Peter J; Chisolm, J Julian
Factors affecting lead and cadmium levels in house dust in industrial areas of eastern Germany
The indoor exposure of 381 women (52�59 years old) to lead and cadmium was assessed by measuring the levels of the contaminants in sedimented house dust. The study was conducted in the areas surrounding the towns of Hettstedt, a region of mining and smelting of non-ferrous ores, of Bitterfeld, a centre of chemical production and coal mining, and of Zerbst,
Ines Meyer; Joachim Heinrich; Ulrich Lippold
The bioaccessibility of lead (Pb) from vacuumed house dust on carpets in urban residences.
Risk assessments for toxicants in environmental media via oral exposure often rely on measurements of total concentration in a collected sample. However, the human digestive system cannot dissolute all of a toxicant present in the binding matrix, and cannot absorb it with nearly 100% efficiency. In vitro bioaccessibility has been developed as a method to estimate oral bioavailability of a toxicant using a physiologically-based extraction procedure. Bioaccessibility measurements are more physiologically relevant than strong acid leaching measurements of concentration. A method for measuring bioaccessible lead in house dust was derived from the bioaccessibility method currently used for heavy metals in contaminated soils. House dust was collected from carpets in typical urban residences. Bioaccessible lead was measured in house dust (<75 microm) from the homes of 15 participants. The bioaccessibility ranged from 52.4% to 77.2% in gastric fluid, and 4.9% to 32.1% in intestinal fluid. House dust samples from five homes were analyzed to assess the relationship among lead bioaccessibility of three particle size fractions (<75, 75-150, and 150-250 microm). Changes in lead bioaccessibility as a function of particle size fraction were not significant for gastric fluid (p= 0.7019); however they were significant for intestinal fluid (p= 0.0067). This decrease of bioaccessibility may result from the readsorption of dissolved lead onto the dust particles or precipitation of lead with phosphates in a high-pH environment. The bioaccessibility data obtained for two biofluids were applied to the IEUBK model, and results for intestinal bioaccessibility of lead provide support for the model default value of 30% lead bioavailability of dust as a reasonable population indicator for dose, but the higher values for gastric bioaccessibility of lead appeared to provide an upper bound that approached actual blood lead levels in the children living in the studied homes. This upper bound seemed to overcome some of the limitations of the model when it lacks child-specific activity data and characterization of all exposure routes. PMID:16492186
Yu, Chang Ho; Yiin, Lih-Ming; Lioy, Paul J
Chemical speciation and bioaccessibility of lead in surface soil and house dust, Lavrion urban area, Attiki, Hellas
In the Lavrion urban area study, Hellas, a five-step sequential extraction method was applied on samples of �soil� (n�=�224), affected by long-term mining and metallurgical activities, and house dust (n�=�127), for the purpose of studying the potential bioaccessibility of lead and other metals to humans. In this paper, the\\u000a Pb concentrations in soil and house dust samples are discussed, together
Alecos Demetriades; Xiangdong Li; Michael H. Ramsey; Iain Thornton
House dust as possible route of environmental exposure to cadmium and lead in the adult general population
Contaminated soil particles and food are established routes of exposure. We investigated the relations between biomarkers of exposure to cadmium and lead, and the metal loading rates in house dust in the adult residents of an area with a soil cadmium concentration of ?3mg\\/kg (n=268) and a reference area (n=205). We determined the metal concentrations in house dust allowed to
Janneke Hogervorst; Michelle Plusquin; Jaco Vangronsveld; Tim Nawrot; Ann Cuypers; Etienne Van Hecke; Harry A. Roels; Robert Carleer; Jan A.. Staessen
House dust mites can be found all over the world where human beings live independent from the climate. Proteins from the gastrointestinal tract- almost all known as enzymes�- are the allergens which induce chronic allergic diseases. The inhalation of small amounts of allergens on a regular base all night leads to a slow beginning of the disease with chronically stuffed nose and an exercise induced asthma which later on persists. House dust mites grow well in a humid climate - this can be in well isolated dwellings or in the tropical climate - and nourish from human skin dander. Scales are found in mattresses, upholstered furniture and carpets. The clinical picture with slowly aggravating complaints leads quite often to a delayed diagnosis, which is accidently done on the occasion of a wider spectrum of allergy skin testing. The beginning of a medical therapy with topical steroids as nasal spray or inhalation leads to a fast relief of the complaints. Although discussed in extensive controversies in the literature�- at least in Switzerland with the cold winter and dry climate - the recommendation of house dust mite avoidance measures is given to patients with good clinical results. The frequent ventilation of the dwelling with cold air in winter time cause a lower indoor humidity. Covering encasings on mattresses, pillow, and duvets reduces the possibility of chronic contact with mite allergens as well as the weekly changing the bed linen. Another option of therapy is the specific immunotherapy with extracts of house dust mites showing good results in children and adults. Using recombinant allergens will show a better quality in diagnostic as well as in therapeutic specific immunotherapy. PMID:22477664
Carrard, A; Pichler, C
House dust as possible route of environmental exposure to cadmium and lead in the adult general population
Contaminated soil particles and food are established routes of exposure. We investigated the relations between biomarkers of exposure to cadmium and lead, and the metal loading rates in house dust in the adult residents of an area with a soil cadmium concentration of >=3mg/kg (n=268) and a reference area (n=205). We determined the metal concentrations in house dust allowed to settle for 3 months in Petri dishes placed in the participants' bedrooms. The continuously distributed vegetable index was the first principal component derived from the metal concentrations in six different vegetables. The biomarkers of exposure (blood cadmium 9.2 vs. 6.2nmol/L; 24-h urinary cadmium 10.5 vs. 7.0nmol; blood lead 0.31 vs. 0.24{mu}mol/L), the loading rates of cadmium and lead in house dust (0.29 vs. 0.12 and 7.52 vs. 3.62ng/cm{sup 2}/92 days), and the vegetable indexes (0.31 vs. -0.44 and 0.13 vs. -0.29 standardized units) were significantly higher in the contaminated area. A two-fold increase in the metal loading rate in house dust was associated with increases (P<0.001) in blood cadmium (+2.3%), 24-h urinary cadmium (+3.0%), and blood lead (+2.0%), independent of the vegetable index and other covariates. The estimated effect sizes on the biomarkers of internal exposure were three times greater for house dust than vegetables. In conclusion, in the adult population, house dust is potentially an important route of exposure to heavy metals in areas with contaminated soils, and should be incorporated in the assessment of health risks.
Hogervorst, Janneke [Centrum voor Milieukunde, Limburgs Universitair Centrum, Diepenbeek (Belgium); Plusquin, Michelle [Studiecooerdinatiecentrum, Departement Hart-en Vaatziekten, Katholieke Universiteit Leuven (Belgium); Vangronsveld, Jaco [Centrum voor Milieukunde, Limburgs Universitair Centrum, Diepenbeek (Belgium); Nawrot, Tim [Studiecooerdinatiecentrum, Departement Hart-en Vaatziekten, Katholieke Universiteit Leuven (Belgium); Cuypers, Ann [Centrum voor Milieukunde, Limburgs Universitair Centrum, Diepenbeek (Belgium); Van Hecke, Etienne [Onderzoeksgroep voor Sociale en Economische Geografie, Katholieke Universiteit Leuven (Belgium); Roels, Harry A. [Unite de Toxicologie Industrielle et de Medecine du Travail, Universite catholique de Louvain, Bruxelles (Belgium); Carleer, Robert [Centrum voor Milieukunde, Limburgs Universitair Centrum, Diepenbeek (Belgium); Staessen, Jan A. [Studiecooerdinatiecentrum, Departement Hart-en Vaatziekten, Katholieke Universiteit Leuven (Belgium)]. E-mail: firstname.lastname@example.com
House dust as possible route of environmental exposure to cadmium and lead in the adult general population.
Contaminated soil particles and food are established routes of exposure. We investigated the relations between biomarkers of exposure to cadmium and lead, and the metal loading rates in house dust in the adult residents of an area with a soil cadmium concentration of > or = 3 mg/kg (n=268) and a reference area (n=205). We determined the metal concentrations in house dust allowed to settle for 3 months in Petri dishes placed in the participants' bedrooms. The continuously distributed vegetable index was the first principal component derived from the metal concentrations in six different vegetables. The biomarkers of exposure (blood cadmium 9.2 vs. 6.2 nmol/L; 24-h urinary cadmium 10.5 vs. 7.0 nmol; blood lead 0.31 vs. 0.24 micromol/L), the loading rates of cadmium and lead in house dust (0.29 vs. 0.12 and 7.52 vs. 3.62 ng/cm(2)/92 days), and the vegetable indexes (0.31 vs. -0.44 and 0.13 vs. -0.29 standardized units) were significantly higher in the contaminated area. A two-fold increase in the metal loading rate in house dust was associated with increases (P<0.001) in blood cadmium (+2.3%), 24-h urinary cadmium (+3.0%), and blood lead (+2.0%), independent of the vegetable index and other covariates. The estimated effect sizes on the biomarkers of internal exposure were three times greater for house dust than vegetables. In conclusion, in the adult population, house dust is potentially an important route of exposure to heavy metals in areas with contaminated soils, and should be incorporated in the assessment of health risks. PMID:16843453
Hogervorst, Janneke; Plusquin, Michelle; Vangronsveld, Jaco; Nawrot, Tim; Cuypers, Ann; Van Hecke, Etienne; Roels, Harry A; Carleer, Robert; Staessen, Jan A
Lead speciation in indoor dust: a case study to assess old paint contribution in a Canadian urban house.
Residents in older homes may experience increased lead (Pb) exposures due to release of lead from interior paints manufactured in past decades, especially pre-1960s. The objective of the study was to determine the speciation of Pb in settled dust from an urban home built during WWII. X-ray absorption near-edge structure (XANES) and micro-X-ray diffraction (XRD) analyses were performed on samples of paint (380-2,920�mg Pb kg(-1)) and dust (200-1,000�mg Pb kg(-1)) collected prior to renovation. All dust samples exhibited a Pb XANES signature similar to that of Pb found in paint. Bulk XANES and micro-XRD identified Pb species commonly found as white paint pigments (Pb oxide, Pb sulfate, and Pb carbonate) as well as rutile, a titanium-based pigment, in the <150�?m house dust samples. In the dust fraction <36�?m, half of the Pb was associated with the Fe-oxyhydroxides, suggesting additional contribution of outdoor sources to Pb in the finer dust. These results confirm that old paints still contribute to Pb in the settled dust for this 65-year-old home. The Pb speciation also provided a clearer understanding of the Pb bioaccessibility: Pb carbonate�>�Pb oxide�>�Pb sulfate. This study underscores the importance of taking precautions to minimize exposures to Pb in house dust, especially in homes where old paint is exposed due to renovations or deterioration of painted surfaces. PMID:21465232
Beauchemin, Suzanne; MacLean, Lachlan C W; Rasmussen, Pat E
Lead speciation in indoor dust: a case study to assess old paint contribution in a Canadian urban house
Residents in older homes may experience increased lead (Pb) exposures due to release of lead from interior paints manufactured in past decades, especially pre-1960s. The objective of the study was to determine the speciation of Pb in settled dust from an urban home built during WWII. X-ray absorption near-edge structure (XANES) and micro-X-ray diffraction (XRD) analyses were performed on samples of paint (380-2,920 mg Pb kg{sup -1}) and dust (200-1,000 mg Pb kg{sup -1}) collected prior to renovation. All dust samples exhibited a Pb XANES signature similar to that of Pb found in paint. Bulk XANES and micro-XRD identified Pb species commonly found as white paint pigments (Pb oxide, Pb sulfate, and Pb carbonate) as well as rutile, a titanium-based pigment, in the <150 {micro}m house dust samples. In the dust fraction <36 {micro}m, half of the Pb was associated with the Fe-oxyhydroxides, suggesting additional contribution of outdoor sources to Pb in the finer dust. These results confirm that old paints still contribute to Pb in the settled dust for this 65-year-old home. The Pb speciation also provided a clearer understanding of the Pb bioaccessibility: Pb carbonate > Pb oxide > Pb sulfate. This study underscores the importance of taking precautions to minimize exposures to Pb in house dust, especially in homes where old paint is exposed due to renovations or deterioration of painted surfaces.
Beauchemin, Suzanne; MacLean, Lachlan C.W.; Rasmussen, Pat E. (Health Canada); (NRC)
Lead Speciation in Indoor Dust: A Case Study to Assess Old Paint Contribution in a Canadian Urban House
Residents in older homes may experience increased lead (Pb) exposures due to release of lead from interior paints manufactured in past decades, especially pre-1960s. The objective of the study was to determine the speciation of Pb in settled dust from an urban home built during WWII. X-ray absorption near-edge structure (XANES) and micro-X-ray diffraction (XRD) analyses were performed on samples of paint (380-2,920 mg Pb kg{sup -1}) and dust (200-1,000 mg Pb kg{sup -1}) collected prior to renovation. All dust samples exhibited a Pb XANES signature similar to that of Pb found in paint. Bulk XANES and micro-XRD identified Pb species commonly found as white paint pigments (Pb oxide, Pb sulfate, and Pb carbonate) as well as rutile, a titanium-based pigment, in the <150 m house dust samples. In the dust fraction <36 {mu}m, half of the Pb was associated with the Fe-oxyhydroxides, suggesting additional contribution of outdoor sources to Pb in the finer dust. These results confirm that old paints still contribute to Pb in the settled dust for this 65-year-old home. The Pb speciation also provided a clearer understanding of the Pb bioaccessibility: Pb carbonate > Pb oxide > Pb sulfate. This study underscores the importance of taking precautions to minimize exposures to Pb in house dust, especially in homes where old paint is exposed due to renovations or deterioration of painted surfaces.
S Beauchemin; L MacLean; P Rasmussen
Factors Affecting Lead, Cadmium, and Arsenic Levels in House Dust in a Smelter Town in Eastern Germany
Hettstedt, a city in eastern Germany with a long history of mining and smelting of nonferrous ores, has several industrial sources of heavy metals. The indoor exposure to metals of children (5 to 14 years old) in the Hettstedt area was assessed by measuring the levels of lead, cadmium, and arsenic contamination in sedimented house dust. Factors which influence the
Ines Meyer; Joachim Heinrich; Ulrich Lippold
Garden soil and house dust as exposure media for lead uptake in the mining village of Stratoni, Greece.
The relationships between two exposure media, garden soil and house dust, were studied for Pb uptake in Stratoni village in northern Greece, an industrial area of mining and processing of sulphide ore. Lead data for the two media were assessed in terms of total and bioaccessible content, measurement and geochemical variability, and mineralogical composition. It was found that total Pb was enriched in house dust samples by a factor of 2 on average. Total Pb concentration in soil samples had a maximum of 2,040�mg/kg and reached a maximum of 7,000�mg/kg in house dust samples. The estimated variability due to measurement uncertainty was dominated by the sampling process, and the proportion of sampling variance was greater for soil samples, indicating a higher degree of Pb heterogeneity in soil on the given spatial scale of sampling strata. Although the same general spatial trend was observed for both sampling media with decreasing Pb concentration by increasing distance from the ore-processing plant, Pb in dust samples displayed the highest concentrations within a 300-600-m zone from the ore-processing facility. The significant differences which were observed in Pb speciation between the studied media were explained by differences in mineralogical composition of outdoor soil and indoor dust. Lead-enriched Fe and Mn oxides predominated in soil samples while fine galena grains (<10-20�?m diameter) were the major Pb-bearing phase in dust samples. The integrated exposure uptake biokinetic model was used to predict the risk of elevated blood lead levels in children of Stratoni. Model prediction indicated an average probability of 61�% for blood-Pb to exceed 10�?g/dl. The results underline the importance of house dust in risk assessment and highlight the effect of outdoor and indoor conditions on the fate of Pb in the particular environment of Stratoni. PMID:24292695
Argyraki, Ariadne
The association of lead-contaminated house dust and blood lead levels of children living on a former landfill in Puerto Rico.
Exposure to lead in children living on a former landfill in Vega Baja-Puerto Rico, a United States Environmental Protection Agency (USEPA) designated Superfund Site, is a major health concern. Direct contact with lead-contaminated soil is considered a major exposure source. However, there is a lack of information regarding the contribution of lead-contaminated house dust to children's blood lead concentrations. This study evaluated the relationship between lead contaminated-house dust and children's blood lead levels. Blood from 42 children, aged 6 years old or less, and dust from 29 houses were analyzed for lead, and face-to-face interviews were performed to gather information on potential risk factors for high blood lead levels. Blood lead levels ranged from 0.97 to 7.79 micrograms/dL. Lead values for floors fluctuated from 0.12 to 98.30 micrograms/ft2, with 17% of houses surpassing the USEPA standard of 40 micrograms/ft2. Multiple regression analysis showed that lead in window sills, toy chewing and soil eating habits were significant predictors of blood lead levels. Further investigations aimed at assessing the long-term effects of constant exposure to environmental lead in these children are warranted. PMID:12866140
S�nchez-Nazario, Elia Enid; Mansilla-Rivera, Imar; Derieux-Cort�s, Jean-Claude; P�rez, Cynthia M; Rodr�guez-Sierra, Carlos J
Chemical speciation and bioaccessibility of lead in surface soil and house dust, Lavrion urban area, Attiki, Hellas.
In the Lavrion urban area study, Hellas, a five-step sequential extraction method was applied on samples of 'soil' (n�=�224), affected by long-term mining and metallurgical activities, and house dust (n�=�127), for the purpose of studying the potential bioaccessibility of lead and other metals to humans. In this paper, the Pb concentrations in soil and house dust samples are discussed, together with those in rocks and children's blood. Lead is mainly associated with the carbonate, Fe-Mn oxides and residual fractions in soil and house dust. Considering the very low pH of gastric fluids (1-3), a high amount of metals, present in soil (810-152,000�mg/kg Pb) and house dust (418-18,600�mg/kg�Pb), could be potentially bioaccessible. Consequently, children in the neighbourhoods with a large amount of metallurgical processing wastes have high blood-Pb concentrations (5.98-60.49�?g/100�ml; median 17.83�?g/100�ml; n�=�235). It is concluded that the Lavrion urban and sub-urban environment is extremely hazardous to human health, and the Hellenic State authorities should urgently tackle this health-related hazard in order to improve the living conditions of local residents. PMID:20524052
Demetriades, Alecos; Li, Xiangdong; Ramsey, Michael H; Thornton, Iain
Factors affecting lead, cadmium, and arsenic levels in house dust in a smelter town in eastern Germany
Hettstedt, a city in eastern Germany with a long history of mining and smelting of nonferrous ores, has several industrial sources of heavy metals. The indoor exposure to metals of children (5 to 14 years old) in the Hettstedt area was assessed by measuring the levels of lead, cadmium, and arsenic contamination in sedimented house dust. Factors which influence the dust loading rate and the surface loading rates of these contaminants in house dust were investigated. The geometric mean of the dust loading rate was 8.9 mg/m[sup 2] day. The geometric means of surface loading rates were 1.14, 0.024, and 0.023 [micro]g/m[sup 2] day for lead, cadmium, and arsenic, respectively. Factors that were significantly associated with surface loading rates included the city area of residence, automobile traffic near home, parent with occupational exposure to heavy metals, type of heating, housing characteristics, whether child's home is damp, number of persons living in the child's home,and parents' education. The most significant of these factors was the city area of residence, which reflects the distance from the metal sources; this factor accounted for about half of the variances explained by the regression models.
Meyer, I.; Heinrich, J. (GSF-Forschungszentrum fuer Umwelt und Gesundheit, Neuherberg (Germany). Inst. fuer Epidemiologie); Lippold, U. (Inst. fuer Wasser-, Boden- und Lufthygiene des Umweltbundesamtes Berlin (Germany))
MedlinePLUS Videos and Cool Tools
... mattress pad, blankets, and bedspread WEEKLY in hot water. Water at a temperature of 130 degrees or higher ... control house dust mites. Although washing in hot water kills house dust mites, the bedding will soon ...
Canadian House Dust Study: population-based concentrations, loads and loading rates of arsenic, cadmium, chromium, copper, nickel, lead, and zinc inside urban homes.
The Canadian House Dust Study was designed to obtain nationally representative urban house dust metal concentrations (?g g(-1)) and metal loadings (?g m(-2)) for arsenic (As), cadmium (Cd), chromium (Cr), copper (Cu), nickel (Ni), lead (Pb), and zinc (Zn). Consistent sampling of active dust of known age and provenance (area sampled) also permitted the calculation of indoor loading rates (mg m(-2) day(-1) for dust and ?g m(-2) day(-1) for metals) for the winter season (from 2007 to 2010) when houses are most tightly sealed. Geomean/median indoor dust loading rates in homes located more than 2 km away from industry of any kind (9.6/9.1 mg m(-2) day(-1); n=580) were significantly lower (p<.001) than geomean (median) dust loading rates in homes located within 2 km of industry (13.5/13.4 mg m(-2) day(-1); n=421). Proximity to industry was characterized by higher indoor metal loading rates (p<.003), but no difference in dust metal concentrations (.29?p?.97). Comparisons of non-smokers' and smokers' homes in non-industrial zones showed higher metal loading rates (.005?p?.038) in smokers' homes, but no difference in dust metal concentrations (.15?p?.97). Relationships between house age and dust metal concentrations were significant for Pb, Cd and Zn (p<.001) but not for the other four metals (.14?p?.87). All seven metals, however, displayed a significant increase in metal loading rates with house age (p<.001) due to the influence of higher dust loading rates in older homes (p<.001). Relationships between three measures of metals in house dust - concentration, load, and loading rate - in the context of house age, smoking behavior and urban setting consistently show that concentration data is a useful indicator of the presence of metal sources in the home, whereas dust mass is the overriding influence on metal loadings and loading rates. PMID:23220142
Rasmussen, Pat E; Levesque, Christine; Ch�nier, Marc; Gardner, H David; Jones-Otazo, Heather; Petrovic, Sanya
Chemical Contaminants in House Dust: Occurrences and Sources.
National Technical Information Service (NTIS)
Pesticides, polynuclear aromatic hydrocarbons (PAHs), lead (Pb), and other metals accumulate in home soil and house dust. Exposure of infants and toddlers to Pb by dust may be greater than other pathways. Many pollutants found in carpet dust are protected...
J. W. Roberts W. T. Budd J. Chuang R. G. Lewis
Sixty-four samples of house dust from 16 long-established households in the Denver, Colorado area were analyzed for the presence of house dust mites (Dermatophagoides sp.). No mites were found in house dust from 12 of the sampled houses and small numbers (10 to 40 mites/g of house dust) were found from the other four. In an additional four houses which contained furniture recently imported from other areas, 100 to 360 mites/g of dust were found, and 2 years later up to 200 mites/g were still present. Twenty-eight percent of the mites in repeat collections from the latter homes were alive. The mite allergen content of house dust samples was analyzed by RAST inhibition against pooled sera from mite allergic patients. When dust from four long-established Denver households where no mites were found was employed, there was an average binding of 37.2%; with dust from the four Denver households with low levels of mites and no imported furniture, binding averaged 39.5%. In contrast, with house dust from four "positive control" homes in California and New York there was only 26.1% binding (P less than .005). The results of this study suggest that there are small numbers of nonintroduced house dust mites in some Denver houses, but that they contribute little mite antigen and are probably of minimal clinical significance in mite-sensitive patients. Large numbers of mites can be introduced with furnishings and may persist for at least 2 years. Similar small mite populations might be expected in other areas with comparable relative humidity. PMID:4061975
Moyer, D B; Nelson, H S; Arlian, L G
Lead Speciation in House Dust from Canadian Urban Homes Using EXAFS Micro-XRF and Micro-XRD
X-ray absorption fine-structure (XAFS) spectroscopy, micro-X-ray fluorescence (μXRF), and micro-X-ray diffraction (μXRD) were used to determine the speciation of Pb in house dust samples from four Canadian urban homes having elevated Pb concentrations (>1000 mg Pb kg⁻¹). Linear combination fitting of the XAFS data, supported by μXRF and μXRD, shows that Pb is complexed in a variety of molecular environments,
L MacLean; S Beauchemin; P Rasmussen
Levels and sources of heavy metals in house dust
The concentration and the sources of heavy metals (Pb, Cd, Zn and Cu) in house dust samples of nine selected houses of Jalil Town, Gujranwala, Pakistan are determined and a comparison with the concentration of these metals in respective street dust samples is given. Sources, exterior as well as interior are identified. The extent of contribution of lead in house
N. Jabeen; S. Ahmed; S. T. Hassan; N. M. Alam
Laboratory and Evaluation of Dust and Dust Lead Recoveries for Samplers and Vacuum Cleaners. Volume 1: Objectives, Methods, and Results.
National Technical Information Service (NTIS)
This project was undertaken by the EPA Office of Pollution Prevention and Toxics (OPPT) to evaluate house dust sampling methods and to assess the efficacy of typical household vacuuming on removing leaded dust from residential surfaces. Dust-lead sampling...
Epidemiology of house-dust mites.
Available epidemiologic data on the occurrence of house-dust mites in dwellings demonstrates a clear association between increased indoor air humidity and the increased occurrence of house-dust mites in house dust. Furthermore, in temperate climates, there is a threshold level of indoor air humidity of 7 g/kg (45% relative humidity at usual indoor air temperatures). Indoor air humidities below this level for extended periods will eradicate house-dust mites from dwellings. A reduction in inhabitant exposure to house-dust mites is implemented by reduction of indoor air humidity by controlled mechanical ventilation. Individual ventilation levels are estimated from the actual size of house, number of inhabitants, and average outdoor air humidity in winter. In contrast, more humid areas of the world with average outdoor humidities above 6-7 g/kg in winter will support uniformly large populations of house-dust mites, and reductions in indoor air humidity will have a comparatively minor effect on the occurrence of house-dust mites. Present-day building of energy-efficient houses with increased sealing of the building envelope, paralleled by a similar renovation of older houses, has increased indoor air humidity and is probably the cause of the almost fourfold increase in the occurrence of house-dust mites in Danish dwellings. PMID:10096805
Korsgaard, J
Encapsulation of steel foundry bag house dusts in cement mortar
The purpose of this study was to investigate the properties of bag house dusts generated by steel foundries when stabilized with Portland cement at high levels of cement addition. The main bag house dust studied was obtained as a byproduct of steel manufacture, at Pacific Steel Limited in Auckland, New Zealand, whereas others were sourced from BHP New Zealand, Masport, and A and G Price foundries. The main examination techniques used in this study were leachate testing, scanning electron microscopy, X-ray diffraction, and compressive strength measurements. The findings showed that all the dusts investigated varied in their composition and physical makeup. Those bag house dusts that contained elevated levels of zinc severely retarded the hydration of cement within the first 2 weeks, but accelerated the strengths at late ages (28 days). The zinc was predominantly in the form of zinc oxide, which, when mixed with cement, produced the complex, calcium zinc hydrate. When cement was doped with zinc oxide, it was also found to display the same type of retardation as was found with the high ZnO bag house dusts. Lead also displayed a slight accelerating phenomena at 28 days, but the retention of lead in stabilized materials, as measured by the toxicity characteristic leaching procedure, was higher than that for zinc. The Masport, A and G Price, and two BHP New Zealand Steel bag house dusts did not show accelerating characteristics; however, Pacific Steel and the other two BHP New Zealand Steel zinc oxide-containing bag house dusts did.
Hamilton, I.W. [Golden Bay Cement, Whangarei (New Zealand)] [Golden Bay Cement, Whangarei (New Zealand); Sammes, N.M. [Univ. of Waikato, Hamilton (New Zealand). Dept. of Technology] [Univ. of Waikato, Hamilton (New Zealand). Dept. of Technology
Laboratory Evaluation of Dust and Dust Lead Recoveries for Samplers and Vacuum Cleaners. Volume 2: Appendices from the Quality Assurance Project Plan.
National Technical Information Service (NTIS)
This project was undertaken by the EPA Office of Pollution Prevention and Toxics (OPPT) to evaluate house dust sampling methods and to assess the efficacy of typical household vacuuming on removing leaded dust from residential surfaces. Dust-lead sampling...
Stability evaluation of house dust mite vaccines for sublingual immunotherapy
Allergen-specific immunotherapy with house dust mite (HDM) aller- gen extracts can effectively alleviate the symptoms of allergic rhinitis and as- thma. The efficacy of the immunotherapeutic treatment is highly dependent on the quality of house dust mite vaccines. This study was performed to assess the stability of house dust mite allergen vaccines prepared for sublingual immuno- therapy. Lyophilized Dermatophagoides pteronyssinus
Lidija Burazer; Katarina Milovanovic; Tanja Cirkovic-Velickovic; Marija Gavrovic-Jankulovic
Method of suppressing lead dust
A method of suppressing lead dust generated in the manufacture of pasted lead acid storage battery plates by coating the surface of a pasted battery plate with a solution or a suspension comprising ammonium sulfate, copolymer and water. The resultant water insoluble film is made porous by the simultaneous evolution of ammonia gas produced during the coating process. The porous water insoluble film on the battery plate results in an electric storage battery with a lower internal resistance, than previously disclosed coatings and produces a battery with performance characteristics less inhibited than those made with previously disclosed coatings.
Wilson, F.
[House dust mite in Kutahya, Turkey.].
The aim of this study was to determine the prevalence and species of house dust mites (HDM) in Kutahya (Turkey). The prevalence of house dust mites (HDM) was found to be 18.05%. The following species were identified: Tyrophagus putrescentiae, (43.96%), Dermatophagoides pteronyssinus (31.03%), Acarus siro (13.79%), Lepidoglyphus destructor (1.72%), Glycphagus domesticus (2.58%) and Cheyletus spp. (1.72%). HDM were found from April to October and a high rate, from April to June. A very high rate of Dermatophagoides pteronyssinus was found in August and of Tyrophagus putrescentiae and Acarus siro in July. The number of collected HDM was high in July. The amount of HDM per gram was determined to be 0.13. PMID:17160837
Akdem?r, Cihangir; G�rdal, H�lya
Further studies in allergenic identity between house dust and the house dust mite, Dermatophagoides farinae Hughes, 1961.
The sera from 99 Japanese asthmatic subjects were studied for the allergenic similarity between house dust and the House-dust Mite, Dermatophagoides farinae Hughes, 1961. A close correlation (correlation coefficient 0.92, P less than 0.01) was obtained between house dust and the mite with the radioallergosorbent test (RAST). High correlation was not noted between house dust and other allergens such as smoky brown cockroach, Periplaneta fuliginosa, Aspergillus, book lice, Liposcelis bostricophilus, Cheyletus malaccensis and Tribolium confusum. IgE antibody to the mite reduced significantly after the incubation of the sera with house dust and IgE antibody to house dust reduced markedly after the incubation of the sera with the mite. These results further support the view that the mite is the most important allergenic component in house dust. PMID:1200424
Morita, Y; Miyamoto, T; Horiuchi, Y; Oshima, S; Katsuhata, A
Analysis of Lead Dust Clearance Testing.
National Technical Information Service (NTIS)
The U.S. Environmental Protection Agency (EPA) gathered data about local clearance dust results to characterize and assess the likelihood of achieving the HUD Interim Guidelines Clearance Standards for a wide variety of housing units, components and surfa...
B. Skarpness W. Strauss Y. L. Chou
Lead, arsenic, and polycyclic aromatic hydrocarbons in soil and house dust in the communities surrounding the Sydney, Nova Scotia, tar ponds.
This study evaluated lead, arsenic, and polycyclic aromatic hydrocarbon (PAH) contamination in the residential communities adjacent to the Sydney, Nova Scotia, tar ponds, the area considered Canada's worst contaminated site. The tar pond remediation policy has been limited to the site and some residential properties. We compared background concentrations in 91 soil samples taken 5-20 km from the coke oven site with those in soil samples from the three communities surrounding the tar ponds: Whitney Pier, Ashby, and North End. These surrounding communities were statistically different from background regarding arsenic, lead, and PAHs. Twenty percent of the background soil samples and 95% of the tar pond soil samples were above the Canadian health-risk-based soil guidelines for arsenic (12 ppm), and 5% of the background samples and 80% of the tar pond soil samples were above the Canadian guidelines for lead (140 ppm). Regarding dust lead and arsenic loading, the results provide no evidence that Whitney Pier is significantly different than Ashby and North End. Children in these communities are predicted to have a 1-15% chance of blood lead > 10 microg/dL. The results suggest that lead and arsenic found in the homes originate outside. The lead content of paint in the homes was not evaluated, but consideration of painted wood at the doorway did not confound the results of the study. The results indicate that the residential environment has been adversely affected by PAHs, lead, and arsenic and should be considered for remediation. PMID:14698928
Lambert, Timothy W; Lane, Stephanie
Lead loadings in household dust in Delhi, India.
Lead in household dust is dangerous to children who ingest lead from playing close to the ground, and having frequent hand-to-mouth contact. Although there have been several investigations of lead levels in India in air, blood and new paint, the literature is sparse on the levels of lead in household dust. This study analyzed 99 samples of dust taken from bare floors and 49 samples of dust taken from windowsills in a cross-section of Delhi, India houses for lead loadings. The arithmetic mean of lead loading for floor samples and windowsill dust samples was found to be 36.24 microg/ft(2) and 129.5 microg/ft(2), respectively. The geometric mean of dust lead loading for floor and interior windowsill samples was found to be 19.7 microg/ft(2) and 75.5 microg/ft(2), respectively. Comparing the results with US geometric mean dust lead levels from a national cross-section of US housing, which in 2000 were 1.1 microg/ft(2) and 9.4 microg/ft(2) on floors and windowsills, respectively as reported by Jacobs et al. (2002) suggests that the lead content of the dust in Delhi homes is much higher than that in the national data in the US and that the levels pose a hazard to children. Practical Implications The present study is first of its kind in this part of the world. In the context of ongoing efforts to eliminate lead from paints worldwide this research will help the scientists and policy makers in assessing the Children's exposure to lead in developing country as well. Since more than one half of the housing units tested had at least one dust lead sample exceeding US health-based standards, health care providers and public health officials need to give attention to possible lead poisoning in Delhi children. Routine blood lead screening of children should follow recommended public health practice for children at risk. Additional larger-scale studies are needed in Delhi and elsewhere to determine how representative these findings are and to attempt to delineate the sources of the high dust lead which are expected to vary depending on the location. Knowledge of the sources is needed to appropriately allocate resources. From other studies performed in India it is likely that lead-based paint is one of the sources and its continued use should be discontinued. PMID:19659889
Kumar, A; Scott Clark, C
Streptomycetes in house dust: associations with housing characteristics and endotoxin
In addition to mold, indoor bioaerosols also contain bacterial components that may have implications for human health. Endotoxin is a cell wall component in Gram-negative bacteria present at varying levels indoors that has been found to have respiratory health implications. Streptomyces is a large genus of Gram-positive bacteria, and some species have been shown to produce inflammatory reactions in vitro and in vivo. The aim of this study was to determine predictors of streptomycetes levels in house dust, and to compare the variation in streptomycetes levels with that in endotoxin levels. Dust was collected by floor vacuuming from 178 homes in the Cincinnati metropolitan area. streptomycetes levels were measured by quantitative PCR and endotoxin was assayed by the Limulus Amebocyte Lysate method. Associations between home characteristics and bacterial contaminants, expressed as concentration and load, were investigated through multiple regression analyses. The presence of two or more dogs was a strong predictor of both streptomycetes and endotoxin levels. Season of dust collection and levels of outdoor molds were predictors of streptomycetes but not endotoxin levels. In contrast, number of inhabitants was a significant predictor of endotoxin load only. Neither streptomycetes nor endotoxin levels were associated with metrics of moisture damage.
Johansson, Elisabet; Vesper, Stephen; Levin, Linda; LeMasters, Grace; Grinshpun, Sergey; Reponen, Tiina
Determinants of polycyclic aromatic hydrocarbon levels in house dust
Estimation of human exposures to polycyclic aromatic hydrocarbons (PAHs) is often desired for the epidemiological studies of cancer. One way to obtain information about indoor levels of PAHs is to measure these chemicals in house dust. In this study, we evaluated the predictive value of self-reported and geographic data for estimating measured levels of nine PAHs in house dust from 583 households in the Northern California Childhood Leukemia Study (NCCLS). Using multivariable linear regression models, we evaluated the effects on house-dust PAH concentrations from the following covariates: residential heating sources, smoking habits, house characteristics, and outdoor emission sources. House dust was collected from 2001 to 2007, usingboth high-volume surface samplers and household vacuum cleaners, and was analyzed for nine PAHs using gas chromatography-mass spectrometry. All nine PAHs were detected in more than 93% of dust samples, with median concentrations ranging from 14 to 94 ng/g dust. Statistically significant effects on PAH concentrations in house dust were found for gas heating, outdoor PAH concentrations, and residence age. Yet, the optimal regression model only explained 15% of the variation in PAH levels in house dust. As self-reported data and outdoor PAH sources were only marginally predictive of observed PAH levels, we recommend that PAH concentrations be measured directly in dust samples for use in epidemiological studies.
Characterization and Immunobiology of House Dust Mite Allergens
The examination of house dust mite extracts has indicated that over 30 different proteins can induce IgE antibody in patients allergic to the house dust mite. There are however dominant specificities especially the group 1 and 2 allergens which can account for much of the allergenicity of extracts. Of the 19 denominated allergens, the major IgE binding has been reported
Wayne R. Thomas; Wendy-Anne Smith; Belinda J. Hales; Kristina L. Mills; Richard M. O�Brien
Archived house-dust samples were analyzed for 13 perfluorinated compounds (PFCs). Results show that PFCs are found in house-dust samples, and the data are log-normally distributed. PFOS/PFOA were present in 94.6% and 96.4% of the samples respectively. Concentrations ranged fro...
House dust in seven Danish offices
Floor dust from Danish offices was collected and analyzed. The dust was to be used in an exposure experiment. The dust was analyzed to show the composition of the dust which can be a source of airborne dust indoors. About 11kg of dust from vacuum cleaner bags from seven Danish office buildings with about 1047 occupants (12751m2) was processed according
L M�lhave; T Schneider; S. K Kj�rgaard; L Larsen; S Norn; O J�rgensen
[Allergenic activity of mites in house dust].
The predominant role of mites in house dust respiratory allergy is now well established. Our laboratory has spent an important part of its time and activity studying the antigens present in D. farinae mites extracts and characterising the specific allergens responsible of respiratory allergy to D. farinae. Physicochemical and immunochemical studies let us to define major allergens in different biochemical fractions obtained from D. farinae extracts used for diagnostic and therapeutic purposes. Amongst the D. farinae specific antigens defined, one (Ag 11) is a specific major allergen and it has been isolated and chemically analysed. It is polypeptide of molecular weight of 28,000 d with p I not equal to 7 containing 5% of cysteine residues. The good stability and resistance to denaturation are in favour of numerous disulfide bonds. PMID:7316612
David, B
Polybrominated diphenyl ether (PBDE) flame retardants are now considered ubiquitous and persistent pollutants. Few studies have examined the concentrations of these chemicals in the home and here we report measurements of PBDEs in house dust samples collected from the Washington...
House dust mite fauna in western Anatolia, Turkey
House dust mites play an important role in the pathogenesis of allergic diseases. Many factors may influence mite growth. The presence of mites is related to mean temperature and humidity as well as altitude. The aim of this study was to analyze the mite fauna in 5 regions of western Anatolia, Turkey, that have similar climatic properties with low mean temperature and humidity, but differ in altitude. During the period October-November 2004, house dust was collected from 290 homes in 5 different cities. House dust mites were isolated in 67 (23.1%) of 290 samples. The family Pyroglyphidae (Astigmata) was present in all positive samples. This study suggests that the selected western Anatolian regions that share similar environmental conditions host similar dust mite populations.
Cetinkaya, Zafer; Atambay, Metin; Kiyildi, Nilay; Aycan, Ozlem M.; Daldal, Nilgun
Absorption of lead from dust and soil
The lead burdens for children and mothers exposed to lead-contaminated soils and dusts have been investigated in a rural district with minimal atmospheric pollution. A significant relationship was observed between the lead content of blood and hair of children exposed to soils of mean lead content in the range 420-13,969 p.p.m. The blood lead concentration of children was consistently greater than that of their mothers. No consistent relationship was found between blood lead values and pica for soil. In this situation, lead in soil provided a small additional burden for children but in itself was insufficient to constitute a hazard.
Barltrop, D.; Thornton, I.; Strehlow, C. D.; Webb, J. S.
Residential dust lead loading immediately after intervention in the HUD lead hazard control grant program.
At the conclusion of most lead hazard control interventions in federally assisted housing built before 1978, a certified clearance examiner must verify that the lead hazard control work was completed as specified and that the area is safe for residents, a process referred to as clearance. This study explores the experience of 14 grantees participating in the Evaluation of the HUD Lead-Based Paint Hazard Control Grant Program in passing clearance. The study also considers how preintervention lead levels (interior dust and paint), building condition/characteristics, and the scope of work influenced initial clearance dust lead loadings and clearance rates. At the initial clearance inspection, 80% of the 2682 dwellings achieved grantee-specific clearance standards on windowsills, window troughs (500 microg/ft2 and 800 microg/ft2, respectively), and floors (80, 100, or 200 microg/ft2 depending on state/local regulations at the dates of clearance in the mid-1990s), with individual grantee success rates ranging from 63 to 100%. Dwellings that failed initial clearance required an average of 1.13 retests to clear. The high level of success at clearance demonstrates that following methods for work site containment, lead hazard control, and cleaning similar to those recommended in the HUD Guidelines for the Evaluation and Control of Lead-Based Paint in Housing is effective. The most common lead hazard control intervention was window abatement accompanied by the repair or abatement of all other deteriorated lead-based paint (56% of dwellings). An additional 5% of dwellings were fully abated, 29% had lower intensity interventions. Interventions including window replacement are recommended to reduce dust lead loading on windowsills and troughs at clearance, but lower level interventions such as full paint stabilization are just as good at reducing floor dust lead loadings. Whatever lead hazard control activities are selected, the condition of the surfaces of interest should be in good condition at clearance. PMID:15673092
Dixon, Sherry L; Wilson, Jonathan W; Succop, Paul A; Chen, Mei; Galke, Warren A; Menrath, William; Clark, C Scott
Enzymatic activity of allergenic house dust and storage mite extracts.
Proteases are involved in the pathogenicity of allergy, increasing epithelial permeability and acting as adjuvants. Enzymatic activity is therefore important for the allergenicity of an extract and also affects its stability and safety. However, the enzymatic activity of extracts is not usually evaluated. The objective of this study was to evaluate the enzymatic activity of the most allergenic mite extracts and to investigate their allergenic properties. Extracts from nine allergenic mite species (Dermatophagoides pteronyssinus, Dermatophagoides farinae Hughes, Euroglyphus maynei, Lepidoglyphus destructor, Tyrophagus putrescentiae (Schrank), Glycyphagus domesticus (DeGeer), Acarus siro L., Chortoglyphus arcuatus, and Blomia tropicalis) were characterized. Protein and allergen profiles were characterized by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and western-blot, respectively. Gelatinolytic activity was evaluated with a zymogram and the activity of other enzymes (cysteine, serine proteases, and esterases) was evaluated individually or with the API-ZYM system. The main differences in protease activity were found between house dust mites and storage mites. House dust mites presented higher cysteine protease activity while storage mites presented higher serine protease activity. These differences are in line with their trophic specialization. A wide range of different activities was found in all the extracts analyzed, reflecting the fact that the extracts preserve the activity of many enzymes, this being necessary for a correct diagnosis. However, enzymes may act as adjuvants and, therefore, could lead to undesirable effects in immunotherapies, making this activity not suitable for treatment products. Modified extracts with lower enzymatic activity could be more appropriate for immunotherapy. PMID:23427664
Morales, Maria; Iraola, V�ctor; Leonor, Jose R; Carn�s, Jer�nimo
Influence of social and environmental factors on dust, lead, hand lead, and blood lead levels in young children
The roles of environmental and behavioral factors in determining blood lead levels were studied in a cohort of young children living in an urban environment. The subjects were observed at 3-month intervals from birth to 24 months of age. Repeated measurements were made of the children's blood lead levels, environmental levels of lead in house dust, and in the dust found on the children's hands. A qualitative rating of the residence and of the socioeconomic status of the family was obtained. Interviews and direct observation of parent and child at home were used to evaluate various aspects of caretaker-child interactions. Data analysis consisted of a comparison of results obtained by (a) simple correlational analysis, (b) multiple regression analysis, and (c) structural equations analysis. The results demonstrated that structural equation modeling offers a useful approach to unraveling the complex interactions present in the data set. In this preliminary analysis, the suspected relationship between the levels of lead in house dust and on hands and the blood lead level was clearly demonstrated. Furthermore, the analyses indicated an important interplay between environmental sources and social factors in the determination of hand lead and blood lead levels in very young children.
Bornschein, R.L.; Succop, P.; Dietrich, K.N.; Clark, C.S.; Que Hee, S.; Hammond, P.B.
The influence of common area lead hazards and lead hazard control on dust lead loadings in multiunit buildings.
Owners of multiunit buildings built before 1978 that have interior common areas, and who receive certain forms of federal assistance are generally required to address lead-based paint hazards in those common areas. This study examines the relationships between common area paint and dust lead levels and the floor dust lead loadings in associated dwelling units, as well as the effects of lead hazard control treatments in common areas. This article presents data from common areas in 145 low-income, mostly pre-1940, multiunit buildings with 342 associated dwellings in the U.S. Department of Housing and Urban Development Lead Hazard Control Grant Program at preintervention, clearance, and 1-year postintervention. Interior common areas in these multiunit buildings were not as well maintained as the dwellings in the buildings. At preintervention, a higher percent of the interior common areas had non-intact, lead-based paint on windows, doors and trim, and other interior components than in associated dwellings (95% versus 85%; 78% versus 67%; and 85% versus 62%). Common areas had preintervention entry and interior (i.e., nonentry) floor dust lead loadings more than four times higher than in dwelling units (128 versus 30 micro g/ft(2); 130 versus 28 micro g/ft(2)) while 1-year postintervention common area dust lead loadings are four to six times that of dwelling dust lead loadings (41 versus 11 micro g/ft(2); 44 versus 8 micro g/ft(2)). Windowsill dust lead loadings in common areas were twice the loadings in dwelling units at preintervention and 1-year postintervention (756 versus 383 mu g/ft(2); 154 versus 68 micro g/ft(2)). Interior common area treatments reduced geometric mean common entry dust lead loadings 71% from preintervention to clearance, and maintained those reduced levels from clearance to 1-year postintervention. Higher level interventions were not more effective than low-level interventions in reducing preintervention levels to clearance or 1-year postintervention. This study demonstrates that interior common areas in the multiunit buildings examined contain substantial amounts of deteriorated lead-based paint and dust. Remediation of common areas can effectively reduce those hazards. PMID:16298951
Dixon, Sherry L; Wilson, Jonathan W; Clark, C Scott; Galke, Warren A; Succop, Paul A; Chen, Mei
House Dust Mite Allergens in Domestic Homes in Cheonan, Korea
House dust mites produce inhalant allergens of importance to allergic patients. We measured the major group 1 allergens, Der p 1 and Der f 1, from the house dust mites Dermatophagoides pteronyssinus and Dermatophagoides farina, respectively in 100 randomly selected domestic homes from Cheonan, Korea. Dust samples were collected by vacuuming from the living room floor and 1 mattress in each home. Der p 1 and Der f 1 were measured by double monoclonal ELISA. Der p 1 levels were very low, with geometric mean levels for floors and mattresses being 0.11 �g/g (range: 0.01-4.05) and 0.14 �g/g (range: 0.01-30.0), respectively. Corresponding levels of Der f 1 were higher, 7.46 �g/g (range: 0.01-262.9) and 10.2 �g/g (range: 0.01-230.9) for floors and mattresses, respectively. D. farinae appears to be the dominant house dust mite in Cheonan.
Nam, Hae-Seon; Lee, Sun-Hwa; Park, Joon-Soo; Kim, Yong-Bae; Choi, Young-Jin; Lee, Sang-Han; Crane, Julian
Studies on house dust mites in Great Cairo, Egypt.
Nowadays, house dust mites have showed themselves as one of the health problem worldwide. They have to be considered in the differential diagnosis of allergy particularly in children. House dust mites were collected from eight different areas in Great Cairo. Nine species of mites were recovered from indoors. In order of abundance, they were Dermatophagoides pteronyssinus, D. farinae, Tyrophagous putrescentiae, Acarus siro, Cheyletus malaccensis, Blomia kulagini, Acheles graciles, Ornithonyssus bacoti and Lepidoglyphus destructor. All these mites were collected mainly from Bolak Al Dakrour (28.8%) and Al Wayly (27.6%). The least number (1.8%) and species (only three) were collected from Madent Al Salam. Pet and stray dogs and cats, domestic birds and commensal rodents were more or less reported in the majority of the examined areas. Also, patients with history of allergy of unknown cause, were reported in ten out of 80 houses examined (12.5%). The role played by house dust mites in causing allergic manifestations was important environmental disease agents. PMID:12561892
Koraiem, M K; Fahmy, I A
Identification of historical lead sources in roof dusts and recent lake sediments from an industrialized area: indications from lead isotopes
X-ray fluorescence and stable lead (Pb) isotopic analyses have been undertaken on dusts, known from microscopic investigation to contain significant quantities of industrially- and urban-derived particulate matter, present in the roof cavities of houses in the Illawarra region (N.S.W., Australia), with the objective of examining the historic record of Pb pollution. All investigated houses contained in excess of 250 ?g
M. Chiaradia; B. E. Chenhall; A. M. Depers; B. L. Gulson; B. G. Jones
Innate Immune Responses in House Dust Mite Allergy
Sensitizations to house dust mites (HDM) trigger strong exacerbated allergen-induced inflammation of the skin and airways mucosa from atopic subjects resulting in atopic dermatitis as well as allergic rhinitis and asthma. Initially, the Th2-biased HDM allergic response was considered to be mediated only by allergen B- and T-cell epitopes to promote allergen-specific IgE production as well as IL-4, IL-5, and IL-13 to recruit inflammatory cells. But this general molecular model of HDM allergenicity must be revisited as a growing literature suggests that stimulations of innate immune activation pathways by HDM allergens offer new answers to the following question: what makes an HDM allergen an allergen? Indeed, HDM is a carrier not only for allergenic proteins but also microbial adjuvant compounds, both of which are able to stimulate innate signaling pathways leading to allergy. This paper will describe the multiple ways used by HDM allergens together with microbial compounds to control the initiation of the allergic response through engagement of innate immunity.
Jacquet, Alain
Surface dust wipes are the best predictors of blood leads in young children with elevated blood lead levels
Background: As part of the only national survey of lead in Australian children, which was undertaken in 1996, lead isotopic and lead concentration measurements were obtained from children from 24 dwellings whose blood lead levels were ?15 �g/dL in an attempt to determine the source(s) of their elevated blood lead. Comparisons were made with data for six children with lower blood lead levels (<10 �g/dL). Methods: Thermal ionisation and isotope dilution mass spectrometry were used to determine high precision lead isotopic ratios ({sup 208}Pb/{sup 206}Pb, {sup 207}Pb/{sup 206}Pb and {sup 206}Pb/{sup 204}Pb) and lead concentrations in blood, dust from floor wipes, soil, drinking water and paint (where available). Evaluation of associations between blood and the environmental samples was based on the analysis of individual cases, and Pearson correlations and multiple regression analyses based on the whole dataset. Results and discussion: The correlations showed an association for isotopic ratios in blood and wipes (r=0.52, 95% CI 0.19�0.74), blood and soil (r=0.33, 95% CI ?0.05�0.62), and blood and paint (r=0.56, 95% CI 0.09�0.83). The regression analyses indicated that the only statistically significant relationship for blood isotopic ratios was with dust wipes (B=0.65, 95% CI 0.35�0.95); there were no significant associations for lead concentrations in blood and environmental samples. There is a strong isotopic correlation of soils and house dust (r=0.53, 95% CI 0.20�0.75) indicative of a common source(s) for lead in soil and house dust. In contrast, as with the regression analyses, no such association is present for bulk lead concentrations (r=?0.003, 95% CI ?0.37�0.36), the most common approach employed in source investigations. In evaluation of the isotopic results on a case by case basis, the strongest associations were for dust wipes and blood. -- Highlights: � Children with elevated blood lead ?15 �g/dL compared with a group with <10 �g/dL. � High precision lead isotopic ratios in blood, house dust wipes, soil, water, paint. � Associations for isotopic measures of blood and dust, blood and soil, blood and paint. � Regressions gave significance for isotopic measures of blood/dust and dust/soil.
Gulson, Brian, E-mail: firstname.lastname@example.com [Graduate School of the Environment, Macquarie University, North Ryde NSW 2109 (Australia) [Graduate School of the Environment, Macquarie University, North Ryde NSW 2109 (Australia); CSIRO Earth Science and Resource Engineering, North Ryde NSW 2113 (Australia); Anderson, Phil [Information and Statistics Group, Australian Institute of Health and Welfare, Canberra ACT 2601 (Australia) [Information and Statistics Group, Australian Institute of Health and Welfare, Canberra ACT 2601 (Australia); Faculty of Health, University of Canberra, Canberra ACT 2601 (Australia); Taylor, Alan [Department of Psychology, Macquarie University, Sydney NSW 2109 (Australia)] [Department of Psychology, Macquarie University, Sydney NSW 2109 (Australia)
Application of synchrotron microprobe methods to solid-phase speciation of metals and metalloids in house dust.
Determination of the source and form of metals in house dust is important to those working to understand human and particularly childhood exposure to metals in residential environments. We report the development of a synchrotron microprobe technique for characterization of multiple metal hosts in house dust. We have applied X-ray fluorescence for chemical characterization and X-ray diffraction for crystal structure identification using microfocused synchrotron X-rays at a less than 10 ?m spot size. The technique has been evaluated by application to archived house dust samples containing elevated concentrations of Pb, Zn, and Ba in bedroom dust, and Pb and As in living room dust. The technique was also applied to a sample of soil from the corresponding garden to identify linkages between indoor and outdoor sources of metals. Paint pigments including white lead (hydrocerussite) and lithopone (wurtzite and barite) are the primary source of Pb, Zn, and Ba in bedroom dust, probably related to renovation activity in the home at the time of sampling. The much lower Pb content in the living room dust shows a relationship to the exterior soil and no specific evidence of Pb and Zn from the bedroom paint pigments. The technique was also successful at confirming the presence of chromated copper arsenate treated wood as a source of As in the living room dust. The results of the study have confirmed the utility of this approach in identifying specific metal forms within the dust. PMID:21842879
Walker, S R; Jamieson, H E; Rasmussen, P E
Application of Synchrotron Microprobe Methods to Solid-Phase Speciation of Metals and Metalloids in House Dust
Determination of the source and form of metals in house dust is important to those working to understand human and particularly childhood exposure to metals in residential environments. We report the development of a synchrotron microprobe technique for characterization of multiple metal hosts in house dust. We have applied X-ray fluorescence for chemical characterization and X-ray diffraction for crystal structure identification using microfocused synchrotron X-rays at a less than 10 {micro}m spot size. The technique has been evaluated by application to archived house dust samples containing elevated concentrations of Pb, Zn, and Ba in bedroom dust, and Pb and As in living room dust. The technique was also applied to a sample of soil from the corresponding garden to identify linkages between indoor and outdoor sources of metals. Paint pigments including white lead (hydrocerussite) and lithopone (wurtzite and barite) are the primary source of Pb, Zn, and Ba in bedroom dust, probably related to renovation activity in the home at the time of sampling. The much lower Pb content in the living room dust shows a relationship to the exterior soil and no specific evidence of Pb and Zn from the bedroom paint pigments. The technique was also successful at confirming the presence of chromated copper arsenate treated wood as a source of As in the living room dust. The results of the study have confirmed the utility of this approach in identifying specific metal forms within the dust.
S Walker; H Jamieson; P Rasmussen
Exposure of children to pollutants in house dust and indoor air.
This review summarizes occurrence and exposure studies for pollutants in house dust and related indoor air exposures. A standard sampling method and control methods to reduce these exposures are discussed, including recommendations for future research. Infants and toddlers receive a broad and significant range of exposures to lead, pesticides, PAHs, allergens, and VOCs in house dust and indoor air. Carpet dust in eight Columbus and nine Seattle homes contained concentrations of potentially carcinogenic PAHs ranging from 3 to 290 micrograms/g, of lead from 250 to 2250 micrograms/g, and of PCBs from 210 to 1900 ng/g. Dust collected from ten used sofas in Seattle averaged 16.3, 37.2, and 229 micrograms/g for dust mite allergen, cat allergen, and lead, respectively; dust samples showed mutagenic activity. Biological and chemical pollutants in indoor dust and air have been associated with lead poisoning, cancer, allergy, asthma, damage to the nervous system, and sick building symptoms. The 11% of toddlers who have pica tend to have the highest exposures and risks. Further, the exposure of toddlers to lead via the dust pathway can be greater than by other routes. Standard method ASTM 5438.94 for sampling house dust has been used to characterize current and chronic exposure of toddlers in epidemiological studies. The accumulation of dust, dust mites, and tracked-in soil in old carpets, sofas, and mattresses appears to be a major source of exposure to lead, pesticides, allergens, PAHs, and VOCs. Remodeling and energy conservation can reduce ventilation and increase relative humidity, dust, dust mites, molds, VOCs, and other indoor air pollutants. The U.S. faces large and increasing costs from asthma and allergy. Asthma incidence in the U.S. has increased from 0.5% in 1930 to 8%-12% in 1991. Asthma hospitalization rates for children are increasing at the rate of 4%/yr in the U.S. and 14%/yr in Seattle. Such hospital visits would be rare with effective diagnosis, patient education, and control of home exposures. Asthma was estimated to cost $6.2 billion in 1990; hospital visits of children in Seattle cost $2,526,000 in 1993. Forty percent of the U.S. population has been sensitized to allergens; one in three homes has high relative humidity, which favors dust mites, molds, allergies, asthma, and other respiratory diseases. Reducing indoor allergens can reduce costs, severity, and the risk of being sensitized and developing allergic disease. Use of volunteer Master Home Environmentalists to do free in-home surveys and education in Seattle may reduce immediate health costs from allergens as well as long-term risks from lead, carcinogens, and home chemicals.(ABSTRACT TRUNCATED AT 400 WORDS) PMID:7501867
Roberts, J W; Dickey, P
The prevalence of lead-based paint hazards in U.S. housing.
In this study we estimated the number of housing units in the United States with lead-based paint and lead-based paint hazards. We included measurements of lead in intact and deteriorated paint, interior dust, and bare soil. A nationally representative, random sample of 831 housing units was evaluated in a survey between 1998 and 2000; the units and their occupants did not differ significantly from nationwide characteristics. Results indicate that 38 million housing units had lead-based paint, down from the 1990 estimate of 64 million. Twenty-four million had significant lead-based paint hazards. Of those with hazards, 1.2 million units housed low-income families (< 30,000 US dollars/year) with children under 6 years of age. Although 17% of government-supported, low-income housing had hazards, 35% of all low-income housing had hazards. For households with incomes greater than or equal to 30,000 US dollars/year, 19% had hazards. Fourteen percent of all houses had significantly deteriorated lead-based paint, and 16% and 7%, respectively, had dust lead and soil lead levels above current standards of the U.S. Department of Housing and Urban Development and the U.S. Environmental Protection Agency. The prevalence of lead-based paint and hazards increases with age of housing, but most painted surfaces, even in older housing, do not have lead-based paint. Between 2% and 25% of painted building components were coated with lead-based paint. Housing in the Northeast and Midwest had about twice the prevalence of hazards compared with housing in the South and West. The greatest risk occurs in older units with lead-based paint hazards that either will be or are currently occupied by families with children under 6 years of age and are low-income and/or are undergoing renovation or maintenance that disturbs lead-based paint. This study also confirms projections made in 2000 by the President's Task Force on Environmental Health Risks and Safety Risks to Children of the number of houses with lead-based paint hazards. Public- and private-sector resources should be directed to units posing the greatest risk if future lead poisoning is to be prevented.
Jacobs, David E; Clickner, Robert P; Zhou, Joey Y; Viet, Susan M; Marker, David A; Rogers, John W; Zeldin, Darryl C; Broene, Pamela; Friedman, Warren
Mite Antigen Concentrations in House Dust and the Occurrence of Wheezing in Children with Dust Mite Allergy.
National Technical Information Service (NTIS)
The authors studied the relationship between dust mite antigen concentrations in house dust samples and the occurrence and frequency of wheezing in 58 children with dust mite allergy (wheal > or = 4 mm. mean diameter in response to a prick test with eithe...
F. W. Henderson A. B. Lindstrom M. A. Beck D. M. Barnes M. M. Henry
We studied the relationship between dust mite antigen concentrations in house dust samples and the occurrence and frequency of wheezing in 58 children with dust mite allergy (wheal > 4 mm. mean diameter in response to a prick test with either D-. farinae or D pteronyssinus antige...
Removal of lead oxide dust from air
This work concerns the removal of lead oxide dust from air using granular beds. Theoretical and experimental aspects of the problem have been studied. It has been found that the order of efficiencies of the different packing types used for capturing lead oxide aerosol at velocity range 17-26 cm/sec, and column height range 5-20 cm is as follows: rashing rings, glass wool, plastic wire mesh and glass beads. The penetration is decreased exponentially as the bed height increases for all types of packing investigated. The overall and individual maximum penetration velocities (at a given packing height) exist for all types of packing studied. The algebraic change of the magnitudes of diffusion, gravitational and impaction mechanisms equals zero at the maximum penetration velocity. At a given air velocity and packing height, a definite particle aerosol diameter appears with maximum penetration for all types of packing considered. The constants in the mathematical model representing the penetration of lead oxide in different types of packing have been determined. 25 references, 10 figures. 1 table.
Abdullah, M.O.; Sulaymon, A.H.; Sameh, S.H.
An Evaluation of Loading Rate of Dust, Pb, Cd, and Ni and Metals Mass Concentration in the Settled Surface Dust in Domestic Houses and Factors Affecting Them
Interior and exterior measurements of surface loading rates for settled surface dust in domestic houses and the content of three metals � lead (Pb), cadmium (Cd) and nickel (Ni) � were conducted weekly during the autumn of 2007 in an urban area of Giza, Egypt. Surface mass concentrations of the metals were also calculated. Results revealed that the interior and
M. I. Khoder; S. K. Hassan; A. A. El-Abssawy
Analysis of brominated flame retardants in house dust.
The main objective of this study was to create a robust analytical method to analyse the flame retardants decabromodiphenylether (BDE-209), hexabromocyclododecane (HBCD), and tetrabromobisphenol-A (TBBPA) in house dust in order to estimate the degree of contamination of indoor environment. A liquid chromatography method equipped with a UV-detector and electro spray-tandem mass spectrometry was used to achieve this result. Applying an external calibration for BDE-209, an internal calibration for TBBPA, and a standard addition method for HBCD low limits of quantification were obtained. The analytical procedure was carried out under exclusion of UV-light as the target compounds potentially degrade when being exposed to UV-light. Empirical data were obtained in addition to the dust samples to estimate potential influences of apartment characteristics. A weak correlation between the number of electric devices and TBBPA was found. PMID:21724229
Abb, Magdalena; Stahl, Beate; Lorenz, Wilhelm
[House dust mites in the etiology of allergic diseases].
One of the more important etiological factors of allergies are mites occuring in the closest vicinity of humans, i.e. in the house dust and in the stored foodstuffs. The most important are the species representing the families: Pyroglyphidae (mainly Dermatophagoides pteronyssinus, D. farinae, and Euroglyphus maynei), Glycyphagidae (e.g. Lepidoglyphus destructor, Blomia sp.), and Acaridae (e.g. Tyrophagus putrescentiae, Acarus siro). Mites shed an abundance of allergenic proteins. Particularly abundant in allergens are the extracts of mite faeces as well as the extracts of their purified bodies or culture substrate. In humans the may inflict atopic allergies (respiratory and dermal), such as bronchial asthma, rhinitis, or atopic eczema. It has been estimated that some 5% of the human population is sensitive to dust mites allergens. PMID:17633128
Henszel, ?ukasz; Ku?na-Grygiel, Wanda
Mite allergy in Nigerians: Studies on house dust mites in houses of allergic patients in Lagos
Summary��Mite composition of samples of house dusts of atopic Nigerian patients were analysed. Out of a total of 263 mites isolated,\\u000a 10 different species, all of which are being documented for the first time in Nigeria have emerged. The result of this analysis\\u000a was correlated with provocative allergic skin tests performed on these patients using allergenic reagents. The role of
A. O. Somorin; O. O. Hunponu-Wusu; Y. Mumcuoglu; D. C. Heiner
Reliability of spot test kits for detecting lead in household dust.
There has been a long-standing need for a technique that can provide fast, accurate and precise results regarding the presence of hazardous levels of lead in settled house dust. Several home testing kits are now available. One kit manufactured by Hybrivet (LeadCheck Swabs) is advertised as able to detect lead dust levels that exceed the US Environmental Protection Agency's dust lead standard for floors (40 microg/ft(2)). The purpose of the study was to determine the ability of LeadCheck Swabs to instantly detect lead in dust above EPA's hazard standard. A trained risk assessor collected 200 LeadCheck Swab samples side-by-side with standard dust wipe samples. The result of the LeadCheck Swab (positive (pink or red) or negative (yellow to brown)) was compared with the laboratory results for the corresponding dust wipe (over or under 40 microg/ft(2)). The LeadCheck Swabs produced a false negative rate of 64% (95% confidence interval: 55%, 72%). The likelihood of a swab producing a false negative depended on substrate (painted or non-painted) and surface type (floor or sill). Changing the interpretation rule by classifying all swab colors except yellow as positive yielded lower false negative rates under some test conditions, but still produced high error rates. LeadCheck Swabs do not reliably detect levels of lead in dust above 40 microg/ft(2) using published methods under field conditions. Further research into alternate methodologies and interpretation guidance is needed to determine whether the swabs can be appropriately used by consumers and others to test homes for lead dust hazards. PMID:17434162
Korfmacher, Katrina Smith; Dixon, Sherry
Associations between bacterial communities of house dust and infant gut.
The human gut is host to a diverse and abundant community of bacteria that influence health and disease susceptibility. This community develops in infancy, and its composition is strongly influenced by environmental factors, notably perinatal anthropogenic exposures such as delivery mode (Cesarean vs. vaginal) and feeding method (breast vs. formula); however, the built environment as a possible source of exposure has not been considered. Here we report on a preliminary investigation of the associations between bacteria in house dust and the nascent fecal microbiota from 20 subjects from the Canadian Healthy Infant Longitudinal Development (CHILD) Study using high-throughput sequence analysis of portions of the 16S rRNA gene. Despite significant differences between the dust and fecal microbiota revealed by Nonmetric Multidimensional Scaling (NMDS) analysis, permutation analysis confirmed that 14 bacterial OTUs representing the classes Actinobacteria (3), Bacilli (3), Clostridia (6) and Gammaproteobacteria (2) co-occurred at a significantly higher frequency in matched dust-stool pairs than in randomly permuted pairs, indicating an association between these dust and stool communities. These associations could indicate a role for the indoor environment in shaping the nascent gut microbiota, but future studies will be needed to confirm that our findings do not solely reflect a reverse pathway. Although pet ownership was strongly associated with the presence of certain genera in the dust for dogs (Agrococcus, Carnobacterium, Exiguobacterium, Herbaspirillum, Leifsonia and Neisseria) and cats (Escherichia), no clear patterns were observed in the NMDS-resolved stool community profiles as a function of pet ownership. PMID:24637181
Konya, T; Koster, B; Maughan, H; Escobar, M; Azad, M B; Guttman, D S; Sears, M R; Becker, A B; Brook, J R; Takaro, T K; Kozyrskyj, A L; Scott, J A
Reducing Dust, Lead, Dust Mites, Bacteria, and Fungi in Carpets by Vacuuming
.�� Old carpets may be reservoirs of dust, lead (Pb), and dust mite allergen. The purpose of this study was to determine if\\u000a the dust, Pb, dust mite allergen, bacteria, and fungi on the surface of carpets could be reduced by 90% in 1 week with the\\u000a use of a Hoover Self Propelled Vacuum with Embedded Dirt Finder (HSPF). A
J. W. Roberts; W. S. Clifford; G. Glass; P. G. Hummer
Characterization of Lipopolysaccharides Present in Settled House Dust
The 3-hydroxy fatty acids (3-OHFAs) in lipopolysaccharides (LPS) play an important role in determining endotoxin activity, and childhood exposure to endotoxin has recently been associated with reduced risk of atopic diseases. To characterize the 3-OHFAs in house dust (HD), we used gas chromatography-mass spectrometry to assay 190 HD samples. Dust from beds, bedroom floors, family rooms, and kitchen floors was collected as part of a birth cohort study of childhood asthma (study 1) and a longitudinal study of home allergen and endotoxin (study 2). We also measured endotoxin activity with a Limulus assay and computed specific activity (endotoxin activity per nanomole of LPS). Longer-chain (C16:0 and C18:0) 3-OHFAs were predominant in HD compared with short-chain (C10:0, C12:0, and C14:0) acids. Endotoxin activity was positively correlated with short-chain 3-OHFAs in both studies. In study 2, 3-OH C16:0 was negatively correlated and 3-OH C18:0 was not correlated with endotoxin activity, consistent with previous findings that the Limulus assay responds preferentially to LPS containing short-chain 3-OHFAs. Kitchen dust contained the highest concentrations of 3-OH C10:0, the highest endotoxin activities, and the highest specific activities (P < 0.03). Bed dust contained the largest amounts of long-chain 3-OHFAs, the highest concentrations of LPS, and the lowest specific activities. Apartments had significantly different types of LPS (P = 0.03) compared with single-family homes in study 2. These data suggest that the Limulus assay may underestimate exposure to certain types of LPS. Because nontoxic LPS may have immune modulating effects, analysis of 3-OHFAs may be useful in epidemiologic studies.
Park, Ju-Hyeong; Szponar, Bogumila; Larsson, Lennart; Gold, Diane R.; Milton, Donald K.
Polychlorinated biphenyls in house dust and yard soil near a Superfund site
Polychlorinated biphenyls (PCBs) were measured in house dust and yard soil at 34 homes surrounding New Bedford Harbor during dredging of highly contaminated harbor sediments. PCBs can volatilize from sediments and seawater and subsequently deposit on surrounding soil, resulting in potential exposures for nearby residents. House dust was collected from carpet, while yard soil was collected from the main entryway
Donna J. Vorhees; L. M. Altshul; A. C. Cullen
Bag-house dust used in clinkerization of portland cements
Many industrial materials considered essential for supporting a better quality of life consume large amounts of energy for their production. Ordinary portland cement (OPC) is used widely as a building material, and its manufacture consumes much energy. In India, the cost of energy accounts for >40% of the total cost of cement manufacture. The cost to manufacture cement is expected to increase because of increasing demands for energy. Scientists are attempting to prepare OPC and other binding materials at lower cost by using agricultural and industrial wastes during clinkerization and by making blended cements. These measures decrease cost of production, conserve mineral resources and protect the environment by beneficial disposal of wastes. This article describes the effect of adding 10% bag-house dust to black meal used in vertical shaft kiln clinkerization in a cement miniplant. The hydration properties of OPC and blended cements made from control and experimental clinkers also have been studied.
Singh, N.B.; Bhattacharjee, K.N.; Shukla, A.K. [Univ. of Gorakhpur (India). Dept. of Chemistry
Evaluation of the presence of house dust mites in horse rugs.
A sample of fourteen horse rugs and two saddle blankets stored in south western Sydney, Australia, an area of known high dust mite prevalence in the human environment, were analysed for the presence of house dust mites. Dust samples from the rugs, blankets and 16 control sites were collected using a vacuum cleaner with a modified attachment and filter. Dust mites were extracted using an adapted floatation technique. Eight rugs and all control samples were positive for mites, which were confirmed to be house dust mites of the genus Dermatophagoides. This study confirms that exposure to house dust mites from horse rugs can occur, indicating that house dust mite allergen reactivity on intradermal and serum allergy testing in atopic horses may represent true dust mite hypersensitivity. Nevertheless, quantification studies will be necessary to ensure that there is adequate mite exposure for development of hypersensitivity, and further evaluation of immunological responses, avoidance and provocation, and specific immunotherapy are required to confirm the clinical relevance. To the authors' knowledge, this is the first study to document the presence of house dust mites in the equine environment. PMID:20529010
Wallace, Jessica C; Vogelnest, Linda J
Impact of soil and dust lead on children's blood lead on Children's blood lead in contaminated areas of Sweden
The impact of lead in soil and dust on blood lead concentrations in young children and the risk of health effects were investigated in an urban and a mining areas of Sweden. Blood, soil, and indoor dust, as well as information on lead-exposure factors, were collected. The blood lead concentrations (total range = 9--77 {micro}g/l) the authors measured indicated a low risk for lead-induced health effects. Lead in soil and in dust had little effect on blood lead concentrations, given the present conditions and present concentration range--especially in the mining area. Urban children had significantly higher blood lead concentrations that children in the mining area, despite higher concentrations of lead in soil in the mining area. In the urban children, blood lead concentrations were influenced by parental smoking and lead in dust at day-care centers.
Berglund, M.; Lind, B.; Soerensen, S.; Vahter, M.
Is House-Dust Nicotine a Good Surrogate for Household Smoking?
The literature is inconsistent regarding associations between parental smoking and childhood leukemia, possibly because previous studies used self-reported smoking habits as surrogates for children's true exposures to cigarette smoke. Here, the authors investigated the use of nicotine concentrations in house dust as measures of children's exposure to cigarette smoke in 469 households from the Northern California Childhood Leukemia Study (1999�2007). House dust was collected by using high-volume surface samplers and household vacuum cleaners and was analyzed for nicotine via gas chromatography�mass spectrometry. Using multivariable linear regression, the authors evaluated the effects of self-reported parental smoking, parental demographics, house characteristics, and other covariates on house-dust nicotine concentrations. They observed that nicotine concentrations in house dust were associated with self-reported smoking for periods of months and years before dust collection. Furthermore, the authors found that the relation between nicotine dust levels and self-reported smoking varied by parental age and socioeconomic status. These findings suggest that house-dust nicotine concentrations reflect long-term exposures to cigarette smoke in the home and that they may be less biased surrogates for children's exposures to cigarette smoke than self-reported smoking habits.
Metayer, Catherine; Ward, Mary H.; Nishioka, Marcia G.; Gunier, Robert; Colt, Joanne S.; Reynolds, Peggy; Selvin, Steve; Buffler, Patricia; Rappaport, Stephen M.
Identification of neryl formate as the airborne aggregation pheromone for the American house dust mite and the European house dust mite (Acari: Epidermoptidae).
The American house dust mite, Dermatophagoidesfarinae Hughes, and European house dust mite, Dermatophagoides pteronyssinus Trouessart, are major pests of medical importance throughout the developed world, causing atopic diseases such as asthma, rhinitis, and atopic dermatitis. Previous studies in our laboratory have shown that the behavioral responses of house dust mites toward volatiles from food sources could be assessed using a Y-tube olfactometer assay. The current study used this Y-tube assay to investigate house dust mite pheromones. A hexane extract of D.farinae, along with fractions of the extract prepared by microscale liquid chromatography over Florisil, were tested for behavioral activity. One of the chromatographic fractions was shown to be significantly attractive (P < 0.05) for D. farinae, compared with a solvent control. Coupled gas chromatography-mass spectrometry analysis of this behaviorally active fraction indicated that neryl or geranyl formate was the major component. Peak enhancement by gas chromatography, using authentic samples of the neryl and geranyl isomers prepared in high purity by chemical synthesis, confirmed the identity of the major peak as neryl formate. In Y-tube assays, male and female D. farinae and D. pteronyssinus both were significantly attracted to synthetic neryl formate at doses of 100 and 10 ng, respectively (P < 0.05). No significant differences were found for D. farinae and D. pteronyssinus when synthetic neryl formate and house dust mite extracts containing natural neryl formate were tested at the same level. Dynamic headspace collection of D. farinae and D. pteronyssinus colonies showed that neryl formate was released as a volatile organic compound by both species. Our study shows that neryl formate is an aggregation pheromone for D. farinae and D. pteronyssinus, and has the potential to be used as part of a novel lure-and-kill system for house dust mite control. PMID:20939374
Skelton, A C; Cameron, M M; Pickett, J A; Birkett, M A
Analytical methods were validated to determine polycyclic aromatic hydrocarbons (PAH) and other semivolatile organic compounds in house dust. e also examined the storage stability of three potential markers (solanesol, nicotine, and continine) for particulate-phase environmental ...
Testing Your Home for Lead in Paint, Dust, and Soil.
National Technical Information Service (NTIS)
This publication is for anyone who is considering having a home or residence tested for lead in paint, dust, or soil by a professional. It explains the technical aspects of lead testing without overwhelming the reader. The first section tells why you woul...
Organotin Compounds, Including Butyltins and Octyltins, in House Dust from Albany, New York, USA
Organotin compounds (OTs) have been used in a wide variety of consumer products. Despite this, very few studies have reported\\u000a the occurrence of OTs in house dust or exposure of humans to OTs through the ingestion of house dust. In the present study,\\u000a concentrations of monobutyltin (MBT), dibutyltin (DBT), tributyltin (TBT), monooctyltin (MOT), dioctyltin (DOT), trioctyltin\\u000a (TOT), diphenyltin (DPT), and
Kurunthachalam Kannan; Shin Takahashi; Naohiro Fujiwara; Hazuki Mizukawa; Shinsuke Tanabe
Development of a Simultaneous Extraction and Cleanup Method for Pyrethroid Pesticides from Indoor House Dust Samples
An ef�cient and reliable analytical method was developed for the sensitive and selective quanti�cation of pyrethroid pesticides (PYRs) in house dust samples. The method is based on selective pressurized liquid extraction (SPLE) of the dust-bound PYRs into dichloromethane (DCM) wi...
Prevention of House Dust Mite Induced Allergic Airways Disease in Mice through Immune Tolerance
Allergic airways disease is a consequence of a Th2 response to an allergen leading to a series of manifestations such as production of allergen-specific IgE, inflammatory infiltrates in the airways, and airway hyper-reactivity (AHR). Several strategies have been reported for tolerance induction to allergens leading to protection from allergic airways disease. We now show that CD4 blockade at the time of house dust mite sensitization induces antigen-specific tolerance in mice. Tolerance induction is robust enough to be effective in pre-sensitized animals, even in those where AHR was pre-established. Tolerant mice are protected from airways eosinophilia, Th2 lung infiltration, and AHR. Furthermore, anti-CD4 treated mice remain immune competent to mount immune responses, including Th2, to unrelated antigens. Our findings, therefore, describe a strategy for tolerance induction potentially applicable to other immunogenic proteins besides allergens.
Agua-Doce, Ana; Graca, Luis
Sequential digestion for measuring leachable and total lead in the same sample of dust or paint chips by ICP-MS.
House lead exposure is generally assessed using total lead, except in France, where acid-leachable lead is used for routine regulatory purposes. In order to allow an international comparison of French lead dust contamination, a sequential digestion protocol is developed to determine both leachable and total lead on the same sample with a two-step digestion stage: firstly, hydrochloric acid is added to the sample at 37�C to solubilize leachable lead; then nitric acid is added to an aliquot at 95�C to solubilize residual (i.e., non-leachable) lead. Both sample fractions are analyzed with inductively coupled plasma mass spectrometry (ICP-MS). The sum of the two fractions allows to determine total lead. This new protocol has been tested with wiped dust (n = 111) and paint chip (n = 46) samples collected in houses (n = 16). The leachability of lead ranged from 63 to 100% in dust and from 4 to 100% in paint. These findings confirm the strong variability of lead leachability in houses samples and thus the importance of considering it for lead poisoning prevention. This double determination of leachable and total lead for each wiped dust or paint sample appears to be a reproducible, simple, low-cost protocol and thus a useful tool for international comparison of house dust lead contamination. PMID:21104496
Le Bot, Barbara; Arcelin, Claire; Briand, Emmanuel; Glorennec, Philippe
In a secondary analysis of data from the Childhood Lead Poisoning Prevention Program of Philadelphia (July 1, 1999 through September 1, 2004), the authors evaluated the effect of housing compliance status and time to achieve compliance on changes in children's blood lead levels. ...
House dust and inorganic urinary arsenic in two Arizona mining towns.
Residents of copper mining and smelting towns may have increased risk of arsenic exposure from elevated arsenic contained in environmental media. To determine the relation of arsenic in house dust to inorganic urinary arsenic concentrations, a door-to-door survey was conducted in Hayden and Winkelman, Arizona. A total of 122 households (404 individuals) participated; 85 provided dust samples. Urine was collected at first morning void and analyzed for total and speciated arsenic. Speciation of arsenic was performed in samples with total arsenic above 10 micro g/l (N=106). The generalized estimating equation was used to determine the relation between urinary and house dust arsenic concentrations, allowing adjustment for the correlation of measurements obtained from the same home. Seafood consumption during the past 3 days and smoking contributed significantly to inorganic urinary arsenic, after adjusting for age and gender. Arsenic in house dust was not significantly associated with inorganic urinary arsenic measurements in this population. PMID:12743615
Hysong, Tracy A; Burgess, Jefferey L; Cebri�n Garcia, Mariano E; O'Rourke, Mary Kay
Polybrominated diphenyl ether (PBDE) concentrations in house dust are related to hormone levels in men
Despite documented widespread human exposure to polybrominated diphenyl ethers (PBDEs) through dietary intake and contact or inhalation of indoor dust, along with growing laboratory evidence for altered endocrine function following exposure, human studies of PBDE exposure and endocrine effects remain limited. We conducted a preliminary study within an ongoing study on the impact of environmental exposures on male reproductive health. We measured serum hormone levels and PBDE concentrations (BDE 47, 99 and 100) in house dust from 24 men recruited through a US infertility clinic. BDE 47 and 99 were detected in 100% of dust samples, and BDE 100 was detected in 67% of dust samples, at concentrations similar to those reported in previous US studies. In multivariable regression models adjusted for age and BMI, there was a statistically significant inverse relationship between dust PBDE concentrations and free androgen index. Dust PBDE concentrations were also strongly and inversely associated with luteinizing hormone (LH) and follicle stimulating hormone (FSH), and positively associated with inhibin B and sex hormone binding globulin (SHBG). Finally, consistent with limited recent human studies of adults, PBDEs were positively associated with free T4. In conclusion, the present study provides compelling evidence of altered hormone levels in relation to PBDE exposures estimated as concentrations in house dust, and that house dust is an important source of human PBDE exposure, but more research is urgently needed.
Meeker, John D.; Johnson, Paula I.; Camann, David; Hauser, Russ
Heavy metals in street and house dust in Bahrain
A total of 106 street and household dusts have been sampled throughout Bahrain and analyzed for Pb, Zn, Cd, Ni and Cr using the atomic absorption spectrophotometric method. The sampling sites were divided into seven categories, including the control site. Results showed that dust samples contained significant levels of the metals studied compared with the control values. The mean values
M. Salim Akhter; Ismail M. Madany
Lead in residential soil and dust in a mining and smelting district in northern Armenia: a pilot study.
This pilot study of sources of lead exposure in residential settings was conducted in a mining and smelting district in northern Armenia. Samples of exterior soil and dust and interior house dust were collected in and around apartment buildings in Alaverdi where the country's largest polymetallic smelter is located, and in nearby mining towns of Aghtala and Shamlugh. The NITON XL-723 Multi-Element XRF analyzer was used for lead testing. Lead levels in samples from Alaverdi were higher than those in Shamlugh and Aghtala. In all three towns, the highest lead levels were found in loose exterior dust samples, and lead concentrations in yard soil were higher than those in garden soil. Many soil samples (34%) and the majority of loose dust samples (77%) in Alaverdi exceeded the US Environmental Protection Agency standard of 400 mg/kg for bare soil in children's play areas. In addition, 36% of floor dust samples from apartments in Alaverdi exceeded the US Environmental Protection Agency standard of 40 microg/ft(2) for lead loading in residential floor dust. The Armenian Ministry of Health and other interested agencies are being informed about the findings of the study so that they can consider and develop educational and preventive programs including blood lead screening among sensitive populations. PMID:15016598
Petrosyan, Varduhi; Orlova, Anna; Dunlap, Charles E; Babayan, Emil; Farfel, Mark; Von Braun, Margrit
Dust mites population in indoor houses of suspected allergic patients of South assam, India.
Background. In the present study, quality and quantity of indoor dust mites was evaluated at the residence of 150 atopic allergic patients from four different districts of South Assam. Methods. Suspected patients with case history of allergic disease were selected for indoor survey. Dust samples (500?mg) were collected from the selected patient's house and were analyzed using standard methods. Results. About 60% of the selected patients were found suffering from respiratory disorders and rest 40% from skin allergy. The dominant mites recorded from indoor dust samples were Dermatophagoides followed by Blomia, Acarus, and Cheyletus while Caloglyphus was recorded in least number. The distribution of mites on the basis of housing pattern indicates that RCC type of buildings supports maximum dust mite's population followed by Assam type (semi-RCC) buildings, and the lowest count was observed in wooden houses. Environmental factors like temperature, rainfall, and relative humidity are found to determine the indoor mite's population. Severity of allergic attack in some of the typical cases was found to be proportional to the allergen load of mites in the dust samples. Conclusions. The economic status, housing pattern, and local environmental factors determine the diversity and abundance of dust mites in indoor environment. PMID:23724231
Sharma, Dhruba; Dutta, B K; Singh, A B
Microchemical investigations of dust emitted by a lead smelter
Dusts emitted by an important pyrometallurgical lead smelter have been sampled within the pipes of the grilling and furnace working units before and after the filtering systems, respectively. Particle size distribution, elementary analyses, and X-ray powder diffraction analysis indicate PbS, PbSO{sub 4}, PbSO{sub 4}{center_dot}PbO, Pb, ZnS small particles less than 5 {micro}m in size to contribute mainly to the current atmospheric pollution. Although at least 90% of dust are retained on the filters, the amounts of the respirable smaller particles are significantly larger in the current emission. The average chemical speciation was found to be analogous for the dust samples collected before and after the filters. The scanning electron microscopy associated with energy-dispersive X-ray analysis and Raman microspectrometry established the morphology and chemical composition at the level of individual particles. A lot of minor compounds were found as small heterogeneous individual particles in the heterogeneous particles of grilling dust. Among the homogeneous particles of furnace dust, amorphous C, {beta}-PbO, PbO-PbCl{sub 2}, FeO, CdS, CdSO{sub 4} were often detected as homogeneous mixtures with the major compounds within the particles.
Sobanska, S.; Ricq, N. [Ecole des Mines de Douai (France). Dept. Chimie et Environnement] [Ecole des Mines de Douai (France). Dept. Chimie et Environnement; [Univ. de Lille I, Villeneuve d`Ascq (France); Laboudigue, A.; Guillermo, R. [Ecole des Mines de Douai (France). Dept. Chimie et Environnement] [Ecole des Mines de Douai (France). Dept. Chimie et Environnement; Bremard, C.; Laureyns, J.; Merlin, J.C.; Wignacourt, J.P. [Univ. de Lille I, Villeneuve d`Ascq (France)] [Univ. de Lille I, Villeneuve d`Ascq (France)
Hazard Elimination Procedures for Leaded Paints in Housing.
National Technical Information Service (NTIS)
Methods currently used to control the hazard caused by leaded paints in housing vary in effectiveness from complete elimination of the hazard to a minimal effort that runs a high risk for recurrence of the hazard. A series of guidelines has been drawn up ...
D. Waksman L. F. Skoda E. J. Clark
Environmental controls in reducing house dust mites and nasal symptoms in patients with allergic rhinitis.
A randomized comparison group pretest-posttest experimental design was used to quantitatively determine the effects of environmental control measures on patients with allergic rhinitis. Environmental controls included wrapping the mattress with a vinyl cover, washing the top bedding cover with 55 degrees C hot water every two weeks, removal of soft furniture, and wet cleaning of the bedroom floor every day. Thirty subjects were randomly assigned to experimental and control groups. The amount of house dust mites in dust samples collected from the bedroom floor, bedding and mattress, as well as the nasal symptoms of patients, were measured twice at one-month intervals. A significant decrease in house dust mites in dust samples and relief in patients' nasal symptoms were observed in the experimental group who had environmental controls. PMID:10412335
Moon, J S; Choi, S O
Investigating A Novel Flame Retardant Known as V6: Measurements in Baby Products, House Dust and Car Dust
With the phase-out of polybrominated diphenyl ether (PBDE) flame retardants, the use of new and alternate flame retardants has been increasing. 2,2-bis(chloromethyl)propane-1,3-diyltetrakis(2-chloroethyl) bisphosphate, known as V6, is a flame retardant applied to polyurethane foam commonly found in furniture and automobile foam. However, to the authors� knowledge, no research has been conducted on V6 levels in the environment. The intention of this study was to measure the concentration of V6 in foam collected from baby products where it was recently detected, and measure levels in dust samples collected from homes and automobiles in the Boston, MA area. To accomplish this a pure V6 commercial standard was purchased from a Chinese manufacturer and purified (> 98%). An analytical method to measure V6 in dust samples using liquid chromatography tandem mass spectrometry (LC/MS-MS) was developed. Extraction was conducted using Accelerated Solvent Extraction (ASE) and extracts were purified using an ENVI-Florisil SPE column (500 mg, 3mL). V6 was measured in foam samples collected from baby products with a concentration ranging from 24,500,000 to 59,500,000 ng/g of foam (n = 12, average � sd: 46,500,000 � 12,000,000 ng/g; i.e., on average, 4.6 % of the foam mass was V6). V6 was also detected in 19 of 20 car dust samples and 14 of 20 house dust samples analyzed. The concentration of V6 in the house dust ranged from < 5 ng/g to 1,110 ng/g with a median of 12.5 ng/g, and < 5 ng/g to 6,160 ng/g in the car dust with a median of 103.0 ng/g. Concentrations in car dust were significantly higher than the house dust, potentially indicating higher use of V6 in automobiles compared to products found in the home. Furthermore, tris (2-chloroethyl) phosphate (TCEP), a known carcinogen, was found in the V6 commercial mixture (14% by weight) as an impurity and was consistently detected with V6 in the foam samples analyzed. A significant correlation was also observed between V6 and TCEP in the dust samples, suggesting that the use of V6 is a significant source of TCEP in the indoor environment.
Fang, Mingliang; Webster, Thomas F.; Gooden, David; Cooper, Ellen M.; McClean, Michael D.; Carignan, Courtney; Makey, Colleen; Stapleton, Heather M.
A pilot study of the measurement and control of deep dust, surface dust, and lead in 10 old carpets using the 3-spot test while vacuuming.
This pilot study measured and examined the relationship between surface dust, deep dust, lead (Pb), and the 3-spot test during vacuuming of carpets. The 3-spot test measures the total time in seconds for the indicator light on a Hoover vacuum with dirt detector (HVDD) to turn from red to green on three spots 3 feet apart at least 4 feet from an entrance door. Ten older carpets were sampled in the Seattle area by using the following: (1) a 3-spot test to estimate the deep dust; (2) measuring the surface dust in g/m(2) with the High-Volume Small Simplified Surface Sampler; (3) vacuuming with an HVDD to extract a portion of the deep dust in g/m(2); and (4) repeating this cycle of a 3-spot test, surface dust sample, and deep dust sample until the clean-carpet criteria was reached. Dust particles <150 mum were analyzed for Pb. The surface dust, deep dust, and dust collection rate (g/min) decreased rapidly at first and then much more slowly as vacuuming continued. The initial 3-spot test ranged from 12 to 110 seconds (median 40). The starting surface dust loading was 0.7 to 21.1 g/m(2) (median 2.9 g/m(2)), and it decreased by 84% to 99% when the deep dust was removed. Total dust-the sum of the surface dust and deep dust-ranged from 8.3 to 465 g/m(2) (median 63.2 g/m(2)). It took from 2.3 to 92 min/m(2) (median of 7.5 min/m(2)) to remove the total dust. The starting dust collection rate of 3.8 to 37 g/min decreased to final rates of 0.5 to 4.3 g/min. The 3-spot test (seconds) correlated with total dust (g/m(2)) (r = 0.63, p = 0.037) and cleaning time (min/m(2)) (r = 0.50, p = 0.12) when the data were log transformed. This study supports the utility of the 3-spot test. It tends to provide families and professional carpet cleaners with a quick and low-cost estimate of the deep dust present and the time required to clean carpets as well as indicating when the carpet is clean. Deep dust tends to accumulate in older carpets and becomes surface and airborne dust after activity on a carpet. Monitoring and removing the deep dust in old carpets may decrease the exposure of infants and sensitive adults to Pb, allergen, and other pollutants in house dust. PMID:15657801
Roberts, J W; Glass, G; Mickelson, L
Application of Synchrotron Microprobe Methods to SolidPhase Speciation of Metals and Metalloids in House Dust
Determination of the source and form of metals in house dust is important to those working to understand human and particularly childhood exposure to metals in residential environments. We report the development of a synchrotron microprobe technique for characterization of multiple metal hosts in house dust. We have applied X-ray fluorescence for chemical characterization and X-ray diffraction for crystal structure
S Walker; H Jamieson; P Rasmussen
Initial results for urban metal distributions in house dusts of Syracuse, New York, USA.
A program of house dust sample collection and analysis has begun in Syracuse, New York, USA, in order to determine the feasibility of a geography-based exposure assessment for urban metals. The sampling program, and the protocols it employs, is described for two different types of wipe media, Ghost Wipes and Whatman Filters. Preliminary results show that strong spatial patterns of floor dust loading (mg dust per square foot) can be observed for data aggregated at a spatial scale of about 1600 m (approximately 2.5 km2). Floor dust metal concentrations were similar to those found in other urban environments, with some regional variation. The median floor dust Pb concentration was approximately 108 mg x kg(-1) for this initial data set of approximately 264 sampled residential locations, and varied from 50 to 1100 mg Pb x kg(-1). PMID:16089334
Johnson, D L; Hager, J; Hunt, A; Griffith, D A; Blount, S; Ellsworth, S; Hintz, J; Lucci, R; Mittiga, A; Prokhorova, D; Tidd, L; Millones, M M; Vincent, M
Assessing remedial effectiveness through the blood lead:soil/dust lead relationship at the Bunker Hill Superfund Site in the Silver Valley of Idaho.
The 21 square mile Bunker Hill Superfund Site in northern Idaho includes several thousand acres of contaminated hillsides and floodplain, a 365-acre abandoned lead/zinc smelter and is home to more than 7000 people in 5 residential communities. Childhood lead poisoning was epidemic in the 1970s with >75% of children exceeding 40 microg/dl blood lead. Health response activities have been ongoing for three decades. In 1991, a blood lead goal of 95% of children with levels less than 10 microg/dl was adopted. The cleanup strategy, based on biokinetic pathways models, was to reduce house dust lead exposure through elimination of soil-borne sources. An interim health intervention program, that included monitoring blood lead and exposures levels, was instituted to reduce exposures through parental education during the cleanup. In 1989 and 2001, 56% and 3% of children, respectively, exceeded the blood lead criteria. More than 4000 paired blood lead/environmental exposure observations were collected during this period. Several analyses of these data were accomplished. Slope factors derived for the relationship between blood lead, soil and dust concentrations are age-dependent and similar to literature reported values. Repeat measures analysis assessing year to year changes found that the remediation effort (without intervention) had approximately a 7.5 microg/dl effect in reducing a 2-year-old child's mean blood lead level over the course of the last ten years. Those receiving intervention had an additional 2-15 microg/dl decrease. Structural equations models indicate that from 40 to 50% of the blood lead absorbed from soils and dusts is through house dust with approximately 30% directly from community-wide soils and 30% from the home yard and immediate neighborhood. Both mean blood lead levels and percent of children to exceed 10 microg/dl have paralleled soil/dust lead intake rates estimated from the pathways model. Application of the IEUBK model for lead indicates that recommended USEPA default parameters overestimate mean blood lead levels, although the magnitude of over-prediction is diminished in recent years. Application of the site-specific model, using the soil and dust partitions suggested in the pathways model and an effective bioavailability of 18%, accurately predicts mean blood lead levels and percent of children to exceed 10 microg/dl throughout the 11-year cleanup period. This reduced response rate application of the IEUBK is consistent with the analysis used to originally develop the cleanup criteria and indicates the blood lead goal will be achieved. PMID:12568769
von Lindern, Ian; Spalinger, Susan; Petroysan, Varduhi; von Braun, Margrit
The relative allergenicity of Stachybotrys chartarum compared to house dust mite extracts in a mouse model
A report by the Institute of Medicine suggested that more research is needed to better understand mold effects on allergic disease, particularly asthma development. The authors compared the ability of the fungus Stachybotrys chartarum (SCE) and house dust mite (HDM) extracts to i...
Diesel and Carbon Particles Enhance House Dust Mite-Induced Pulmonary Hypersensitivity in Brown Norway Rats. P. Singh1, M.J. Daniels2, D. Winsett2, J. Richards2, K. Crissman2, M. Madden2 and M.I. Gilmour2. 1NCSU, Raleigh, NC and 2 USEPA, Research Triangle Park, NC. Ep...
Eradication of house dust mite from homes of atopic asthmatic subjects: A double-blind trial
Background: House dust mite (HDM) allergens can accumulate to very high levels in homes. From the observed sensitivity of HDMs to heat and their allergens to steam, a novel treatment of furnishings has been developed. Objective: We sought to determine whether combined steam and heat treatment of home furnishings reduced asthmatic patients� bronchial hyperreactivity (BHR) and lowered HDM antigen loads.
Tin Htut; Tim W. Higenbottam; Gordon W. Gill; Sr Ruth Darwin; Paul B. Anderson; Nasir Syed
Identification of historical lead sources in roof dusts and recent lake sediments from an industrialized area: indications from lead isotopes.
X-ray fluorescence and stable lead (Pb) isotopic analyses have been undertaken on dusts, known from microscopic investigation to contain significant quantities of industrially- and urban-derived particulate matter, present in the roof cavities of houses in the Illawarra region (N.S.W., Australia), with the objective of examining the historic record of Pb pollution. All investigated houses contained in excess of 250 micrograms g-1 Pb, with dwellings close to a copper smelter, in a large industrial complex including a major steelworks, containing higher (> 2500 micrograms g-1) Pb concentrations. The isotopic composition in the dusts, expressed here as 206Pb/204Pb, is relatively constant at 17.0, irrespective of dwelling age or distance from the industrial complex. Contamination of the dusts by Pb sourced from paint cannot explain the isotopic uniformity of the dust samples. Isotopic modelling indicates that the dusts contain Pb derived from the copper smelter, gasoline-air Pb and a minor contribution from coal-utilising sources. Lead loading was also investigated in the adjacent lagoon, which acts as a natural sink for particulate matter in the Illawarra region. Isotopic data and modelling indicate that one natural and four anthropogenic sources contribute to the Pb burden of this lagoon. The natural source consists of Permian rocks cropping out in the catchment area which have a 206Pb/204Pb of approximately 18.7. The suggested anthropogenic sources are an old disbanded base-metal (Pb) smelter (206Pb/204Pb approximately 16.2-16.3), the copper smelter (206Pb/204Pb approximately 17.9), gasoline-air derived Pb (206Pb/204Pb approximately 16.4-16.5) and industries utilising coal, for example the recently closed thermal coal-fired power station (206Pb/204Pb approximately 18.9). The relative contributions of the base-metal (mainly lead) smelter and gasoline-air Pb in the sediment can only be partly assessed due to the isotopic similarity of these sources. Likewise the natural background and coal source (e.g. power station) contributions can only be estimated from historical data. Age estimations for sediment cores, using 137Cs, provide some control on these assessments. Near surface sediments in the lagoon have a relatively constant 206Pb/204Pb of 17.6-17.7, irrespective of sample location. Isotopic calculations, together with records of particulate matter pollution emissions, indicate a link between the Pb in roof dusts (206Pb/204Pb approximately 17.0) and Pb contamination of the near surface (upper 20 cm) lagoonal sediments via a homogeneous, non-unique source of lead whose isotopic composition closely matches that of the dusts. Over the last 5 decades, atmospheric fallout of Pb-bearing particulate matter appears to have been the dominant pathway for addition of Pb to the lagoon and dwellings in the Illawarra region. PMID:9372624
Chiaradia, M; Chenhall, B E; Depers, A M; Gulson, B L; Jones, B G
It has been conjectured that jet turbine exhaust near airplane flight paths may result in significant human exposure to PAH. The fallout from the aerosol plume could be introduced into the residence directly as drafts through the interior of the house or through accumulation of ...
A survey of spatially distributed exterior dust lead loadings in New York City
This work documents ambient lead dust deposition values (lead loading) for the boroughs of New York City in 2003-2004. Currently, no regulatory standards exist for exterior concentrations of lead in settled dust. This is in contrast to the clearance and risk assessment standards that exist for interior residential dust. The reported potential for neurobehavioral toxicity and adverse cognitive development in children due to lead exposure prompts public health concerns about undocumented lead sources. Such sources may include settled dust of outdoor origin. Dust sampling throughout the five boroughs of NYC was done from the top horizontal portion of pedestrian traffic control signals (PTCS) at selected street intersections along main thoroughfares. The data (n=214 samples) show that lead in dust varies within each borough with Brooklyn having the highest median concentration (730{mu}g/ft{sup 2}), followed in descending order by Staten Island (452{mu}g/ft{sup 2}), the Bronx (382{mu}g/ft{sup 2}), Queens (198{mu}g/ft{sup 2}) and finally, Manhattan (175{mu}g/ft{sup 2}). When compared to the HUD/EPA indoor lead in dust standard of 40{mu}g/ft{sup 2}, our data show that this value is exceeded in 86% of the samples taken. An effort was made to determine the source of the lead in the dust atop of the PTCS. The lead in the dust and the yellow signage paint (which contains lead) were compared using isotopic ratio analysis. Results showed that the lead-based paint chip samples from intact signage did not isotopically match the dust wipe samples taken from the same surface. We know that exterior dust containing lead contributes to interior dust lead loading. Therefore, settled leaded dust in the outdoor environment poses a risk for lead exposure to children living in urban areas, namely, areas with elevated childhood blood lead levels and background lead dust levels from a variety of unidentified sources.
Caravanos, Jack [Hunter College-CUNY, School of Health Sciences (United States); Weiss, Arlene L. [Environmental Medicine Inc., 263 Center Avenue, Westwood, NJ 07675 (United States); School of Medicine, New York University, NY 10016 (United States); Blaise, Marc J. [Hunter College-CUNY, School of Health Sciences (United States); Jaeger, Rudolph J. [Environmental Medicine Inc., 263 Center Avenue, Westwood, NJ 07675 (United States) and School of Medicine, New York University, NY 10016 (United States)]. E-mail: email@example.com
... can become contaminated from household dust or exterior soil. Both are known lead sources. Regularly wet-mop ... of lead. Move play areas away from bare soil and away from the sides of the house . ...
Electrostatic charge characteristics of Der p1 allergen-carrying particles and the house dust mite dermatophagoides pteronyssinus
Control of the house dust mite allergen has received considerable attention owing to its importance in some allergic diseases.\\u000a One aspect of dust mites and their allergen-carrying faecal particles that has not been reported on, which may have allergen\\u000a control applications, is the electrostatic charge they carry in the natural environment. To promote tribo-electric charging,\\u000a household dust containing dust mite
P. T. Gaynor; J. F. Hughes
The impact of drinking water, indoor dust and paint on blood lead levels of children aged 1-5 years in Montr?al (Qu?bec, Canada)
Lead is neurotoxic at very low dose and there is a need to better characterize the impact of domestic sources of lead on the biological exposure of young children. A cross-sectional survey evaluated the contribution of drinking water, house dust and paint to blood lead levels (BLLs) of young children living in old boroughs of Montr�al (Canada). Three hundred and six children aged 1 to 5 years and currently drinking tap water participated in the study. For each participant, residential lead was measured in kitchen tap water, floor dust, windowsill dust and house paint and a venous blood sample was analyzed. Multivariate logistic regression was used to evaluate the association between elevated BLL in the children (? 75th percentile) and indoor lead contamination by means of odds ratios (OR) using 95% confidence intervals (CI). There was an association between BLL ?75th percentile (1.78??g/dL) and water lead when the mean water concentration was >3.3??g/L: adjusted OR=4.7 (95% CI: 2.1�10.2). Windowsill dust loading >14.1??g/ft2 was also associated with BLL ?1.78??g/dL: adjusted OR=3.2 (95% CI: 1.3�7.8). Despite relatively low BLLs, tap water and house dust lead contribute to an increase of BLLs in exposed young children.
Levallois, Patrick; St-Laurent, Julie; Gauvin, Denis; Courteau, Marilene; Prevost, Michele; Campagna, Celine; Lemieux, France; Nour, Shokoufeh; D'Amour, Monique; Rasmussen, Pat E
Primary prevention of lead poisoning: protecting children from unsafe housing.
Objectives. We examined the effects of changes in Rhode Island's Lead Hazard Mitigation Law in 2005 on children's blood lead levels. Methods. We used 2005 to 2009 data from Rhode Island's Lead Elimination Surveillance System; city tax assessor records in Central Falls, Pawtucket, Providence, and Woonsocket, Rhode Island; and records of conformance to the state's lead hazard mitigation law, to assess the extent to which legislation changes resulted in minimizing children's exposure to lead. Results. During the 5-year study, the proportion of properties that complied with the new law increased for properties that housed young children. However, the majority of rental properties did not comply with the law. Children's lead levels declined by approximately 1 microgram per deciliter on average in properties that did comply, demonstrating that the law could have a protective effect for children. Conclusions. Legislation changes increased the proportion of properties that were certified as nonhazardous, leading to decreased blood lead levels for children living in these properties. However, legislation cannot be a highly effective primary prevention strategy if it does not cover all properties where children live and is not strictly enforced. PMID:24922160
Rogers, Michelle L; Lucht, James A; Sylvaria, Alyssa J; Cigna, Jessica; Vanderslice, Robert; Vivier, Patrick M
House dust mites in naval ships, military barracks, and homes in the Hampton Roads area of Virginia.
This survey was undertaken to determine the possible exposure of military personnel to house dust mites in ships, barracks, and homes in the Hampton Roads area of Virginia. During the period from April 1, 1982 through August 31, 1983, 524 dust samples were collected with vacuum cleaners. Mites were extracted from aliquots of dust, counted, and identified as to species and life stage. Dermatophagoides pterynssinus (European house dust mite) was more common in private homes, while Dermatophagoides farinae (North American house dust mite) was more common on ships. Berthing compartments had the highest density of mites of areas sampled aboard ships. There appears to be a trend between the density of personnel and mites. Ships had a smaller percentage of mite-infested samples than houses. PMID:2507967
King, M J; Betts, L S; Sonenshine, D E
Urinary Metabolites of Organophosphate Flame Retardants: Temporal Variability and Correlations with House Dust Concentrations
Background: A reduction in the use of polybrominated diphenyl ethers (PBDEs) because of human health concerns may result in an increased use of and human exposure to organophosphate flame retardants (OPFRs). Human exposure and health studies of OPFRs are lacking. Objectives: We sought to define the degree of temporal variability in urinary OPFR metabolites in order to inform epidemiologic study design, and to explore a potential primary source of exposure by examining the relationship between OPFRs in house dust and their metabolites in urine. Methods: Nine repeated urine samples were collected from 7 men over the course of 3 months and analyzed for bis(1,3-dichloro-2-propyl) phosphate (BDCPP) and diphenyl phosphate (DPP), metabolites of the OPFRs tris(1,3-dichloro-2-propyl) phosphate (TDCPP) and triphenyl phosphate (TPP), respectively. Intraclass correlation coefficients (ICCs) were calculated to characterize temporal reliability. Paired house dust and urine samples were collected from 45 men. Results: BDCPP was detected in 91% of urine samples, and DPP in 96%. Urinary BDCPP showed moderate-to-strong temporal reliability (ICC range, 0.55�0.72). ICCs for DPP were lower, but moderately reliable (range, 0.35�0.51). There was a weak [Spearman r (rS) = 0.31] but significant (p = 0.03) correlation between urinary BDCPP and TDCPP concentrations in house dust that strengthened when nondetects (rS = 0.47) were excluded. There was no correlation between uncorrected DPP and TPP measured in house dust (rS < 0.1). Conclusions: Household dust may be an important source of exposure to TDCPP but not TPP. Urinary concentrations of BDCPP and DPP were moderately to highly reliable within individuals over 3 months.
Cooper, Ellen M.; Stapleton, Heather M.; Hauser, Russ
42 CFR 84.1146 - Lead fume test for dust, fume, and mist respirators; minimum requirements.
Code of Federal Regulations, 2010 CFR
... 1 2010-10-01 2010-10-01 false Lead fume test for dust, fume, and mist respirators; minimum requirements. 84...APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Dust, Fume, and Mist; Pesticide; Paint Spray; Powered...
42 CFR 84.1146 - Lead fume test for dust, fume, and mist respirators; minimum requirements.
Code of Federal Regulations, 2010 CFR
... 1 2009-10-01 2009-10-01 false Lead fume test for dust, fume, and mist respirators; minimum requirements. 84...APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Dust, Fume, and Mist; Pesticide; Paint Spray; Powered...
Application of Synchrotron X-ray Techniques for the Determination of Metal Speciation in (House) Dust Particles
\\u000a An overview of synchrotron radiation-based X-ray absorption and scattering techniques for characterizing the speciation of\\u000a metals in complex, heterogeneous samples, such as house dust, is presented. The complementary techniques are demonstrated\\u000a on a house dust sample elevated in Pb (1,670�mg�kg?1). The X-ray techniques successfully identified the speciation and sources of Pb in house dust samples, and provided an explanation\\u000a for
Lachlan C. W. MacLean; Suzanne Beauchemin; Pat E. Rasmussen
The Innate Immune Response in House Dust Mite-Induced Allergic Inflammation
Hypersensitivity to house dust mite (HDM; Dermatophagoides sp.) allergens is one of the most common allergic responses, affecting up to 85% of asthmatics. Sensitization to indoor allergens is the strongest independent risk factor associated with asthma. Additionally, >50% of children and adolescents with asthma are sensitized to HDM. Although allergen-specific CD4+ Th2 cells orchestrate the HDM allergic response through induction of IgE directed toward mite allergens, activation of innate immunity also plays a critical role in HDM-induced allergic inflammation. This review highlights the HDM components that lead to activation of the innate immune response. Activation may due to HDM proteases. Proteases may be recognized by protease-activation receptors (PARs), Toll-like receptors (TLRs), or C-type lectin receptors (CTRs), or act as a molecular mimic for PAMP activation signaling pathways. Understanding the role of mite allergen-induced innate immunity will facilitate the development of therapeutic strategies that exploit innate immunity receptors and associated signaling pathways for the treatment of allergic asthma.
Distribution of pesticides and polycyclic aromatic hydrocarbons in house dust as a function of particle size.
House dust is a repository for environmental pollutants that may accumulate indoors from both internal and external sources over long periods of time. Dust and tracked-in soil accumulate most efficiently in carpets, and the pollutants associated with dust and soil may present an exposure risk to infants and toddlers, who spend significant portions of their time in contact with or in close proximity to the floor and who engage in frequent mouthing activities. The availability of carpet dust for exposure by transfer to the skin or by suspension into the air depends on particle size. In this study, a large sample of residential house dust was obtained from a commercial cleaning service whose clients were homeowners residing in the Raleigh-Durham-Chapel Hill (Research Triangle) area of North Carolina. The composite dust was separated into seven size fractions ranging from < 4 to 500 microm in diameter, and each fraction was analyzed for 28 pesticides and 10 polycyclic aromatic hydrocarbons (PAHs). Over 20% of the fractionated dust sample consisted of particles < 25 microm in diameter. Fourteen pesticides and all 10 of the target PAHs were detected in one or more of the seven size-fractionated samples. Sample concentrations reported range from 0.02 to 22 microg/g; the synthetic pyrethroids cis- and trans-permethrin were the most abundant pesticide residue. The concentrations of nearly all of the target analytes increased gradually with decreasing particle size for the larger particles, then increased dramatically for the two smallest particle sizes (4-25 microm and < 4 microm). PMID:10464072
Lewis, R G; Fortune, C R; Willis, R D; Camann, D E; Antley, J T
Distribution of pesticides and polycyclic aromatic hydrocarbons in house dust as a function of particle size.
House dust is a repository for environmental pollutants that may accumulate indoors from both internal and external sources over long periods of time. Dust and tracked-in soil accumulate most efficiently in carpets, and the pollutants associated with dust and soil may present an exposure risk to infants and toddlers, who spend significant portions of their time in contact with or in close proximity to the floor and who engage in frequent mouthing activities. The availability of carpet dust for exposure by transfer to the skin or by suspension into the air depends on particle size. In this study, a large sample of residential house dust was obtained from a commercial cleaning service whose clients were homeowners residing in the Raleigh-Durham-Chapel Hill (Research Triangle) area of North Carolina. The composite dust was separated into seven size fractions ranging from < 4 to 500 microm in diameter, and each fraction was analyzed for 28 pesticides and 10 polycyclic aromatic hydrocarbons (PAHs). Over 20% of the fractionated dust sample consisted of particles < 25 microm in diameter. Fourteen pesticides and all 10 of the target PAHs were detected in one or more of the seven size-fractionated samples. Sample concentrations reported range from 0.02 to 22 microg/g; the synthetic pyrethroids cis- and trans-permethrin were the most abundant pesticide residue. The concentrations of nearly all of the target analytes increased gradually with decreasing particle size for the larger particles, then increased dramatically for the two smallest particle sizes (4-25 microm and < 4 microm). Images Figure 1 Figure 2 Figure 3 Figure 4
Lewis, R G; Fortune, C R; Willis, R D; Camann, D E; Antley, J T
Supercritical fluid extraction of polybrominated diphenyl ethers (PBDEs) from house dust with supercritical 1,1,1,2-tetrafluoroethane (R134a)
The extraction of polybrominated diphenyl ethers (PBDEs) from SRM 2585 (Organic Contaminants in House Dust) was investigated using supercritical fluid R134a as an extraction solvent. Three methods of dust extraction were studied: (1) extraction of dry dust, (2) extraction of dry dust dispersed on Ottawa sand and (3) extraction of dust wet with dichloromethane. For each of the three sample
Frank C. Calvosa; Anthony F. Lagalante
Pesticides in house dust from urban and farmworker households in California: an observational measurement study
Background��Studies report that residential use of pesticides in low-income homes is common because of poor housing conditions and pest\\u000a infestations; however, exposure data on contemporary-use pesticides in low-income households is limited. We conducted a study\\u000a in low-income homes from urban and agricultural communities to: characterize and compare house dust levels of agricultural\\u000a and residential-use pesticides; evaluate the correlation of pesticide
Lesliam Quir�s-Alcal�; Asa Bradman; Marcia Nishioka; Martha E Harnly; Alan Hubbard; Thomas E McKone; Jeannette Ferber; Brenda Eskenazi
Rasamsonia pulvericola sp. nov., isolated from house dust.
In the course of a global survey of the indoor mycobiota, we sampled and analysed settled dust from 87 buildings from 14 countries, using both a modified dilution-to-extinction method and 454-pyrosequencing. Rasamsonia is a recently established genus including thermotolerant or thermophilic species, five of which have been isolated from humans, including the emerging pathogen R. argillacea. A new species, R. pulvericola, was recovered from one residence in Songkhla, Thailand, and is morphologically characterised and compared phylogenetically with other members of the genus. Rasamsonia pulvericola forms a clade with R. brevistipitata and shares morphological characters such as usually biverticillate and never terverticillate conidiophores, and subglobose to ellipsoidal conidia. It has a lower maximum growth temperature and is the first mesophilic species added to the genus. The ITS sequence of R. pulvericola was not detected in the 454-pyrosequencing data for Thailand or other countries, but a similar ITS sequence was detected in Micronesia, probably representing another undescribed Rasamsonia species. PMID:24563833
Tanney, Joey B; Seifert, Keith A
First National Survey of Lead and Allergens in Housing: survey design and methods for the allergen and endotoxin components.
From July 1998 to August 1999, the U.S. Department of Housing and Urban Development and the National Institute of Environmental Health Sciences conducted the first National Survey of Lead and Allergens in Housing. The purpose of the survey was to assess children's potential household exposure to lead, allergens, and bacterial endotoxins. We surveyed a sample of 831 homes, representing 96 million permanently occupied, noninstitutional housing units that permit resident children. We administered questionnaires to household members, made home observations, and took environmental samples. This article provides general background information on the survey, an overview of the survey design, and a description of the data collection and laboratory methods pertaining to the allergen and endotoxin components. We collected dust samples from a bed, the bedroom floor, a sofa or chair, the living room floor, the kitchen floor, and a basement floor and analyzed them for cockroach allergen Bla g 1, the dust mite allergens Der f 1 and Der p 1, the cat allergen Fel d 1, the dog allergen Can f 1, the rodent allergens Rat n 1 and mouse urinary protein, allergens of the fungus Alternaria alternata, and endotoxin. This article provides the essential context for subsequent reports that will describe the prevalence of allergens and endotoxin in U.S. households, their distribution by various housing characteristics, and their associations with allergic diseases such as asthma and rhinitis.
Vojta, Patrick J; Friedman, Warren; Marker, David A; Clickner, Robert; Rogers, John W; Viet, Susan M; Muilenberg, Michael L; Thorne, Peter S; Arbes, Samuel J; Zeldin, Darryl C
Impact of Sublingual Immunotherapy on Specific Antibody Levels in Asthmatic Children Allergic to House Dust Mites
Objective: To evaluate the clinical outcome and changes in allergen-specific antibodies during sublingual immunotherapy (SLIT) in house dust mite (HDM)-allergic asthma patients and to compare levels of allergen-specific antibodies in HDM-allergic patients before and after treatment with that of healthy controls. Method: Thirty-one asthma patients allergic to HDM were studied. Patients in groups I (n = 17) and II (n
Nerin N. Bahceciler; Cigdem Arikan; Alison Taylor; Mubeccel Akdis; Kurt Blaser; Isil B. Barlan; Cezmi A. Akdis
Initial results for urban metal distributions in house dusts of syracuse, New York, USA
A program of house dust sample collection and analysis has begun in Syracuse, New York, USA, in order to determine the feasibility\\u000a of a geography-based exposure assessment for urban metals. The sampling program, and the protocols it employs, is described\\u000a for two different types of wipe media, Ghost Wipes and Whatman Filters. Preliminary results show that strong spatial patterns\\u000a of
D. L. Johnson; J. Hager; A. Hunt; D. A. Griffith; S. Blount; S. Ellsworth; J. Hintz; R. Lucci; A. Mittiga; D. Prokhorova; L. Tidd; M. M. Millones; M. Vincent
House-dust Mite Asthma. Results of Challenge Tests on Five Criteria with Dermatophagoides pteronyssinus
Twenty-eight patients with asthma and house-dust allergy were investigated by five different challenge tests with mite extract (Dermatophagoides pteronyssinus). These tests were performed on the skin, bronchi, nasal mucosa, and leucocytes, and on normal human lung tissue passively sensitized by the patients' serum. The results were compared with each other and with the clinical state of the patients.Of 21 patients
Monica K. McAllen; E. S. K. Assem; K. Maunsell
The correlations between heavy metals in residential indoor dust and outdoor street dust in Bahrain
The lead, zinc, cadmium, chromium, and nickel contents in both indoor house dust and outdoor street dust from 76 sites in Bahrain were determined by ICP-ES. The results showed widespread heavy metal contamination, especially lead, with an overall mean value in house dust for Pb, Zn, Cd, Cr, and Ni of 517, 202, 1.9, 11, and 10, respectively. The mean
I. M. Madany; M. S. Akhter; O. A. Al Jowder
Environmental and childhood lead contamination in the proximity of boat-repair yards in southern Thailand--I: pattern and factors related to soil and household dust lead levels.
High blood lead levels have recently been documented in schoolchildren living in communities adjacent to boat-repair yards in southern Thailand. In this study, the spatial pattern of lead contamination of soil and household dust in an area surrounding several boat-repair yards is described, and household factors associated with elevated dust lead are identified. A cross-sectional spatial study was conducted in a coastal residential area within a distance of 2 km from three major boat-repair yards situated on the east coast of peninsular Thailand. Household dust specimens were collected from an undisturbed position in the residences of children, aged 4-14 years, sampled randomly from all children living in the study area. Soil specimens were obtained from the interstices of a square grid, 70 x 70 m2, superimposed on the area. Geographic coordinates of residence and soil sampling positions were recorded and semivariograms and kriging used to contour the spatial distribution of lead in dust and soil. Environmental lead levels were also modeled in terms of direction and minimum distance from a boat-repair yard and, for household dust lead content, in terms of household variables, including occupation of household members in boat-repair work, type of house construction, and general cleanliness. Household dust and soil lead content ranged from 10 to 3025 mg/kg and from 1 to 7700 mg/kg, respectively. The distribution of soil lead peaked at the location of the boat-repair yards, but outside the yards the distribution was generally below 400 mg/kg and irregular. About 24% of household dust lead specimens were equal to or above 400 mg/kg, but showed significant decrease with increasing distance from the boat-repair yards, at rates of between 7% and 14% per 100 m. In houses where a family member was a worker in one of the major boatyards and in houses where occasional repair of small boats was undertaken, household dust lead levels were significantly elevated, by 65% (95% CI: 18-130%) and 31% (95% CI: 5-63%), respectively. Siting of boat-repair yards at a distance from residential areas and measures to reduce the spread of lead-containing dust are recommended to alleviate the problem of elevated household dust lead levels. PMID:16832871
Maharachpong, Nipa; Geater, Alan; Chongsuvivatwong, Virasakdi
[Does the average dust concentration modify the critical dust dose leading to silicosis?].
This article is based on the established fact that there is a relationship between the probability of the occurrence of silicosis and the inhaled amount of dust, the latter being represented by the concept of "dust dose" which is a product of dust concentration multiplied by the period of exposure. On investigating the "dust dose" values in 179 former coal miners in the East German town of Zwickau, however, we found that the "dust dose" principle does not apply to low to medium dust concentrations. We can now outline our idea of the origin and development of silicosis as follows: Below an initial threshold value of the "dust dose" it is improbable that silicosis will develop. Beyond that value, i.e. at medium dust concentrations, the time that elapses between the beginning of exposure and the onset of the disease is constant, namely, 20 years. However, the "dust dose" values that trigger the disease vary greatly. For dust concentrations beyond a second threshold value matters are as originally expected: the dust dose being constant, the disease will set in the earlier, the higher the dust concentration. To visualize these effects, a smoothing mathematical evaluation method was combined with a variant of the t test. PMID:1946255
Pangert, R; Ludwig, V; G�ntner, S
Condition and type of housing as an indicator of potential environmental lead exposure and pediatric blood lead levels
Environmental evaluations in a prospective behavior study of children with blood lead levels up to about 50 g\\/dl were performed by an intensive environmental survey and by exterior visual evaluations of housing quality. Serial blood lead values for infants in the study were compared to exterior housing type and quality, which itself was also compared with results of the intensive
C. S. Clark; R. L. Bornschein; P. Succop; S. S. Que Hee; P. B. Hammond; B. Peace
Levels of phthalate esters in settled house dust from urban dwellings with young children in Nanjing, China
NASA Astrophysics Data System (ADS)
To investigate the levels and possible determinants of phthalate esters (PEs) in settled house dust from urban dwellings with young children, dust was collected from 215 urban houses in Nanjing, China, and 145 outdoor settled dust samples were collected nearby. Six PEs were measured by gas chromatography/mass spectrometry. All PEs were detected in the dust from approximately 90% of the houses, with the exception of dioctyl phthalate (DOP), which had only a 59% detection rate. Di-2-ethylhexyl phthalate (DEHP) and di-n-butyl phthalate (DBP) were the most abundant PEs, with geometric means of 110 and 16.4 ?g g-1, respectively, and maximal concentrations 9950 and 2150 ?g g-1. Factor analysis showed that DBP, DEHP and benzyl butyl phthalate (BBP) might come from the same source and were significantly influenced by the use of solid-wood floor wax. High BBP, DEHP, DOP and total PE levels were associated with indices of dampness, and high DOP was associated with humidifier use. In conclusion, six PEs are ubiquitous in urban settled house dust in Nanjing, China, and both plastic materials and cosmetic and personal care products are important sources. Flooring material, dampness and humidifier use potentially influence house dust PE levels.
Zhang, Qi; Lu, Xiao-Mei; Zhang, Xiao-Ling; Sun, Yong-Gang; Zhu, Dong-Mei; Wang, Bing-Ling; Zhao, Ren-Zheng; Zhang, Zheng-Dong
Effects of physical interventions on house dust mite allergen levels in carpet, bed, and upholstery dust in low-income, urban homes.
House dust mite allergen exposure is a postulated risk factor for allergic sensitization, asthma development, and asthma morbidity; however, practical and effective methods to mitigate these allergens from low-income, urban home environments remain elusive. The purpose of this study was to assess the feasibility and effectiveness of physical interventions to mitigate house dust mite allergens in this setting. Homes with high levels of house dust mite allergen (Der f 1 + Der p 1 > or = 10 microg/g dust by enzyme-linked immunosorbent assay) in the bed, bedroom carpet, and/or upholstered furniture were enrolled in the study. Carpets and upholstered furniture were subjected to a single treatment of either dry steam cleaning plus vacuuming (carpet only) or intensive vacuuming alone. Bed interventions consisted of complete encasement of the mattress, box spring, and pillows plus either weekly professional or in-home laundering of nonencased bedding. Dust samples were collected at baseline and again at 3 days (carpet and upholstery only) and 2, 4, and 8 weeks posttreatment. We compared pretreatment mean allergen concentrations and loads to posttreatment values and performed between-group analyses after adjusting for differences in the pretreatment means. Both dry steam cleaning plus vacuuming and vacuuming alone resulted in a significant reduction in carpet house dust mite allergen concentration and load (p < 0.05). Levels approached pretreatment values by 4 weeks posttreatment in the intensive vacuuming group, whereas steam cleaning plus vacuuming effected a decrease that persisted for up to 8 weeks. Significant decreases in bed house dust mite allergen concentration and load were obtained in response to encasement and either professional or in-home laundering (p < 0.001). Between-group analysis revealed significantly less postintervention house dust mite allergen load in professionally laundered compared to home-laundered beds (p < 0.05). Intensive vacuuming and dry steam cleaning both caused a significant reduction in allergen concentration and load in upholstered furniture samples (p < 0.005). Based on these data, we conclude that physical interventions offer practical, effective means of reducing house dust mite allergen levels in low-income, urban home environments.
Vojta, P J; Randels, S P; Stout, J; Muilenberg, M; Burge, H A; Lynn, H; Mitchell, H; O'Connor, G T; Zeldin, D C
42 CFR 84.1146 - Lead fume test for dust, fume, and mist respirators; minimum requirements.
Code of Federal Regulations, 2012 CFR
...2012-10-01 2012-10-01 false Lead fume test for dust, fume, and mist respirators...Combination Gas Masks § 84.1146 Lead fume test for dust, fume, and mist respirators... (b) The relative humidity in the test chamber will be 20-80 percent, and...
Assessment of cleaning to control lead dust in homes of children with moderate lead poisoning: treatment of lead-exposed children trial.
In this article we describe the assessment and control of lead dust exposure in the Treatment of Lead-exposed Children (TLC) Trial, a clinical trial of the effects of oral chelation on developmental end points in urban children with moderately elevated blood lead levels. To reduce potential lead exposure from settled dust or deteriorated paint during the drug treatment phase of the trial, the homes of 765 (98%) of the randomized children (both active and placebo drug treatment groups) were professionally cleaned. Lead dust measurements were made in a sample of 213 homes before and after cleaning. Geometric mean dust lead loadings before cleaning were 43, 29, 308, and 707 micro g/ft2 in the kitchen floor, playroom floor, playroom windowsill, and playroom window well samples respectively. Following cleaning, floor dust lead loadings were reduced on average 32% for paired floor samples (p < 0.0001), 66% for windowsills (p < 0.0001), and 93% for window wells (p < 0.0001). Cleaning was most effective for 146 homes with precleaning dust lead levels above the recommended clearance levels, with average reductions of 44%, 74%, and 93% for floors (p < 0.0001), windowsills (p < 0.0001), and window wells (p < 0.0001), respectively. Despite these substantial reductions in dust lead loadings, a single professional cleaning did not reduce the lead loadings of all dust samples to levels below current federal standards for lead in residential dust. Attainment of dust levels below current standards will require more intensive cleaning and lead hazard reduction strategies.
Ettinger, Adrienne S; Bornschein, Robert L; Farfel, Mark; Campbell, Carla; Ragan, N Beth; Rhoads, George G; Brophy, Merrill; Wilkens, Sherry; Dockery, Douglas W
Comparison of techniques to reduce residential lead dust on carpet and upholstery: the new jersey assessment of cleaning techniques trial.
High-efficiency particulate air (HEPA) filtered vacuum cleaners are recommended by the U.S. Department of Housing and Urban Development for cleaning lead-contaminated house dust. We performed a randomized field study to determine whether a conventional (non-HEPA) vacuum cleaner could achieve cleaning results comparable with those of a HEPA vacuum cleaner. We compared the lead loading reductions of these two vacuum cleaners in a total of 127 New Jersey homes of lead-exposed children. We used wet towelettes and a vacuum sampler to collect lead dust from carpets and upholstery before and after vacuum cleaning. The vacuum sampling data showed that the HEPA and non-HEPA vacuum cleaners resulted in 54.7% (p = 0.006) and 36.4% (p = 0.020) reductions in lead loading, respectively, when used on soiled carpets, although the overall difference in lead loading reduction between the two vacuum cleaners was not statistically significant (p = 0.293). The wipe sampling data did not show any significant lead loading reduction for either of the vacuum cleaners, suggesting that both vacuum cleaners fail to clean the surfaces of carpet effectively, considering that wipe sampling media simulate surface contact. On upholstery, the wipe sampling data showed a significant reduction in lead loading for the non-HEPA vacuum cleaner (22.2%, p = 0.047). Even with the significant reduction, the postcleaning lead loadings on upholstery were similar to those on carpets. The similar lead loading results for carpets and upholstery indicate that soiled upholstery may be as important a source of childhood lead exposure as carpets.
Yiin, Lih-Ming; Rhoads, George G; Rich, David Q; Zhang, Junfeng; Bai, Zhipeng; Adgate, John L; Ashley, Peter J; Lioy, Paul J
Comparison of techniques to reduce residential lead dust on carpet and upholstery: the new jersey assessment of cleaning techniques trial.
High-efficiency particulate air (HEPA) filtered vacuum cleaners are recommended by the U.S. Department of Housing and Urban Development for cleaning lead-contaminated house dust. We performed a randomized field study to determine whether a conventional (non-HEPA) vacuum cleaner could achieve cleaning results comparable with those of a HEPA vacuum cleaner. We compared the lead loading reductions of these two vacuum cleaners in a total of 127 New Jersey homes of lead-exposed children. We used wet towelettes and a vacuum sampler to collect lead dust from carpets and upholstery before and after vacuum cleaning. The vacuum sampling data showed that the HEPA and non-HEPA vacuum cleaners resulted in 54.7% (p = 0.006) and 36.4% (p = 0.020) reductions in lead loading, respectively, when used on soiled carpets, although the overall difference in lead loading reduction between the two vacuum cleaners was not statistically significant (p = 0.293). The wipe sampling data did not show any significant lead loading reduction for either of the vacuum cleaners, suggesting that both vacuum cleaners fail to clean the surfaces of carpet effectively, considering that wipe sampling media simulate surface contact. On upholstery, the wipe sampling data showed a significant reduction in lead loading for the non-HEPA vacuum cleaner (22.2%, p = 0.047). Even with the significant reduction, the postcleaning lead loadings on upholstery were similar to those on carpets. The similar lead loading results for carpets and upholstery indicate that soiled upholstery may be as important a source of childhood lead exposure as carpets. PMID:12460803
Yiin, Lih-Ming; Rhoads, George G; Rich, David Q; Zhang, Junfeng; Bai, Zhipeng; Adgate, John L; Ashley, Peter J; Lioy, Paul J
The distribution of dust mite allergen in the houses of patients with asthma
Using an inhibition radioimmunoassay for the major allergen from Dermatophagoides pteronyssinus (antigen P1), we studied the distribution of this dust allergen in the houses of patients with asthma. Both bed and floor dust samples contained a wide range of antigen P1, 100 to 100,000 ng/g of fine dust, and this concentration correlated well with the number of mite bodies (r . 0.81, p less than 0.001). We were unable to detect antigen P1 in the air of undisturbed rooms. However, during domestic activity, between 1 and 30 ng were collected on a filter than sampled air for 45 min at 17 L/min. Using a cascade impactor it was shown that greater than 80% of the airborne antigen P1 was associated with particles greater than 10 mu in diameter. Some of the particles containing allergen could be identified because they formed precipitin rings when impacted onto agarose containing rabbit antimite antiserum. These particles had the physical appearance of mite feces, which are the major source of antigen P1 in mite cultures. The results suggested that natural exposure to this dust allergen allows occasional fecal particles to enter the lungs and that these particles contain very concentrated allergen.
Tovey, E.R.; Chapman, M.D.; Wells, C.W.; Platts-Mills, T.A.
Coal-Tar-Based Parking Lot Sealcoat: An Unrecognized Source of PAH to Settled House Dust
Despite much speculation, the principal factors controlling concentrations of polycyclic aromatic hydrocarbons (PAH) in settled house dust (SHD) have not yet been identified. In response to recent reports that dust from pavement with coal-tar-based sealcoat contains extremely high concentrations of PAH, we measured PAH in SHD from 23 apartments and in dust from their associated parking lots, one-half of which had coal-tar-based sealcoat (CT). The median concentration of total PAH (T-PAH) in dust from CT parking lots (4760 ?g/g, n = 11) was 530 times higher than that from parking lots with other pavement surface types (asphalt-based sealcoat, unsealed asphalt, concrete [median 9.0 ?g/g, n = 12]). T-PAH in SHD from apartments with CT parking lots (median 129 ?g/g) was 25 times higher than that in SHD from apartments with parking lots with other pavement surface types (median 5.1 ?g/g). Presence or absence of CT on a parking lot explained 48% of the variance in log-transformed T-PAH in SHD. Urban land-use intensity near the residence also had a significant but weaker relation to T-PAH. No other variables tested, including carpeting, frequency of vacuuming, and indoor burning, were significant.
Coal-tar-based parking lot sealcoat: An unrecognized source of PAH to settled house dust
Despite much speculation, the principal factors controlling concentrations of polycyclic aromatic hydrocarbons (PAH) in settled house dust (SHD) have not yet been identified. In response to recent reports that dust from pavement with coaltar-based sealcoat contains extremely high concentrations of PAH, we measured PAH in SHD from 23 apartments and in dust from their associated parking lots, one-half of which had coal-tar-based sealcoat (CT). The median concentration of total PAH (T-PAH) in dust from CT parking lots (4760 ??g/g, n = 11) was 530 times higher than that from parking lots with other pavement surface types (asphalt-based sealcoat, unsealed asphalt, concrete [median 9.0 ??g/g, n = 12]). T-PAH in SHD from apartments with CT parking lots (median 129 ??g/g) was 25 times higher than that in SHD from apartments with parking lots with other pavement surface types (median 5.1 ??g/g). Presence or absence of CT on a parking lot explained 48% of the variance in log-transformed T-PAH in SHD. Urban land-use intensity near the residence also had a significant but weaker relation to T-PAH. No other variables tested, including carpeting, frequency of vacuuming, and indoor burning, were significant. ?? 2010 American Chemical Society.
Mahler, B. J.; Van Metre, P. C.; Wilson, J. T.; Musgrove, M.; Burbank, T. L.; Ennis, T. E.; Bashara, T. J.
Differences in metal concentration by particle size in house dust and soil.
The majority of particles that adhere to hands are <63 ?m in diameter yet risk assessments for soil remediation are typically based on soil samples sieved to <250 ?m. The objective of our study was to determine if there is a significant difference in metal concentration by particle size in both house dust and soil. We obtained indoor dust and yard soil samples from 10 houses in Tucson, Arizona. All samples were sieved to <63 ?m and 63 to <150 ?m and analyzed for 30 elements via ICP-MS following nitric acid digestion. We conducted t-tests of the log-transformed data to assess for significant differences that were adjusted with a Bonferroni correction to account for multiple comparisons. In house dust, significant differences in concentration were observed for Be, Al, and Mo between particles sizes, with a higher concentration observed in the smaller particle sizes. Significant differences were also determined for Mg, Ca, Cr, Co, Cu, Ge, Zr, Ag, Ba, and Pb concentration in yard soil samples, with the higher concentration observed in the smaller particles size for each element. The results of this exploratory study indicate that current risk assessment practices for soil remediation may under estimate non-dietary ingestion exposure. This is of particular concern for young children who are more vulnerable to this exposure route due to their high hand mouthing frequencies. Additional studies with a greater number of samples and wider geographic distribution with different climates and soil types should be completed to determine the most relevant sampling practices for risk assessment. PMID:22245917
Beamer, Paloma I; Elish, Christina A; Roe, Denise J; Loh, Miranda M; Layton, David W
Differences in Metal Concentration by Particle Size in House Dust and Soil
The majority of particles that adhere to hands are <63 ?m in diameter yet risk assessments for soil remediation are typically based on soil samples sieved to <250 ?m. The objective of our study was to determine if there is a significant difference in metal concentration by particle size in both house dust and soil. We obtained indoor dust and yard soil samples from 10 houses in Tucson, Arizona. All samples were sieved to <63 ?m and 63 to <150 ?m and analyzed for 30 elements via ICP-MS following nitric acid digestion. We conducted t-tests of the log-transformed data to assess for significant differences that were adjusted with a Bonferroni correction to account for multiple comparisons. In house dust significant differences in concentration were observed for Be, Al, and Mo between particles sizes, with a higher concentration observed in the smaller particles size. Significant differences were also determined for Mg, Ca, Cr, Co, Cu, Ge, Zr, Ag, Ba, and Pb concentration in yard soil samples, with the higher concentration observed in the smaller particles size for each element. The results of this exploratory study indicate that current risk assessment practices for soil remediation may under estimate non-dietary ingestion exposure. This is of particular concern for young children who are more vulnerable to this exposure route due to their high hand mouthing frequencies. Additional studies with a greater number of samples and wider geographic distribution with different climates and soil types should be completed to determine the most relevant sampling practices for risk assessment.
Elish, Christina A.; Roe, Denise J.; Loh, Miranda; Layton, David W.
Beta(1-->3)-glucan in house dust of German homes: housing characteristics, occupant behavior, and relations with endotoxins, allergens, and molds.
beta(1-->3)-Glucans are potent proinflammatory agents that have been suggested to play a role in indoor-related respiratory health effects. The aim of this study was to assess whether beta(1-->3)-glucan concentrations in house dust are correlated with levels of endotoxins, allergens, and culturable mold spore counts in house dust. Further, the associations of beta(1-->3)-glucan with housing characteristics and occupant behavior were assessed. beta(1-->3)-Glucan was measured in settled house dust from living room floors of 395 homes of two German cities, Erfurt and Hamburg, with a specific enzyme immunoassay. Concentrations ranged from below the limit of detection to 19,013 microg/m(2) (22,588 microg/g dust). Concentrations per square meter were found to be correlated with endotoxins, mite and cat allergens, and culturable mold spores. Correlations were weaker when concentrations were expressed per gram of dust, indicating that variance in concentrations of all factors is largely determined by the amount of dust sampled. Associations between beta(1-->3)-glucan, housing characteristics, and occupant behavior were found for concentrations per square meter but not for concentrations per gram of dust. The following characteristics were associated with a significant increase in beta(1-->3)-glucan levels: carpets in the living room [means ratio (MR) = 1.9-2.1], keeping a dog inside (MR = 1.4), use of the home by four or more persons (MR = 1.4), use of the living room for > 180 hr/week (MR = 2.1), lower frequency of vacuum cleaning (MR = 1.6-3.0) and dust cleaning (MR = 1.2 and 1.4, respectively), and presence of mold spots during the past 12 months (MR = 1.4). We conclude that that the amount of dust sampled can be used as a proxy for hygiene and that beta(1-->3)-glucan concentrations per square meter are related to the amount of dust sampled.
Gehring, U; Douwes, J; Doekes, G; Koch, A; Bischof, W; Fahlbusch, B; Richter, K; Wichmann, H E; Heinrich, J
Evaluation of HEPA vacuum cleaning and dry steam cleaning in reducing levels of polycyclic aromatic hydrocarbons and house dust mite allergens in carpets
Dry steam cleaning, which has gained recent attention as an effective method to reduce house dust mite (HDM) allergen concentration and loading in carpets, was evaluated in this study for its efficacy in lowering levels of polycyclic aromatic hydrocarbons (PAHs) as well as HDM allergens. Fifty urban homes with wail-to-wall carpets, mostly low-income and with known lead contamination, were studied in 2003 and 2004. Two carpet-cleaning interventions were compared: Repeated HEPA (High Efficiency Particulate Air filtered) vacuuming alone and repeated HEPA vacuuming supplemented with dry steam cleaning. Vacuum samples were collected to measure carpet loading of dust and contaminants immediately before and after cleaning. Paired comparisons were conducted to evaluate the effectiveness of the cleaning protocols in reducing the levels of PAHs and HDM allergens in carpets. The results indicated that both cleaning methods substantially reduced the loading of PAHs and HDM allergens as well as dust in carpets (p < 0.0001). The reductions in loading of dust (64.4%), PAHs (69.1%), and HDM allergens (85.5%), by dry steam cleaning plus repetitive HEPA vacuuming were larger than the reductions by regular HEPA vacuuming alone: dust (55.5%), PAHs (58.6%), and HDM allergens (80.8%), although the difference was statistically significant only for dust and PAHs. We conclude that intensive HEPA vacuum cleaning substantially reduced the loading of PAHs and HDM allergens in carpets in these urban homes and that dry steam cleaning added modestly to cleaning effectiveness.
Yu, Chang Ho; Yiin, Lih-Ming; Fan, Zhi-Hua (Tina); Rhoads, George G.
Per- and polyfluorinated compounds in house dust and indoor air from northern Norway - a pilot study.
Polyfluorinated compounds (PFCs) are an extremely versatile class of compounds and are used in a variety of consumer applications and products. Recent studies have suggested that PFCs in indoor air and dust could act as sources of human exposure and outdoor air contamination. This study presents method development and analysis of a wide range of PFCs in dust and air using active sampling techniques with commercially available sampling equipment (forensic nozzles with filter housings for dust collection and polyurethane foam (PUF)-XAD(2)-PUF sandwich-tubes for air sampling) using both liquid and gas chromatography mass spectrometry. The developed method was validated and tested for applicability to analyze dust and air samples at both low and high concentrations (0.5 ng and 25 ng per analyte per air sample, respectively). Samples from private households and an office building were analyzed to explore differences in distribution patterns and concentrations. Perfluorooctane sulfonate, perfluorodecane sulfonate, perfluoroheptanoate, perfluorooctanoate and perfluorononanoate were observed in all samples of dust from private households, in the range from 1 to 80.1 ng g(-1). Fluorotelomer alcohols (FTOHs) were the predominant PFCs in indoor air samples with ?FTOHs ranging between 4.7 and 17.9 ng m(-3). The concentrations found in the present study are generally lower than those previously reported. This variation may be due to differences associated with geographical locations and lifestyles. However, use of different sampling techniques and strategies among studies can introduce large variations in PFC concentration found, making direct comparisons challenging. PMID:21632089
Huber, Sandra; Haug, Line Sm�stuen; Schlabach, Martin
Exposure to house dust phthalates in relation to asthma and allergies in both children and adults.
Although an association between exposure to phthalates in house dust and childhood asthma or allergies has been reported in recent years, there have been no reports of these associations focusing on both adults and children. We aimed to investigate the relationships between phthalate levels in Japanese dwellings and the prevalence of asthma and allergies in both children and adult inhabitants in a cross-sectional study. The levels of seven phthalates in floor dust and multi-surface dust in 156 single-family homes were measured. According to a self-reported questionnaire, the prevalence of bronchial asthma, allergic rhinitis, allergic conjunctivitis, and atopic dermatitis in the 2years preceding the study was 4.7%, 18.6%, 7.6%, and 10.3%, respectively. After evaluating the interaction effects of age and exposure categories with generalized liner mixed models, interaction effects were obtained for DiNP and bronchial asthma in adults (Pinteraction=0.028) and for DMP and allergic rhinitis in children (Pinteraction=0.015). Although not statistically significant, children had higher ORs of allergic rhinitis for DiNP, allergic conjunctivitis for DEHP, and atopic dermatitis for DiBP and BBzP than adults, and liner associations were observed (Ptrend<0.05). On the other hand, adults had a higher OR for atopic dermatitis and DEHP compared to children. No significant associations were found in phthalates levels collected from multi-surfaces. This study suggests that the levels of DMP, DEHP, DiBP, and BBzP in floor dust were associated with the prevalence of allergic rhinitis, conjunctivitis, and atopic dermatitis in children, and children are more vulnerable to phthalate exposure via household floor dust than are adults. The results from this study were shown by cross-sectional nature of the analyses and elaborate assessments for metabolism of phthalates were not considered. Further studies are needed to advance our understanding of phthalate toxicity. PMID:24704966
Ait Bamai, Yu; Shibata, Eiji; Saito, Ikue; Araki, Atsuko; Kanazawa, Ayako; Morimoto, Kanehisa; Nakayama, Kunio; Tanaka, Masatoshi; Takigawa, Tomoko; Yoshimura, Takesumi; Chikara, Hisao; Saijo, Yasuaki; Kishi, Reiko
The Effectiveness of Acupuncture Compared to Loratadine in Patients Allergic to House Dust Mites
Background. The aim of this work was to evaluate the clinical effectiveness of acupuncture and its impact on the immune system in comparison to loratadine in the treatment of persistent allergic rhinitis caused by house dust mites. Methods. In this study, 24 patients suffering from persistent allergic rhinitis induced by house dust mites were treated either with acupuncture (n = 15) or with loratadine (n = 9). The evaluation of the data was based on the subjective and the objective rhinoconjunctivitis symptom scores, specific and total IgE, and interleukins (IL-4, IL-10, and IFN-?) as markers for the activity of Th1 or Th2 cells. Results. The treatments with acupuncture as well as with loratadine were considered effective in the patients' subjective assessment, whereby the effect of the acupuncture tended to be assessed as more persistent after the end of treatment. A change in the specific or the total IgE was not detectable in either group. The interleukin profile showed the tendency of an increasing IL-10 value in the acupuncture group. The results of the study show that the effectiveness of acupuncture is comparable to that of loratadine. Conclusion. Acupuncture is a clinically effective form of therapy in the treatment of patients suffering from persistent allergic rhinitis. The results indicate the probability of an immunomodulatory effect.
Hauswald, Bettina; Dill, Christina; Boxberger, Jurgen; Kuhlisch, Eberhard; Zahnert, Thomas; Yarin, Yury M.
Recombinant Lactobacillus plantarum inhibits house dust mite-specific T-cell responses.
Recent evidence suggests that chronic exposure to lactobacilli, which are part of the normal intestinal flora, inhibits the development of allergic disorders. Allergy is mediated by Th2 cells, which produce high levels of IL4 and IL5, and suppressive effects of lactic acid bacteria on the development of allergy have been attributed to their Th1-inducing properties. On the other hand, lactic acid bacteria have also been shown to suppress autoimmune disorders which are mediated by Th1 cells producing high levels of IFNgamma. To study this apparent discrepancy, the immunomodulatory potential of lactobacilli was evaluated using recombinants that express an immunodominant T-cell epitope of Der p 1 of house dust mites. Mucosal immunization of C57BL/6 J mice with such recombinants resulted in the induction of T cells which produced low amounts of IFNgamma. Immunization with the house dust mite peptide followed by treatment with recombinant Lactobacillus plantarum resulted in the inhibition of both IFNgamma and IL5 production. The effect on IFNgamma production was shown to be a non-specific effect of L. plantarum. The effect on IL5 production, however, was only observed when the recombinant expressing the Der p 1 peptide, but not the control recombinant, was used for treatment. Neither of the recombinants had an effect on the antibody response. Taken together, these data suggest that recombinant L. plantarum may be a suitable candidate for the treatment of allergic disorders. PMID:11678893
Kruisselbrink, A; Heijne Den Bak-Glashouwer, M J; Havenith, C E; Thole, J E; Janssen, R
Laboratory Comparison of Vacuum, OSHA, and HUD Sampling Methods for Lead in Household Dust
The goals of this project were to evaluate and compare the efficiency and reproducibility of three methods for sampling lead-containing dust in homes. Lead-containing dust was generated in a 1-m3 chamber and uniformly deposited onto surfaces typically found in the home (painted wood, unpainted wood, varnished wood, linoleum, and carpet). Trials with three levels of lead concentrations were performed for
Stephen J. Reynolds; Lois Etre; Peter S. Thorne; Paul Whitten; Mustafa Selim; William J. Popendorf
Lead contamination of UK dusts and soils and implications for childhood exposure: An overview of the work of the Environmental Geochemistry Research Group, Imperial College, London, England 1981-1992.
Over the course of the last decade, research conducted by the Imperial College Environmental Geochemistry Research Group has focused on the nature and effects of lead in UK dusts and soils. An initial nationwide reconnaissance survey demonstrated that approximately 10% of the population is exposed to lead levels in excess of 2,000 ?g g(-1) in house-hold dust. Subsequent exposure studies revealed that for 2 year old children in the UK urban environment, approximately 50% of lead intake was from dust ingested as a result of hand-to-mouth activity. Follow-up computer controlled scanning electron microscopy (CCSEM) analysis of urban household dust and particulate material wiped from children's hands showed that important sources of dust lead include lead-based paint, road dust and soils. CCSEM identification of specific soil lead tracer particles (from minewaste contaminated soils) in dusts and on children's hands further documented the important role of soil as a source of exposure. Speciation studies of soil lead of this origin indicated that the form of the lead, which is largely influenced by the soil environment, is the primary control on bioavailability. It appears that although lead of minewaste origin may be present at elevated levels in dusts and soils, it does not necessarily contribute to elevated blood lead levels when the lead is present in relatively insoluble form. PMID:24197205
Thornton, I; Watt, J M; Davies, D J; Hunt, A; Cotter-Howells, J; Johnson, D L
Knowledge and performance regarding management of house dust mites in a military hospital.
House dust mites (HDM) are microscopic arthropods live indoor and/or outdoor inhibited by vertebrates including man. This study improved nurses' knowledge and performance regarding the management of HDM to minimize nosocomial patient's exposure in a Military Hospital. All staff nurses with working experience of at least one year were included (n=60 nurses). Three tools were used for data collection: 1- a self-administered questionnaire sheet to assess subjects sociodemographic data and knowledge regarding management of HDM, 2- an observation check list to evaluate performance as regard environmental care related to HDMs' control, and 3- practical dust collection from indicative areas whenever possible to isolate mites from dust patients' dwelling for identification following standard local and international keys. The results showed that the implementation of educational intervention program led to significant improvement of nurses' knoweledge and performance related to management of HDM post program implementation. This fact was practically approved as some nurse's requested to examine even their own homes. Also, seven species of mites were isolated. PMID:24640881
Saleh, Ahmed Megahed Ahmed; Ali, Hesham Abd El-Raouf; Ahmed, Salwa Abdalla Mohamed; Mohammad, Naema Mahmoud; Morsy, Tosson Aly
Optimal efficacy of a fungicide preparation, natamycin, in the control of the house-dust mite, Dermatophagoides pteronyssinus
The efficacy of a fungicidal preparation, natamycin, for the effective control ofDermatophagoides pteronyssinus (Trouessart), was determined at different concentrations on mattress-dust microsites, including ticking. One treatment with the commercially available natamycin concentration (Tymasil) resulted in a 65% reduction of house-dust mite populations within 4 weeks of treatment. The acaricidal control could be proven despite the protective role of mattress fibres
D. De Saint Georges-Gridelet
Lead contamination of UK dusts and soils and implications for childhood exposure: An overview of the work of the Environmental Geochemistry Research Group, Imperial College, London, England 1981�1992
Over the course of the last decade, research conducted by the Imperial College Environmental Geochemistry Research Group has focused on the nature and effects of lead in UK dusts and soils. An initial nationwide reconnaissance survey demonstrated that approximately 10% of the population is exposed to lead levels in excess of 2,000 �g g-1 in house-hold dust. Subsequent exposure studies
I. Thornton; J. M. Watt; D. J. A. Davies; A. Hunt; J. Cotter-Howells; D. L. Johnson
Lead Poisoning Prevention Tips
... can become contaminated from household dust or exterior soil. Both are known lead sources. Regularly wet-mop ... entering the house to prevent bringing lead-contaminated soil in from outside. Prevent children from playing in ...
House dust mite control measures in the management of asthma: meta-analysis
Objective To determine whether patients with asthma who are sensitive to mites benefit from measures designed to reduce their exposure to house dust mite antigen in the home. Design Meta-analysis of randomised trials that investigated the effects on asthma patients of chemical or physical measures to control mites, or both, in comparison with an untreated control group. All trials in any language were eligible for inclusion. Subjects Patients with bronchial asthma as diagnosed by a doctor and sensitisation to mites as determined by skin prick testing, bronchial provocation testing, or serum assays for specific IgE antibodies. Main outcome measures Number of patients whose allergic symptoms improved, improvement in asthma symptoms, improvement in peak expiratory flow rate. Outcomes measured on different scales were combined using the standardised effect size method (the difference in effect was divided by the standard deviation of the measurements). Results 23 studies were included in the meta-analysis; 6 studies used chemical methods to reduce exposure to mites, 13 used physical methods, and 4 used a combination. Altogether, 41/113 patients exposed to treatment interventions improved compared with 38/117 in the control groups (odds ratio 1.20, 95% confidence interval 0.66 to 2.18). The standardised mean difference for improvement in asthma symptoms was ?0.06 (95% confidence interval ?0.54 to 0.41). For peak flow rate measured in the morning the standardised mean difference was ?0.03 (?0.25 to 0.19). As measured in the original units this difference between the treatment and the control group corresponds to ?3?l/min (95% confidence interval ?25?l/min to 19?l/min). The results were similar in the subgroups of trials that reported successful reduction in exposure to mites or had long follow up times. Conclusion Current chemical and physical methods aimed at reducing exposure to allergens from house dust mites seem to be ineffective and cannot be recommended as prophylactic treatment for asthma patients sensitive to mites. Key messagesCurrent chemical and physical methods aimed at reducing exposure to allergens from house dust mites seem to be ineffective; these methods cannot be recommended as prophylactic treatment for asthma patients who are sensitive to mitesIt is unlikely that a worthwhile effect has been overlooked in this meta-analysis since the confidence interval for the peak expiratory flow rate was quite narrowFuture studies should be much larger and more rigorous than those in this meta-analysis and should evaluate other methods of mite control than those used to date
G?tzsche, Peter C; Hammarquist, Cecilia; Burr, Michael
Suspension-cultured BY-2 tobacco cells produce and mature immunologically active house dust mite allergens.
The replacement of crude allergen extracts by selected allergens currently represents a major goal for the improvement of allergy diagnosis and immunotherapy. Indeed, the development of molecularly defined vaccines would facilitate both standardization and enhance batch-to-batch reproducibility as well as treatment specificity. In this study, we have investigated the potential of tobacco plant cells to produce biologically active forms of the two major allergens from the house dust mite. A detailed characterization of these plant-made allergens has shown similar proteolytic maturation and folding as well as comparable immunoreactivity to their natural counterparts. Altogether, our results exemplify that suspension-cultured BY-2 tobacco cells represent a low cost and environmentally safe expression system suitable to produce recombinant allergens from Dermatophagoides pteronyssinus under a form appropriate for diagnostic and therapeutic purposes. PMID:17207260
Lienard, David; Tran Dinh, Olivia; van Oort, Erika; Van Overtvelt, Laurence; Bonneau, Caroline; Wambre, Eric; Bardor, Muriel; Cosette, Pascal; Didier-Laurent, Alain; de Borne, Fran�ois Dorlhac; Delon, Rene; van Ree, Ronald; Moingeon, Philippe; Faye, Lo�c; Gomord, V�ronique
Pesticides in house dust from urban and farmworker households in California: an observational measurement study
Background Studies report that residential use of pesticides in low-income homes is common because of poor housing conditions and pest infestations; however, exposure data on contemporary-use pesticides in low-income households is limited. We conducted a study in low-income homes from urban and agricultural communities to: characterize and compare house dust levels of agricultural and residential-use pesticides; evaluate the correlation of pesticide concentrations in samples collected several days apart; examine whether concentrations of pesticides phased-out for residential uses, but still used in agriculture (i.e., chlorpyrifos and diazinon) have declined in homes in the agricultural community; and estimate resident children's pesticide exposures via inadvertent dust ingestion. Methods In 2006, we collected up to two dust samples 5-8 days apart from each of 13 urban homes in Oakland, California and 15 farmworker homes in Salinas, California, an agricultural community (54 samples total). We measured 22 insecticides including organophosphates (chlorpyrifos, diazinon, diazinon-oxon, malathion, methidathion, methyl parathion, phorate, and tetrachlorvinphos) and pyrethroids (allethrin-two isomers, bifenthrin, cypermethrin-four isomers, deltamethrin, esfenvalerate, imiprothrin, permethrin-two isomers, prallethrin, and sumithrin), one phthalate herbicide (chlorthal-dimethyl), one dicarboximide fungicide (iprodione), and one pesticide synergist (piperonyl butoxide). Results More than half of the households reported applying pesticides indoors. Analytes frequently detected in both locations included chlorpyrifos, diazinon, permethrin, allethrin, cypermethrin, and piperonyl butoxide; no differences in concentrations or loadings were observed between locations for these analytes. Chlorthal-dimethyl was detected solely in farmworker homes, suggesting contamination due to regional agricultural use. Concentrations in samples collected 5-8 days apart in the same home were strongly correlated for the majority of the frequently detected analytes (Spearman ? = 0.70-1.00, p < 0.01). Additionally, diazinon and chlorpyrifos concentrations in Salinas farmworker homes were 40-80% lower than concentrations reported in samples from Salinas farmworker homes studied between 2000-2002, suggesting a temporal reduction after their residential phase-out. Finally, estimated non-dietary pesticide intake for resident children did not exceed current U.S. Environmental Protection Agency's (U.S. EPA) recommended chronic reference doses (RfDs). Conclusion Low-income children are potentially exposed to a mixture of pesticides as a result of poorer housing quality. Historical or current pesticide use indoors is likely to contribute to ongoing exposures. Agricultural pesticide use may also contribute to additional exposures to some pesticides in rural areas. Although children's non-dietary intake did not exceed U.S. EPA RfDs for select pesticides, this does not ensure that children are free of any health risks as RfDs have their own limitations, and the children may be exposed indoors via other pathways. The frequent pesticide use reported and high detection of several home-use pesticides in house dust suggests that families would benefit from integrated pest management strategies to control pests and minimize current and future exposures.
Molecular Determinants for Antibody Binding on Group 1 House Dust Mite Allergens*
House dust mites produce potent allergens, Der p 1 and Der f 1, that cause allergic sensitization and asthma. Der p 1 and Der f 1 are cysteine proteases that elicit IgE responses in 80% of mite-allergic subjects and have proinflammatory properties. Their antigenic structure is unknown. Here, we present crystal structures of natural Der p 1 and Der f 1 in complex with a monoclonal antibody, 4C1, which binds to a unique cross-reactive epitope on both allergens associated with IgE recognition. The 4C1 epitope is formed by almost identical amino acid sequences and contact residues. Mutations of the contact residues abrogate mAb 4C1 binding and reduce IgE antibody binding. These surface-exposed residues are molecular targets that can be exploited for development of recombinant allergen vaccines.
Chruszcz, Maksymilian; Pomes, Anna; Glesner, Jill; Vailes, Lisa D.; Osinski, Tomasz; Porebski, Przemyslaw J.; Majorek, Karolina A.; Heymann, Peter W.; Platts-Mills, Thomas A. E.; Minor, Wladek; Chapman, Martin D.
Dose of house dust mite antigen (P1) inhaled by infants aged one month
A survey of the habitats occupied by 12 infants of one month of age revealed that approximately 10% of their day was spent in conditions of potential exposure to the major (P1) allergen of the house dust mite, Dermatophagoides pteronyssinus. A respiratory pump which reproduced the minute ventilation of an infant was placed in representative infant habitats. The P1 allergen trapped by the filter in this pump was measured as an estimate of infants' allergen intake. Detectable P1 intake was only present when there was active air disturbance (bed making and vacuuming). The average P1 intake was approximately 3 ng P1/24 hours. Comparison of this P1 intake with that which sensitizes in other situations suggests that it is usually inadequate to sensitize infants.
Carswell, F.; Clark, J.; Robinson, P.; Platts-Mills, T.A.
House dust mite allergen induces asthma via TLR4 triggering of airway structural cells
Barrier epithelial cells and airway dendritic cells (DC) make up the first line of defence against inhaled substances like house dust mite (HDM) allergen and endotoxin. We hypothesized that these cells need to communicate to cause allergic disease. Using irradiated chimeric mice, we demonstrate that TLR4 expression on radioresistant lung structural cells is required and sufficient for DC activation in the lung and for priming of effector T helper responses to HDM. TLR4 triggering on structural cells caused production of the innate proallergic cytokines thymic stromal lymphopoietin, granulocyte-macrophage colony stimulating factor, interleukin-25 and IL-33. The absence of TLR4 on structural cells, but not on hematopoietic cells, abolished HDM driven allergic airway inflammation. Finally, inhalation of a TLR4 antagonist to target exposed epithelial cells suppressed the salient features of asthma including bronchial hyperreactivity. Our data identify an innate immune function of airway epithelial cells that drives allergic inflammation via activation of mucosal DCs.
HAMMAD, Hamida; CHIEPPA, Marcello; PERROS, Frederic; WILLART, Monique A.; GERMAIN, Ronald N.; LAMBRECHT, Bart N.
Utilizing Pyrosequencing and Quantitative PCR to Characterize Fungal Populations among House Dust Samples
Molecular techniques are replacing culturing and counting methods in quantifying indoor fungal contamination. Pyrosequencing offers the possibility of identifying unexpected indoor fungi. In this study, 50 house dust samples were collected from homes in the Yakima Valley, WA. Each sample was analyzed by quantitative PCR (QPCR) for 36 common fungi and by fungal tag-encoded flexible (FLX) amplicon pyrosequencing (fTEFAP) for these and additional fungi. Only 24 of the samples yielded amplified results using fTEFAP but QPCR successfully amplified all 50 samples. Over 450 fungal species were detected by fTEFAP but most were rare. Twenty-two fungi were found by fTEFAP to occur with at least an average of ? 0.5% relative occurrence. Many of these fungi seem to be associated with plants, soil or human skin. Combining fTEFAP and QPCR can enhance studies of fungal contamination in homes.
Nonnenmann, Matthew W.; Coronado, Gloria; Thompson, Beti; Griffith, William C.; Hanson, John Delton; Vesper, Stephen; Faustman, Elaine M.
Molecular Determinants for Antibody Binding on Group 1 House Dust Mite Allergens
House dust mites produce potent allergens, Der p 1 and Der f 1, that cause allergic sensitization and asthma. Der p 1 and Der f 1 are cysteine proteases that elicit IgE responses in 80% of mite-allergic subjects and have proinflammatory properties. Their antigenic structure is unknown. Here, we present crystal structures of natural Der p 1 and Der f 1 in complex with a monoclonal antibody, 4C1, which binds to a unique cross-reactive epitope on both allergens associated with IgE recognition. The 4C1 epitope is formed by almost identical amino acid sequences and contact residues. Mutations of the contact residues abrogate mAb 4C1 binding and reduce IgE antibody binding. These surface-exposed residues are molecular targets that can be exploited for development of recombinant allergen vaccines.
Chruszcz, Maksymilian; Pom�s, Anna; Glesner, Jill; Vailes, Lisa D.; Osinski, Tomasz; Porebski, Przemyslaw J.; Majorek, Karolina A.; Heymann, Peter W.; Platts-Mills, Thomas A.E.; Minor, Wladek; Chapman, Martin D. (INDOOR Bio.); (UV); (UVHS)
An analytical method was developed and employed to determine polycyclic aromatic hydrocarbons (PAH) in house dust and soil. he method was applied to the analysis of samples collected in an eight-home pilot study that was conducted in Columbus, OH, before and after the 1992/1993 h...
House dust mite allergen induces asthma via Toll-like receptor 4 triggering of airway structural cells
Barrier epithelial cells and airway dendritic cells (DCs) make up the first line of defense against inhaled substances such as house dust mite (HDM) allergen and endotoxin (lipopolysaccharide, LPS). We hypothesized that these cells need to communicate with each other to cause allergic disease. We show in irradiated chimeric mice that Toll-like receptor 4 (TLR4) expression on radioresistant lung structural
Hamida Hammad; Marcello Chieppa; Frederic Perros; Monique A Willart; Ronald N Germain; Bart N Lambrecht
Comparison of the Allergic Responses Induced by PeniciIlium chrysogenum and House Dust Mite Extracts in a Mouse Model
A report by the Institute of Medicine suggested that more research is needed to better understand mold effects on allergic disease, particularly asthma development. We compared the ability of the fungal Penicillium chrysogenum (PCE) and house dust mite (HDM) extracts to induce al...
Use of fluorinated polybrominated diphenyl ethers and simplified cleanup for the analysis of polybrominated diphenyl ethers in house dust
A simple, cost-effective method is described for the analysis of polybrominated diphenyl ethers (PBDEs) in house dust using pressurized fluid extraction, cleanup with modified silica solid phase extraction tubes, and fluorinated internal standards. There are 14 PBDE congeners inc...
Comparison of Lead Species in Household Dust Wipes, Soil, and Airborne Particulate Matter in El Paso, Texas, by X-Ray Absorption Spectroscopy
NASA Astrophysics Data System (ADS)
Understanding the interplay of indoor and outdoor sources of lead in an urban setting is one foundation in establishing risk for lead exposure in children in our cities. A household may be the source for lead contamination due to the deterioration of interior lead-based paint, or a sink if lead particles are tracked or blown into the home from such potential ambient sources as yard soil or urban street dust. In addressing this issue, X-Ray Absorption Spectroscopy (XAS) presents the opportunity to directly and quantitatively speciate lead at low concentrations in bulk samples. We performed XAS analyses on dust wipes from window sills or floors from 8 houses that exceeded Federal standards for lead in dust. We entered these data into a Principal Components Analysis (PCA) that also included El Paso environmental samples: lead-based paints, soils, and airborne particulate matter. A simple two-component mixing system accounted for more than 95% of the variance of this data set. Paint and lead oxide appear to be the principal components, with all the samples falling in a compositional range from pure paint to 75% paint, 25% lead oxide. Note that several different lead compounds are possible constituents of a given lead-based paint. The paints spread from one end out along perhaps a fifth of the range of the compositional axis, followed closely, but not overlapped, by the soil samples, which covered the remainder of the compositional range. Two of the dust wipes plotted within the paint range, and the remaining 6 dust wipes plotted randomly through the soil range. Samples of airborne particulate matter plotted in both the paint and soil ranges. These observations suggest that the lead on most of the dust wipes originated outside the house, probably from deteriorated exterior lead-based paint deposited in adjacent yards. This paint mixed with lead oxide present in the soil and entered the houses by the airborne route. The probable source of the oxide in the soil is former airborne deposition of automobile exhaust from leaded gasoline (lead halides quickly react to form oxide). The dust wipes that fall within the compositional range of the paints may have originated from deterioration of interior paint. The XAS findings are consistent with our tests of several hundred houses in El Paso: most of the wipes that exceeded Federal lead standards came from houses in the oldest neighborhoods of the city, where lead paint is still present. X-Ray absorption spectroscopy experiments were conducted at the Stanford Synchrotron Radiation Laboratory on beam lines 7-3 and 10-2. Spectra were collected at the Pb L-III absorption edge in fluorescence mode using a 13-element or a 30-element Ge solid-state detector. This publication was made possible by grant numbers 1RO1-ES11367 and 1 S11 ES013339-01A1 from the National Institute of Environmental Health Sciences (NIEHS), NIH. Its contents are solely the responsibility of the authors and do not necessarily represent the official views of the NIEHS, NIH.
Pingitore, N. E.; Clague, J.; Amaya, M. A.
House Dust Concentrations of Organophosphate Flame Retardants in Relation to Hormone Levels and Semen Quality Parameters
Background Organophosphate (OP) compounds, such as tris(1,3-dichloro-2-propyl) phosphate (TDCPP) and triphenyl phosphate (TPP), are commonly used as additive flame retardants and plasticizers in a wide range of materials. Although widespread human exposure to OP flame retardants is likely, there is a lack of human and animal data on potential health effects. Objective We explored relationships of TDCPP and TPP concentrations in house dust with hormone levels and semen quality parameters. Methods We analyzed house dust from 50 men recruited through a U.S. infertility clinic for TDCPP and TPP. Relationships with reproductive and thyroid hormone levels, as well as semen quality parameters, were assessed using crude and multivariable linear regression. Results TDCPP and TPP were detected in 96% and 98% of samples, respectively, with widely varying concentrations up to 1.8 mg/g. In models adjusted for age and body mass index, an interquartile range (IQR) increase in TDCPP was associated with a 3% [95% confidence interval (CI), ?5% to ?1%) decline in free thyroxine and a 17% (95% CI, 4�32%) increase in prolactin. There was a suggestive inverse association between TDCPP and free androgen index that became less evident in adjusted models. In the adjusted models, an IQR increase in TPP was associated with a 10% (95% CI, 2�19%) increase in prolactin and a 19% (95% CI, ?30% to ?5%) decrease in sperm concentration. Conclusion OP flame retardants may be associated with altered hormone levels and decreased semen quality in men. More research on sources and levels of human exposure to OP flame retardants and associated health outcomes are needed.
Meeker, John D.; Stapleton, Heather M.
Optimization of a Der p 2-based prophylactic DNA vaccine against house dust mite allergy.
DNA vaccines encoding allergens are promising immunotherapeutics to prevent or to treat allergy through induction of allergen-specific Th1 responses. Despite anti-allergy effects observed in small rodents, DNA-based vaccines are weak immunogens in primates and humans and particularly when administered by conventional injection. The goal of the present study was to improve the immunogenicity of a prophylactic vaccine encoding the major house dust mite allergen Der p 2. In this context, we evaluated the influence of different DNA backbones including notably intron and CpG enriched sequence, the DNA dose, the in vivo delivery by electroporation as well as the heterologous prime boost regimen on the vaccine efficiency. We found that a minimal allergen expression level threshold must be reached to induce the production of specific antibodies but beyond this limit, the intensity of the immune response was independent on the DNA dose and allergen expression. The in vivo DNA delivery by electroporation drastically enhanced the production of specific antibodies but not the IFNg secretion. Vaccination of na�ve mice with DNA encoding Der p 2 delivered by electroporation even at very low dose (2?g) prevented the development of house dust mite allergy through Th1-skewed immune response characterized by the drastic reduction of allergen-specific IgE, IL-5 and lung inflammation together with the induction of strong specific IgG2a titers and IFNg secretion. CpG cassette in the DNA backbone does not play a critical role in the efficient prophylaxis. Finally, comparable protective immune responses were observed when using heterologous DNA prime/protein boost or homologous DNA prime/boost. Taken together, these data suggest that the potent Th1 response induced by DNA-based vaccine encoding allergens through electroporation provides the rationale for the evaluation of DNA encoding Der p 2 into HDM allergy clinical trials. PMID:23396105
Pulsawat, Pinya; Pitakpolrat, Patrawadee; Prompetchara, Eakachai; Kaewamatawong, Theerayuth; Techakriengkrai, Navapon; Sirivichayakul, Sunee; Buranapraditkun, Supranee; Hannaman, Drew; Ruxrungtham, Kiat; Jacquet, Alain
Health and housing collaboration at LAST: the Philadelphia Lead Abatement Strike Team.
The Lead Abatement Strike Team (LAST) was developed in 2002 by the Philadelphia Department of Public Health (PDPH) in response to community concern about management of children with elevated blood lead levels (EBLLs). Fourteen hundred backlog properties (housing at least one child with EBLLs) were identified through inspection as having housing-based lead hazards for which no satisfactory environmental remediation (control of lead hazards) had been achieved. In the first two years of LAST, 834 new housing cases also were identified. The heightened awareness of this problem, sparked in part by community advocacy efforts, led to the appropriation of 1.5 million dollars for environmental remediation. A collaborative group of health, housing, and other officials was convened. Enforcement for remediation of properties with lead hazards was strengthened with the development of the Lead Court, a special judicial court devoted exclusively to hearing cases where owners had violated local lead poisoning prevention laws. Identifying a group of Pennsylvania-certified lead abatement contractors, expanding the health department's abatement team, creating temporary relocation capacity, and providing funding for basic housing system repair work were crucial to obtaining rapid remediation of homes. In the first two years of the LAST program, 1,037 properties (both backlog and new properties) that housed 1,476 children were remediated, representing a significant increase in remediation capacity.
Campbell, Carla; Himmelsbach, Robert; Palermo, Peter; Tobin, Richard
Polybrominated diphenyl ethers (PBDEs), hexabromocyclododecane (HBCD) and "novel" brominated flame retardants in house dust in Germany.
Brominated flame retardants (BFRs) are used in a wide variety of products such as electronic devices, upholstery and carpets and in insulation boards. The study presented here aimed to quantify the amounts of BFRs in house dust in Germany. For this purpose 20 residences' dust samples were collected from vacuum cleaner bags and analysed with LC-MS/MS and simultaneously with GC/MS. Using GC/MS, the median (95th percentile) concentrations of PBDEs (sum of tetra- to hepta-congeners), BDE 209, ?-HBCD (sum of three congeners), and decabromodiphenylethane (DBDPE) were 42ng/g (230ng/g), 950ng/g (3426ng/g), 335ng/g (1545ng/g), and 146ng/g (1059ng/g), respectively. Using LC-MS/MS some "novel" flame retardants were found in median concentrations of 343ng/g (bis(2-ethyl-1-hexyl)tetrabromophthalate, TBPH), and 28ng/g (tetrabromobisphenol A, TBBPA). Whilst 1,2-bis-(2,4,6-tribromophenoxy)ethane (BTBPE) and 2-ethyl-1-hexyl-2,3,4,5-tetrabromobenzoate (EH-TBB) could not be detected. Based on these measurements an exposure assessment for the sum of tetra- to heptabrominated congeners, BDE 209, and ?-HBCD resulted in a "high" daily intake for toddlers (based on 95th percentiles) of 1.2ng/kg b.w., 0.69ng/kg b.w., and 8.9ng/kg b.w., respectively. For TBPH the "high" intake was calculated at 4.1ng/kg b.w. and for DBDPE at 5.3ng/kg b.w. A clear tendency was observed to apply "novel" BFRs in Germany. Moreover, the results suggest that the recent exposure to PBDEs and HBCD via house dust in Germany is well below the levels that are associated with health effects. For the "novel" brominated flame retardants such an assessment is not possible due to limited toxicological information. PMID:24368294
Fromme, H; Hilger, B; Kopp, E; Miserok, M; V�lkel, W
Skin-associated Bacillus, staphylococcal and micrococcal species from the house dust mite, Dermatophagoides pteronyssinus and bacteriolytic enzymes.
Dust mites produce bacteriolytic enzymes, one of which belongs to the NlpC/P60 superfamily comprising bacterial and fungal proteins. Whether this enzyme is derived from the mite or from mite-associated microbes is unclear. To this end, the bacteriology of mites per se, and carpet and mattress dust from a group of asthmatic children and their parents was investigated. Dust from parents' and children's mattresses yielded significantly more colony forming units compared with dust from their corresponding carpets. Zymography demonstrated some dusts contained bacteriolytic enzymes, and in nine of the twelve dust samples from three of five houses examined, a prominent bacteriolytic band was obtained that corresponded to the mite band, although in one home, other lytic bands were detected. Fifty bacterial isolates were obtained from surface-sterilised, commercially obtained Dermatophagoides pteronyssinus. 16S rRNA, tuf and rpoB gene sequencing of nine Gram-positive isolates identified them as Bacillus cereus, B. licheniformis, Staphylococcus aureus, S. epidermidis, S. capitis and Micrococcus luteus, known human skin commensals. 16S rRNA sequence homologies of four of the nine isolates identified as B. licheniformis formed a distinct phylogenetic cluster. All species secreted lytic enzymes during culture although the lytic profiles obtained differed between the rods and the cocci, and none of the bands detected corresponded to those observed in dust or mites. In conclusion, mites harbour a variety of bacterial species often associated with human skin and house dusts contain bacteriolytic enzymes that may be mite-derived. The identification of a novel cluster of B. licheniformis isolates suggests an ecological adaptation to laboratory-reared D. pteronyssinus. It remains to be determined whether the previously described mite-associated 14�K lytic enzyme is derived from a microbial source. PMID:23783892
Tang, Vivian H; Chang, Barbara J; Srinivasan, Ambuja; Mathaba, Leslie T; Harnett, Gerald B; Stewart, Geoffrey A
Data Analysis of Lead in Soil and Dust.
National Technical Information Service (NTIS)
The purpose of this study is to supplement the prior reports through additional data analyses focusing on the contribution of lead in exterior soil to the lead hazard in homes. The specific objectives of this study are two-fold: First, to conduct analyses...
A comparison of the effect of conventional and filter vacuum cleaners on airborne house dust mite allergen.
The efficiency (dust collection and recirculation) of a conventional upright vacuum cleaner with a prototype vacuum bag (I) with pore size of 0.1 micron was compared with a standard vacuum cleaner bag (II), in the homes of 11 atopic asthmatic subjects with a known allergy to house dust mite. Four filter vacuum cleaners were assessed in pairs-the Vax 2000 with the Vorwerk VK121 ET340 (in 10 homes), and the Nilfisk GS90 'Allergy Vac' with the Bosch maxima 43 (in nine homes). All of the selected homes were vacuumed throughout (carpets and soft furnishings) for a 15 min period with each of the cleaners, and air was sampled simultaneously at 21 min-1 (Casella personal sampler). The weight of dust retrieved was recorded, and a sample of sieved dust (2 g) and the air filters were extracted to determine the concentrations of the major allergen, Der pI, by ELISA (ALK). No significant difference was observed in either total weight of dust, or airborne and dust concentrations of Der pI between using the conventional cleaner with vacuum bags I, or vacuum bags II. The Vax and the Vorwerk filter vacuum cleaners produced no measurable airborne Der pI concentrations during use in any of the 10 homes tested, whilst the Nilfisk produced airborne Der pI in two, and the Bosch in one of the nine homes tested. The Vorwerk retrieved significantly more dust from the floors than the Vax (P < 0.002). There was no significant difference in dust retrieval between the Nilfisk and the Bosch. All of the filter vacuum cleaners investigated produced lower concentrations of airborne Der pI, compared to the conventional cleaner with or without a special dust bag. However, the amount of dust and concentration/amount of Der pI that these cleaners actually retrieved, varied and the Vorwerk appeared most effective overall. PMID:7597267
Hegarty, J M; Rouhbakhsh, S; Warner, J A; Warner, J O
House dust and storage mite contamination of dry dog food stored in open bags and sealed boxes in 10 domestic households.
Dry pet food is a potential source of exposure to house dust and storage mite allergens in canine atopic dermatitis. This study evaluated contamination of house dust and dry dog food stored in paper bags, sealable plastic bags and sealable plastic boxes in 10 households for 90 days using Acarex(�) tests for guanine, a Der p 1 ELISA and mite flotation. Acarex(�) tests were negative in all the food samples but positive in all the house dust samples. The Der p 1 levels and mite numbers significantly increased in food from paper bags (P = 0.0073 and P = 0.02, respectively), but not plastic bags or boxes. Mite numbers and Der p 1 levels were 10-1000 times higher in house dust than the corresponding food samples (P < 0.0001). There were significant correlations between Der p 1 in house dust and food from the paper (P < 0.0001) and plastic bags (P = 0.003), and mite numbers in house dust and food from the paper bags (P = 0.0007). Bedding and carpets were significantly associated with Der p 1 levels in house dust (P = 0.015 and P = 0.01, respectively), and food from the paper (both P = 0.02) and plastic bags (P = 0.03 and P = 0.04, respectively). Mites were identified in six of 10 paper bag, three of 10 plastic bag, one of 10 plastic box and nine of 10 house dust samples. These comprised Dermatophagoides (54%), Tyrophagus (10%; all from food) and unidentified mites (36%). Storage of food in sealable plastic boxes largely prevented contamination for 3 months. Exposure to mites and mite proteins in all the stored food, however, appeared to be trivial compared with house dust. PMID:21106038
Gill, Christina; McEwan, Neil; McGarry, John; Nuttall, Tim
ead from dust is potentially the major contributor to blood lead levels in children living in urban environments in Australia' and is likely to make a substantial contribution to blood lead levels of children living in the vicinity of lead smelters. We undertook a trial of measuring dust in petri dishes to estimate the long-term flux of lead in indoor
John Wlodarczyk; Ruth Toneguzzi; Charles Gruszynski
Understanding and predicting metal release from pipes of all sizes and types from the treatment plant to the consumer?s tap is critical, specifically for regulatory compliance with the Lead and Copper Rule, as well as the performance, corrosion morphology, and longevity of infras...
Persistent organic pollutants in dust from older homes: learning from lead.
Objectives. We aimed to (1) evaluate the relation between home age and concentrations of multiple chemical contaminants in settled dust and (2) discuss the feasibility of using lead hazard controls to reduce children's exposure to persistent organic pollutants. Methods. As part of the California Childhood Leukemia Study, from 2001 to 2007, we used a high-volume small surface sampler and household vacuum cleaners to collect dust samples from 583 homes and analyzed the samples for 94 chemicals with gas chromatography-mass spectrometry and inductively coupled plasma mass spectrometry. We evaluated relations between chemical concentrations in dust and home age with Spearman rank correlation coefficients. Results. Dust concentrations of lead, polychlorinated biphenyls, organochlorine insecticides, and polycyclic aromatic hydrocarbons were correlated with home age (??>?0.2; P?.001), whereas concentrations of pyrethroid insecticides and polybrominated diphenyl ethers were not. Conclusions. Dust in older homes contains higher levels of multiple, persistent chemicals than does dust in newer homes. Further development of strategies to reduce chemical exposures for children living in older homes is warranted. PMID:24832145
Whitehead, Todd P; Metayer, Catherine; Ward, Mary H; Colt, Joanne S; Gunier, Robert B; Deziel, Nicole C; Rappaport, Stephen M; Buffler, Patricia A
Acaricidal activities of some essential oils and their monoterpenoidal constituents against house dust mite, Dermatophagoides pteronyssinus (Acari: Pyroglyphidae)
The acaricidal activities of fourteen essential oils and fourteen of their major monoterpenoids were tested against house dust mites Dermatophagoides pteronyssinus. Five concentrations were used over two different time intervals 24 and 48 h under laboratory conditions. In general, it was noticed that the acaricidal effect based on LC 50 of either essential oils or monoterpenoids against the mite was time dependant. The LC 50 values were decreased by increasing of exposure time. Clove, matrecary, chenopodium, rosemary, eucalyptus and caraway oils were shown to have high activity. As for the monoterpenoids, cinnamaldehyde and chlorothymol were found to be the most effective followed by citronellol. This study suggests the use of the essential oils and their major constituents as ecofriendly biodegradable agents for the control of house dust mite, D. pteronyssinus.
Saad, El-Zemity; Hussien, Rezk; Saher, Farok; Ahmed, Zaitoon
Characterization of macrophage phenotypes in three murine models of house-dust-mite-induced asthma.
In asthma, an important role for innate immunity is increasingly being recognized. Key innate immune cells in the lungs are macrophages. Depending on the signals they receive, macrophages can at least have an M1, M2, or M2-like phenotype. It is unknown how these macrophage phenotypes behave with regard to (the severity of) asthma. We have quantified the phenotypes in three models of house dust mite (HDM-)induced asthma (14, 21, and 24 days). M1, M2, and M2-like phenotypes were identified by interferon regulatory factor 5 (IRF5), YM1, and IL-10, respectively. We found higher percentages of eosinophils in HDM-exposed mice compared to control but no differences between HDM models. T cell numbers were higher after HDM exposure and were the highest in the 24-day HDM protocol. Higher numbers of M2 macrophages after HDM correlated with higher eosinophil numbers. In mice with less severe asthma, M1 macrophage numbers were higher and correlated negatively with M2 macrophages numbers. Lower numbers of M2-like macrophages were found after HDM exposure and these correlated negatively with M2 macrophages. The balance between macrophage phenotypes changes as the severity of allergic airway inflammation increases. Influencing this imbalanced relationship could be a novel approach to treat asthma. PMID:23533309
Draijer, Christina; Robbe, Patricia; Boorsma, Carian E; Hylkema, Machteld N; Melgert, Barbro N
Characterization of Macrophage Phenotypes in Three Murine Models of House-Dust-Mite-Induced Asthma
In asthma, an important role for innate immunity is increasingly being recognized. Key innate immune cells in the lungs are macrophages. Depending on the signals they receive, macrophages can at least have an M1, M2, or M2-like phenotype. It is unknown how these macrophage phenotypes behave with regard to (the severity of) asthma. We have quantified the phenotypes in three models of house dust mite (HDM-)induced asthma (14, 21, and 24 days). M1, M2, and M2-like phenotypes were identified by interferon regulatory factor 5 (IRF5), YM1, and IL-10, respectively. We found higher percentages of eosinophils in HDM-exposed mice compared to control but no differences between HDM models. T cell numbers were higher after HDM exposure and were the highest in the 24-day HDM protocol. Higher numbers of M2 macrophages after HDM correlated with higher eosinophil numbers. In mice with less severe asthma, M1 macrophage numbers were higher and correlated negatively with M2 macrophages numbers. Lower numbers of M2-like macrophages were found after HDM exposure and these correlated negatively with M2 macrophages. The balance between macrophage phenotypes changes as the severity of allergic airway inflammation increases. Influencing this imbalanced relationship could be a novel approach to treat asthma.
Draijer, Christina; Robbe, Patricia; Boorsma, Carian E.; Hylkema, Machteld N.; Melgert, Barbro N.
Orchestration of an Uncommon Maturation Cascade of the House Dust Mite Protease Allergen Quartet
In more than 20% of the world population, sensitization to house dust mite allergens triggers typical allergic diseases such as allergic rhinitis and asthma. Amongst the 23 mite allergen groups hitherto identified, group 1 is cysteine proteases belonging to the papain-like family whereas groups 3, 6, and 9 are serine proteases displaying trypsin, chymotrypsin, and collagenolytic activities, respectively. While these proteases are more likely to be involved in the mite digestive system, they also play critical roles in the initiation and in the chronicity of the allergic response notably through the activation of innate immune pathways. All these allergenic proteases are expressed in mite as inactive precursor form. Until recently, the exact mechanisms of their maturation into active proteases remained to be fully elucidated. Recent breakthroughs in the understanding of the activation mechanisms of mite allergenic protease precursors have highlighted an uncommon and unique maturation pathway orchestrated by group 1 proteases that tightly regulates the proteolytic activities of groups 1, 3, 6, and 9 through complex intra- or inter-molecular mechanisms. This review presents and discusses the currently available knowledge of the activation mechanisms of group 1, 3, 6, and 9 allergens of Dermatophagoides pteronyssinus laying special emphasis on their localization, regulation, and interconnection.
Dumez, Marie-Eve; Herman, Julie; Campizi, Vincenzo; Galleni, Moreno; Jacquet, Alain; Chevigne, Andy
Production of Egg Yolk Antibodies Specific to House Dust Mite Proteins
Purpose House dust mites (HDMs) are an important source of indoor allergens associated with asthma, rhinitis and atopic dermatitis. Chicken immunoglobulin (Ig) Y is known to be a good alternative to mice and rabbit antibody production. In this study, we produced IgYs specific to HDMs and investigated their IgE immunoreactivities. Materials and Methods Total IgYs were isolated from the yolks of White Leghorn hens immunized with either Dermatophagoides pteronyssinus or D. farinae protein extract. Control antibodies were separated from the yolks of immunized hens with phosphate buffered saline. IgYs specific to HDMs were analyzed using enzyme-linked immunosorbent assay and Western blotting analysis. Results The concentration of egg IgY specific to D. farinae in an immunized hen increased and the highest achieved was 661.3 ug/mg (per an egg) on day 47, compared with 760 ug/mg IgY specific to D. pteronyssinus on day 16. The D. pteronyssinus or D. farinae-specific IgY was detected by binding of each mite proteins, and their immunoreactivities were elevated dependent of the specific IgY concentration. Conclusion IgY specific to HDMs may be a promising antibody for immunological diagnosis as well as identification of possible resistance relating to HDM allergy.
Lee, Kyung Eun; Han, Beom Ku; Han, Jae Yong; Hong, Jung Yeon; Kim, Mi Na; Heo, Won Il; Sohn, Myung Hyun; Kim, Kyung Won
A collaborative study on the first international standard of Dermatophagoides pteronyssinus (house dust mite) extract.
A collaborative study was carried out to assess the suitability of a preparation to serve as the International Standard for Dermatophagoides pteronyssinus (house dust mite) extract. The proposed international standard of D. pteronyssinus, two additional freeze-dried extracts, and a commercially available skin testing solution were tested in the study. Nineteen laboratories in 11 different countries participated. The assay methods used included RAST inhibition, crossed immunoelectrophoresis/crossed radioimmunoelectrophoresis, isoelectric focusing, quantitative skin testing, and various other methods for assessing total allergenic activity. In addition, six laboratories measured the quantity of antigen P1, and three laboratories measured antigen DpX in each of the preparations. On the basis of the results from this study, the World Health Organization established the preparation as the International Standard for D. pteronyssinus extract with an assigned unitage of 100,000 IU per ampule. The units refer both to the total allergenic activity of the ampule and to that of the individual allergens, such as P1 and DpX. PMID:4008796
Ford, A; Seagroatt, V; Platts-Mills, T A; L�wenstein, H
Most Personal Exposure to House Dust Mite Aeroallergen Occurs during the Day
Background The bed is commonly regarded as the main site of house dust mite exposure; however this has not been directly established by continuous measurements. The objective of this study was to determine the pattern of personal exposure to mite aeroallergen over 24 hours. Methods 12 adults each collected 9 sequential samples (8 during the day, mean 115 mins, and one overnight, mean 514 mins) over 24 hours using a portable air-pump (2L/min) connected to an IOM filter located on the shoulder during the day and on the bed head overnight. Samples were analysed for mite allergen Der p 1 by ELISA. Location and activity were recorded. A mixed model analysis was performed to determine exposure as a function of 14 categories of activity. Results Personal aeroallergen exposure differed widely over time, both within and between subjects. The highest average exposure (1117 pg/m3, 95% CI: 289-4314) occurred on public transport and the lowest overnight in bed (45 pg/m3, 95% CI: 17-17), which contributed only 9.8% (95% CI: 4.4%-15.1%) of total daily exposure. Aeroallergens were not related to bed reservoirs. Conclusion The study challenges the current paradigm that the bed is the main site of HDM exposure and instead suggests most exposure occurs in association with domestic activity and proximity to other people. Effective mite interventions, designed to improve asthma outcomes, need to first identify and then address the multiple sources of aeroallergen exposure.
Tovey, Euan R.; Willenborg, Christiana M.; Crisafulli, Daniele A.; Rimmer, Janet; Marks, Guy B.
GPR17 Regulates Immune Pulmonary Inflammation Induced By House Dust Mite
Antagonists of the type 1 cysteinyl leukotriene receptor (CysLT1R) are efficacious for bronchoconstriction in humans with bronchial asthma; however, the clinical response to these drugs is heterogeneous. In particular, how CysLT1R expression and function are constitutively regulated in vivo is not known. Here we show that a 7-transmembrane receptor GPR17 negatively regulates the CysLT1R-mediated inflammatory cell accumulation in the bronchoalveolar lavage fluid and lung, the levels of IgE and specific IgG1 in serum, and Th2/Th17 cytokine expression in the lung after intranasal sensitization and challenge with house dust mite (Df) in mice. Sensitization of na�ve wild-type recipients with Df-pulsed bone marrow-derived dendritic cells (BMDCs) of each genotype or sensitization of each genotype with Df-pulsed wild-type BMDCs and Df challenge revealed markedly increased pulmonary inflammatory and serum IgE responses for GPR17-deficient mice as compared to wild-type mice and reduced responses in the genotypes lacking CysLT1R. These findings reveal a constitutive negative regulation of CysLT1R functions by GPR17 in both the antigen presentation and downstream phases of allergic pulmonary inflammation.
Maekawa, Akiko; Xing, Wei; Austen, K. Frank; Kanaoka, Yoshihide
Acaricidal activity of Cymbopogon citratus and Azadirachta indica against house dust mites
Objective To examine the acaricidal effects of the essential oil of Cymbopogon citratus leaf extract (lemongrass) and ethanolic Azadirachta indica leaf extract (neem) against house dust mites Dermatophagoides farinae (D. farinae) and Dermatophagoides pteronyssinus (D. pteronyssinus). Methods Twenty-five adults mites were placed onto treated filter paper that is soaked with plant extract and been tested at different concentrations (50.00%, 25.00%, 12.50%, 6.25% and 3.13%) and exposure times (24hrs, 48hrs, 72hrs and 96 hrs). All treatments were replicated 7 times, and the experiment repeated once. The topical and contact activities of the two herbs were investigated. Results Mortalities from lemongrass extract were higher than neem for both topical and contact activities. At 50 % concentration, both 24 hrs topical and contact exposures to lemongrass resulted in more than 91% mortalities for both species of mites. At the same concentration and exposure time, neem resulted in topical mortalities of 40.3% and 15.7% against D. pteronyssinus and D. farinae respectively; contact mortalities were 8.0% and 8.9% against the 2 mites, respectively. There was no difference in topical mortalities of D. pteronyssinus from exposure to concentrations of lemongrass and neem up to 12.50%; lemongrass was more effective than neem at the higher concentrations. Conclusions Generally, topical mortalities of D. farinae due to lemongrass are higher than that due to neem. Contact mortalities of lemongrass are always higher that neem against both species of mites.
Hanifah, Azima Laili; Awang, Siti Hazar; Ming, Ho Tze; Abidin, Suhaili Zainal; Omar, Maizatul Hashima
A successful method for mass culture of the house dust mite, Dermatophagoides pteronyssinus (Troussart, 1897).
Comparative studies have been carried out to find out an optimum condition for efficient mass culture of Dermatophagoides pteronyssinus (Troussart, 1897), the most dominant species of the house dust mites. Among various food materials tested for culture media, the mixture composed of 2 parts of powdered laboratory animal food, 2 parts of dried yeast and 1 part of dried fish powder was found to be most fitted. The humidity content of the medium was best when adjusted to 16% beforehand and thin layer of the food medium was prepared in Roux's-bottle with a paper plug. The plug of the bottle was opened once a week and the medium was mixed thoroughly by shaking to prevent clotting. When about 15,000 mites were inoculated into 100 g of culture media, the highest yield was obtained with relative humidity regulated at 75% and the temperature at 25 degrees C after 12 weeks of incubation. Purified mites were separated from culture media by floatation with saturated NaCl solution and the average yield of the mice was 2 to 3 g in wet weight per 100 g of the food mixture. PMID:1228234
Miyamoto, J; Ishii, A; Sasa, M
House dust mites: a risk factor to be considered for occupational safety or source of work-related allergens.
House dust mites (HDM) can be found worldwide where human beings live independent from the climate and are a major source of multiple allergens. Mite allergens sensitize and induce perennial rhinitis, asthma, or atopic dermatitis in a large portion of patients with allergic disease particularly children. There is convincing evidence that avoidance of mite allergen can effectively reduce allergic symptoms. This study examined dust from a military hospital and the private home of some nursing staff. A total of seven species of mites belonging to six genera were recovered. The commonest species was Dermatophagoides farinae followed by D. pteronyssinus and the lowest Laelaps nuttalli. Besides, the 7th mite or Parasitus consanguineous live free on dust as a bio-control agent of mites. The presence of mites in and out doors in a hospital and dwellings of medical personnel pave the way to consider HDM as occupational or nosocomial Allergens. PMID:24640866
Saleh, Ahmed Megahed Ahmed; Ali, Hisham Abd El-Raouf; Ahmed, Salwa Abdalla Mohamed; Mohammad, Naema Mahmoud; Morsy, Tosson A
Lead exposure in young children from dust and soil in the United Kingdom
A survey of metals in United Kingdom dusts and soils has confirmed widespread lead contamination with a geometric mean value for lead in surface (0-5 cm) garden soils of 266 {mu}g/g and in housedusts of 561 {mu}g/g (excluding old mining areas). A subsequent detailed survey of 97 householders in Birmingham with 2-year-old children showed dust lead loading in the home environment to be an important predictor of blood lead concentrations in young children, when both variables fell within the normal range for the UK. The total estimated lead uptake by the young child was 36 {mu}g/day of which 1 {mu}g was by inhalation and 35 {mu}g by ingestion.
Thornton, I.; Watt, J.M. (Imperial College, London (England)); Davies, D.J.A.; Quinn, M.J. (Dept. of the Environment, London (England))
Enzyme-linked immunosorbent assay for quantifying antigens of Dermatophagoides farinae and D. pteronyssinus (Acari: Pyroglyphidae) in house dust samples.
Double-antibody sandwich enzyme-linked immunosorbent assay (ELISA) using a monoclonal antibody as capture and detector antibodies was developed for quantifying antigens of Dermatophagoides farinae Hughes and D. pteronyssinus (Trouessart) mites contained in house dust samples. This monoclonal antibody was directed against mite antigens that were also reactive to immunoglobulin E antibody in all of 10 serum samples obtained from patients allergic to mites. Histological study using fluorescent antibody revealed that the monoclonal antibody was bound to the major part of the D. farinae mite body section including fecal matter and cuticles. The detection limit of the assay system was 0.17 microgram of soluble antigens of both mite species and the antigen amount corresponding to 0.5 mites per microplate well, whether in live or dead mites. This system did not react to antigens of Tyrophagus putrescentiae (Schrank) and Cheyletus malaccensis Oudemans. Slight inhibition of less than or equal to 21.3% was observed with nonspecific substances contained in house dust, such as wool, cotton, human dander, human hair, soil, and biscuit, but no direct ELISA reactions were obtained with any of these materials. In 49 house dust samples, ELISA was significantly correlated with the conventional microscopic observation method. PMID:2280398
Konishi, E; Uehara, K
After the PBDE Phase-Out: A Broad Suite of Flame Retardants in Repeat House Dust Samples from California
Higher house dust levels of PBDE flame retardants (FRs) have been reported in California than other parts of the world, due to the state�s furniture flammability standard. However, changing levels of these and other FRs have not been evaluated following the 2004 U.S. phase-out of PentaBDE and OctaBDE. We analyzed dust collected in 16 California homes in 2006 and again in 2011 for 62 FRs and organohalogens, which represents the broadest investigation of FRs in homes. Fifty-five compounds were detected in at least one sample; 41 in at least 50% of samples. Concentrations of chlorinated OPFRs, including two (TCEP and TDCIPP) listed as carcinogens under California�s Proposition 65, were found up to 0.01% in dust, higher than previously reported in the U.S. In 75% of the homes, we detected TDBPP, or brominated �Tris,� which was banned in children�s sleepwear because of carcinogenicity. To our knowledge, this is the first report on TDBPP in house dust. Concentrations of Firemaster 550 components (EH-TBB, BEH-TEBP, and TPHP) were higher in 2011 than 2006, consistent with its use as a PentaBDE replacement. Results highlight the evolving nature of FR exposures and suggest that manufacturers continue to use hazardous chemicals and replace chemicals of concern with chemicals with uncharacterized toxicity.
The use of a sequential extraction procedure for heavy metal analysis of house dusts by atomic absorption spectrometry.
In general, dust is considered as house or street dust. Indoor dust, as a contamination source, has been studied for many years. In this work, the original Community Bureau of Reference of the European Commission (BCR) three-stage sequential extraction procedure was applied to the fractionation of Cr, Cu, Fe, Mn, Pb, and Zn in 20 house dust samples from five different areas of Sakarya, Turkey. Acetic acid, hydroxylammonium chloride, and hydrogen peroxide plus ammonium acetate were used for the first, second, and third steps of the BCR method, respectively. The extracts were analyzed for the studied heavy metals using flame atomic absorption spectrometry. Validation of the results was performed by using a standard reference material (BCR 701 Sediment) to certify the experimental results obtained and to evaluate the reliability of the method used. The elemental loadings typically increased in magnitude according to the area order: Izmit Caddesi>Ankara Caddesi >Erenler>Karaman>Korucuk. The results were in agreement with values reported in the literature. PMID:23513973
Altundag, Huseyin; Dundar, Mustafa Sahin; Doganci, Secil; Celik, Muhammed; Tuzen, Mustafa
The University of Michigan Dioxin Exposure Study: estimating residential soil and house dust exposures to young children.
The University of Michigan Dioxin Exposure Study provides extensive data on elevated residential soil and house dust concentrations of polychlorinated dioxins and dibenzofurans (PCDD/Fs) and adult body burdens among residents near a chemical manufacturing plant in Midland, Michigan. Recent reports found no significant contribution of residential soil/dust concentrations to serum lipid PCDD/Fs in adults. Although child body burdens were not studied by the University of Michigan, internal dose modeling that incorporates recent findings on demonstrated shorter elimination half life of PCDD/Fs in children (1-2 year half life in children vs. ~7 years in older adults) can be applied to assess this important issue. The model examines children (ages 0-7 years) with background dietary intake and exposure to residential soils at selected concentrations (10, 100 and 1000 pg/g 2,3,7,8-tetrachlorodibenzo-p-dioxin toxic equivalents, TEQ) using the congener patterns observed in Midland. Model predictions assuming 50th percentile TEQ uptake from soil/dust-related dermal and ingestion exposures indicate no measurable changes in serum lipid TEQ concentrations up to 1000 pg/g in soil/dust. Assuming 95th percentile uptake, the model shows no measurable serum lipid TEQ change up to 100 pg/g in soil/dust, but serum lipid TEQ levels rose ~2 pg/g at 1000 pg/g in soil/dust. Since the vast majority of soil/dust data were below 100 pg/g, Michigan children exposed to such soil/dust TEQ concentrations are not reasonably expected to exhibit measurable changes in serum lipid TEQ concentrations when compared to typical background dietary exposures. With adequate data, this approach can be applied to evaluate child dose and risk for other persistent chemicals. PMID:23351485
Paustenbach, Dennis J; Kerger, Brent D
A Pilot Study of the Measurement and Control of Deep Dust, Surface Dust, and Lead in 10 Old Carpets Using the 3Spot Test While Vacuuming
This pilot study measured and examined the relationship between surface dust, deep dust, lead (Pb), and the 3-spot test during vacuuming of carpets. The 3-spot test measures the total time in seconds for the indicator light on a Hoover vacuum with dirt detector (HVDD) to turn from red to green on three spots 3 feet apart at least 4 feet
J. W. Roberts; G. Glass; L. Mickelson
Distribution patterns of lead in urban soil and dust in Shenyang city, Northeast China.
We investigated the spatial distribution of Pb in soil and dust samples collected from 54 sites in Shenyang city, Liaoning province, Northeast China. Soil background Pb concentration was 22 mg kg(-1) and control values from non-industrial areas were 33 mg kg(-1) for soil and 38 mg kg(-1) for dust. Soil Pb concentrations varied widely, ranging from 26 to 2911 mg kg(-1), with a mean concentration of 200 mg kg(-1), 9 times the background value and 6 times the control value. There was great variation in soil Pb, with a coefficient of variation (CV) of 1.06 and a standard deviation (SD) of 212 mg kg(-1). Dust Pb concentrations fluctuated from 20 to 2810 mg kg(-1), with a mean value of 220 mg kg(-1), almost 6 times the control value. No significant differences in distribution were observed between soil Pb and dust Pb. The highest Pb concentration was observed in Tiexi district in an industrial area. Soil Pb concentration decreased with depth and with distance from the pollution source. Lead concentrations initially changed little but then decreased with distance from the roadside, and were generally higher on the east side of roads than on the west. Lead contents in different categories of urban area differed substantially with dust and soil Pb concentrations decreasing in the sequence: industrial >business >mixed (residential, culture and education)> reference areas. PMID:16528594
Wang, Jinda; Ren, Huimin; Zhang, Xuelin
Recovery of Zinc, Copper, and Lead-Tin Mixtures from Brass Smelter Flue Dusts.
National Technical Information Service (NTIS)
The smelting of brass and bronze generates a dust composed primarily of zinc oxide, with lesser amounts of other metal oxides, such as copper, lead, and tin. The small quantity of this waste generated by individual smelters and the relatively low unit val...
H. Fukubayashi H. E. Powell L. L. Smith L. W. Higley
The purpose of this SOP is to describe the procedures for collecting house dust samples. Dust from the floor was collected using a high-volume, small surface sampler (HVS3). Half of the sample was analyzed for metal content, and half was analyzed for pesticides and PAHs. Keywo...
The purpose of this SOP is to describe the procedures to be used for the extraction of pesticides and polynuclear aromatic hydrocarbons (PAHs) from house dust and soil. This procedure also describes the splitting of dust and soil samples for metal extractions for shipment to Emo...
Hexavalent chromium in house dust--a comparison between an area with historic contamination from chromate production and background locations.
In contrast to Cr(+3), Cr(+6) is carcinogenic and allergenic. Although Cr(+6) can occur naturally, it is thought that most soil Cr(+6) is anthropogenic, however, the extent of Cr(+6) in the background environment is unknown. Cr(+6)-containing chromite ore processing residue (COPR) from chromate manufacture was deposited in numerous locations in Jersey City (JC), New Jersey. In the 1990's, significantly elevated concentrations of total Cr (Cr(+6)+Cr(+3)) were found in house dust near COPR sites. We undertook a follow-up study to determine ongoing COPR exposure. We compared Cr(+6) in house dust in JC to selected background communities with no known sources of Cr(+6). Samples were collected from living areas, basements and window wells. Cr(+6) was detected in dust from all JC and background houses. In the JC homes, the mean (+ or - SD) Cr(+6) concentration for all samples was 3.9 + or - 7.0 microg/g (range: non-detect-90.4 microg/g), and the mean Cr(+6) loading was 5.8 + or - 15.7 microg/m(2) (range: non-detect-196.4 microg/m(2)). In background homes, the mean Cr(+6) concentrations of all samples was 4.6 + or - 7.8 microg/g, (range, 0.05-56.6 microg/g). The mean loading was 10.0 + or - 27.9 microg/m(2) (range, 0.22-169.3 microg/m(2)). There was no significant difference between Cr(+6) dust concentrations in Jersey City and background locations. Stratification by sample location within houses and sampling method gave similar results. Samples exceeding 20 microg/g were obtained only from single wood surfaces in different homes. Lower concentrations in window well samples suggests transport from outside is not the major source of indoor Cr(+6). Landscaping and groundcover may influence indoor Cr(+6). There appears to be a widespread low level background of Cr(+6) that is not elevated in Jersey City homes despite its historic COPR contamination. It is possible that house dust, in general, is a source of Cr(+6) exposure with potential implications for persistence of chromium allergic contact dermatitis. PMID:20692023
Stern, Alan H; Yu, Chang Ho; Black, Kathleen; Lin, Lin; Lioy, Paul J; Gochfeld, Michael; Fan, Zhi-Hua Tina
Where's the Dust? Characterizing Locations of Azinphos-Methyl Residues in House and Vehicle Dust Among Farmworkers with Young Children
Organophosphate pesticides (OPs) are commonly used in the United States, and farm workers are at risk for chronic exposure. Using data from a community randomized trial to interrupt the take-home pathway of pesticide exposure, we examined the association between floor surface type (smooth floor, thin carpet, and thick carpet) and rooms in which dust samples were collected (living room vs. non-living room) and concentrations of azinphos-methyl residues in home environments. We also examined the association between vehicle type (truck, auto, or other) and footwell floor surfaces (carpeted, smooth surface, or no mat) and concentrations of azinphos-methyl in vehicle dust samples. Dust samples were collected from 203 and 179 households and vehicles, respectively. All households had at least one child aged 2�6. Vehicle dust samples were collected from footwells of the vehicle used for commuting to and from work. A total of 183 samples were collected from living rooms, and 20 were collected from other rooms in the home. Forty-two samples were collected from thick carpets, 130 from thin carpets, and 27 from smooth floor surfaces. Thick and thin carpets had a significantly greater dust mass than smooth floor surfaces (6.0 g/m2 for thick carpets, 7.8 g/m2 for thin carpets, and 1.5 g/m2 for smooth surfaces). Of the 179 vehicle samples, 113 were from cars, 34 from trucks, and 32 from other vehicles. Vehicles with no mats had a significantly higher mass of dust (21.3 g) than those with hard mats (9.3 g) but did not differ from vehicles with plush mats (12.0g). Further research is needed to characterize the environment in which children may be exposed to pesticides.
Coronado, Gloria D.; Griffith, William C.; Vigoren, Eric M.; Faustman, Elaine M.; Thompson, Beti
Lead in housing paints: an exposure source still not taken seriously for children lead poisoning in China.
After prohibitions on lead gasoline additives, which have proved to be a public health accomplishment world wide, many countries focus on other exposure source of children lead poisoning. Removing lead from paints is one of the important measures. Although there have been regulatory limits on lead in paints in China, evidence reported in this article indicates that lead-based paints were very common in new paints available for housing and in existing residential paints. Twenty-nine of 58 new paint samples (50%) had lead content equal to or exceeding 600 ppm, including 14 (24%) equal to or exceeding 5000 ppm. The highest sample contained 153,000 ppm lead, about 15% of the paint weight. Thirty-two new paints (55%) contained "soluble" lead exceeding 90 ppm, the current lead limit on paints in China. Of the existing paints, 16 of 28 samples of existing paint (57%) collected from 24 kindergartens and primary schools had lead concentrations equal to or exceeding 600 ppm, including six samples (21%) equal to or exceeding 5000 ppm. The highest concentration sample contained 51,800 ppm lead, accounting for 5.2% of the paint weight. It has been shown in many areas that paint lead is a major exposure source for lead poisoning in children. This is particularly true after the phasing out of lead from gasoline. Effective limitation on lead content in new paint, and lead hazard control measures directed towards existing paint, could reduce children blood lead levels (BLLs). There has been a lead standard for paints in China since 1986 and a stricter limit was introduced in recent years. Governments should take it seriously and enforce regulations, commit a long-term challenge to eliminate paint lead as it is the threat to current and the next generation. PMID:18976991
Lin, G Z; Peng, R F; Chen, Q; Wu, Z G; Du, L
Methods of exposure assessment: lead-contaminated dust in Philadelphia schools.
This study was conducted to develop a method that would accurately assess children's exposure to lead in schools in Philadelphia, Pennsylvania. We examined three wipe sample protocols: one included accessible surfaces such as desktops and windowsills, the second included inaccessible surfaces such as the top of filing cabinets and light fixtures, and the third included hand wipes of the study participants. Surface wipes were collected at 10 locations from accessible and inaccessible classroom surfaces (n = 11 at each location) and from the palms of student subjects in the same locations (n = 168). We found a significant difference in lead dust concentrations determined by the three protocols (F = 4.619; 2,27 degrees of freedom; p = 0.019). Lead dust concentrations were significantly elevated at the inaccessible surfaces yet they were uniformly low on the accessible surfaces and the children's palms. These findings were consistent with observed changes in blood lead levels of study participants: after 6 months of exposure to the study locations, 156 of 168 children experienced no change in blood lead level, whereas 12 experienced only a minimal change of 1-2 microg/dL. The mere presence of lead in inaccessible dust in the school environment does not automatically constitute a health hazard because there may not be a completed exposure pathway. Images Figure 1 Figure 2
Shorten, C V; Hooven, M K
Isomer Profiles of Perfluorochemicals in Matched Maternal, Cord, and House Dust Samples: Manufacturing Sources and Transplacental Transfer
Background: Perfluorochemicals (PFCs) are detectable in the general population and in the human environment, including house dust. Sources are not well characterized, but isomer patterns should enable differentiation of historical and contemporary manufacturing sources. Isomer-specific maternal�fetal transfer of PFCs has not been examined despite known developmental toxicity of perfluorooctane sulfonate (PFOS) and perfluorooctanoate (PFOA) in rodents. Objectives: We elucidated relative contributions of electrochemical (phased out in 2001) and telomer (contemporary) PFCs in dust and measured how transplacental transfer efficiency (TTE; based on a comparison of maternal and cord sera concentrations) is affected by perfluorinated chain length and isomer branching pattern. Methods: We analyzed matching samples of house dust (n = 18), maternal sera (n = 20), and umbilical cord sera (n = 20) by isomer-specific high-performance liquid chromatography tandem mass spectrometry. Results: PFOA isomer signatures revealed that telomer sources accounted for 0�95% of total PFOA in house dust (median, 31%). This may partly explain why serum PFOA concentrations are not declining in some countries despite the phase-out of electrochemical PFOA. TTE data indicate that total branched isomers crossed the placenta more efficiently than did linear isomers for both PFOS (p < 0.01) and PFOA (p = 0.02) and that placental transfer of branched isomers of PFOS increased as the branching point moved closer to the sulfonate (SO3�) end of the molecule. Conclusions: Results suggest that humans are exposed to telomer PFOA, but larger studies that also account for dietary sources should be conducted. The exposure profile of PFOS and PFOA isomers can differ between the mother and fetus�an important consideration for perinatal epidemiology studies of PFCs.
Beesoon, Sanjay; Webster, Glenys M.; Shoeib, Mahiba; Harner, Tom; Benskin, Jonathan P.
National evaluation of the US Department of Housing and Urban Development Lead-Based Paint Hazard Control Grant Program: study methods.
The US Department of Housing and Urban Development (HUD) undertook an evaluation of its Lead Hazard Control Grant Program between 1994 and 1999. The Evaluation is the largest study ever done on the effectiveness of lead hazard controls implemented in residential dwellings. The Evaluation had several major objectives: determining the effectiveness of various lead hazard controls in reducing residential dust lead levels and children's blood lead levels, establishing the costs of doing lead hazard control work and factors that influence those costs, determining the rate of clearance testing failures and their causes, and identifying possible negative effects of lead hazard control work on children's blood lead levels. This paper reports the overall research design and data collection methods of the Evaluation. The large number of dwelling units enrolled in the Evaluation was possible only by the innovative partnership among HUD, the Evaluators, and the grantees. HUD and the Evaluators relied on the grantees for essentially all of the data collection. The 14 participating HUD Lead Hazard Control Grantees were responsible for implementing the lead hazard control programs in their communities and collecting the study data. This paper describes the methods for recruiting and enrolling dwellings and families, collecting environmental and housing data, interviewing participating families, and collecting data on lead hazard control work performed and its costs. The paper also describes the basic quality control and quality assurance procedures used. The principal outcome measures were lead in dust collected using wipes from floors, window sills, and window troughs and lead in blood collected from children who were 6 years old or younger at enrollment. Data collection was conducted before intervention, immediately postintervention, and 6 and 12 months postintervention. For a subset of dwellings undergoing an extended follow-up data were also collected at 24 and 36 months postintervention. This paper provides the context for subsequent reports that will describe such findings as the influence of lead hazard control work on serial dust lead levels, the influence of lead hazard control work on serial blood lead levels in children, the nature and costs of the lead hazard control work done at the dwellings, and the experience of the grantees in meeting clearance testing requirements. PMID:15910786
Galke, Warren; Clark, Scott; McLaine, Pat; Bornschein, Robert; Wilson, Jonathan; Succop, Paul; Roda, Sandy; Breysse, Jill; Jacobs, David; Grote, Joann; Menrath, William; Dixon, Sherry; Chen, Mei; Buncher, Ralph
Cognitive Factors Mediate Placebo Responses in Patients with House Dust Mite Allergy
Background Placebo effects have been reported in type I allergic reactions. However the neuropsychological mechanisms steering placebo responses in allergies are largely unknown. The study analyzed whether and to what extend a conditioned placebo response is affecting type I allergic reactions and whether this response can be reproduced at multiple occasions. Methods 62 patients with house dust mite allergy were randomly allocated to either a conditioned (n?=?25), sham-conditioned (n?=?25) or natural history (n?=?12) group. During the learning phase (acquisition), patients in the conditioned group received the H1-receptor antagonist desloratadine (5mg) (unconditioned stimulus/US) together with a novel tasting gustatory stimulus (conditioned stimulus/CS). Patients in the sham-conditioned control group received the CS together with a placebo pill. After a wash out time of 9 days patients in the conditioned and sham-conditioned group received placebo pills together with the CS during evocation. Allergic responses documented by wheal size after skin prick test and symptom scores after nasal provocation were analyzed at baseline, after last desloratadine treatment and after the 1st and 5th CS re-exposure. Results Both conditioned and sham-conditioned patients showed significantly decreased wheal sizes after the 1st CS-evocation and significantly decreased symptom scores after the 1st as well as after the 5th evocation compared to the natural history control group. Conclusions These results indicate that placebo responses in type I allergy are not primarily mediated by learning processes, but seemed to be induced by cognitive factors such as patients� expectation, with these effects not restricted to a single evocation.
Benson, Sven; Rueckert, Annika; Hillen, Uwe; Schadendorf, Dirk; Schedlowski, Manfred
The Effects of Storage Conditions on the Stability of House Dust Mite Extracts
Purpose Allergen extracts from the house dust mite (HDM, Dermatophagoides pteronyssinus) are widely utilized for diagnosis and treatment of allergic diseases. It is known that allergen extracts degrade and lose potency when stored over time. Methods This study aimed to determine the optimal conditions for stability of allergen extracts. This study was undertaken to investigate the optimal storage conditions for HDM extracts, the effects of adding 0.03% human serum albumin (HSA) and 50% glycerol were evaluated at -20?, 4?, and room temperature (RT). Changes in protein and group 1 major allergen (Der p 1) concentration, as well as allergenicity were measured over a 1 year period using the Bradford assay, two-site ELISA, and ELISA inhibition. Results Protein concentrations decreased by 86%, 51%, and 6% at RT, 4?, and -20?, respectively, when stored in distilled water. Overall allergenicity remained high (89.9%) when the extracts was reconstituted in 50% glycerol solution, and was 93.1% when reconstituted in 50% glycerol and 0.03% HSA at RT. Allergenicity was decreased to 36.6% and 33.3%, however, reconstitution in DW or 0.03% HSA solution at RT, respectively. Allergenicity was remained high as 92.0%-97.0% when stored at 4? regardless of the buffer conditions. Conclusions Storage temperature is the most important factor in preserving allergenicity of HDM extracts, which is ideal at 4?. The addition of 50% glycerol to the storage buffer was also found to play an important role in increasing the shelf-life of HDM extracts at RT.
Jeong, Kyoung Yong; Choi, Soo-Young; Han, In-Soo; Lee, Jae-Hyun; Lee, Joo-Shil; Hong, Chein-Soo
Paradoxical Effects of Rapamycin on Experimental House Dust Mite-Induced Asthma
The mammalian target of rapamycin (mTOR) modulates immune responses and cellular proliferation. The objective of this study was to assess whether inhibition of mTOR with rapamycin modifies disease severity in two experimental murine models of house dust mite (HDM)-induced asthma. In an induction model, rapamycin was administered to BALB/c mice coincident with nasal HDM challenges for 3 weeks. In a treatment model, nasal HDM challenges were performed for 6 weeks and rapamycin treatment was administered during weeks 4 through 6. In the induction model, rapamycin significantly attenuated airway inflammation, airway hyperreactivity (AHR) and goblet cell hyperplasia. In contrast, treatment of established HDM-induced asthma with rapamycin exacerbated AHR and airway inflammation, whereas goblet cell hyperplasia was not modified. Phosphorylation of the S6 ribosomal protein, which is downstream of mTORC1, was increased after 3 weeks, but not 6 weeks of HDM-challenge. Rapamycin reduced S6 phosphorylation in HDM-challenged mice in both the induction and treatment models. Thus, the paradoxical effects of rapamycin on asthma severity paralleled the activation of mTOR signaling. Lastly, mediastinal lymph node re-stimulation experiments showed that treatment of rapamycin-naive T cells with ex vivo rapamycin decreased antigen-specific Th2 cytokine production, whereas prior exposure to in vivo rapamycin rendered T cells refractory to the suppressive effects of ex vivo rapamycin. We conclude that rapamycin had paradoxical effects on the pathogenesis of experimental HDM-induced asthma. Thus, consistent with the context-dependent effects of rapamycin on inflammation, the timing of mTOR inhibition may be an important determinant of efficacy and toxicity in HDM-induced asthma.
Fredriksson, Karin; Yao, Xianglan; Meyer, Katharine S.; Keeran, Karen J.; Zywicke, Gayle J.; Qu, Xuan; Yu, Zu-Xi; Moss, Joel; Kristof, Arnold S.; Levine, Stewart J.
Epithelial NF-?B orchestrates house dust mite-induced airway inflammation, hyperresponsiveness, and fibrotic remodeling.
NF-?B activation within the epithelium has been implicated in the pathogenesis of asthma, yet the exact role of epithelial NF-?B in allergen-induced inflammation and airway remodeling remains unclear. In the current study, we used an intranasal house dust mite (HDM) extract exposure regimen time course in BALB/c mice to evaluate inflammation, NF-?B activation, airway hyperresponsiveness (AHR), and airway remodeling. We used CC10-I?B?SR transgenic mice to evaluate the functional importance of epithelial NF-?B in response to HDM. After a single exposure of HDM, mRNA expression of proinflammatory mediators was significantly elevated in lung tissue of wild-type (WT) mice, in association with increases in nuclear RelA and RelB, components of the classical and alternative NF-?B pathway, respectively, in the bronchiolar epithelium. In contrast, CC10-I?B?SR mice displayed marked decreases in nuclear RelA and RelB and mRNA expression of proinflammatory mediators compared with WT mice. After 15 challenges with HDM, WT mice exhibited increases in inflammation, AHR, mucus metaplasia, and peribronchiolar fibrosis. CC10-I?B?SR transgenic mice displayed marked decreases in neutrophilic infiltration, tissue damping, and elastance parameters, in association will less peribronchiolar fibrosis and decreases in nuclear RelB in lung tissue. However, central airway resistance and mucus metaplasia remained elevated in CC10-I?B?SR transgenic mice, in association with the continued presence of lymphocytes, and partial decreases in eosinophils and IL-13. The current study demonstrates that following airway exposure with an asthma-relevant allergen, activation of classical and alternative NF-?B pathways occurs within the airway epithelium and may coordinately contribute to allergic inflammation, AHR, and fibrotic airway remodeling. PMID:24227776
Tully, Jane E; Hoffman, Sidra M; Lahue, Karolyn G; Nolin, James D; Anathy, Vikas; Lundblad, Lennart K A; Daphtary, Nirav; Aliyeva, Minara; Black, Kendall E; Dixon, Anne E; Poynter, Matthew E; Irvin, Charles G; Janssen-Heininger, Yvonne M W
Peptidoglycan recognition protein 1 promotes house dust mite-induced airway inflammation in mice.
Peptidoglycan recognition protein (Pglyrp) 1 is a pattern-recognition protein that mediates antibacterial host defense. Because we had previously shown that Pglyrp1 expression is increased in the lungs of house dust mite (HDM)-challenged mice, we hypothesized that it might modulate the pathogenesis of asthma. Wild-type and Pglyrp1(-/-) mice on a BALB/c background received intranasal HDM or saline, 5 days/week for 3 weeks. HDM-challenged Pglyrp1(-/-) mice showed decreases in bronchoalveolar lavage fluid eosinophils and lymphocytes, serum IgE, and mucous cell metaplasia, whereas airway hyperresponsiveness was not changed when compared with wild-type mice. T helper type 2 (Th2) cytokines were reduced in the lungs of HDM-challenged Pglyrp1(-/-) mice, which reflected a decreased number of CD4(+) Th2 cells. There was also a reduction in C-C chemokines in bronchoalveolar lavage fluid and lung homogenates from HDM-challenged Pglyrp1(-/-) mice. Furthermore, secretion of CCL17, CCL22, and CCL24 by alveolar macrophages from HDM-challenged Pglyrp1(-/-) mice was markedly reduced. As both inflammatory cells and airway epithelial cells express Pglyrp1, bone marrow transplantation was performed to generate chimeric mice and assess which cell type promotes HDM-induced airway inflammation. Chimeric mice lacking Pglyrp1 on hematopoietic cells, not structural cells, showed a reduction in HDM-induced eosinophilic and lymphocytic airway inflammation. We conclude that Pglyrp1 expressed by hematopoietic cells, such as alveolar macrophages, mediates HDM-induced airway inflammation by up-regulating the production of C-C chemokines that recruit eosinophils and Th2 cells to the lung. This identifies a new family of innate immune response proteins that promotes HDM-induced airway inflammation in asthma. PMID:23808363
Yao, Xianglan; Gao, Meixia; Dai, Cuilian; Meyer, Katharine S; Chen, Jichun; Keeran, Karen J; Nugent, Gayle Z; Qu, Xuan; Yu, Zu-Xi; Dagur, Pradeep K; McCoy, J Philip; Levine, Stewart J
Effects of astragaloside IV on eosinophil activation induced by house dust mite allergen.
Astragaloside IV (AS-IV) has been noted for its reduction of eosinophilic airway inflammation in a murine model of chronic asthma. To gain a better understanding of the mechanisms involved in this anti-inflammatory phenomenon, the effect of AS-IV on human blood eosinophils was studied in vitro. Eosinophils were isolated from the blood of patients with mild atopic asthma, preincubated with AS-IV for 1 h and stimulated in the presence or absence of the house dust mite allergen Dermatophagoides pteronyssinus (Der p) 1 for 4 h. The survival of the eosinophils at 48 h was investigated using trypan blue and the surface expression of CC chemokine receptor 3 (CCR3) and intercellular adhesion molecule-1 (ICAM-1) by the eosinophils was analyzed using flow cytometry. The secretion of cytokines in the supernatants and the chemotaxis of the eosinophils were measured by ELISA and the transwell system, respectively. Der p 1 was found to prolong the survival of the eosinophils. Similarly, the expression of CCR3 and ICAM-1, secretion of interleukin (IL)-1?, IL-5, tumor necrosis factor (TNF)-? and the granulocyte macrophage colony stimulating factor (GM-CSF) and transmigration of the eosinophils were increased in the presence of Der p 1. However, these inductive effects on the eosinophils were significantly inhibited by AS-IV (50 �g/ml). These findings suggest that AS-IV modulates eosinophil activation and trafficking in response to Der p 1 and may therefore be a useful therapeutic option in eosinophilic asthma. PMID:22505212
Gu, Xiaoyan; Jiang, Desheng; Wang, Yuwei; Du, Qiang; Cai, Jiankang
Epigenetic alterations by DNA methylation in house dust mite-induced airway hyperresponsiveness.
Asthma is one of the most prevalent chronic lung diseases, affecting 235 million individuals around the world, with its related morbidity and mortality increasing steadily over the last 20 years. Exposure to the environmental allergen, house dust mite (HDM), results in airway inflammation with a variable degree of airway obstruction. Although there has been much experimental work in the past using HDM challenge models to understand mechanistic details in allergic inflammation and airway hyperresponsiveness (AHR), there has been no study on reprogramming of lung or airways mediated through epigenetic mechanisms in response to an acute HDM exposure. Male mice, 6 weeks of age, were administrated HDM extracts or saline at Days 1, 14, and 21. Exposure of mice to HDM extracts caused significant airway inflammation and increased AHR. These HDM-challenged mice also exhibited a change in global DNA methylation as compared with saline-exposed (control) mice. Next, by employing methylation-sensitive restriction fingerprinting, we identified a set of genes, showing aberrant methylation status, associated with the HDM-induced AHR. These candidate genes are known to be involved in cAMP signaling (pde4 d), Akt-signaling (akt1 s1), ion transport (tm6 sf1, pom121l2, and slc8a3), and fatty acid metabolism (acsl3). Slc8a3 and acsl3 were down-regulated, whereas pde4 d, akt1 s1, tm6 sf1, and pom121l2 were up-regulated in the mice exposed to HDM. Hence, our results suggest that HDM exposure induces a series of aberrant methylated genes that are potentially important for the development of allergic AHR. PMID:23526225
Shang, Yan; Das, Sandhya; Rabold, Richard; Sham, James S K; Mitzner, Wayne; Tang, Wan-yee
Lung Macrophages Contribute to House Dust Mite Driven Airway Remodeling via HIF-1?
HIF-1? is a transcription factor that is activated during hypoxia and inflammation and is a key regulator of angiogenesis in vivo. During the development of asthma, peribronchial angiogenesis is induced in response to aeroallergens and is thought to be an important feature of sustained chronic allergic inflammation. Recently, elevated HIF-1? levels have been demonstrated in both the lung tissue and bronchoalveolar lavage of allergic patients, respectively. Therefore, we investigated the role of HIF-1? on the development of angiogenesis and inflammation following acute and chronic allergen exposure. Our data shows that intranasal exposure to house dust mite (HDM) increases the expression of HIF-1? in the lung, whilst reducing the expression of the HIF-1? negative regulators, PHD1 and PHD3. Blockade of HIF-1? in vivo, significantly decreased allergic inflammation and eosinophilia induced by allergen, due to a reduction in the levels of IL-5 and Eotaxin-2. Importantly, HIF-1? blockade significantly decreased levels of VEGF-A and CXCL1 in the lungs, which in turn led to a profound decrease in the recruitment of endothelial progenitor cells and a reduction of peribronchial angiogenesis. Furthermore, HDM or IL-4 treatment of primary lung macrophages resulted in significant production of both VEGF-A and CXCL1; inhibition of HIF-1? activity abrogated the production of these factors via an up-regulation of PHD1 and PHD3. These findings suggest that novel strategies to reduce the expression and activation of HIF-1? in lung macrophages may be used to attenuate allergen-induced airway inflammation and angiogenesis through the modulation of VEGF-A and CXCL1 expression. Clinical Relevance This study provides new insights into the role of HIF-1? in the development of peribronchial angiogenesis and inflammation in a murine model of allergic airway disease. These findings indicate that strategies to reduce activation of macrophage derived HIF-1? may be used as a target to improve asthma pathology.
Gowers, Kate; Rankin, Sara M.; Lloyd, Clare M.
76 FR 12106 - Lead-Based Paint Renovation, Repair and Painting Activities in Target Housing and Child Occupied...
Federal Register 2010, 2011, 2012, 2013
...individuals who provide specific lead-based paint activity training. KDHE...specialized activities such as lead-based paint abatement, and environmental inspections and risk assessments that identify lead-based paint in housing and other...
Concentration of the genera Aspergillus, Eurotium and Penicillium in 63-?m house dust fraction as a method to predict hidden moisture damage in homes
Background Quantitative measurements of mould enrichment of indoor air or house dust might be suitable surrogates to evaluate present but hidden moisture damage. Our intent was to develop a house-dust monitoring method to detect hidden moisture damage excluding the influence of outdoor air, accumulated old dust, and dust swirled up from room surfaces. Methods Based on standardized measurement of mould spores in the 63-?m fraction of house dust yielded by carpets, the background concentrations were determined and compared to simultaneously obtained colony numbers and total spore numbers of the indoor air in 80 non-mouldy living areas during summer and winter periods. Additionally, sampling with a vacuum-cleaner or manual sieve was compared to sampling with a filter holder or sieving machine, and the evaluative power of an established two-step assessment model (lower and upper limits) was compared to that of a one-step model (one limit) in order to derive concentration limits for mould load in house dust. Results Comparison with existing evaluation procedures proved the developed method to be the most reliable means of evaluating hidden moisture damage, yielding the lowest false-positive results (specificity 98.7%). Background measurements and measurements in 14 mouldy rooms show that even by evaluating just the indicator genera in summer and winter, a relatively certain assessment of mould infestation is possible. Conclusion A one-step evaluation is finally possible for house dust. The house-dust evaluation method is based on analysis of the indicator genera Aspergillus, Eurotium and Penicillium spp., which depend on the total fungal count. Inclusion of further moisture indicators currently appears questionable, because of outdoor air influence and the paucity of measurements.
Baudisch, Christoph; Assadian, Ojan; Kramer, Axel
Simultaneous determination of thirteen organophosphate esters in settled indoor house dust and a comparison between two sampling techniques.
An analytical method for the simultaneous determination of 13 organophosphate esters (OPEs) in house dust was developed. The method is based on solvent extraction by sonication, sample cleanup by solid phase extraction (SPE), and analysis by gas chromatography-positive chemical ionization-tandem mass spectrometry (GC/PCI-MS/MS). Method detection limits (MDLs) ranged from 0.03 to 0.43?g/g and recoveries from 60% to 118%. The inter- and intra-day variations ranged from 3% to 23%. The method was applied to dust samples collected using two vacuum sampling techniques from 134 urban Canadian homes: a sample of fresh or "active" dust (FD) collected by technicians and a composite sample taken from the household vacuum cleaner (HD). Results show that the two sampling methods (i.e., FD vs HD) provided comparable results. Tributoxyethyl phosphate (TBEP), triphenyl phosphate (TPhP), tris(chloropropyl) phosphate (TCPP), tri(2-chloroethyl) phosphate (TCEP), tris(dichloro-isopropyl) phosphate (TDCPP), tricresyl phosphate (TCrP), and tri-n-butyl phosphate (TnBP) were detected in the majority of samples. The most predominant OPE was TBEP, with median concentrations of 31.9?g/g and 22.8?g/g in FD and HD samples, respectively, 1 to 2 orders of magnitude higher than other OPEs. The method was also applied to the analysis of OPEs in the National Institute of Standards and Technology (NIST) standard reference material (NIST SRM 2585, organic contaminants in house dust). The results from SRM 2585 may contribute to the certification of OPE concentration values in this SRM. PMID:24462133
Fan, Xinghua; Kubwabo, Cariton; Rasmussen, Pat E; Wu, Fang
Conversion of Der p 23, a New Major House Dust Mite Allergen, into a Hypoallergenic Vaccine.
Der p 23, a new, major house dust mite (HDM) allergen that is recognized by >70% of HDM-allergic patients, has high allergenic activity and, therefore, must be considered an important component for HDM-specific immunotherapy. We constructed and characterized a hypoallergenic Der p 23 vaccine for HDM immunotherapy. Three nonallergenic peptides from the C-terminal IgE epitope-containing part of Der p 23 (P4, P5) and P6, a mutant peptide containing serines instead of cysteines, were identified. Peptides were fused to the hepatitis B virus-derived PreS domain as recombinant fusion proteins (i.e., PreS-2XP4P5 and PreS-4XP6) that were expressed in Escherichia coli and purified to homogeneity. Compared with Der p 23, PreS-2XP4P5 and PreS-4XP6 showed no relevant IgE reactivity and exhibited considerably reduced allergenic activity in basophil activation tests using blood from HDM-allergic patients. Upon immunization of rabbits, only PreS-2XP4P5 induced high levels of Der p 23-specific IgG Abs that inhibited binding of patients' IgE to Der p 23, comparable to IgG Abs induced with Der p 23, whereas Abs induced with PreS-4XP6 had only low blocking capacity. Additionally, IgG Abs induced with PreS-2XP4P5 inhibited Der p 23-induced basophil activation comparable to IgG Abs induced with Der p 23. Compared with Der p 23, PreS-2XP4P5 induced lower T cell proliferation but higher levels of the tolerogenic cytokine IL-10 and the Th1 cytokine IFN-? in PBMCs from HDM-allergic patients, indicating an immunomodulatory capacity of the fusion protein. Therefore, PreS-2XP4P5 represents a promising candidate for immunotherapy of HDM-allergic patients. PMID:24733847
Banerjee, Srinita; Weber, Milena; Blatt, Katharina; Swoboda, Ines; Focke-Tejkl, Margit; Valent, Peter; Valenta, Rudolf; Vrtala, Susanne
Expression of a major house dust mite allergen gene from Dermatophagoides farinae in Lotus japonicus accession Miyakojima MG-20.
Transformation of a model legume Lotus japonicus accession Miyakojima MG-20 was examined using Agrobacterium tumefaciens with a binary expression vector. Using the improved transformation method, we introduced a major allergen gene from a house dust mite, Der f 1, into MG-20. Analyses by Southern hybridization, reverse transcription (RT)-PCR, and Western blotting showed that the Der f 1 gene was integrated into the genome of L. japonicus, expressing the gene product in the T1 lines. Our results imply future application of oral allergen-specific immunotherapy using legume plants. PMID:16233773
Kato, Tomoaki; Goto, Yuji; Ono, Kazuhisa; Hayashi, Makoto; Murooka, Yoshikatsu
Supercritical fluid extraction of polybrominated diphenyl ethers (PBDEs) from house dust with supercritical 1,1,1,2-tetrafluoroethane (R134a).
The extraction of polybrominated diphenyl ethers (PBDEs) from SRM 2585 (Organic Contaminants in House Dust) was investigated using supercritical fluid R134a as an extraction solvent. Three methods of dust extraction were studied: (1) extraction of dry dust, (2) extraction of dry dust dispersed on Ottawa sand and (3) extraction of dust wet with dichloromethane. For each of the three sample preparation methods, extracts at three temperatures (110, 150, and 200 degrees C) above the critical temperature of R134a were performed. Eight PBDE congeners (BDE-28, -47, -99, 100, -153, -154, -183, and -209) in the SFE extracts were analyzed by liquid chromatography negative-ion atmospheric pressure photoionization tandem mass spectrometry (LC/NI-APPI/MS/MS). The optimum extraction of PBDEs from house dust using supercritical R134a is obtained when the dust is pre-wet with dichloromethane prior to extraction to swell the dust. For all sample preparation methods, higher temperatures afforded higher percent recoveries of the eight PBDE congeners. Only a combination of high-temperature (200 degrees C) and pre-wetting the dust with dichloromethane produced high recovery of the environmentally important, fully brominated PBDE congener, BDE-209. PMID:20006061
Calvosa, Frank C; Lagalante, Anthony F
The association between state housing policy and lead poisoning in children.
OBJECTIVES: This study examined the effect of an active program of household lead paint hazard abatement, applied over 22 years, on childhood lead poisoning in Massachusetts. METHODS: A small areas analysis was used to compare screening blood lead levels of children in Worcester County, Mass (n = 27,590), with those in Providence County, RI (n = 19,071). Data were collapsed according to census tract. RESULTS: The percentage of children with lead poisoning (blood lead level > or = 20 micrograms/dL [Pe20]) was, on average, 3 times higher in Providence County census tracts (3.2% vs 0.9% in Worcester County census tracts, P < .0001), despite similar percentages of pre-1950s housing in both counties. The ratio of Pe20 in Providence vs Worcester County census tracts was 2.2 (95% confidence interval = 1.8, 2.7), after adjustment for differences in housing, sociodemographic, and screening characteristics. This estimate was robust to alternative regression methods and sensitivity analyses. CONCLUSIONS: Massachusetts policy, which requires lead paint abatement of children's homes and places liability for lead paint poisoning on property owners, may have substantially reduced childhood lead poisoning in that state.
Sargent, J D; Dalton, M; Demidenko, E; Simon, P; Klein, R Z
Determination of nicotine and N-nitrosamines in house dust by pressurized liquid extraction and comprehensive gas chromatography--nitrogen chemiluminiscence detection.
A novel, highly selective method for the determination of nicotine, N-nitrosamines and tobacco-specific nitrosamines (TSNAs) in indoor dust samples is presented in this study. Samples were extracted by in-cell clean-up pressurized liquid extraction (PLE) that allows high extraction efficiency with moderate consumption of organic solvents. The extracts were analyzed by comprehensive gas chromatography and detected with a nitrogen chemiluminiscence detector (GC�GC-NCD) that provided enhanced selectivity and sensitivity for organic nitrogen containing compounds. Method validation showed good linearity, repeatability and reproducibility (%RSD<8%). Recovery was higher than 80% for most target compounds and limits of detection lower than 16 ng g(-1). The method was used for the determination of the nitrosamine target compounds in house dust samples from both smoking and non-smoking households. All the analytes were found in the samples, nicotine being the most abundant compound in smokers' dust and one of the most abundant in non-smokers' dust. To our knowledge this is the first time that volatile N-nitrosamines and TSNAs have been determined in indoor dust samples. The results demonstrate the presence of these highly carcinogenic compounds in house dust, with inherent human exposure through inhalation and/or involuntary ingestion of house dust. PMID:22153283
Ram�rez, Noelia; Ozel, Mustafa Z; Lewis, Alastair C; Marc�, Rosa M; Borrull, Francesc; Hamilton, Jacqueline F
Chamber studies on mass-transfer of di(2-ethylhexyl)phthalate (DEHP) and di- n-butylphthalate (DnBP) from emission sources into house dust
NASA Astrophysics Data System (ADS)
For a number of phthalates and especially for di(2-ethylhexyl)phthalate (DEHP), surprisingly high house dust concentrations are reported in the literature. Therefore, the uptake of the most prominent compounds DEHP and di- n-butylphthalate (DnBP) from plasticized indoor materials into house dust samples of different organic content has been experimentally determined. The experiments have been performed within 45 days which is sufficient for the more volatile phthalate (DnBP) to reach equilibrium conditions. DnBP reaches considerably higher concentrations in the chamber air compared to real room measurements and, thus, also elevated dust concentrations. In contrast, the mass transfer of DEHP in the dust via the gas phase was significantly lower. However, small chamber experiments showed elevated mass transfer of DEHP in case of direct contact between emission source and sink. This aspect is experimentally determined using an plasticized PVC polymer with and without direct contact to house dust. A transfer into the dust could be observed in dependence of the initial concentration in the material. However, the results do not allow the differentiation between the two uptake mechanisms via capillary forces and contact to the material's boundary layer. The results illustrate that the reasons for elevated DEHP concentrations in dust indoors can be traced back to direct contact of source and sink, abrasion from the source, and transport via airborne particles.
Schripp, Tobias; Fauck, Christian; Salthammer, Tunga
A new exposure metric for traffic-related air pollution? An analysis of determinants of hopanes in settled indoor house dust
Background Exposure to traffic-related air pollution (TRAP) can adversely impact health but epidemiologic studies are limited in their abilities to assess long-term exposures and incorporate variability in indoor pollutant infiltration. Methods In order to examine settled house dust levels of hopanes, engine lubricating oil byproducts found in vehicle exhaust, as a novel TRAP exposure measure, dust samples were collected from 171 homes in five Canadian cities and analyzed by gas chromatography�mass spectrometry. To evaluate source contributions, the relative abundance of the highest concentration hopane monomer in house dust was compared to that in outdoor air. Geographic variables related to TRAP emissions and outdoor NO2 concentrations from city-specific TRAP land use regression (LUR) models were calculated at each georeferenced residence location and assessed as predictors of variability in dust hopanes. Results Hopanes relative abundance in house dust and ambient air were significantly correlated (Pearson�s r=0.48, p<0.05), suggesting that dust hopanes likely result from traffic emissions. The proportion of variance in dust hopanes concentrations explained by LUR NO2 was less than 10% in Vancouver, Winnipeg and Toronto while the correlations in Edmonton and Windsor explained 20 to 40% of the variance. Modeling with household factors such as air conditioning and shoe removal along with geographic predictors related to TRAP generally increased the proportion of explained variability (10-80%) in measured indoor hopanes dust levels. Conclusions Hopanes can consistently be detected in house dust and may be a useful tracer of TRAP exposure if determinants of their spatiotemporal variability are well-characterized, and when home-specific factors are considered.
Impact of Dermatophagoides pteronyssinus mite body raw material on house dust mite allergy diagnosis in a Serbian population.
House dust mite (HDM) allergy has different clinical and immunological patterns in different geographic regions. The impact of raw material of commercial Dermatophadoides pteronyssinus (Acari: Pyroglyphidae) mite bodies on the quality of allergen extracts for allergy diagnosis in the Serbian population has not been previously evaluated. House dust mite bodies obtained from manufacturers in Europe, South America and Australia were used in the preparation of allergen extracts for in vivo diagnosis and serological analysis in a group of 14 HDM-allergic adults. In the group of mite-allergic patients, there was no statistically significant difference in skin test reactivity (Wilcoxon matched pairs test) among the three HDM body extract preparations. In a CAP inhibition assay, two extracts (A and C) achieved maximum inhibition of >90%, whereas extract B demonstrated a different inhibition slope and lower inhibition potential (80%). However, a remarkable difference in immunoglobulin E reactivity using Western blot analysis with individual patients' sera was observed in one of the preparations (extract B). These findings emphasize the need for the careful selection of starting material for the preparation of HDM diagnostic reagents intended for use in patients from geographically distinct regions as these preparations can have implications on the selection criteria for patient-tailored immunotherapy of HDM allergy. PMID:20819152
Burazer, L; Milovanovic, K; Milovanovic, M; Vuckovic, O; Velickovic, T C; Gavrovic-Jankulovic, M
Effect of Alpinia katsumadai Hayata on House Dust Mite-Induced Atopic Dermatitis in NC/Nga Mice
We evaluated the effects of Alpinia katsumadai Hayata (AKH, Zingiberaceae) extract on the production of nitric oxide (NO) and prostaglandin E2 (PGE2) in RAW 264.7 cells, thymus- and-activation-regulated chemokine (TARC/CCL17) in HaCaT cells, and histamine level in HMC-1 cells. In an in vivo experiment, atopic dermatitis was induced by topical application of house dust mites for 4 weeks, and the protective effects of AKH was investigated by measuring the severity of the skin reaction on the back and ears, and plasma levels of immunoglobulin E (IgE) and histamine. AKH extract suppressed the production of NO and PGE2 in RAW 264.7 cells, TARC in HaCaT cells, and histamine in HMC-1 cells in a dose-dependent manner. In in vivo experiments, the severity of dermatitis, including erythema/hemorrhage, edema, erosion and scaling, and plasma levels of IgE, and histamine were lower in NC/Nga mice with atopic dermatitis, treated with AKH extract than in untreated mice. AKH extract reduced the histological manifestations of atopic dermatitis-like skin lesions such as erosion, hyperplasia of the epidermis and dermis, and inflammatory cell infiltration on the skin of the back and ear. These results suggest that AKH inhibits the development of house dust mite-induced atopic dermatitis in NC/Nga mice.
Lim, Hye-Sun; Seo, Chang-Seob; Ha, Hyekyung; Lee, Hoyoung; Lee, Jun Kyung; Lee, Mee-Young; Shin, HyeunKyoo
Brominated flame retardants in house dust from e-waste recycling and urban areas in South China: implications on human exposure.
Brominated flame retardants (BFRs) were examined in house dust from the electronic waste (e-waste) recycling and urban areas of South China. The concentrations of polybrominated diphenyl ethers (PBDEs) were in the range of 227-160,000 ng/g in the e-waste recycling area and 530-44,000 ng/g in the urban area. These values were much higher than other BFRs, except for novel decabromodiphenyl ethane (DBDPE) whose value of 100-47,000 ng/g was dominant in approximately 1/4 of the samples from the urban area. Urban dust PBDE levels were generally higher than those in many European and Asian countries and comparable to the values found in North America. Urban dust DBDPE levels were higher than those of other areas in the world. The distinct dust BFR profiles observed in the two studied areas were reflective of activities in these areas (electronics industry vs. e-waste recycling). The presence of BDE202, as well as the BDE197 to BDE201 and the nona-BDEs to deca-BDE ratios in the dust samples from the studied areas were probably indicative of environmental degradation of deca-BDE. The estimated daily intakes (EDIs) of average adult and toddler via house dust ranged from 37.0 to 304 ng/day for PBDEs and from 3.01 to 87.6 ng/day for all other BFRs in the studied areas. The EDIs via house dust were much higher than those via other indoor pathways (air, fish, human milk, and toys). Despite the potentially low deleterious risk of PBDE exposure via house dust as suggested by the hazard quotients, this exposure pathway should be of great concern because of the higher BFR exposures for children and the presence of other BFRs (such as DBDPE) which have not yet been fully investigated. PMID:20452672
Wang, Jing; Ma, Yun-Juan; Chen, She-Jun; Tian, Mi; Luo, Xiao-Jun; Mai, Bi-Xian
... Safety and Health (ABLES/ NIOSH) Lead in the environment Agency for Toxic Substances and Disease Registry (ATSDR) Department of Housing and Urban Development (HUD) U.S. Environmental Protection Agency (EPA) More Click ...
... Homeless Assistance programs. For more information on housing programs, see HUD's Online Library . Taking Care Of Yourself Doctor, Clinic, & Dental Visits Treatment Adherence Mental Health Substance Abuse Issues Sexual Health Nutrition & Food Safety Exercise Immunizations Aging With HIV ...
Cycling of Lead Through Soil, Air, and Household Dust in El Paso, Texas
NASA Astrophysics Data System (ADS)
Elimination of leaded gasoline in the US is associated with a dramatic overall decrease in ambient lead in the environment and blood lead levels in our population. However, Pb is such a potent neurotoxin for children during the formative growth years that legislation for additional reduction of airborne lead levels is under consideration. X-ray absorption spectroscopy of a suite of samples of local (El Paso) soil, airborne particulate matter, and household dust reveals that lead humate is the dominant Pb species in these diverse environmental materials. Lead humate is a stable complex of Pb with the humus component of soil, a product of interaction between the humus and such introduced contaminant lead species as lead oxide, lead sulfate, etc. Because lead humate forms only in soil, we conclude that the source of the majority of the lead in El Paso's airborne particulate matter and household dust is local soils. Analysis of lead isotopes in selected samples is consistent with this conclusion. Re-entrainment of low-density (relative to most Pb species) humus soil particles is the apparent pathway from soil to air. Deposition of airborne particulate matter and pedal traction are the presumed mechanisms for transfer to household interiors. Reduction of airborne lead in El Paso by reducing input from its dominant local source may require extensive soil remediation, a tedious and expensive prospect. X-Ray absorption spectroscopy experiments were conducted at the Stanford Synchrotron Radiation Laboratory on beam lines 7-3, 10-2, and 11-2. Spectra were collected at the Pb L-III absorption edge in fluorescence mode using a 13-element or a 30-element Ge solid-state detector. This publication was made possible by grant numbers 1RO1-ES11367 and 1 S11 ES013339-04 from the National Institute of Environmental Health Sciences (NIEHS), NIH. Its contents are solely the responsibility of the authors and do not necessarily represent the official views of the NIEHS, NIH. Partial travel support provided by SSRL-DOE- UTEP Gateway Program.
Pingitore, N. E.; Clague, J.; Amaya, M. A.
Evaluation of four sampling methods for determining exposure of children to lead-contaminated household dust.
Childhood exposure to lead has been demonstrated to result in health effects and lead-contaminated household dust is a primary exposure source. There is a need to establish reliable methods for sampling surfaces to determine levels of lead contamination. Three vacuums (HVS3, GS80, and MVM) and one wipe method were evaluated for the collection of household floor dust under field sampling conditions within a Superfund site and demographically similar control area. Side-by-side floor samples were taken from three locations within 41 randomly selected households between August and September 1995: a child's bedroom, primary play area, and primary entrance. Analysis was performed to assess the relative collection performance of each sampler, spatial distribution of lead within a household, and correlation of lead loading with observed blood lead level, and to determine if discrete or composites samples were more predictive of blood lead levels. Approximately 90% of the floor surfaces were carpeted. The rank order of sampling methods from greatest to lowest collection efficiency was HVS3 > GS80 > wipe > MVM. The HVS3 had the highest level of precision (CV=0.05), with the GS80 and wipe precisions 0.48 and 0.053, respectively. Lead loadings for samples collected in bedrooms and living areas and composite samples using the HVS3 and wipe methods were significantly correlated with blood lead levels. Correlations between blood lead levels and composite samples were stronger for the HVS3 (R(2)=0.33, P=0.003) and wipe (R(2)=0.25, P=0.002) methods than the respective discrete samples. Regression analysis indicated that a blood lead level of 10 microgram/dl corresponds to a carpet wipe sample geometric mean of 68 microgram/ft(2). For ongoing public health purposes, such as screening and clearance testing, use of the wipe sampling method is the most appropriate. This investigation supports findings by others that the present HUD risk levels for lead in floor wipe samples may not be adequate for reducing children's blood lead levels below 10 microgram/dl. PMID:10433844
Sterling, D A; Roegner, K C; Lewis, R D; Luke, D A; Wilder, L C; Burchette, S M
Evaluation of errors and limits of the 63-?m house-dust-fraction method, a surrogate to predict hidden moisture damage
Background The aim of this study is to analyze possible random and systematic measurement errors and to detect methodological limits of the previously established method. Findings To examine the distribution of random errors (repeatability standard deviation) of the detection procedure, collective samples were taken from two uncontaminated rooms using a sampling vacuum cleaner, and 10 sub-samples each were examined with 3 parallel cultivation plates (DG18). In this two collective samples of new dust, the total counts of Aspergillus spp. varied moderately by 25 and 29% (both 9 cfu per plate). At an average of 28 cfu/plate, the total number varied only by 13%. For the evaluation of the influence of old dust, old and fresh dust samples were examined. In both cases with old dust, the old dust influenced the results indicating false positive results, where hidden moist was indicated but was not present. To quantify the influence of sand and sieving, 13 sites were sampled in parallel using the 63-?m- and total dust collection approaches. Sieving to 63-?m resulted in a more then 10-fold enrichment, due to the different quantity of inert sand in each total dust sample. Conclusion The major errors during the quantitative evaluation from house dust samples for mould fungi as reference values for assessment resulted from missing filtration, contamination with old dust and the massive influence of soil. If the assessment is guided by indicator genera, the percentage standard deviation lies in a moderate range.
Baudisch, Christoph; Assadian, Ojan; Kramer, Axel
Exposure to herbicides in house dust and risk of childhood acute lymphoblastic leukemia.
We examine the association between exposure to herbicides and childhood acute lymphoblastic leukemia (ALL). Dust samples were collected from homes of 269 ALL cases and 333 healthy controls (<8 years of age at diagnosis/reference date and residing in same home since diagnosis/reference date) in California, using a high-volume surface sampler or household vacuum bags. Amounts of agricultural or professional herbicides (alachlor, metolachlor, bromoxynil, bromoxynil octanoate, pebulate, butylate, prometryn, simazine, ethalfluralin, and pendimethalin) and residential herbicides (cyanazine, trifluralin, 2-methyl-4-chlorophenoxyacetic acid (MCPA), mecoprop, 2,4-dichlorophenoxyacetic acid (2,4-D), chlorthal, and dicamba) were measured. Odds ratios (OR) and 95% confidence intervals (CI) were estimated by logistic regression. Models included the herbicide of interest, age, sex, race/ethnicity, household income, year and season of dust sampling, neighborhood type, and residence type. The risk of childhood ALL was associated with dust levels of chlorthal; compared to homes with no detections, ORs for the first, second, and third tertiles were 1.49 (95% CI: 0.82-2.72), 1.49 (95% CI: 0.83-2.67), and 1.57 (95% CI: 0.90-2.73), respectively (P-value for linear trend=0.05). The magnitude of this association appeared to be higher in the presence of alachlor. No other herbicides were identified as risk factors of childhood ALL. The data suggest that home dust levels of chlorthal, and possibly alachlor, are associated with increased risks of childhood ALL. PMID:23321862
Metayer, Catherine; Colt, Joanne S; Buffler, Patricia A; Reed, Helen D; Selvin, Steve; Crouse, Vonda; Ward, Mary H
Inhalable and Respirable Dust, Bacteria and Endotoxins in the Air of Poultry Houses
The air in livestock buildings contains a large variety of different gases, micro-organisms and considerable amounts of dust. These particles have a complex nature, can carry substances such as endotoxins and antibiotic residues, can remain suspended in the air for longer periods because of their minute dimensions and can therefore be inhaled by animal and man. Strong epidemiological evidence suggests
M. Saleh; J. Seedorf; J. Hartung
Quantification of Ergosterol and 3Hydroxy Fatty Acids in Settled House Dust by Gas Chromatography-Mass Spectrometry: Comparison with Fungal Culture and Determination of Endotoxin by a Limulus Amebocyte Lysate Assay
Ergosterol and 3-hydroxy fatty acids, chemical markers for fungal biomass and the endotoxin of gram- negative bacteria, respectively, may be useful in studies of health effects of organic dusts, including domestic house dust. This paper reports a method for the combined determination of ergosterol and 3-hydroxy fatty acids in a single dust sample and a comparison of these chemical biomarkers
Allergic Responses Induced by a Fungal Biopesticide Metarhizium anisopliae and House Dust Mite Are Compared in a Mouse Model
Biopesticides can be effective in controlling their target pest. However, research regarding allergenicity and asthma development is limited. We compared the ability of fungal biopesticide Metarhizium anisopliae (MACA) and house dust mite (HDM) extracts to induce allergic responses in BALB/c mice. The extracts were administered by intratracheal aspiration at doubling doses (2.5�80??g protein) 4X over a four-week period. Three days after the last exposure, serum and bronchoalveolar lavage fluid (BALF) were collected. The extracts' relative allergenicity was evaluated based on response robustness (lowest significant dose response compared to control (0??g)). MACA induced a more robust serum total IgE response than HDM. However, in the antigen-specific IgE assay, a similar dose of both MACA and HDM was required to achieve the same response level. Our data suggest a threshold dose of MACA for allergy induction and that M. anisopliae may be similar to HDM in allergy induction potential.
Ward, Marsha D. W.; Chung, Yong Joo; Copeland, Lisa B.; Doerfler, Donald L.
Monocyte-Derived Dendritic Cells Induce a House Dust Mite-Specific Th2 Allergic Inflammation in the Lung of Humanized SCID Mice: Involvement of CCR7
In rodents, airway dendritic cells (DCs) capture inhaled Ag, undergo maturation, and migrate to the draining mediastinal lymph nodes (MLN) to initiate the Ag-specific T cell response. However, the role of human DCs in the pathogenesis of the Th2 cell- mediated disease asthma remains to be clarified. Here, by using SCID mice engrafted with T cells from either house dust
Hamida Hammad; Bart N. Lambrecht; Pierre Pochard; Philippe Gosset
Eighteen-month outcomes of house dust mite avoidance and dietary fatty acid modification in the childhood asthma prevention study (CAPS)
Background: Observational studies have linked house dust mite (HDM) exposure and dietary fatty acid intake with asthma in childhood. However, definitive evidence of their role in the etiology of asthma requires a randomized controlled trial. Objective: We hypothesized that the incidence of asthma and allergy in high-risk children would be reduced by avoidance of HDM allergens, supplementation with omega-3 fatty
Seema Mihrshahi; Jennifer K. Peat; Guy B. Marks; Craig M. Mellis; Euan R. Tovey; Karen Webb; Warwick J. Britton; Stephen R. Leeder
Acaricidal activities of major constituents of essential oil of Juniperus chinensis leaves against house dust and stored food mites.
The acaricidal activities of major constituents from the oil of Juniperus chinensis (var. globosa) leaves were compared with those of DEET (N,N-diethyl-m-toluamide) by using impregnated fabric disk bioassay against Dermatophagoides spp. and Tyrophagus putrescentiae. Toxicity varied with doses as well as chemical composition. The 50% lethal doses (LD50) of J. chinensis oil against Dermatophagoides farinae, Dermatophagoides pteronyssinus, and T. putrescentiae were 21.60, 19.89, and 38.10 microg/cm2, respectively. The active constituent was purified using silica gel chromatography and high-performance liquid chromatography. The acaricidal component was identified as bomyl acetate through gas chromatography-mass spectrometry, 1H nuclear magnetic resonance (NMR), 13C-NMR, 1H-13C shift correlation spectrum-NMR, and distortionless enhancement by polarization transfer-NMR. The LD50 of bornyl acetate (2.94 microg/cm2) against D. farinae was significantly lower than those of DEET (37.13 microg/cm2) and alpha-eudesmol (29.72 microg/cm2). Similar results were observed when bomyl acetate and alpha-eudesmol were tested against D. pteronyssinus and T. putrescentiae. The lower LD50 of bornyl acetate indicates that it may be responsible for the major acaricidal activity against house dust and stored food mites, even though it constitutes only 19.5% of J. chinensis oil. Overall, these findings indicated that bornyl acetate and c-eudesmol have potential for use as control agents against house dust and stored food mites. PMID:19722401
Lee, Chi-Hoon; Park, Joon-Moh; Song, Ha-Yun; Jeong, Eun-Young; Lee, Hoi-Seon
Total suspended dust and heavy metal levels emitted from a workplace compared with nearby residential houses
NASA Astrophysics Data System (ADS)
Total suspended particulate matter (TSP) were collected from the workplace in Sohar Industrial Estate (SIE) in Oman. The samples were taken from 19 different industrial activities that represent major sources of particulate matter in the SIE. The collected samples were analyzed for 9 heavy metals (Cr, Cu, Mn, Ni, Pb, Zn, Cd, V and Mo) by using the inductively coupled plasma optical emission spectrometry analysis (ICP-OES). Furthermore, the indoor TSP and heavy metal concentrations were measured inside 12 houses within Sohar residential area to determine the contributions of various industrial activities on nearby residential houses. The results indicated that the mean concentrations of heavy metals in the TSP were too low to yield any known environmental health effects. In general, the results showed that the concentrations of heavy metals in the workplaces of SIE and its nearby houses were low compared to the guideline values. In addition, the values were low in comparison with other known sites around the world. Moreover, significant contribution from industrial sources at SIE was evidenced at nearby houses.
Abdul-Wahab, Sabah A.; Yaghi, Basma
[Nursery schools, a site for exposure to house dust mite allergens?].
In June 1988, 110 dust samples from carpets, cushions, mattresses and upholstered furniture were collected by vacuum cleaner in 33 municipal nursery schools. All samples were assessed with guanine test strips (Acarex). In all samples giving moderately or strongly positive results in these tests (guanine stages 2 and 3) and in 10 random samples each from of stages 1 (weakly positive) and 0 (negative), mites were counted by light microscope. In 36% of the nursery schools, objects with guanine stages 2 or 3 were found, which indicates a high allergen burden. The high guanine stages were found only in mattresses, cushions and upholstered furniture. Nursery schools can be source areas of significant allergen exposure relevant for children with dust mite allergies. PMID:2586533
Rebmann, H; Weller, A
Interleukin-1? controls allergic sensitization to inhaled house dust mite via the epithelial release of GM-CSF and IL-33
House dust mite (HDM) is one of the most common allergens worldwide. In this study, we have addressed the involvement of IL-1 in the interaction between HDM and the innate immune response driven by lung epithelial cells (ECs) and dendritic cells (DCs) that leads to asthma. Mice lacking IL-1R on radioresistant cells, but not hematopoietic cells, failed to mount a Th2 immune response and did not develop asthma to HDM. Experiments performed in vivo and in isolated air�liquid interface cultures of bronchial ECs showed that TLR4 signals induced the release of IL-1?, which then acted in an autocrine manner to trigger the release of DC-attracting chemokines, GM-CSF, and IL-33. Consequently, allergic sensitization to HDM was abolished in vivo when IL-1?, GM-CSF, or IL-33 was neutralized. Thymic stromal lymphopoietin (TSLP) became important only when high doses of allergen were administered. These findings put IL-1? upstream in the cytokine cascade leading to epithelial and DC activation in response to inhaled HDM allergen.
Willart, Monique A.M.; Deswarte, Kim; Pouliot, Philippe; Braun, Harald; Beyaert, Rudi; Lambrecht, Bart N.
Risk Analysis to Support Standards for Lead in Paint, Dust, and Soil. Volume 2. Appendices B to G.
National Technical Information Service (NTIS)
Contents: Appendix A-Glossary; Appendix B-Health Effects Associated with Exposure to Lead and Internal Lead Doses in Humans; Appendix C1-Characterizing Baseline Environmental-Lead Levels in the Nation's Housing Stock; Appendix C-2 Method for Computing Con...
Quantitative PCR analysis of house dust can reveal abnormal mold conditions�
Indoor mold concentrations were measured in the dust of moldy homes (MH) and reference homes (RH) by quantitative PCR (QPCR) assays for 82 species or related groups of species (assay groups). About 70% of the species and groups were never or only rarely detected. The ratios (MH geometric mean : RH geometric mean) for 6 commonly detected species (Aspergillus ochraceus, A. penicillioides, A. unguis, A. versicolor, Eurotium group, and Cladosporium sphaerospermum) were > 1 (Group I). Logistic regression analysis of the sum of the logs of the concentrations of Group I species resulted in a 95% probability for separating MH from RH. These results suggest that it may be possible to evaluate whether a home has an abnormal mold condition by quantifying a limited number of mold species in a dust sample. Also, four common species of Aspergillus were quantified by standard culturing procedures and their concentrations compared to QPCR results. Culturing underestimated the concentrations of these four species by 2 to 3 orders of magnitude compared to QPCR.
Meklin, Teija; Haugland, Richard A.; Reponen, Tiina; Varma, Manju; Lummus, Zana; Bernstein, David; Wymer, Larry J.; Vesper, Stephen J.
Duration of exposure--histological effects on broiler lungs, performance, and house environment with Mt. St. Helens' volcanic ash dust.
Fourteen hundred broilers were exposed to Mt. St. Helens' volcanic ash (VA) dust (D) from 28 to 49 days of age to correlate the duration of exposure time to histological effect on lungs and to determine the effects on broiler performance and house environment. Histological examinations of the lungs from birds exposed each day for 4 days to either VAD for 60 min (VAD 60) in the morning and afternoon (3276 g VA/day), or VAD after one direct application (DiAp) (20 kg/m2) on wood shaving litter revealed mild lymphoid hyperplasia and granuloma formation accompanied by phagocytized crystalline material seen in some alveolar macrophages; however, no effect was observed in lung tissues from broilers exposed each day for 4 days to VAD for 15 min (VAD 15) in the morning and afternoon (82 g VAD/day). Birds exposed to all VAD treatments and examined after 7 days had histological changes in the lungs, including giant cell granuloma formation, similar to those seen at 4 days. No significant histopathological changes were found in the turbinates with any VAD treatments. Levels of mean body weight, ammonia concentration, mortality, and respiratory dust (particles ranging in size from .5 to 10 micron) levels were not significantly different among the treatments. Significantly poorer mean feed conversion was observed with broilers exposed to VAD 60 than the VA DiAp exposure. No difference in feed conversion was observed between the control and either VAD 15 or VAD 60 treatments. From this experiment, the observed histological changes in the lungs occurred with 4 days or less exposure to VAD 60 (3276 g/day). PMID:3975198
Bland, M C; Nakaue, H S; Goeger, M P; Helfer, D H
Duration of exposure--histological effects on broiler lungs, performance, and house environment with Mt. St. Helens volcanic ash dust
Fourteen hundred broilers were exposed to Mt. St. Helens volcanic ash (VA) dust (D) from 28 to 49 days of age to correlate the duration of exposure time to histological effect on lungs and to determine the effects on broiler performance and house environment. Histological examinations of the lungs from birds exposed each day for 4 days to either VAD for 60 min (VAD 60) in the morning and afternoon (3276 g VA/day), or VAD after one direct application (DiAp) (20 kg/m2) on wood shaving litter revealed mild lymphoid hyperplasia and granuloma formation accompanied by phagocytized crystalline material seen in some alveolar macrophages; however, no effect was observed in lung tissues from broilers exposed each day for 4 days to VAD for 15 min (VAD 15) in the morning and afternoon (82 g VAD/day). Birds exposed to all VAD treatments and examined after 7 days had histological changes in the lungs, including giant cell granuloma formation, similar to those seen at 4 days. No significant histopathological changes were found in the turbinates with any VAD treatments. Levels of mean body weight, ammonia concentration, mortality, and respiratory dust (particles ranging in size from .5 to 10 micron) levels were not significantly different among the treatments. Significantly poorer mean feed conversion was observed with broilers exposed to VAD 60 than the VA DiAp exposure. No difference in feed conversion was observed between the control and either VAD 15 or VAD 60 treatments. From this experiment, the observed histological changes in the lungs occurred with 4 days or less exposure to VAD 60 (3276 g/day).
Bland, M.C.; Nakaue, H.S.; Goeger, M.P.; Helfer, D.H.
Seasonal concentrations of lead in outdoor and indoor dust and blood of children in Riyadh, Saudi Arabia.
Because detrimental effects of exposure to lead (Pb) on human health have been observed, we previously investigated concentrations of Pb in water supplies and blood of adult residents of Riyadh, Saudi Arabia. The objectives of the present study were to: (1) examine seasonal rates of deposition of Pb in dust in several areas of Riyadh city, (2) measure concentrations of Pb in both outdoor and indoor dust, (3) compare concentrations of Pb in dust in Riyadh with those reported for other cities, and (4) quantify Pb in blood of children living in Riyadh. Mean, monthly deposition of PB in outdoor dust was 4.7�נ10(1)���3.6�tons�km(-2), with a mean Pb concentration of 2.4�נ10(2)���4.4�נ10(1)�?g/g. Mean, monthly deposition of Pb in indoor dust was 2.7���0.70�tons�km(-2), with a mean concentration of 2.9�נ10(1)���1.5�נ10(1)�?g Pb/g. There was a significant (P�<�0.01) correlation between concentrations of Pb in outdoor and indoor dust. There was no correlation between concentrations of Pb in indoor dust and that in blood of children of Riyadh, whereas there was a weakly significant (P�<�0.05) correlation between concentrations of Pb in outdoor dust and that in blood of children. The mean (�SD) concentration of Pb in blood of children in Riyadh was 5.2���1.7, with a range of 1.7-1.6�נ10(1)�?g/dl. Concentrations of Pb in blood of 17.8�% of children in Riyadh were greater than 10�?g/dl, which is the CDC's level of concern. PMID:24213703
El-Desoky, Gaber E; Aboul-Soud, Mourad A M; Al-Othman, Zeid A; Habila, Mohamed; Giesy, John P
40 CFR 745.227 - Work practice standards for conducting lead-based paint activities: target housing and child...
Code of Federal Regulations, 2010 CFR
...air at 99.97 percent or greater efficiency; (iii) Dry scraping of lead-based paint is permitted only in conjunction with...employing single-surface sampling or composite sampling techniques. (iii) Dust samples for clearance purposes shall be...
40 CFR 745.227 - Work practice standards for conducting lead-based paint activities: target housing and child...
Code of Federal Regulations, 2010 CFR
...air at 99.97 percent or greater efficiency; (iii) Dry scraping of lead-based paint is permitted only in conjunction with...employing single-surface sampling or composite sampling techniques. (iii) Dust samples for clearance purposes shall be...
Comparison of sample preparation procedures for the determination of trace heavy metals in house dust, tobacco and tea samples by atomic absorption spectrometry.
The effect of wet ashing, dry ashing and microwave procedure for the determination of trace metal levels was investigated in house dust, tobacco and tea samples by atomic absorption spectrometry. The study of sample preparation procedures showed that the microwave method was the best. The recovery of trace metals was very good and precision and accuracy were compatible with standard reference material. The relative standard deviations for all measured metal concentrations were lower than 10%. The digestions of HNO3/H2SO4/HClO4 (4: 1: 1) mixture for house dust, HNO3/H2SO4/H2O2 (2: 2: 2) mixture for tea and HNO3/H2O2 (4: 2) mixture for tobacco were very efficient. PMID:15626247
Narin, Ibrahim; Tuzen, Mustafa; Soylak, Mustafa
MHC Class II-Restricted Presentation of the Major House Dust Mite Allergen Der p 1 Is GILT-Dependent: Implications for Allergic Asthma
Gamma-interferon-inducible lysosomal thiol reductase (GILT) is known to reduce disulfide bonds present in proteins internalized by antigen presenting cells, facilitating optimal processing and presentation of peptides on Major Histocompatibility Complex class II molecules, as well as the subsequent activation of CD4-positive T lymphocytes. Here, we show that GILT is required for class II-restricted processing and presentation of immunodominant epitopes from the major house dust mite allergen Der p 1. In the absence of GILT, CD4-positive T cell responses to Der p 1 are significantly reduced, resulting in mitigated allergic airway inflammation in response to Der p 1 and house dust mite extracts in a murine model of asthma.
West, Laura Ciaccia; Grotzke, Jeff E.; Cresswell, Peter
MHC class II-restricted presentation of the major house dust mite allergen Der p 1 Is GILT-dependent: implications for allergic asthma.
Gamma-interferon-inducible lysosomal thiol reductase (GILT) is known to reduce disulfide bonds present in proteins internalized by antigen presenting cells, facilitating optimal processing and presentation of peptides on Major Histocompatibility Complex class II molecules, as well as the subsequent activation of CD4-positive T lymphocytes. Here, we show that GILT is required for class II-restricted processing and presentation of immunodominant epitopes from the major house dust mite allergen Der p 1. In the absence of GILT, CD4-positive T cell responses to Der p 1 are significantly reduced, resulting in mitigated allergic airway inflammation in response to Der p 1 and house dust mite extracts in a murine model of asthma. PMID:23326313
West, Laura Ciaccia; Grotzke, Jeff E; Cresswell, Peter
Hydrometallurgical recovery of zinc and lead from electric arc furnace dust using mononitrilotriacetate anion and hexahydrated ferric chloride
The purpose of this work was to study the feasibility at laboratory-scale of a new hydrometallurgical process for treating electric arc furnace dusts (EAFD). The proposed process is intended to extract zinc and lead from EAFD without destroying the iron oxides matrix. So, this material can be recycled by the steel industry. Independently of the origin of the samples, major
Nathalie Leclerc; Eric Meux; Jean-Marie Lecuire
A rapid, simple, inexpensive, and relatively accurate field test method for the determination of lead (Pb) in paints, dusts, and soils has been developed. The method involves the ultrasonic leaching of 0.19 - 0.5g of the sample in 5 mL of 25% (v/v) nitric acid for 30 minutes foll...
Development of a Field Test Method for the Determination of Lead in Paint and Paint-Contaminated Dust and Soil.
National Technical Information Service (NTIS)
A rapid, simple, inexpensive, and relatively accurate field test method for the determination of lead (Pb) in paints, dusts, and soils has been developed. The method involves the ultrasonic leaching of 0.1g - 0.5g of the sample in 5 mL of 25% (v/v) nitric...
P. M. Grohse K. K. Luk L. L. Hodson B. M. Wilson W. F. Gutknecht
Production of a chimeric allergen derived from the major allergen group 1 of house dust mite species in Nicotiana benthamiana.
Plants are widely accepted as a general platform for the large-scale production of recombinant proteins, which has been demonstrated by the successful expression of various exogenous proteins. Using plants as a bioreactor for mass production of target proteins for vaccines is thought to show the most potential. This study explores whether a chimeric allergen R8, derived from the major allergen group 1 of house dust mites species (Dermatophagoides farinae and Dermatophagoides pteronyssinus), is expressed in tobacco. The highly efficient and useful Tobacco mosaic virus RNA-based overexpression (TRBO) vector was used to investigate expression of the R8 molecule in tobacco by agroinfection. Presence of R8 was detected using SDS-PAGE and Western blotting. Purified allergens were characterized using IgE-binding activity assay and allergen-specific immunotherapy (ASIT) in murine asthmatic models. The recombinant R8 was successfully expressed in tobacco leaves. The pro-peptide was observed in the herbaceous leaf extracts. This protein exhibits properties similar to the parental allergen ProDer f 1 expressed in Escherichia coli or tobacco with respect to IgE immunoreactivity. R8 also rectifies imbalance of TH1/TH2 cells. An herbaceous plant expression system model allows mass production of R8, which might be used in the future for diagnosis of asthma or production of a candidate vaccine for allergen-specific immunotherapy of asthma. PMID:23354320
Li, Chaopin; Jiang, Yuxin; Guo, Wei; Liu, Zhiming
Group 10 allergens (tropomyosins) from house-dust mites may cause covariation of sensitization to allergens from other invertebrates
Group 10 allergens (tropomyosins) have been assumed to be a major cause of cross-reactivity between house-dust mites (HDMs) and other invertebrates. Despite all of the published data regarding the epidemiology, percent IgE binding and level of sensitization in the population, the role of tropomyosin as a cross-reactive allergen in patients with multiple allergy syndrome still remains to be elucidated. Homology between amino acid sequences reported in allergen databases of selected invertebrate tropomyosins was determined with Der f 10 as the reference allergen. The 66.9 and 54.4% identities were found with selected crustacean and insect species, respectively, whereas only 20.4% identity was seen with mollusks. A similar analysis was performed using reported B-cell IgE-binding epitopes from Met e1 (shrimp allergen) and Bla g7 (cockroach allergen) with other invertebrate tropomyosins. The percent identity in linear sequences was higher than 35% in mites, crustaceans, and cockroaches. The polar and hydrophobic regions in these groups were highly conserved. These findings suggest that tropomyosin may be a major cause of covariation of sensitization between HDMs, crustaceans, and some species of insects and mollusks.
Inam, Muhammad; Ismail, Muhammad; Chaudhary, Farhana Riaz
A GM-CSF/IL-33 pathway facilitates allergic airway responses to sub-threshold house dust mite exposure.
Allergic asthma is a chronic immune-inflammatory disease of the airways. Despite aeroallergen exposure being universal, allergic asthma affects only a fraction of individuals. This is likely related, at least in part, to the extent of allergen exposure. Regarding house dust mite (HDM), we previously identified the threshold required to elicit allergic responses in BALB/c mice. Here, we investigated the impact of an initial immune perturbation on the response to sub-threshold HDM exposure. We show that transient GM-CSF expression in the lung facilitated robust eosinophilic inflammation, long-lasting antigen-specific Th2 responses, mucus production and airway hyperresponsiveness. This was associated with increased IL-33 levels and activated CD11b(+) DCs expressing OX40L. GM-CSF-driven allergic responses were significantly blunted in IL-33-deficient mice. IL-33 was localized on alveolar type II cells and in vitro stimulation of human epithelial cells with GM-CSF enhanced intracellular IL-33 independently of IL-1?. Likewise, GM-CSF administration in vivo resulted in increased levels of IL-33 but not IL-1?. These findings suggest that exposures to environmental agents associated with GM-CSF production, including airway infections and pollutants, may decrease the threshold of allergen responsiveness and, hence, increase the susceptibility to develop allergic asthma through a GM-CSF/IL-33/OX40L pathway. PMID:24551140
Llop-Guevara, Alba; Chu, Derek K; Walker, Tina D; Goncharova, Susanna; Fattouh, Ramzi; Silver, Jonathan S; Moore, Cheryl Lynn; Xie, Juliana L; O'Byrne, Paul M; Coyle, Anthony J; Kolbeck, Roland; Humbles, Alison A; St�mpfli, Martin R; Jordana, Manel
House-dust mite allergen and ozone exposure decreases histamine H3 receptors in the brainstem respiratory nuclei
Allergic airway diseases in children are a common and a growing health problem. Changes in the central nervous system (CNS) have been implicated in contributing to some of the symptoms. We hypothesized that airway allergic diseases are associated with altered histamine H3 receptor expression in the nucleus tractus solitarius (NTS) and caudal spinal trigeminal nucleus, where lung/airway and nasal sensory afferents terminate, respectively. Immunohistochemistry for histamine H3 receptors was performed on brainstem sections containing the NTS and the caudal spinal trigeminal nucleus from 6- and 12-month-old rhesus monkeys who had been exposed for 5 months to house dust mite allergen (HDMA) + O{sub 3} or to filtered air (FA). While histamine H3 receptors were found exclusively in astrocytes in the caudal spinal trigeminal nucleus, they were localized to both neuronal terminals and processes in the NTS. HDMA + O{sub 3} exposure significantly decreased histamine H3 receptor immunoreactivity in the NTS at 6 months and in the caudal spinal trigeminal nucleus at 12 months of age. In conclusion, exposing young primates to HDMA + O{sub 3} changed histamine H3 receptor expression in CNS pathways involving lung and nasal afferent nerves in an age-related manner. Histamine H3 receptors may be a therapeutic target for allergic asthma and rhinitis in children.
Sekizawa, Shin-ichi, E-mail: email@example.com [Department of Pharmacology, School of Medicine, University of California Davis, GBSF Rm. 3617, 451 Health Sciences Drive, Davis, CA 95616-0635 (United States); Bechtold, Andrea G.; Tham, Rick C. [Department of Pharmacology, School of Medicine, University of California Davis, GBSF Rm. 3617, 451 Health Sciences Drive, Davis, CA 95616-0635 (United States); Kott, Kayleen S. [Department of Pharmacology, School of Medicine, University of California Davis, GBSF Rm. 3617, 451 Health Sciences Drive, Davis, CA 95616-0635 (United States); Department of Pediatrics, School of Medicine, University of California Davis, Davis, CA 95616-0635 (United States); Hyde, Dallas M. [School of Medicine, California National Primate Research Center, University of California Davis, Davis, CA 95616-0635 (United States); Joad, Jesse P. [Department of Pediatrics, School of Medicine, University of California Davis, Davis, CA 95616-0635 (United States); Bonham, Ann C. [Department of Pharmacology, School of Medicine, University of California Davis, GBSF Rm. 3617, 451 Health Sciences Drive, Davis, CA 95616-0635 (United States)
House dust mite extract activates apical Cl(-) channels through protease-activated receptor 2 in human airway epithelia.
Adequate fluid secretion from airway mucosa is essential for maintaining mucociliary clearance, and fluid hypersecretion is a prominent feature of inflammatory airway diseases such as allergic rhinitis. House dust mite extract (HDM) has been reported to activate protease-activated receptors (PARs), which play various roles in airway epithelia. However, the role of HDM in regulating ion transporters and fluid secretion has not been investigated. We examined the effect of HDM on ion transport in human primary nasal epithelial cells. The Ca(2+)-sensitive dye Fura2-AM was used to determine intracellular Ca(2+) concentration ([Ca(2+)](i)) by means of spectrofluorometry in human normal nasal epithelial cells (NHNE). Short-circuit current (Isc) was measured using Ussing chambers. Fluid secretion from porcine airway mucosa was observed by optical measurement. HDM extract (10 microg/Ml) effectively cleaved the PAR-2 peptide and induced an increase of [Ca(2+)](i) that was abolished by desensitization with trypsin, but not with thrombin. Apical application of HDM-induced Isc sensitive to both a cystic fibrosis transmembrane conductance regulator (CFTR) inhibitor and a Ca(2+)-activated Cl(-) channel (CaCC) inhibitor. HDM extract also stimulated fluid secretion from porcine airway mucosa. HDM extract activated PAR-2 and apical Cl(-) secretion via CaCC and CFTR, and HDM-induced fluid secretion in porcine airway mucosa. Our results suggest a role for PAR-2 in mucociliary clearance and fluid hypersecretion of airway mucosa in response to air-borne allergens such as HDM. PMID:20186875
Cho, Hyung-Ju; Choi, Jae Young; Yang, Yu-Mi; Hong, Jeong Hee; Kim, Chang-Hoon; Gee, Heon Young; Lee, Hyun Jae; Shin, Dong Min; Yoon, Joo-Heon
House dust mite allergen activates human eosinophils via formyl peptide receptor and formyl peptide receptor-like 1.
The objective was to evaluate which receptors house dust mite (HDM) and birch pollen extracts engage to activate human eosinophils. Chemotaxis and degranulation were studied in eosinophils pretreated with pertussis toxin and other antagonists of G protein-coupled receptors, e.g. the formyl peptide receptor (FPR), CC chemokine receptor 3 (CCR3) and leukotriene receptor B4 (LTB(4)R). Inhibition of the FPR as well as desensitization of the receptor rendered eosinophils anergic to activation by the allergens. Blockade of CCR3 or LTB(4)R did not affect eosinophilic reactivity. It was determined by PCR that human eosinophils express the FPR family members FPR and FPR-like 1 (FPRL1). HDM, unlike birch pollen, evoked calcium fluxes in HL-60 cells transfected with FPR or FPRL1. Although both allergens gave rise to calcium transients in neutrophils, which also express FPR and FPRL1, only the HDM response was decreased by the FPR antagonist. Moreover, neutrophils migrated toward HDM but not to birch pollen. Eosinophils pretreated with inhibitors of MAPK p38, ERK1/2 or protein kinase C exhibited diminished responsiveness to the aeroallergens. This study indicates that FPR and FPRL1 mediate the activation of eosinophils by HDM, whereas birch pollen employs other pathways shared with FPR to activate human eosinophils. PMID:17559171
Svensson, Lena; Redvall, Elin; Bj�rn, Camilla; Karlsson, Jennie; Bergin, Ann-Marie; Rabiet, Marie-Jos�phe; Dahlgren, Claes; Wenner�s, Christine
House-dust mite allergen and ozone exposure decreases histamine H3 receptors in the brainstem respiratory nuclei.
Allergic airway diseases in children are a common and a growing health problem. Changes in the central nervous system (CNS) have been implicated in contributing to some of the symptoms. We hypothesized that airway allergic diseases are associated with altered histamine H3 receptor expression in the nucleus tractus solitarius (NTS) and caudal spinal trigeminal nucleus, where lung/airway and nasal sensory afferents terminate, respectively. Immunohistochemistry for histamine H3 receptors was performed on brainstem sections containing the NTS and the caudal spinal trigeminal nucleus from 6- and 12-month-old rhesus monkeys who had been exposed for 5 months to house dust mite allergen (HDMA)+O3 or to filtered air (FA). While histamine H3 receptors were found exclusively in astrocytes in the caudal spinal trigeminal nucleus, they were localized to both neuronal terminals and processes in the NTS. HDMA+O3 exposure significantly decreased histamine H3 receptor immunoreactivity in the NTS at 6 months and in the caudal spinal trigeminal nucleus at 12 months of age. In conclusion, exposing young primates to HDMA+O3 changed histamine H3 receptor expression in CNS pathways involving lung and nasal afferent nerves in an age-related manner. Histamine H3 receptors may be a therapeutic target for allergic asthma and rhinitis in children. PMID:20600210
Sekizawa, Shin-ichi; Bechtold, Andrea G; Tham, Rick C; Kott, Kayleen S; Hyde, Dallas M; Joad, Jesse P; Bonham, Ann C
House dust mite allergen induces asthma via Toll-like receptor 4 triggering of airway structural cells.
Barrier epithelial cells and airway dendritic cells (DCs) make up the first line of defense against inhaled substances such as house dust mite (HDM) allergen and endotoxin (lipopolysaccharide, LPS). We hypothesized that these cells need to communicate with each other to cause allergic disease. We show in irradiated chimeric mice that Toll-like receptor 4 (TLR4) expression on radioresistant lung structural cells, but not on DCs, is necessary and sufficient for DC activation in the lung and for priming of effector T helper responses to HDM. TLR4 triggering on structural cells caused production of the innate proallergic cytokines thymic stromal lymphopoietin, granulocyte-macrophage colony-stimulating factor, interleukin-25 and interleukin-33. The absence of TLR4 on structural cells, but not on hematopoietic cells, abolished HDM-driven allergic airway inflammation. Finally, inhalation of a TLR4 antagonist to target exposed epithelial cells suppressed the salient features of asthma, including bronchial hyperreactivity. Our data identify an innate immune function of airway epithelial cells that drives allergic inflammation via activation of mucosal DCs. PMID:19330007
Hammad, Hamida; Chieppa, Marcello; Perros, Frederic; Willart, Monique A; Germain, Ronald N; Lambrecht, Bart N
Correlation of house dust mite�specific lymphocyte proliferation with IL5 production, eosinophilia, and the severity of symptoms in infants with atopic dermatitis
Because house dust mite (HDM)�specific IgE antibody (IgE-RAST) is usually not detectable in infants with atopic dermatitis (AD), HDM has not been regarded as the cause of infantile AD. The level of HDM�specific lymphocyte proliferation (expressed as stimulation index measured by flow cytometry [SIF]), however, was found to be markedly elevated in AD infants. This suggests that the sensitization of
Mitsuaki Kimura; Satoru Tsuruta; Takami Yoshida
Determination of parabens in house dust by pressurised hot water extraction followed by stir bar sorptive extraction and thermal desorption-gas chromatography-mass spectrometry.
This study describes the development of a new method for determining p-hydroxybenzoic esters (parabens) in house dust. This optimised method was based on the pressurised hot water extraction (PHWE) of house dust, followed by the acetylation of the extracted parabens, stir bar sorptive extraction (SBSE) with a polydimethylsiloxane stir bar, and finally analysis using thermal desorption-gas chromatography-mass spectrometry (TD-GC-MS). The combination of SBSE and PHWE allows the analytes to be preconcentrated and extracted from the aqueous extract in a single step with minimal manipulation of the sample. Furthermore the in situ acetylation of parabens prior to SBSE improved their extraction efficiency and their GC-MS signal. The method showed recoveries of between 40 and 80%, good linearity, repeatability and reproducibility (<10% RSD, at 100 ng g(-1), n=5), low limits of detection (from 1.0 ng g(-1) for propyl paraben to 2.1 ng g(-1) for methyl paraben) and quantification (from 3.3 ng g(-1) for propyl paraben to 8.5 ng g(-1) for methyl paraben). The proposed method was applied to the analysis of house dust samples. All the target parabens were found in the samples. Methyl and propyl parabens were the most abundant, with concentrations up to 2440 ng g(-1) and 910 ng g(-1), respectively. The high levels of parabens found in the samples confirm the importance of determining organic contaminants in indoor environments. PMID:21802088
Ram�rez, Noelia; Marc�, Rosa Maria; Borrull, Francesc
Origin and patterns of distribution of trace elements in street dust: Unleaded petrol and urban lead
The elemental composition, patterns of distribution and possible sources of street dust are not common to all urban environments, but vary according to the peculiarities of each city. The common features and dissimilarities in the origin and nature of street dust were investigated through a series of studies in two widely different cities, Madrid (Spain) and Oslo (Norway), between 1990
Eduardo de Miguel; Juan F. Llamas; Enrique Chac�n; Torunn Berg; Steinar Larssen; Oddvar R�yset; Marit Vadset
Proteolytic Activity Present in House-Dust-Mite Extracts Degrades ENA-78/CXCL5 and Reduces Neutrophil Migration
Background. Bronchial smooth muscle cells (BSMC) are a major source of proinflammatory and proangiogenic cytokines and chemokines, including VEGF and CXC-chemokines. CXC-chemokines act primarily on neutrophils, mediating their recruitment to and activation at the site of inflammation. In humans, house-dust mite (HDM) allergens can cause asthmatic exacerbations and trigger an inflammatory response through protease-dependent mechanisms. Objective. We investigated the effect HDM extract on the release of pro-angiogenic and proinflammatory cytokines from BSMC. Methods. Human primary BSMC were stimulated with HDM extract in the absence or presence of fetal calf serum (FCS). Twenty angiogenic cytokines were detected by a specific antibody array and modified protein levels were confirmed by ELISA. Neutrophil migration was measured using a 96-well Boyden chamber. Results. ENA-78/CXCL5 protein levels in conditioned medium of BSMC stimulated with HDM extract were significantly reduced (n = 10, P < 0.05) but restored in the presence of 5% FCS. HDM extracts did not affect ENA-78/CXCL5 mRNA levels. Recombinant ENA-78/CXCL5 was degraded after incubation with HDM extracts (n = 7, P < 0.05) but restored after the addition of the serine protease AEBSF. Neutrophil migration towards recombinant ENA-78/CXCL5 was also reduced in the presence of HDM extract. Conclusion. HDM proteases degrade ENA-78/CXCL5. Thus exposure to HDM allergens may alter ENA-78/CXCL5 levels in the lungs and may affect angiogenesis and the inflammatory response in the airways of asthma patients.
Keglowich, Laura; Tamm, Michael; Zhong, Jun; Miglino, Nicola; Borger, Pieter
Oncostatin M synergises with house dust mite proteases to induce the production of PGE2 from cultured lung epithelial cells
The release of PGE2 and nitric oxide (NO) from the respiratory epithelium may act to dampen inflammation. In other tissues, oncostatin M (OSM), a potent inducer of epithelial antiproteases, has also been shown to interact with IL-1? to stimulate PGE2 release. However, whether OSM interacts with pro-inflammatory cytokines and proteases in the production of anti-inflammatory eicosanoids and NO from airway epithelium is unknown.The effect of OSM and the related cytokine leukaemia inhibitory factor (LIF) on PGE2 and NO production by the respiratory epithelial cell line, A549 in response to pro-inflammatory cytokines as well as protease-rich house dust mite (HDM) fractions and a protease-deficient rye grass pollen extract was examined by immunohistochemistry, cell culture, ELISA and enzyme-immunoassay.Cells treated with a mixture of IL-1?, IFN? and LPS for 48?h produced a 9 fold increase in PGE2 and a 3 fold increase in NO levels (both P<0.05). Both OSM and LIF were without effect. However, OSM added together with the cytokine mixture synergistically enhanced PGE2 production (22 fold, P<0.05). OSM also synergistically enhanced PGE2 production in response to a cysteine protease-enriched, but not serine protease-enriched HDM fraction (P<0.05). Rye grass extract, neither alone nor in combination with OSM, induced PGE2 or NO production, although it did induce the release of GM-CSF.These observations suggest that OSM is an important co-factor in the release of PGE2 and NO from respiratory epithelial cells and may play a role in defense against exogenous proteases such as those derived from HDM.
Knight, Darryl A; Asokananthan, Nithiananthan; Watkins, D Neil; Misso, Neil L A; Thompson, Philip J; Stewart, Geoffrey A
High Degree of Overlap between Responses to a Virus and to the House Dust Mite Allergen in Airway Epithelial Cells
Background Airway epithelium is widely considered to play an active role in immune responses through its ability to detect changes in the environment and to generate a microenvironment for immune competent cells. Therefore, besides its role as a physical barrier, epithelium affects the outcome of the immune response by the production of various pro-inflammatory mediators. Methods We stimulated airway epithelial cells with viral double stranded RNA analogue poly(I:C) or with house dust mite in a time course of 24 hours. In order to determine cytokines production by stimulated cells, we performed multiplex enzyme linked immunosorbant assay (ELISA). Results We demonstrate that the temporal pattern of the genes that respond to virus exposure in airway epithelium resembles to a significant degree their pattern of response to HDM. The gene expression pattern of EGR1, DUSP1, FOSL1, JUN, MYC, and IL6 is rather similar after viral (poly(I:C)) and HDM exposure. However, both triggers also induce a specific response (e.g. ATF3, FOS, and NFKB1). We confirmed these data by showing that epithelial cells produce a variety of similar mediators in response to both poly(I:C) and HDM challenge (IL1-RA, IL-17, IFN-? and MIP1-?), sometimes with a quantitative difference in response (IL2-R, IL-6, IL-8, MCP-1, MIG, and HGF). Interestingly, only four mediators (IL-12, IP-10, RANTES and VEGF) where up-regulated specifically by poly(I:C) and not by HDM. Additionally, we report that pre-exposure to HDM deregulates production of cytokines and mediators in response to poly(I:C). Conclusions Epithelial cells responses to the HDM-allergen and a virus strongly resemble both in gene expression and in protein level explaining why these two responses may affect each other.
Golebski, Korneliusz; Luiten, Silvia; van Egmond, Danielle; de Groot, Esther; Roschmann, Kristina Irene Lisolette; Fokkens, Wytske Johanna; van Drunen, Cornelis Maria
Characteristics and management of sublingual allergen immunotherapy in children with allergic rhinitis and asthma induced by house dust mite allergens
Background Allergen immunotherapy is a recognised intervention in patients with allergies not responding to standard pharmacotherapy or in whom pharmacotherapy is contraindicated. We describe the sublingual immunotherapy (SLIT) regimens used in children and adolescents with house dust mite (HDM) respiratory allergies in France and assess the efficacy and safety of this treatment. Methods This was a sub-analysis of paediatric patients included in a previous retrospective, observational, multicentre study. Inclusion criteria were: age 5�17 years; respiratory allergy and proven sensitisation to HDM; at least 2�years follow-up after SLIT initiation. The following data were recorded at SLIT initiation: clinical characteristics; sensitisation profile; concomitant symptomatic medications; details of SLIT protocol. During follow-up and at the end of treatment the following data were recorded: any changes to SLIT treatment; any changes to symptomatic medications; symptom progression; adverse events. SLIT efficacy, patient compliance and satisfaction, and safety were assessed. Results 736 paediatric patients were included in this analysis. Most patients (95.5%) had allergic rhinitis, which was moderate to severe persistent in 62.8%. Allergic asthma was present in 64.0% and was mild to moderate persistent in 52.7% of these patients. The majority of patients had rhinitis with asthma (59.5%). Three-hundred and seventy five (62.3%) patients were polysensitised. Compliance was good in 86.5% of patients and SLIT was effective in 83.8%. Symptoms of rhinitis and asthma were improved in 64.6% and 64.3% of patients, respectively. A decrease in symptomatic medication was observed following SLIT initiation in patients with rhinitis and/or asthma. SLIT was well tolerated with mainly local reactions reported. Conclusions HDM SLIT appears to be effective in children and adolescents with rhinitis and/or asthma due to HDM allergens, with no tolerability issues and similar benefits as in adults.
Morus alba L. suppresses the development of atopic dermatitis induced by the house dust mite in NC/Nga mice
Background Morus alba, a medicinal plant in Asia, has been used traditionally to treat diabetes mellitus and hypoglycemia. However, the effects of M. alba extract (MAE) on atopic dermatitis have not been verified scientifically. We investigated the effects of MAE on atopic dermatitis through in vitro and in vivo experiments. Methods We evaluated the effects of MAE on the production of nitric oxide (NO) and prostaglandin E2 (PGE2) in RAW 264.7, as well as thymus and activation-regulated chemokine (TARC/CCL17) in HaCaT cells. In an in vivo experiment, atopic dermatitis was induced by topical application of house dust mites for four weeks, and the protective effects of MAE were investigated by measuring the severity of the skin reaction on the back and ears, the plasma levels of immunoglobulin E (IgE) and histamine, and histopathological changes in the skin on the back and ears. Results MAE suppressed the production of NO and PGE2 in RAW 264.7 cells, as well as TARC in HaCaT cells, in a dose-dependent manner. MAE treatment of NC/Nga mice reduced the severity of dermatitis and the plasma levels of IgE and histamine. MAE also reduced the histological manifestations of atopic dermatitis-like skin lesions such as erosion, hyperplasia of the epidermis and dermis, and inflammatory cell infiltration in the skin on the back and ears. Conclusion Our results suggest that MAE has potent inhibitory effects on atopic dermatitis-like lesion and may be a beneficial natural resource for the treatment of atopic dermatitis.
Absence of c-Jun NH2-terminal kinase 1 protects against house dust mite-induced pulmonary remodeling but not airway hyperresponsiveness and inflammation.
Chronic allergic asthma leads to airway remodeling and subepithelial fibrosis via mechanisms not fully understood. Airway remodeling is amplified by profibrotic mediators, such as transforming growth factor-?1 (TGF-?1), which plays a cardinal role in various models of fibrosis. We recently have identified a critical role for c-Jun-NH2-terminal-kinase (JNK) 1 in augmenting the profibrotic effects of TGF-?1, linked to epithelial-to-mesenchymal transition of airway epithelial cells. To examine the role of JNK1 in house dust mite (HDM)-induced airway remodeling, we induced allergic airway inflammation in wild-type (WT) and JNK1-/- mice by intranasal administration of HDM extract. WT and JNK1-/- mice were sensitized with intranasal aspirations of HDM extract for 15 days over 3 wk. HDM caused similar increases in airway hyperresponsiveness, mucus metaplasia, and airway inflammation in WT and JNK1-/- mice. In addition, the profibrotic cytokine TGF-?1 and phosphorylation of Smad3 were equally increased in WT and JNK1-/- mice. In contrast, increases in collagen content in lung tissue induced by HDM were significantly attenuated in JNK1-/- mice compared with WT controls. Furthermore HDM-induced increases of ?-smooth muscle actin (?-SMA) protein and mRNA expression as well as the mesenchymal markers high-mobility group AT-hook 2 and collagen1A1 in WT mice were attenuated in JNK1-/- mice. The let-7 family of microRNAs has previously been linked to fibrosis. HDM exposure in WT mice and primary lung epithelial cells resulted in striking decreases in let-7g miRNA that were not observed in mice or primary lung epithelial cells lacking JNK1-/- mice. Overexpression of let-7g in lung epithelial cells reversed the HDM-induced increases in ?-SMA. Collectively, these findings demonstrate an important requirement for JNK1 in promoting HDM-induced fibrotic airway remodeling. PMID:24610935
van der Velden, Jos L J; Hoffman, Sidra M; Alcorn, John F; Tully, Jane E; Chapman, David G; Lahue, Karolyn G; Guala, Amy S; Lundblad, Lennart K A; Aliyeva, Minara; Daphtary, Nirav; Irvin, Charles G; Janssen-Heininger, Yvonne M W
The role of interleukin-4Ralpha in the induction of glutamic acid decarboxylase in airway epithelium following acute house dust mite exposure.
Background Asthma is a disease characterized by airway inflammation, remodelling and dysfunction. Airway inflammation contributes to remodelling, a term that is used to describe structural changes including goblet cell metaplasia (GCM), matrix deposition, and smooth muscle hyperplasia/hypertrophy. GCM has been implicated in asthma mortality by contributing to mucus plugs and leading to asphyxiation. In animal models, this process is highly dependent on IL-13. Recently, we have described an IL-13-dependent up-regulation of a GABAergic signalling system in airway epithelium that contributes to GCM. The mechanism by which IL-13 up-regulates GABA signalling in airway epithelium is unknown. Objectives To test the hypothesis that IL-4Ralpha signalling is required for allergen induced up-regulation of GABAergic signalling and GCM. Methods BALB/c mice were exposed to an acute house dust mite (HDM) protocol and received vehicle, anti-IL-4Ralpha-monoclonal antibody, or control antibody. Outcomes included airway responses to inhaled methacholine (MCh), histology for eosinophilia and GCM, phosphorylated STAT6 levels using immunohistochemistry and immunoblot, and glutamic acid decarboxylase (GAD) 65/67 and GABA(A)beta(2/3) receptor subunit expression using confocal microscopy. Results Acute HDM exposure resulted in increased airway responses to MCh, lung eosinophilia, STAT6 phosphorylation, elevations in GAD65/67 and GABA(A)beta(2/3) receptor expression, and GCM that were inhibited with anti-IL-4Ralpha-monoclonal treatment. Control antibody had no effect. Conclusion The IL-4Ralpha is required for allergen-induced up-regulation of a GABAergic system in airway epithelium implicated in GCM following acute HDM exposure. PMID:20337645
Hirota, J A; Budelsky, A; Smith, D; Lipsky, B; Ellis, R; Xiang, Y-Y; Lu, W-Y; Inman, M D
77 FR 16796 - Lead Requirements for Lead-Based Paint Activities in Target Housing and Child-Occupied Facilities...
Federal Register 2010, 2011, 2012, 2013
...engaged in lead-based paint activities...administer and enforce training and certification requirements, training program accreditation...standards for lead-based paint activities in...Legislature, in the Regular Session of the 88th...
The correlations between heavy metals in residential indoor dust and outdoor street dust in Bahrain
The lead, zinc, cadmium, chromium, and nickel contents in both indoor house dust and outdoor street dust from 76 sites in Bahrain were determined by ICP-ES. The results showed widespread heavy metal contamination, especially lead, with an overall mean value in house dust for Pb, Zn, Cd, Cr, and Ni of 517, 202, 1.9, 11, and 10, respectively. The mean values in street dust were 742, 67, 1.5, 9.6, and 12 mg/kg, respectively. The major source of metals in street dust was automobile exhaust. The major source of heavy metals indoors was also from automobile dust, i.e., lead and nickel. With respect to zinc, cadmium, and chromium, indoor sources were more important than outdoor sources. The distribution of lead both indoors and outdoors in Bahrain showed high levels of contamination occurring generally in the north and northeastern part where traffic is concentrated. The levels of these toxic metals found in indoor house dust may be a significant source of exposure, especially for children.
Madany, I.M. (Arabian Gulf Univ. (Bahrain)); Akhter, M.S.; Al Jowder, O.A. (Univ. of Bahrain (Bahrain))
Impact of dust filter installation in ironworks and construction on brownfield area on the toxic metal concentration in street and house dust (Celje, Slovenia).
This article presents the impact of the ecological investment in ironworks (dust filter installation) and construction works at a highly contaminated brownfield site on the chemical composition of household dust (HD) and street sediment (SS) in Celje, Slovenia. The evaluation is based on two sampling campaigns: the first was undertaken 1 month before the ecological investment became operational and the second 3 years later. The results show that dust filter installations reduced the content of Co, Cr, Fe, Mn, Mo, W and Zn on average by 58% in HD and by 51% in SS. No reduction was observed at sampling points in the upwind direction from the ironworks. By contrast, the impact of the construction works on the highly contaminated brownfield site was detected by a significant increase (on average by 37%) of elements connected to the brownfield contamination in SS. Such increase was not detected in HD. PMID:22535428
Zibret, Gorazd
Determinants of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans in house dust samples from four areas of the United States.
Determinants of levels of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/F) in dust in U.S. homes are not well characterized. We conducted a pilot study to evaluate the relationship between concentrations of PCDD/F in house dust and residential proximity to known sources, including industrial facilities and traffic. Samples from vacuum bag dust from homes of 40 residents of Detroit, Los Angeles, Seattle, or Iowa who participated in a population-based case-control study of non-Hodgkin lymphoma conducted in 1998-2000 were analyzed using high resolution gas chromatography/high resolution mass spectrometry for 7 PCDD and 10 PCDF congeners considered toxic by the U.S. Environmental Protection Agency (EPA). Locations of 10 types of PCDD/F-emitting facilities were obtained from the EPA; however only 4 types were located near study homes (non-hazardous waste cement kilns, coal-fired power plants, sewage sludge incinerators, and medical waste incinerators). Relationships between concentrations of each PCDD/F and proximity to industrial facilities, freight routes, and major roads were evaluated using separate multivariate regression models for each congener. The median (inter-quartile range [IQR]) toxic equivalence (TEQ) concentration of these congeners in the house dust was 20.3 pg/g (IQR=14.3, 32.7). Homes within 3 or 5 km of a cement kiln had 2 to 9-fold higher concentrations of 5 PCDD and 5 PCDF (p<0.1 in each model). Proximity to freight routes and major roads was associated with elevated concentrations of 1 PCDD and 8 PCDF. Higher concentrations of certain PCDD/F in homes near cement kilns, freight routes, and major roads suggest that these outdoor sources are contributing to indoor environmental exposures. Further study of the contribution of these sources and other facility types to total PCDD/F exposure in a larger number of homes is warranted. PMID:22832089
Deziel, N C; Nuckols, J R; Colt, J S; De Roos, A J; Pronk, A; Gourley, C; Severson, R K; Cozen, W; Cerhan, J R; Hartge, P; Ward, M H
Determinants of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans in house dust samples from four areas of the United States
Determinants of levels of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/F) in dust in U.S. homes are not well characterized. We conducted a pilot study to evaluate the relationship between concentrations of PCDD/F in house dust and residential proximity to known sources, including industrial facilities and traffic. Samples from vacuum bag dust from homes of 40 residents of Detroit, Los Angeles, Seattle, or Iowa who participated in a population-based case-control study of non-Hodgkin lymphoma conducted in 1998�2000 were analyzed using high resolution gas chromatography/high resolution mass spectrometry for 7 PCDD and 10 PCDF congeners considered toxic by the U.S. Environmental Protection Agency (EPA). Locations of 10 types of PCDD/F-emitting facilities were obtained from the EPA; however only 4 types were located near study homes (non-hazardous waste cement kilns, coal-fired power plants, sewage sludge incinerators, and medical waste incinerators). Relationships between concentrations of each PCDD/F and proximity to industrial facilities, freight routes, and major roads were evaluated using separate multivariate regression models for each congener. The median (inter-quartile range [IQR]) toxic equivalence (TEQ) concentration of these congeners in the house dust was 20.3 pg/g (IQR=14.3, 32.7). Homes within 3 or 5 km of a cement kiln had 2 to 9-fold higher concentrations of 5 PCDD and 5 PCDF (p<0.1 in each model). Proximity to freight routes and major roads was associated with elevated concentrations of 1 PCDD and 8 PCDF. Higher concentrations of certain PCDD/F in homes near cement kilns, freight routes, and major roads suggest these outdoor sources are contributing to indoor environmental exposures. Further study of the contribution of these sources and other facility types to total PCDD/F exposure in a larger number of homes is warranted.
NC, Deziel; Nuckols; JS, Colt; AJ, De Roos; A, Pronk; C, Gourley; RK, Severson; W, Cozen; Cerhan; P, Hartge; MH, Ward
The complete mitochondrial genome of the house dust mite Dermatophagoides pteronyssinus (Trouessart): a novel gene arrangement among arthropods
Background The apparent scarcity of available sequence data has greatly impeded evolutionary studies in Acari (mites and ticks). This subclass encompasses over 48,000 species and forms the largest group within the Arachnida. Although mitochondrial genomes are widely utilised for phylogenetic and population genetic studies, only 20 mitochondrial genomes of Acari have been determined, of which only one belongs to the diverse order of the Sarcoptiformes. In this study, we describe the mitochondrial genome of the European house dust mite Dermatophagoides pteronyssinus, the most important member of this largely neglected group. Results The mitochondrial genome of D. pteronyssinus is a circular DNA molecule of 14,203 bp. It contains the complete set of 37 genes (13 protein coding genes, 2 rRNA genes and 22 tRNA genes), usually present in metazoan mitochondrial genomes. The mitochondrial gene order differs considerably from that of other Acari mitochondrial genomes. Compared to the mitochondrial genome of Limulus polyphemus, considered as the ancestral arthropod pattern, only 11 of the 38 gene boundaries are conserved. The majority strand has a 72.6% AT-content but a GC-skew of 0.194. This skew is the reverse of that normally observed for typical animal mitochondrial genomes. A microsatellite was detected in a large non-coding region (286 bp), which probably functions as the control region. Almost all tRNA genes lack a T-arm, provoking the formation of canonical cloverleaf tRNA-structures, and both rRNA genes are considerably reduced in size. Finally, the genomic sequence was used to perform a phylogenetic study. Both maximum likelihood and Bayesian inference analysis clustered D. pteronyssinus with Steganacarus magnus, forming a sistergroup of the Trombidiformes. Conclusion Although the mitochondrial genome of D. pteronyssinus shares different features with previously characterised Acari mitochondrial genomes, it is unique in many ways. Gene order is extremely rearranged and represents a new pattern within the Acari. Both tRNAs and rRNAs are truncated, corroborating the theory of the functional co-evolution of these molecules. Furthermore, the strong and reversed GC- and AT-skews suggest the inversion of the control region as an evolutionary event. Finally, phylogenetic analysis using concatenated mt gene sequences succeeded in recovering Acari relationships concordant with traditional views of phylogeny of Acari.
Dermauw, Wannes; Van Leeuwen, Thomas; Vanholme, Bartel; Tirry, Luc
Department of Housing and Urban Development, Office of Healthy Homes and Lead Hazard Control
... Programs Lead Hazard Control and Lead Hazard Reduction Demonstration grants Healthy Homes Technical Studies Grant Lead Technical Studies grant Healthy Homes Demonstration grant Helpful Resources The National Lead Information Center ( ...
Thermodynamical computations for removal of alkali halides and lead compounds from electric arc furnace dust
Thermodynamical aspects of a separation process, proposed by the authors for the removal of volatile species from EAF dust, have been studied. Computations have been performed using FACT (Facility for Analysis of Chemical Thermodynamics) software. Different conditions have been considered through calculations of equilibrium state. Effects of different additives, temperature and atmosphere at different total pressure were investigated. It has
Ahad Zabett; Wei-Kao Lu
Addressing Lead-Based Paint Hazards During Renovation, Remodeling, and Rehabilitation in Federally Owned and Assisted Housing. Instructor Manual for Use in HUD-Sponsored Lead-Safe Work Practices Training.
ERIC Educational Resources Information Center
This document is the instructor's manual for a U.S. Department of Housing and Urban Development (HUD) training course that reflects the requirements of HUD's Lead Safe Housing Rule and is designed to provide training contractors with information regarding containment, minimization, and cleanup of lead hazards during activities that disturb�
Environmental Protection Agency, Washington, DC. Office of Pollution Prevention and Toxics.
Road Dust Lead (Pb) in Two Neighborhoods of Urban Atlanta, (GA, USA)
Road dust continues to be a major potential reservoir of Pb in the urban environment, and an important potential component of child Pb exposure. This study presents ICP-AES analyses of metals in 72 samples of road dust (<250 �m) collected in the urban core of Atlanta, Georgia. In the Downtown area, median Pb concentrations are ~63 mg/kg Pb, with high values of 278 mg/kg. For comparison, median Pb values in a nearby residential neighborhood (also in the urban core) were ~93 mg/kg, with a high of 972 mg/kg. Geospatial variability is high, with significant variation observed over tens to hundreds of meters. Spearman Rank Correlation tests suggest that Pb and other metals (Cu, Ni, V, Zn) are associated with iron and manganese oxide phases in the residential area, as reported in other cities. However, Pb in the Downtown area is not correlated with the others, suggesting a difference in source or transport history. Given these complexities and the expected differences between road dust and soil Pb, future efforts to assess exposure risk should therefore be based on spatially distributed sampling at very high spatial resolution.
Deocampo, Daniel M.; Reed, Jack; Kalenuik, Alexander P.
House dust mite potentiates capsaicin-evoked Ca2+ transients in mouse pulmonary sensory neurons via activation of protease-activated receptor-2
House dust mite (HDM) is a major source of allergen in house dust and has been suggested to be involved in the pathogenesis of asthma. In this study, we aimed to investigate whether HDM can modulate the sensitivity of pulmonary sensory neurons, and if so, to elucidate the underlying mechanism. Fura-2 based ratiometric Ca2+ imaging was carried out to determine the effect of HDM extract on the capsaicin-evoked Ca2+ transient in mouse vagal pulmonary sensory neurons. Pretreatment with HDM (50 ?g/ml, 5 min) significantly enhanced the Ca2+ transient evoked by capsaicin in these neurons isolated from wildtype mice. This potentiating effect of HDM was not antagonized by E-64, a selective cysteine protease inhibitor, but was completely prevented by AEBSF, a specific serine protease inhibitor. In addition, the potentiating effect of HDM on capsaicin-evoked Ca2+ transient was absent in the pulmonary sensory neurons isolated from protease-activated receptor-2 (PAR2) knockout mice. Further, the sensitizing effect of HDM was completely abolished by U73122, a PLC inhibitor, or chelerythrine, a PKC inhibitor. In summary, our results demonstrate that HDM, mainly through its serine protease activity, potentiates capsaicin-evoked Ca2+ transient in mouse pulmonary sensory neurons via the activation of PAR2 and PLC-PKC intracellular transduction cascade.
Gu, Qihai; Lee, Lu-Yuan
House dust mite potentiates capsaicin-evoked Ca2+ transients in mouse pulmonary sensory neurons via activation of protease-activated receptor-2.
House dust mite (HDM) is a major source of allergen in house dust and has been suggested to be involved in the pathogenesis of asthma. In this study, we aimed to investigate whether HDM can modulate the sensitivity of pulmonary sensory neurons and, if so, to elucidate the underlying mechanism. Fura-2-based ratiometric Ca(2+) imaging was carried out to determine the effect of HDM extract on the capsaicin-evoked Ca(2+) transient in mouse vagal pulmonary sensory neurons. Pretreatment with HDM (50 ?g ml(-1), 5 min) significantly enhanced the Ca(2+) transient evoked by capsaicin in these neurons isolated from wild-type mice. This potentiating effect of HDM was not antagonized by E-64, a selective cysteine protease inhibitor, but was completely prevented by AEBSF, a specific serine protease inhibitor. In addition, the potentiating effect of HDM on capsaicin-evoked Ca(2+) transient was absent in the pulmonary sensory neurons isolated from protease-activated receptor-2 (PAR(2)) knockout mice. Furthermore, the sensitizing effect of HDM was completely abolished by U73122, a phosholipase C inhibitor, or chelerythrine, a protein kinase C inhibitor. In summary, our results demonstrate that HDM, mainly through its serine protease activity, potentiates capsaicin-evoked Ca(2+) transient in mouse pulmonary sensory neurons via the activation of PAR(2) and the phosholipase C-protein kinase C intracellular transduction cascade. PMID:22125310
Gu, Qihai; Lee, Lu-Yuan
Prevalence of house dust mites and dermatophagoides group 1 antigens collected from bedding, skin and hair coat of dogs in south-west England.
The house dust mites Dermatophagoides farinae (Df) and D. pteronyssinus (Dpt) are commonly implicated as allergens causing canine atopic dermatitis in the UK. However, there are few studies that characterize the exposure of UK pet dogs to these mites. The objectives of this study were to determine the prevalence of the mite species on the skin, hair coat and bedding of a population of pet dogs. Dust samples (n = 68) were collected from both dogs and their beds using a standardized vacuuming technique and stored at -20 degrees C. Mites were identified using accepted morphological criteria. House dust mite allergen concentrations were assayed using standardized ELISA for Dpt and Df group 1 allergens (Der p 1 and Der f 1). Mites were identified in 15/68 samples (22%) and Dpt was the most common. Df mites were not present. Der p 1 allergens were detected in 60% of samples, and Der f 1 in 6% of samples. There were no significant differences between the number of Der p 1 positive samples from dogs and the number of those from their bedding, or between the average Der p 1 concentrations from dogs and the number of those from their bedding. Contrary to studies elsewhere in Europe and the USA, these findings support studies of human asthma patients in the UK, where exposure to Df is rare, but to Dpt is common. As the prevalence of positive intradermal and serological reactions to Df in atopic dogs is high, further investigations are warranted to clarify true Df hypersensitivity or potential immunological cross-reactivity between mite allergens. PMID:15725103
Jackson, Anna P; Foster, Aiden P; Hart, Barbara J; Helps, Chris R; Shaw, Susan E
Cycling of Lead Through Soil, Air, and Household Dust in El Paso, Texas
Elimination of leaded gasoline in the US is associated with a dramatic overall decrease in ambient lead in the environment and blood lead levels in our population. However, Pb is such a potent neurotoxin for children during the formative growth years that legislation for additional reduction of airborne lead levels is under consideration. X-ray absorption spectroscopy of a suite of
N. E. Pingitore; J. Clague; M. A. Amaya
Comparative assessment of human exposure to phthalate esters from house dust in China and the United States.
Because of volatilization and leaching from their application in consumer and personal care products, phthalate esters are ubiquitous contaminants in the indoor environment. In this study, we measured concentrations and profiles of 9 phthalate esters in indoor dust samples collected from six cities in China (n = 75). For comparison, we also analyzed samples collected from Albany, New York, USA (n = 33). The results indicated that concentrations, except for dicyclohexyl phthalate (DCHP) and bis(2-ethylhexyl) phthalate (DEHP), and profiles of phthalate esters varied significantly between the two countries. Concentrations of diethyl phthalate (DEP), di-n-hexyl phthalate (DNHP), and benzyl butyl phthalate (BzBP) were 5 to 10 times higher in dust samples collected from Albany than those from the Chinese cities. In contrast, concentrations of di-iso-butyl phthalate (DIBP) in dust samples from Albany were 5 times lower than those from the Chinese cities. We estimated the daily intake (DI) of phthalate esters through the routes of dust ingestion and dermal dust absorption. The extent of contribution of indoor dust to human exposures varied, depending on the type of phthalate esters. The contribution of dust to DEHP exposure was 2-5% and 10-58% of the estimated total DIs in China and the USA, respectively. On the basis of the estimates of total DIs of phthalates, extrapolated from urinary metabolite concentrations, the contributions of inhalation, dermal absorption, and dietary intake to total DIs were estimated. The results indicated that dietary intake is the main source of exposure to DEHP (especially in China), whereas dermal exposure was a major source for DEP. This is the first study to elucidate sources of human exposure to phthalates among the general population in China. PMID:21434628
Guo, Ying; Kannan, Kurunthachalam
Removal of lead by using Raschig rings manufactured with mixture of cement kiln dust, zeolite and bentonite.
The present investigation is a follow-up of study on manufacturing Raschig ring for removal of lead from aqueous solution. The mixtures were formulated using cement kiln dust, zeolite, and bentonite, normally used as natural adsorbents in the industrial scale, according to mixture design algorithm and response surface method. The pastes were prepared by addition of 28.0wt.% de-ionized water, containing 0.1wt.% carboxymethyl cellulose, with mixed powders. The adsorbents were fabricated by extrusion of the pastes in Raschig ring form and calcination at 500�C after drying in oven. The effects of starting materials on the mechanical behavior of rings were studied from view point of mixture design algorithm to optimize the adsorbent composition. This method demonstrated to yield valuable information on the effects of used materials on mechanical characteristics. The study concluded that the strength, reliability and sorption capacity of ring can be simultaneously optimized by the addition of 47.5wt.% cement kiln dust, 32.5wt.% zeolite, and 20.0wt.% bentonite. In the next part of work, the sorption kinetics was investigated. The kinetic study indicated that the modified model can successfully correlate the sorption data. The equilibrium result showed the possibility of lead immobilization by fabricated rings. PMID:22608209
Salem, A; Afshin, H; Behsaz, H
Lead, mercury, cadmium, chromium, nickel, copper, zinc, calcium, iron, manganese and chromium (VI) levels in Nigeria and United States of America cement dust.
This study was aimed at investigating the relative abundance of heavy metals in cement dust from different cement dust factories in order to predict their possible roles in the severity of cement dust toxicity. The concentrations of total mercury (Hg), copper (Cu), chromium (Cr), cadmium (Cd), nickel (Ni), manganese (Mn), lead (Pb), iron (Fe) and chromium (VI) (Cr (VI)) levels in cement dust and clinker samples from Nigeria and cement dust sample from the United States of America (USA) were determined using graphite furnace atomic absorption (GFAAS), while Zn and Ca were measured by flame atomic absorption spectrophotometry (FAAS), and Cr (VI) by colorimetric method. Total Cu, Ni and Mn were significantly higher in cement dust sample from USA (p<0.05), also, both total Cr and Cr (VI) were 5.4-26 folds higher in USA cement dust compared with Nigeria cement dust or clinker (p<0.001). Total Cd was higher in both Nigeria cement dust and clinker (p<0.05 and p<0.001), respectively. Mercury was more in both Nigeria cement dust and clinker (p<0.05), while Pb was only significantly higher in clinker from Nigeria (p<0.001). These results show that cement dust contain mixture of metals that are known human carcinogens and also have been implicated in other debilitating health conditions. Additionally, it revealed that metal content concentrations are factory dependent. This study appears to indicate the need for additional human studies relating the toxicity of these metals and their health impacts on cement factory workers. PMID:23261125
Ogunbileje, J O; Sadagoparamanujam, V-M; Anetor, J I; Farombi, E O; Akinosun, O M; Okorodudu, A O
Decreased mitochondrial DNA content in association with exposure to polycyclic aromatic hydrocarbons in house dust during wintertime: from a population enquiry to cell culture.
Polycyclic aromatic hydrocarbons (PAHs) are widespread environmental pollutants that are formed in combustion processes. At the cellular level, exposure to PAHs causes oxidative stress and/or some of it congeners bind to DNA, which may interact with mitochondrial function. However, the influence of these pollutants on mitochondrial DNA (mtDNA) content remains largely unknown. We determined whether indoor exposure to PAHs is associated with mitochondrial damage as represented by blood mtDNA content. Blood mtDNA content (ratio mitochondrial/nuclear DNA copy number) was determined by real-time qPCR in 46 persons, both in winter and summer. Indoor PAH exposure was estimated by measuring PAHs in sedimented house dust, including 6 volatile PAHs and 8 non-volatile PAHs. Biomarkers of oxidative stress at the level of DNA and lipid peroxidation were measured. In addition to the epidemiologic enquiry, we exposed human TK6 cells during 24 h at various concentrations (range: 0 to 500 �M) of benzo(a)pyrene and determined mtDNA content. Mean blood mtDNA content averaged (� SD) 0.95 � 0.185. The median PAH content amounted 554.1 ng/g dust (25(th)-75(th) percentile: 390.7-767.3) and 1385 ng/g dust (25(th)-75(th) percentile: 1000-1980) in winter for volatile and non-volatile PAHs respectively. Independent for gender, age, BMI and the consumption of grilled meat or fish, blood mtDNA content decreased by 9.85% (95% CI: -15.16 to -4.2; p = 0.002) for each doubling of non-volatile PAH content in the house dust in winter. The corresponding estimate for volatile PAHs was -7.3% (95% CI: -13.71 to -0.42; p = 0.04). Measurements of oxidative stress were not correlated with PAH exposure. During summer months no association was found between mtDNA content and PAH concentration. The ability of benzo(a)pyrene (range 0 �M to 500 �M) to lower mtDNA content was confirmed in vitro in human TK6 cells. Based on these findings, mtDNA content can be a target of PAH toxicity in humans. PMID:23658810
Pieters, Nicky; Koppen, Gudrun; Smeets, Karen; Napierska, Dorota; Plusquin, Michelle; De Prins, Sofie; Van De Weghe, Hendrik; Nelen, Vera; Cox, Bianca; Cuypers, Ann; Hoet, Peter; Schoeters, Greet; Nawrot, Tim S
Decreased Mitochondrial DNA Content in Association with Exposure to Polycyclic Aromatic Hydrocarbons in House Dust during Wintertime: From a Population Enquiry to Cell Culture
Polycyclic aromatic hydrocarbons (PAHs) are widespread environmental pollutants that are formed in combustion processes. At the cellular level, exposure to PAHs causes oxidative stress and/or some of it congeners bind to DNA, which may interact with mitochondrial function. However, the influence of these pollutants on mitochondrial DNA (mtDNA) content remains largely unknown. We determined whether indoor exposure to PAHs is associated with mitochondrial damage as represented by blood mtDNA content. Blood mtDNA content (ratio mitochondrial/nuclear DNA copy number) was determined by real-time qPCR in 46 persons, both in winter and summer. Indoor PAH exposure was estimated by measuring PAHs in sedimented house dust, including 6 volatile PAHs and 8 non-volatile PAHs. Biomarkers of oxidative stress at the level of DNA and lipid peroxidation were measured. In addition to the epidemiologic enquiry, we exposed human TK6 cells during 24 h at various concentrations (range: 0 to 500 �M) of benzo(a)pyrene and determined mtDNA content. Mean blood mtDNA content averaged (�SD) 0.95�0.185. The median PAH content amounted 554.1 ng/g dust (25th�75th percentile: 390.7�767.3) and 1385ng/g dust (25th�75th percentile: 1000�1980) in winter for volatile and non-volatile PAHs respectively. Independent for gender, age, BMI and the consumption of grilled meat or fish, blood mtDNA content decreased by 9.85% (95% CI: ?15.16 to ?4.2; p?=?0.002) for each doubling of non-volatile PAH content in the house dust in winter. The corresponding estimate for volatile PAHs was ?7.3% (95% CI: ?13.71 to ?0.42; p?=?0.04). Measurements of oxidative stress were not correlated with PAH exposure. During summer months no association was found between mtDNA content and PAH concentration. The ability of benzo(a)pyrene (range 0 �M to 500 �M) to lower mtDNA content was confirmed in vitro in human TK6 cells. Based on these findings, mtDNA content can be a target of PAH toxicity in humans.
Pieters, Nicky; Koppen, Gudrun; Smeets, Karen; Napierska, Dorota; Plusquin, Michelle; De Prins, Sofie; Van De Weghe, Hendrik; Nelen, Vera; Cox, Bianca; Cuypers, Ann; Hoet, Peter; Schoeters, Greet; Nawrot, Tim S.
Anaphylaxis following the ingestion of flour contaminated by house dust mites--a report of two cases from Singapore.
This study presents two patients who developed anaphylaxis after eating mite-contaminated food, and also contains a survey of dust-mites contamination in flour samples from Singapore households. The clinical records of each patient was studied. Patient A developed anaphylaxis twenty minutes following the ingestion of home-made fried fish coated with Japanese flour, while Patient B developed similar life-threatening symptoms one hour after the ingestion of home baked scones. Both patients were NSAID-intolerant and had a history of allergic rhinitis. Skin prick tests showed a strong positive result for dust-mites and for extracts prepared from the ingested flour. Flour samples were also examined microscopically which revealed large numbers of live Dermatophagoides farinae dust-mites. A survey of 57 flour samples showed that 4 samples (7%) were contaminated with dust mites. The findings in the present study confirm that mite-contamination of flour exists in Singaporean households, and it may trigger anaphylaxis in susceptible individuals. PMID:19054935
Tay, S Y; Yan, Tay Sok; Tham, E; Elizabeth, Tham; Yeo, C T; Tzien, Yeo Chor; Yi, F C; Cheng, Yi Fong; Chen, J Y; Jiayi, Chen; Cheong, N; Nge, Cheong; Chua, K Y; Yan, Chua Kaw; Lee, B W; Wah, Lee Bee
The analytical methods were developed for the determination of PAH and PCBs in the dust and soil based on sonication with hexane and 10% ether/hexane, respectively, and analysis by gas chromatography/mass spectrometry (GC/MS). uantitative recoveries of spiked perdeuterated PAH an...
Development and field trial of a household surface lead loading rate sampling device in a lead-contaminated community of southern Thailand
A new dust-collecting device was developed to assess surface lead loading rates in houses in communities contaminated with\\u000a lead oxide dust used for caulking in nearby boat-repair yards. The device consists of two small glass sheets with total area\\u000a of 1,200�cm2 placed in two plastic trays suspended from the ceiling in the house for 3�months before wiping and sending the
Orrapan Untimanon; Alan Geater; Virasakdi Chongsuvivatwong; Somkiat Thoumsang; Pia K. Verkasalo; Wiyada Saetia
ABSTRAGT.--In urban environments, lead (Pb) has been recognized as a health threat to humans as well as wildlife. Although this hazard has waned since the banning of leaded gasoline and paint in the 1970s, soil and atmospheric Pb concentrations have remained higher in disturbed habitats than in exurban habitats. Our study evaluated the threat of Pb exposure to Sharp-shinned Hawks
Blood lead levels among rural Thai children exposed to lead-acid batteries from solar energy conversion systems.
We evaluate blood lead levels among Thai children to determine if exposure to lead-acid batteries is associated with elevated blood lead levels (EBLL). We screened 254 children aged 1-14 years old from 2 rural Thai villages for blood lead levels. We also screened 18 of 92 houses in these 2 villages for the presence of environmental lead. The overall prevalence of EBLL (> or = 10 microg/dl) was 43.3% and the mean lead level among study subjects was 9.8 +/- 5.1 microg/dl. The blood lead levels significantly decreased with increasing age. Fifty point eight percent of children who lived in a house with vented lead-acid batteries had EBLL while 23.3% of children who lived in a house without vented lead-acid batteries had EBLL. Multiple logistic regression analysis revealed a significant positive association between the presence of vented lead-acid batteries and EBLL, after adjusting for other variables. Forty-two point nine percent of house floor dust samples collected near the batteries had elevated lead levels, 7.1% of house floor dust samples collected from other areas in the house had elevated lead levels and 0% of the house floor dust samples collected in houses without vented lead-acid batteries had elevated lead levels. In the sampled houses with vented lead-acid batteries, lead contamination was found in the drinking-water kept in household containers, but not in the tap water or other village sources of water. Improper care and placement of vented lead-acid batteries can result in lead contamination in the home environment causing EBLL in exposed children. PMID:24450246
Swaddiwudhipong, Witaya; Tontiwattanasap, Worawit; Khunyotying, Wanlee; Sanreun, Cherd
Lead test kits offer a potentially rapid, inexpensive, and simple to use technique for the analysis of low levels of lead in paint, soil, and house dust. n order to assess the feasibility of homeowners and contractors using test kits as an indicator of the need for or success of ...
Major house dust mite allergens Dermatophagoides pteronyssinus 1 and Dermatophagoides farinae 1 degrade and inactivate lung surfactant proteins A and D.
Lung surfactant proteins (SP) A and D are calcium-dependent carbohydrate-binding proteins. In addition to playing multiple roles in innate immune defense such as bacterial aggregation and modulation of leukocyte function, SP-A and SP-D have also been implicated in the allergic response. They interact with a wide range of inhaled allergens, competing with their binding to cell-sequestered IgE resulting in inhibition of mast cell degranulation, and exogenous administration of SP-A and SP-D diminishes allergic hypersensitivity in vivo. House dust mite allergens are a major cause of allergic asthma in the western world, and here we confirm the interaction of SP-A and SP-D with two major mite allergens, Dermatophagoides pteronyssinus 1 and Dermatophagoides farinae 1, and show that the cysteine protease activity of these allergens results in the degradation of SP-A and SP-D under physiological conditions, with multiple sites of cleavage. A recombinant fragment of SP-D that is effective in diminishing allergic hypersensitivity in mouse models of dust mite allergy was more susceptible to degradation than the native full-length protein. Degradation was enhanced in the absence of calcium, with different sites of cleavage, indicating that the calcium associated with SP-A and SP-D influences accessibility to the allergens. Degradation of SP-A and SP-D was associated with diminished binding to carbohydrates and to D. pteronyssinus 1 itself and diminished capacity to agglutinate bacteria. Thus, the degradation and consequent inactivation of SP-A and SP-D may be a novel mechanism to account for the potent allergenicity of these common dust mite allergens. PMID:17848554
Deb, Roona; Shakib, Farouk; Reid, Kenneth; Clark, Howard
Acute lead intoxication in cattle housed in an old battery factory.
Six cows died 5 d after the owner put them in an old battery factory. The clinical symptoms were ataxia, blindness, rapid and difficult breathing, increased heart rate, tremors and coma. Necropsy was performed on 1 cow and pieces of metals were observed in the rumen. Serosal vessels of the rumen were hyperemic and slight fluid accumulation was observed in the abdominal cavity. Oedema was seen at the cerebrum. Severe necrosis and lipid accumulations were seen in the liver. All visceral organs were hyperemic. Zinc in the liver, kidney and lungs were 232, 103.5 and 97.3 ppm, respectively. Copper was 123.6 ppm in the liver 23.2 ppm in kidney and 11.8 ppm in lungs. The cadmium levels were normal, these were 66.7 ppm lead in liver, 80.5 ppm lead in kidneys and 35.8 ppm lead in lungs. PMID:15487647
Ozmen, Ozlem; Mor, Firdevs
Retrofit wall system for insulation and lead encasement in older multi-family housing.
This paper presents an approach to modernization or rehabilitation of buildings with uninsulated masonry walls that have lead-based paint hazards or deteriorated plaster walls. The approach provides a solution to lead contamination on the walls, increased energy efficiency and comfort improvements associated with better insulated building envelopes. The system sheaths or replaces damaged or contaminated walls with a tight, well-insulated, durable interior surface. The costs of this system are estimated to be less than those of other insulated wall systems. Modeling of the impact of this system shows significant improvement in energy performance. The energy savings over the life of this durable system contribute to significantly offset the often-times sizeable cost of lead hazard remediation.
Wendt, R. L.
Investigation of Test Kits for Detection of Lead in Paint, Soil and Dust.
National Technical Information Service (NTIS)
A study of commercial lead test kits available as of fall, 1990, was performed. The intent was to perform an initial study of the general behavior and responsiveness of all kits to the same but limited number of test parameters and materials. The manufact...
W. F. Gutknecht K. K. Luk L. L. Hodson J. A. O'Rourke D. S. Smith
Life in cellulose houses: Symbiotic bacterial biosynthesis of ascidian drugs and drug leads
Ascidians (tunicates; sea squirts) are sources of diverse, bioactive natural products, one of which is an approved drug and many of which are potent drug leads. It has been shown that symbiotic bacteria living with ascidians produce some of the bioactive compounds isolated from whole animals, and indirect evidence strongly implicates symbiotic bacteria in the synthesis of many others. However, for the majority the producing organism has not been identified. In cases where a symbiotic origin has been definitively assigned, the resulting data lead to improved paths to drug discovery and development from marine animals. This review traces evidence for symbiotic production where such evidence exists and describes the strengths and limitations of that evidence.
Schmidt, Eric W.; Donia, Mohamed S.
The Association between Asthma and Allergic Symptoms in Children and Phthalates in House Dust: A Nested Case-Control Study
Global phthalate ester production has increased from very low levels at the end of World War II to approximately 3.5 million metric tons/year. The aim of the present study was to investigate potential associations between persistent allergic symptoms in children, which have increased markedly in developed countries over the past three decades, and the concentration of phthalates in dust collected from their homes. This investigation is a case�control study nested within a cohort of 10,852 children. From the cohort, we selected 198 cases with persistent allergic symptoms and 202 controls without allergic symptoms. A clinical and a technical team investigated each child and her or his environment. We found higher median concentrations of butyl benzyl phthalate (BBzP) in dust among cases than among controls (0.15 vs. 0.12 mg/g dust). Analyzing the case group by symptoms showed that BBzP was associated with rhinitis (p = 0.001) and eczema (p = 0.001), whereas di(2-ethylhexyl) phthalate (DEHP) was associated with asthma (p = 0.022). Furthermore, dose�response relationships for these associations are supported by trend analyses. This study shows that phthalates, within the range of what is normally found in indoor environments, are associated with allergic symptoms in children. We believe that the different associations of symptoms for the three major phthalates�BBzP, DEHP, and di-n-butyl phthalate�can be explained by a combination of chemical physical properties and toxicologic potential. Given the phthalate exposures of children worldwide, the results from this study of Swedish children have global implications.
Bornehag, Carl-Gustaf; Sundell, Jan; Weschler, Charles J.; Sigsgaard, Torben; Lundgren, Bjorn; Hasselgren, Mikael; Hagerhed-Engman, Linda
Quantification of ergosterol and 3-hydroxy fatty acids in settled house dust by gas chromatography-mass spectrometry: comparison with fungal culture and determination of endotoxin by a Limulus amebocyte lysate assay.
Ergosterol and 3-hydroxy fatty acids, chemical markers for fungal biomass and the endotoxin of gram-negative bacteria, respectively, may be useful in studies of health effects of organic dusts, including domestic house dust. This paper reports a method for the combined determination of ergosterol and 3-hydroxy fatty acids in a single dust sample and a comparison of these chemical biomarkers determined by gas chromatography-mass spectrometry with results from fungal culture and Limulus assay. Analyses of replicate house dust samples resulted in correlations of 0.91 (ergosterol in six replicates; P < 0.01) and 0.94 (3-hydroxy fatty acids in nine replicates; P < 0.001). The amounts of ergosterol (range, 2 to 16.5 ng/mg of dust) correlated with those of total culturable fungi (range, 6 to 1,400 CFU/mg of dust) in 17 samples, (r = 0.65; P < 0.005). The amounts of endotoxin (range, 11 to 243 endotoxin units/mg of dust) measured with a modified chromogenic Limulus assay correlated with those of lipopolysaccharide (LPS) determined from 3-hydroxy fatty acid analysis of 15 samples. The correlation coefficient depended on the chain lengths of 3-hydroxy acids used to compute the LPS content. The correlation was high (r = 0.88 +/- 0.01; P < 0.001) when fatty acid chains of 10 to 14 carbon atoms were included; the correlation was much lower when hydroxy acids of 16- or 18-carbon chains were included. In conclusion, the results of the described extraction and analysis procedure for ergosterol and 3-hydroxy fatty acids are reproducible, and the results can be correlated with fungal culture and endotoxin activity of organic dust samples.
Saraf, A; Larsson, L; Burge, H; Milton, D
Encasing lead hazards and adding energy efficiency in low-income housing
Field research has confirmed that the lower the incremental (marginal) cost of producing an outcome, the more likely that production will occur. In residential building rehabilitation the economic truth suggests that energy efficiency is likely to become part of the scope of work of a project when the additional cost of conservation measures are relatively small, i.e., comparing gut rehab to moderate rehab, replacement of a furnace with an energy efficient model, and low-cost solutions to address lead poisoning hazards. Energy efficiency must fit into the overall needs and opportunities of a building retrofit. If little is being done to the building, then few measures can be expected to be justified. If much must be done, however, the opportunities for conservation are likely to be great. An example of this is the composite wall system described, therein, that was developed to address the problem of lead poisoning hazards on wall surfaces while adding a tight, well-insulated, and strong interior surface to perimeter walls at the lowest possible cost.
Cavallo, J.D. [Argonne National Lab., IL (United States); Wendt, R. [Oak Ridge National Lab., TN (United States)
A quantitative field method was developed for the analysis of lead (Pb) in paint, bulk dust, and soil. 5% (v/v) HNO3 ultrasonic digestion was followed by colorimetric measurement of the digest using a commercially available water Pb test kit. or paints, the range of the method is...
Associations of allergic sensitization and clinical phenotypes with innate immune response genes polymorphisms are modified by house dust mite allergen exposure
Introduction Polymorphisms within innate immunity genes are associated with allergic phenotypes but results are variable. These associations were not analyzed with respect to allergen exposure. We investigated associations of TLR and CD14 polymorphisms with allergy phenotypes in the context of house dust mite (HDM) exposure. Material and methods Children, aged 12-16 years (n=326), were recruited from downtown and rural locations and assessed by allergist. Skin prick tests, total and HDM-specific sIgE measurements were done. HDM allergen concentrations in dust were measured. Genetic polymorphisms were identified using restriction fragment length polymorphism (RFLP). Results Allergic rhinitis, asthma and atopy were more prevalent in urban area. Although HDM allergen concentrations were higher in rural households, sIgE were present more frequently in urban children. In the whole population no association was found between HDM exposure and sensitization. In children with CD14/?159CC, CD14/?159TT and TLR9/2848GA genotypes increased exposure to HDM was associated with reduced incidence of allergic rhinitis. Significant associations of increased HDM exposure with reduced incidence of atopy were found for the whole population and subjects with CD14/?159CC, CD14/?1359GT, TLR4/896AA and TLR9/2848GA genotypes. Among children with CD14/?159CC and CD14/?1359GG significant positive correlation between HDM allergen concentrations in household and sensitization to HDM was observed. In contrast, protective effect of high HDM allergen exposure against specific sensitization was seen in subjects with TLR4/896 AG. Conclusions Development of specific sensitization and allergy may be associated with innate immune response genes polymorphisms and is modified by allergen exposure.
Kurowski, Marcin; Majkowska-Wojciechowska, Barbara; Wardzynska, Aleksandra
The lead isotopic composition of dust in the vicinity of a uranium mine in northern Australia and its use for radiation dose assessment.
Airborne lead isotope ratios were measured via Thermal Ionisation Mass Spectrometry in samples from the vicinity of Ranger uranium mine in northern Australia. Dust deposited on leaves of Acacia spp. was washed off and analysed to gain a geographical snapshot of lead isotope ratios in the region. Aerosols were also collected on Teflon filters that were changed monthly over one seasonal cycle using a low volume diaphragm pump. Lead isotope ratios in dust deposited on leaves overestimate the relative amount of mine origin airborne lead, most likely due to a difference of the size distribution of particles collected on leaves and true aerosol size distribution. Seasonal measurements show that the annual average mine contribution to airborne lead concentrations in Jabiru East, approximately 2.5 km northwest of the mine, amounted to 13%, with distinct differences between the wet and dry season. The relative contribution of mine origin lead deposited on leaves in the dry season drops to less than 1% at a distance of 12.5 km from the mine along the major wind direction. An approach is outlined, in which lead isotope ratios are used to estimate the effective radiation dose received from the inhalation of mine origin radioactivity trapped in or on dust. Using the data from our study, this dose has been calculated to be approximately 2 microSv year(-1) for people living and working in the area. PMID:16388836
Bollh�fer, Andreas; Honeybun, Russell; Rosman, Kevin; Martin, Paul
Can Serum-Specific IgE/Total IgE Ratio Predict Clinical Response to Allergen-Specific Immunotherapy in Children Monosensitized to House Dust Mite?
Background. Allergen-specific immunotherapy (SIT) is one of the important regimens for the treatment of allergic diseases. Predictive tests for the clinical response to SIT are limited. In this study we aimed to evaluate whether specific IgE/total IgE levels can predict clinical improvement in monosensitized patients to house dust mite treated with immunotherapy. Patients and Methods. We analyzed 32 patients who had undergone 2 years of SIT. Serum t-IgE and s-IgE levels, and serum s-IgE/t-IgE ratios were calculated and tested for correlation with clinical response to SIT. Asthma symptom score (ASS), rhinitis symptom score (RSS), pulmonary functions and visual analogue scales (VAS) were evaluated at the beginning and after 2 years. Results. There were 17 boys and 15 girls with the mean age of 10.78 � 3.03 years. The mean serum house dust mite s-IgE level was 128.62 � 142.61?kU/L, t-IgE 608.90 � 529.98?IU/mL, and s-IgE/t-IgE ratio 33.83 � 53.18. Before immunotherapy, ASS was 6.23 � 1.63, RSS; 8.20 � 1.88, VAS; 7.38 � 2.01, FEV1 (%); 89.14 � 8.48, PEF (%); 88.93 � 13.57, and after 2 years, these values were determined as 1.90 � 1.10, 3.05 � 1.39, 1.35 � 1.24, 97.6 � 11.26, and 97.0 � 11.55, respectively. s-IgE/t-IgE ratio was correlated with change in RSS (r = -0.392, P = 0.08) and VAS (r = -0.367, P = 0.05). Conclusion. Although SIT is very effective treatment, all patients do not benefit from treatment. We assumed that s-IgE/t-IgE ratio would be useful to predict the clinical response to SIT. PMID:22536274
Karakoc, Gulbin Bingol; Yilmaz, Mustafa; Alt?nta?, Derya Ufuk; Kendirli, Seval G�ne?er
Resident CD11b(+)Ly6C(-) lung dendritic cells are responsible for allergic airway sensitization to house dust mite in mice.
Conventional dendritic cells (DCs) are considered to be the prime initiators of airway allergy. Yet, it remains unclear whether specific DC subsets are preferentially involved in allergic airway sensitization. Here, we systematically assessed the respective pro-allergic potential of individually sorted lung DC subsets isolated from house dust mite antigen (HDM)-treated donor mice, following transfer to na�ve recipients. Transfer of lung CD11c(+)CD11b(+) DCs, but not CD11c(+)CD11b(-)CD103(+) DCs, was sufficient to prime airway allergy. The CD11c(+)CD11b(+) DC subpopulation was composed of CD11c(+)CD11b(+)Ly6C(+) inflammatory monocyte-derived cells, whose numbers increase in the lungs following HDM exposure, and of CD11c(+)CD11b(+)Ly6C(-) DCs, which remain stable. Counterintuitively, only CD11c(+)CD11b(+)Ly6C(-) DCs, and not CD11c(+)CD11b(+)Ly6C(+) DCs, were able to convey antigen to the lymph nodes and induce adaptive T cell responses and subsequent airway allergy. Our results thus support that lung resident non-inflammatory CD11c(+)CD11b(+)Ly6C(-) DCs are the essential inducers of allergic airway sensitization to the common aeroallergen HDM in mice. PMID:23300898
Mesnil, Claire; Sabatel, Catherine M; Marichal, Thomas; Toussaint, Marie; Cataldo, Didier; Drion, Pierre-Vincent; Lekeux, Pierre; Bureau, Fabrice; Desmet, Christophe J
Resident CD11b+Ly6C? Lung Dendritic Cells Are Responsible for Allergic Airway Sensitization to House Dust Mite in Mice
Conventional dendritic cells (DCs) are considered to be the prime initiators of airway allergy. Yet, it remains unclear whether specific DC subsets are preferentially involved in allergic airway sensitization. Here, we systematically assessed the respective pro-allergic potential of individually sorted lung DC subsets isolated from house dust mite antigen (HDM)-treated donor mice, following transfer to na�ve recipients. Transfer of lung CD11c+CD11b+ DCs, but not CD11c+CD11b?CD103+ DCs, was sufficient to prime airway allergy. The CD11c+CD11b+ DC subpopulation was composed of CD11c+CD11b+Ly6C+ inflammatory monocyte-derived cells, whose numbers increase in the lungs following HDM exposure, and of CD11c+CD11b+Ly6C? DCs, which remain stable. Counterintuitively, only CD11c+CD11b+Ly6C? DCs, and not CD11c+CD11b+Ly6C+ DCs, were able to convey antigen to the lymph nodes and induce adaptive T cell responses and subsequent airway allergy. Our results thus support that lung resident non-inflammatory CD11c+CD11b+Ly6C? DCs are the essential inducers of allergic airway sensitization to the common aeroallergen HDM in mice.
Marichal, Thomas; Toussaint, Marie; Cataldo, Didier; Drion, Pierre-Vincent; Lekeux, Pierre
Cloned human T lymphocytes reactive with Dermatophagoides farinae (house dust mite): a comparison of T- and B-cell antigen recognition.
In this report, T-cell and B-cell recognition of the house dust mite Dermatophagoides farinae (D. far.) is compared. Nitrocellulose immunoblots of polyacrylamide gel electrophoresis (SDS-PAGE)-fractionated D. far. were added to proliferation assays to map the antigen specificity of cloned human helper T cells and a long-term line induced with D. far. T-cell recognition was of a polypeptide of molecular weight 9000-13,000, that migrates with the serologically defined allergen Der fII (12,500 MW). Since the cloned T cells, unlike the polyclonal response, failed to respond to Dermatophagoides pteronyssinus (D. pter.), this suggests that they recognize a species-specific epitope. In contrast, analysis of the B-cell response using Western blotting demonstrated that, in addition to Der fII, antibodies reactive with the major allergens Der fI (26,000 MW) and Der fIII (29,000 MW) were present in the serum. Similar specificities were seen in the antibody response to D. pter., and while it has been reported that the B-cell response to D. far. and D. pter. are predominantly cross-reactive, our observations suggest that species-specific CD4-positive T cells are present in the overall cellular response to D. far. Images Figure 1 Figure 4
O'Hehir, R E; Young, D B; Kay, A B; Lamb, J R
Lead Sampling Technician Training Course. Trainer Manual.
ERIC Educational Resources Information Center
This document presents a model curriculum for use by trainers presenting training course in assessing and reporting dust and debris from deteriorated lead-based paint. The course, which was developed by the U.S. Environmental Protection Agency, is intended for use with housing quality standard inspectors, rehabilitation specialists, home�
ICF, Inc., Washington, DC.
Eco-Self-Build Housing Communities: Are They Feasible and Can They Lead to Sustainable and Low Carbon Lifestyles?
This paper concerns how sustainable and low carbon living can be enabled in new housing developments in the UK. It is here recognized that consumption of energy and resources is not just what goes into the building, but also long-term through occupancy and activities. Current approaches, which require housing developers to reduce the carbon emissions of the homes they build
Steffie Broer; Helena Titheridge
Hydrometallurgical recovery of zinc and lead from electric arc furnace dust using mononitrilotriacetate anion and hexahydrated ferric chloride.
The purpose of this work was to study the feasibility at laboratory-scale of a new hydrometallurgical process for treating electric arc furnace dusts (EAFD). The proposed process is intended to extract zinc and lead from EAFD without destroying the iron oxides matrix. So, this material can be recycled by the steel industry. Independently of the origin of the samples, major mineralogical forms present in these wastes are Fe3O4, ZnO, ZnFe2O4 and PbOHCl. The proposed process consists of a hydrometallurgical treatment of wastes based on selective leaching of zinc and lead. Initially, a leaching is carried out utilizing a chelating agent, nitrilotriacetate anion (NTA3-), as the protonated form HNTA2-. Treatment of five EAFD samples for an hour at room temperature with a molar solution of reagent results in total leaching of the ZnO. In all cases the solubilized iron does not exceed 3 wt.%. The recovery of zinc and lead is performed by precipitation of metallic sulfides with a solution of Na2S4 sodium tetrasulfide 2M. These metallic sulfides can be used as metallurgical raw materials and the chelating reagent can be reused in the process after pH adjustment. The results of the normalized leaching test AFNOR X31-210 conducted on the leaching residues, shows that all the samples meet acceptance thresholds for hazardous wastes landfill. However, the residues contain a considerable amount of zinc as ZnFe2O4. The extraction of the zinc element requires the destruction of the ferrite structure. In this process, ZnFe2O4 is treated by FeCl3.6H2O. The reaction consists in a particle O2-/Cl- exchange allowing the recovery of zinc as ZnCl2 and iron as hematite Fe2O3. The separation of these products is accomplished by simple aqueous leaching. All of the zinc is extracted in a 8h treatment at 150 degrees C with a molar ratio FeCl3.6H2O/ZnFe2O4 equal to 10. Ultimate solid residues, which have been concentrated in iron, can be oriented towards the steel industry. PMID:11900917
Leclerc, Nathalie; Meux, Eric; Lecuire, Jean Marie
Comparison of home lead dust reduction techniques on hard surfaces: the New Jersey assessment of cleaning techniques trial.
High efficiency particulate air filter (HEPA) vacuums, which collect particles > 0.3 micro m, and trisodium phosphate (TSP), a detergent claimed to selectively remove lead, have been included in the HUD Guidelines for the Evaluation and Control of Lead Based Paint Hazards in Housing without systematic validation of their effectiveness. At the time the study was initiated, both HEPA vacuums and TSP were relatively expensive, they were not readily found in urban retail centers, and there were environmental concerns about the use and disposal of high-phosphate detergents. A randomized, controlled trial was conducted in urban high-risk homes in northern New Jersey to determine whether a more readily available and less expensive low-phosphate, non-TSP detergent and non-HEPA vacuum could perform as well as TSP and a HEPA vacuum in a cleaning protocol. Homes were randomized to one of three cleaning methods: TSP/HEPA vacuum, TSP/non-HEPA vacuum, or non-TSP/non-HEPA vacuum. Change in log-transformed lead loading was used in mixed models to compare the efficacy of the three cleaning techniques separately for uncarpeted floors, window sills, and window troughs. After we adjusted for baseline lead loading, the non-HEPA vacuum produced larger reductions on hard floors [19%; 95% confidence interval (CI), 3-38%], but the HEPA vacuum produced larger reductions on window sills (22%; 95% CI, 11-32%) and larger reductions on window troughs (16%; 95% CI, -4 to 33%). The non-TSP produced larger reductions on window troughs (21%; 95% CI, -2 to 50%), but TSP produced larger reductions on hard floors (5%; 95% CI, -12 to 19%) and window sills (8%; 95% CI, -5 to 20%). TSP/HEPA produced larger reductions on window sills (28%; 95% CI, 18-37%) and larger reductions on window troughs (2%; 95% CI, -24 to 23%), whereas the non-TSP/non-HEPA method produced larger reductions on hard floors (13%; 95% CI, -5 to 34%). Because neither vacuum nor detergent produced consistent results across surface types, the use of low-phosphate detergents and non-HEPA vacuums in a temporary control measure is supported.
Rich, David Q; Rhoads, George G; Yiin, Lih-Ming; Zhang, Junfeng; Bai, Zhipeng; Adgate, John L; Ashley, Peter J; Lioy, Paul J
The distribution of lead between sea salt, dust, and lead-rich aerosols in the mid South Pacific Easterlies at American Samoa
Aerosols in the South Pacific Easterlies have been sampled at American Samoa with a cascade impactor and analyzed for Pb, Ba, K, Ca, Sr, and Rb by isotope dilution mass spectrometry using ultraclean procedures. Some 84% of the Pb was found in fine ({le}0.5 {mu}m) aerosols which were collected on the backup filter with an efficiency of only 33%. Sea salt and eroded terrestrial material (dust) containing 6% and < 1% respectively, of the Pb (sea salt indexed by the metals K, Ca, Sr, and Rb and dust indexed by Ba) were collected on early stages of the impactor, although 65% of the dust, because of its larger size, was lost to surfaces of the rain shelter before reaching the impactor. The remaining 10% of the Pb was associated with plant leaf waxes of continental origin which produced Pb and Ba peaks on stage 4 (0.5 {mu}m) of the impactor.
Rosman, K.J.R.; Patterson, C.C.; Settle, D.M. (California Inst. of Tech., Pasadena (United States))
... be found are in lead-based paint, contaminated soil, household dust, drinking water, lead crystal, lead-glazed ... eating or inhaling dust or paint chips. The soil around your home can pick up lead from ...
Differences in respiratory syncytial virus and influenza infection in a house-dust-mite-induced asthma mouse model: consequences for steroid sensitivity.
A significant number of clinical asthma exacerbations are triggered by viral infection. We aimed to characterize the effect of virus infection in an HDM (house dust mite) mouse model of asthma and assess the effect of oral corticosteroids. HDM alone significantly increased eosinophils, lymphocytes, neutrophils, macrophages and a number of cytokines in BAL (bronchoalveolar lavage), all of which were sensitive to treatment with prednisolone (with the exception of neutrophils). Virus infection also induced cell infiltration and cytokines. RSV (respiratory syncytial virus) infection in HDM-treated animals further increased all cell types in BAL (except eosinophils, which declined), but induced no further increase in HDM-elicited cytokines. However, while HDM-elicited TNF-? (tumour necrosis factor-?), IFN-? (interferon-?), IL (interleukin)-2, IL-5 and IL-10 were sensitive to prednisolone treatment, concomitant infection with RSV blocked the sensitivity towards steroid. In contrast, influenza infection in HDM- challenged animals resulted in increased BAL lymphocytes, neutrophils, IFN-?, IL-1?, IL-4, IL-5, IL-10 and IL-12, but all were attenuated by prednisolone treatment. HDM also increased eNO (exhaled NO), which was further increased by concomitant virus infection. This increase was only partially attenuated by prednisolone. RSV infection alone increased BAL mucin. However, BAL mucin was increased in HDM animals with virus infection. Chronic HDM challenge in mice elicits a broad inflammatory response that shares many characteristics with clinical asthma. Concomitant influenza or RSV infection elicits differing inflammatory profiles that differ in their sensitivity towards steroids. This model may be suitable for the assessment of novel pharmacological interventions for asthmatic exacerbation. PMID:23789621
Mori, Hiroki; Parker, Nicole S; Rodrigues, Deborah; Hulland, Kathryn; Chappell, Deborah; Hincks, Jennifer S; Bright, Helen; Evans, Steven M; Lamb, David J
Hyposensitization in asthmatics with mPEG-modified and unmodified house dust mite extract. IV. Occurrence and prediction of side effects.
A double-blind study on hyposensitization (HS) with two extracts prepared from the house dust mite Dermatophagoides pteronyssinus (Dp) was performed on a group of asthmatics with bronchial sensitivity to Dp. In 18 patients, aluminium-hydroxide was added to the Dp-extract to give a depot effect (Dp-group). Nineteen patients were treated with a similar extract in which allergenicity had been reduced by coupling to monomethoxypolyethylene glycol (mPEG-Dp-group). This extract had previously been shown to have less effect on clinical symptoms and skin sensitivity compared to the Dp-extract. In the Dp- and mPEG-Dp-groups, 778 and 675 injections were administered. Fifteen and 12 patients in the Dp- and mPEG-Dp-groups had systemic reactions (P greater than 0.05). The frequency of injections giving systemic reactions was reduced in the mPEG-Dp-group: 5.1% compared to 9.0% in the Dp-group (P less than 0.01). In the mPEG-Dp-group, reactions were mild to moderate, mainly late-occurring asthma and urticaria, whereas two episodes of anaphylaxis and four of severe asthma occurred in the Dp-group. The reduction in side effects seems promising, but a further dose increase in the mPEG-Dp-group would be necessary to compare the side effects of doses with equal therapeutic effectiveness. High frequency of late local reactions made dose increase impossible with the present slightly modified extract. The systemic side effects occurred more frequently in patients highly skin test-sensitive to Dp prior to treatment. All patients skin test-positive to less than or equal to 100 BU had systemic reactions. Systemic side effects could not be predicted from the size of previous local reactions. PMID:2316824
Mosbech, H; Dirksen, A; Dreborg, S; Fr�lund, L; Heinig, J H; Svendsen, U G; S�borg, M; Taudorf, E; Weeke, B
The effects of inhaled corticosteroids on intrinsic responsiveness and histology of airways from infant monkeys exposed to house dust mite allergen and ozone
Inhaled corticosteroids (ICS) are recommended to treat infants with asthma, some with intermittent asthma. We previously showed that exposing infant monkeys to allergen/ozone resulted in asthma-like characteristics of their airways. We evaluated the effects of ICS on histology and intrinsic responsiveness of allergen/ozone-exposed and normal infant primate airways. Infant monkeys were exposed by inhalation to (1) filtered air and saline, (2) house dust mite allergen (HDMA) + ozone and saline, (3) filtered air and ICS (budesonide) or (4) HDMA + ozone and ICS. Allergen/ozone exposures started at 1 month and ICS at 3 months of age. At 6 months of age, methacholine-induced changes in luminal area of airways in proximal and distal lung slices were determined using videomicrometry, followed by histology of the same slices. Proximal airway responsiveness was increased by allergen/ozone and by ICS. Eosinophil profiles were increased by allergen/ozone in both proximal and distal airways, an effect that was decreased by ICS in distal airways. In both allergen/ozone- and air-exposed monkeys, ICS increased the number of alveolar attachments in distal airways, decreased mucin in proximal airways and decreased epithelial volume in both airways. ICS increased smooth muscle in air-exposed animals while decreasing it in allergen/ozone-exposed animals in both airways. In proximal airways, there was a small but significant positive correlation between smooth muscle and airway responsiveness, as well as between alveolar attachments and responsiveness. ICS change morphology and function in normal airways as well as allergen/ozone-exposed airways, suggesting that they should be reserved for infants with active symptoms.
Joad, Jesse P. [Department of Pediatrics, School of Medicine, University of California at Davis, Davis, CA 95616 (United States)], E-mail: firstname.lastname@example.com; Kott, Kayleen S.; Bric, John M. [Department of Pediatrics, School of Medicine, University of California at Davis, Davis, CA 95616 (United States); Schelegle, Edward S. [Department of Anatomy, Physiology, and Cell Biology, School of Veterinary Medicine, University of California at Davis, Davis, CA 95616 (United States); Gershwin, Laurel J. [Department of Pathology, Microbiology and Immunology, School of Veterinary Medicine, University of California at Davis, Davis, CA 95616 (United States); Plopper, Charles G. [Department of Anatomy, Physiology, and Cell Biology, School of Veterinary Medicine, University of California at Davis, Davis, CA 95616 (United States); Peake, Janice L.; Pinkerton, Kent E. [Department of Pediatrics, School of Medicine, University of California at Davis, Davis, CA 95616 (United States)
The very low density lipoprotein receptor attenuates house dust mite-induced airway inflammation by suppressing dendritic cell-mediated adaptive immune responses.
The very low density lipoprotein receptor (VLDLR) is a member of the low-density lipoprotein receptor family that binds multiple ligands and plays a key role in brain development. Although the VLDLR mediates pleiotropic biological processes, only a limited amount of information is available regarding its role in adaptive immunity. In this study, we identify an important role for the VLDLR in attenuating house dust mite (HDM)-induced airway inflammation in experimental murine asthma. We show that HDM-challenged Vldlr(-/-) mice have augmented eosinophilic and lymphocytic airway inflammation with increases in Th2 cytokines, C-C chemokines, IgE production, and mucous cell metaplasia. A genome-wide analysis of the lung transcriptome identified that mRNA levels of CD209e (DC-SIGNR4), a murine homolog of DC-SIGN, were increased in the lungs of HDM-challenged Vldlr(-/-) mice, which suggested that the VLDLR might modify dendritic cell (DC) function. Consistent with this, VLDLR expression by human monocyte-derived DCs was increased by HDM stimulation. In addition, 55% of peripheral blood CD11c(+) DCs from individuals with allergy expressed VLDLR under basal conditions. Lastly, the adoptive transfer of HDM-pulsed, CD11c(+) bone marrow-derived DCs (BMDCs) from Vldlr(-/-) mice to the airways of wild type recipient mice induced augmented eosinophilic and lymphocytic airway inflammation upon HDM challenge with increases in Th2 cytokines, C-C chemokines, IgE production, and mucous cell metaplasia, as compared with the adoptive transfer of HDM-pulsed, CD11c(+) BMDCs from wild type mice. Collectively, these results identify a novel role for the VLDLR as a negative regulator of DC-mediated adaptive immune responses in HDM-induced allergic airway inflammation. PMID:24733846
Fredriksson, Karin; Mishra, Amarjit; Lam, Jonathan K; Mushaben, Elizabeth M; Cuento, Rosemarie A; Meyer, Katharine S; Yao, Xianglan; Keeran, Karen J; Nugent, Gayle Z; Qu, Xuan; Yu, Zu-Xi; Yang, Yanqin; Raghavachari, Nalini; Dagur, Pradeep K; McCoy, J Philip; Levine, Stewart J
Lead abatement training for workers
This training program is designed to be a 16 hour training course. The course is designed to meet the requirements of 40 CFR Part 745 Lead. Requirements for Lead-Based Paint Activities in Target Housing and Child Occupied Facilities, a federal regulation under section 402 of the Toxic Substance Control Act (TSCA). Topics covered in the course include: where and what is lead; health effects; regulations and laws; identifying and evaluating hazards; controlling lead hazards; abatement methods; cleanup, disposal and clearance; and soil and exterior dust abatement.
Not Available
... Services U.S. DEPARTMENT OF HEALTH AND HUMAN SERVICES, Public Health Service Agency for Toxic Substances and Disease Registry ... for lead (Update). Atlanta, GA: U.S. Department of Public Health and Human Services, Public Health Service. LEAD CAS # ...
NSDL National Science Digital Library
The dust around us is composed of bits of detritus of all manner of things, but it is mostly bits of human skin. This radio broadcast explores the universe through tiny dust particles and discovers what it can tell us about our past as well as our future. The broadcast discusses dust from ice cores that reveal the climate record and the cosmic dust that Earth is gathering every day. There is also explanation of the microscopic composition of the dust around us and the damage dust can do to museum exhibits, especially when the dust interacts with the moisture in the atmosphere. The broadcast is 28 minutes in length.
Silica Dust Inhalation and Resistance to Infections.
National Technical Information Service (NTIS)
To determine the effects of silica dust inhalation on the immunological defense mechanisms which are involved in pulmonary resistance to infection, mice were housed in exposure chambers and subjected to various concentrations of silica dust for various le...
A. Zarkower F. G. Ferguson
House dust allergy and immunotherapy
HDM allergy is associated with asthma, allergic rhinitis and atopic dermatitis. In many countries childhood asthma is predominantly found in HDM-allergic children with their probability of developing disease being proportional to their IgE antibody titers and the early development of Th2 responses. While the pathogenesis is complex and increasingly linked to infection the immunologically-based allergen immunotherapy and anti-IgE antibody therapy are highly beneficial. Immunotherapy could be a short-term treatment providing lifelong relief but the current regimens depend on repeated administration of allergen over years. Immunological investigations point to a contribution of responses outside the Th2 pathway and multiple potential but unproven control mechanisms. Over half of the IgE antibodies are directed to the group 1 and 2 allergens with most of remainder to the group 4, 5, 7 and 21 allergens. This hierarchy found in high and low responders provides a platform for introducing defined allergens into immunotherapy and defined reagents for investigation.
Thomas, Wayne R.
Comparative modelling of major house dust mite allergen Der p I: structure validation using an extended environmental amino acid propensity table.
A model of the 3-D structure of a major house dust mite allergen Der p I associated with hypersensitivity reactions in humans was built from its amino acid sequence and its homology to three known structures, papain, actinidin and papaya proteinase omega of the cysteine proteinase family. Comparative modelling using COMPOSER was used to arrive at an initial model. This was refined using interactive graphics and energy minimization with the AMBER force field incorporated in SYBYL (Tripos Associates). Compatibility of the Der p I amino acid sequence with the cysteine proteinase fold was checked using an environment-dependent amino acid propensity table incorporated into a new program HARMONY with a variable length windowing facility. A five-residue window was used to probe local conformational integrity. Propensities were derived from a structural alignment database of homologous proteins using a robust entropy-driven smoothing procedure. Der p I shares essential structural and mechanistic features with other papain-like cysteine proteinases, including cathepsin B. The active-site thiolate-imidazolium ion pair comprises the side chains of Cys34 and His170. A cystine disulfide not present in other known structures bridges residue 4 of an N-terminal extension and the core residue 117. Two conserved disulfide bridges are formed by residues 31 and 71 and residues 65 and 103. Model building of peptide substrate analogue complexes suggests a preference for phenylalanyl or basic residues at the P2 position, whilst selectivity may be of minor importance at the S1 subsite. The electrostatic influences on the Der p I active-site ion pair and extended peptide binding region are markedly different from those in known structures. A highly immunogenic surface exposed region (residues 107-131), comprising several overlapping T cell epitope sites, has no shared sequence identity with human liver cathepsin B and contains three insertion-deletion sites. The structure provides a basis for testing the substrate specificity of Der p I and the potential role of proteinase activity in hypersensitivity reactions. These studies may offer a new treatment strategy by hyposensitization with inactive mutants or mutants with significantly altered proteinase activity, either alone or complexed with antibody. PMID:7971950
Topham, C M; Srinivasan, N; Thorpe, C J; Overington, J P; Kalsheker, N A
Block Copolymer/DNA Vaccination Induces a Strong Allergen-Specific Local Response in a Mouse Model of House Dust Mite Asthma
Background Allergic asthma is caused by abnormal immunoreactivity against allergens such as house dust mites among which Dermatophagoides farinae (Der f) is a common species. Currently, immunotherapy is based on allergen administration, which has variable effect from patient to patient and may cause serious side effects, principally the sustained risk of anaphylaxis. DNA vaccination is a promising approach by triggering a specific immune response with reduced allergenicity. Objective The aim of the study is to evaluate the effects of DNA immunization with Der f1 allergen specific DNA on allergic sensitization, inflammation and respiratory function in mice. Methods Mice were vaccinated 28 and 7 days before allergen exposure with a Der f1-encoding plasmid formulated with a block copolymer. Asthma was induced by skin sensitization followed by intra-nasal challenges with Der f extract. Total lung, broncho-alveolar lavage (BAL) and spleen cells were analyzed by flow cytometry for their surface antigen and cytokine expression. Splenocytes and lung cell IFN-? production by CD8+ cells in response to Der f CMH1-restricted peptides was assessed by ELISPOT. IgE, IgG1 and IgG2a were measured in serum by ELISA. Specific bronchial hyperresponsiveness was assessed by direct resistance measurements. Results Compared to animals vaccinated with an irrelevant plasmid, pVAX-Der f1 vaccination induced an increase of B cells in BAL, and an elevation of IL-10 and IFN-? but also of IL-4, IL-13 and IL-17 producing CD4+ lymphocytes in lungs and of IL-4 and IL-5 in spleen. In response to CD8-restricted peptides an increase of IFN-? was observed among lung cells. IgG2a levels non-specifically increased following block copolymer/DNA vaccination although IgE, IgG1 levels and airways resistances were not impacted. Conclusions & Clinical Relevance DNA vaccination using a plasmid coding for Der f1 formulated with the block copolymer 704 induces a specific immune response in the model of asthma used herein.
Roussey-Bihouee, Tiphaine; Hassoun, Dorian; Evrard, Justine; Cheminant, Marie-Aude; Chesne, Julie; Braza, Faouzi; Mahay, Guillaume; Portero, Vincent; Sagan, Christine; Pitard, Bruno; Magnan, Antoine
159 Therapeutic Effect and Safety of the Sublingual Immunotherapy With Tropical House Dust Mite Allergen Vaccines in Asthmatic Cuban Adult Patients
Background Subcutaneous injection route (SCIT) is burdened with the risk of severe adverse events; therefore, sublingual immunotherapy (SLIT) is being increasingly investigated. The efficacy of SLIT in asthma has been reviewed in a Cochrane meta-analysis. Allergic sensitization to Dermatophagoides pteronyssinus (Dp), Dermatophagoides siboney (Ds) and Blomia tropicalis (Bt) is strongly linked to respiratory allergy and asthma in Cuba (3). These last 2 species are relevant in tropical countries or even only in the Caribbean region (4). Nevertheless, well conducted clinical studies of immunotherapy with standardized allergen vaccines of these particular species are very scarce. Objective This study was conducted to assess the therapeutic effect and safety of allergen therapeutic vaccines of Dermatophagoides pteronyssinus, Dermatophagoides siboney and Blomia tropicalis House-Dust mites (VALERGEN, BIOCEN, Cuba) by sublingual route, in asthmatic patients. Methods Three Double-Blind Placebo-Controlled clinical trials were performed in 40 patients each, showing asthmatic symptoms and positive predominant Skin Prick Test (SPT) to each mite, respectively. Half of subjects were randomized to active group. Treatment consisted of sublingual drops with increasing daily doses for 3 weeks and maintenance doses (2000 BU) twice a week until 12 months. Results Therapeutic effect was assessed after 6 and 12 months using symptoms/medication diary cards, peak expiratory flow (PEF) measures and skin sensitivity to investigated mites. Adverse reactions were classified using the World Allergy Organization scale. The treatment reduced significantly (P < 0.01) clinical symptoms (38%, 95% CI, 33-44) and medication intake (26%, 95% CI, 21-32) with respect to placebo. The skin sensitivity to the allergens decreased also significantly (P < 0.01). The allergen amount needed to induce a positive SPT increased 52-fold. PEF variability decreased also significantly (P < 0.05). The treatment was considered effective in 77% of patients. A major advantage as compared to subcutaneous route was a remarked lower frequency of adverse effects. Local reactions were noted only in 0.43% of administrations. No systemic reactions were observed. Conclusions The results indicate that sublingual immunotherapy using allergen vaccines of tropical mite species is effective and safe in mite-sensitive asthmatic patients.
Castro Almarales, Raul Lazaro; Ronquillo, Mercedes; Labrada, Alexis; Castello, Mirta Alvarez; Gonzalez, Mayda; Rodriguez, Jose; Enriquez, Irene; Navarro Viltres, Barbara I; DiazLic, Yunia Oliva; Mateo, Maytee
24 CFR 1000.40 - Do lead-based paint poisoning prevention requirements apply to affordable housing activities...
Code of Federal Regulations, 2010 CFR
...2009-04-01 false Do lead-based paint poisoning prevention requirements...General § 1000.40 Do lead-based paint poisoning prevention requirements...title, which implement the Lead-Based Paint Poisoning Prevention Act (42...
24 CFR 1000.40 - Do lead-based paint poisoning prevention requirements apply to affordable housing activities...
Code of Federal Regulations, 2010 CFR
...2010-04-01 false Do lead-based paint poisoning prevention requirements...General § 1000.40 Do lead-based paint poisoning prevention requirements...title, which implement the Lead-Based Paint Poisoning Prevention Act (42...
Children and lead: new findings and concerns
An editorial dealing with lead in the environment and its health risks to children is presented. Young children are particularly vulnerable to lead exposure. Through hand-to-mouth activities, such as thumb sucking, nail biting, or eating with dirty hands, lead in house dust and garden soil readily enters their bodies. Children with pica are exposed to more lead because they eat such items as paint chips, broken plaster, and dirt. Moreover, intestinal lead absorption is greater in children than in adults. The author recommends a concerted effort to reduce undue lead absorption in children. (JMT)
Lin-Fu, J.S.
Identification of trace metal pollution in urban dust from kindergartens using magnetic, geochemical and lead isotopic analyses
NASA Astrophysics Data System (ADS)
In the present study, magnetic measurements were combined with geochemical analysis and stable Pb isotopic ratios to reveal the distribution and origination of trace metal pollutants in kindergarten dusts from a typical urban environment of Wuhan, central China. The geoaccumulation index (Igeo) of magnetic properties was more prominent than those of individual metals. The magnetic susceptibility (MS) and trace metals (Zn, Pb, and Cu) in this study together with published results from other Chinese cities formed a liner relationship, suggesting that metal contaminants in Chinese urban areas had similar MS to metal ratios, which could be used as an indicator for identification of pollution sources between Chinese cities and the other Asian cities. Stable Pb isotopic ratios (1.1125�1.1734 for 206Pb/207Pb and 2.4457�2.4679 for 208Pb/207Pb) in the urban dusts from Wuhan were characterized by higher 208Pb component in comparison with those from other Chinese cities. This result combined with principal component analysis (PCA) indicated that metal pollutants in the dusts were derived from industrial activities and coal combustion, whereas the traffic emissions were no longer a predominant pollution source in urban environment. Our study demonstrated that environmental magnetic methods could not only reveal the overall situation of trace metal contamination, but also prove evidence in the identification of pollution sources.
Zhu, Zongmin; Sun, Guangyi; Bi, Xiangyang; Li, Zhonggen; Yu, Genhua
Assessing remedial effectiveness through the blood lead:soil\\/dust lead relationship at the Bunker Hill Superfund Site in the Silver Valley of Idaho
The 21 square mile Bunker Hill Superfund Site in northern Idaho includes several thousand acres of contaminated hillsides and floodplain, a 365-acre abandoned lead\\/zinc smelter and is home to more than 7000 people in 5 residential communities. Childhood lead poisoning was epidemic in the 1970s with >75% of children exceeding 40 ?g\\/dl blood lead. Health response activities have been ongoing
Ian von Lindern; Susan Spalinger; Varduhi Petroysan; Margrit von Braun
Distribution of Chlorphyrifos in Air, Carpeting, and Dust and Its Reemission from Carpeting Following the Use of Total Release Aerosols in an Indoor Air Quality Test House.
National Technical Information Service (NTIS)
The paper gives results of experiments to explore the relationships between the insecticide chlorpyrifos and its distribution into carpet, carpet dust, and reemission into air. Two total release aerosols containing 0.5% chlorpyrifos were applied in the li...
M. A. Mason L. S. Sheldon Z. Guo D. M. Stout
Identification and Characterization of Arsenic and Metal Compounds in Contaminated Soil, Mine Tailings, and House Dust Using Synchrotron-Based Microanalysis
A comprehensive understanding of the risk associated with metal-rich soils and other materials includes identification of the solid phases hosting the metals. Synchrotron microanalysis provides a powerful diagnostic tool to characterize metal-bearing particles in mine tailings, soils, lake sediments, windblown dust, and household dust. A near simultaneous combination of X-ray fluorescence, diffraction, and absorption experiments using a microfocused beam can
Heather E. Jamieson; Stephen R. Walker; Claudio F. Andrade; Lori A. Wrye; Pat E. Rasmussen; Antonio Lanzirotti; Michael B. Parsons
This patent describes a dust collector comprising: (a) a housing having inlet means for receiving air to be cleaned; (b) a plurality of filter units within the housing; (c) a first centrifugal fan arranged for drawing air through the units for removing dust from the air; (d) a plurality of ducts each connected to a corresponding one of the units at one end and to the first fan at the other end to provide passages for air from the units to the first fan, the ducts through a portion of their length being arranged in side-by-side relationship; (e) a second centrifugal fan for providing reverse flow of air through the ducts to the units, the second fan providing a high volume of air at low pressure; (f) a transverse duct connected to the second fan and extending transversely of the portion of the plurality of ducts and adjacent thereto: (g) a plurality of openings providing communication between the transverse duct and each of the plurality of ducts; (i) rotatable means engaging the vanes for sequentially moving the vanes between the first and second positions.
Nelson, R.T.
Occurrence and levels of polybrominated diphenyl ethers (PBDEs) in house dust and hair samples from Northern Poland; an assessment of human exposure.
Polybrominated diphenyl ethers (PBDEs) are among most ubiquitous compounds to be found in indoor environment and ingestion of household dust is considered an important route of exposure to PBDEs, especially in toddlers and young children. The present work reported concentration levels of PBDE congeners (PBDE-28, -47, -99, -100, -153, -154, -183 and -209) in hair and dust samples from selected households from Northern Poland. The concentrations of PBDEs in dust ranged from
Kr�l, Sylwia; Namie?nik, Jacek; Zabiega?a, Bo?ena
Nurse Case Management and Housing Interventions Reduce Allergen Exposures: The Milwaukee Randomized Controlled Trial
Objective We examined the impact of a combination of home environmental interventions and nurse case management services on total settled dust loadings and on allergen concentrations in the homes of asthmatic children. Methods Using a randomized longitudinal controlled trial study design, we randomly assigned homes of asthmatic children in Milwaukee to either a control (n=64) or an intervention (n=57) group. Control group homes received a visual assessment, education, bed/pillow dust mite encasings, and treatment of lead-based paint hazards. The intervention group received these same services plus nurse case management that included tailored, individual asthma action plans, provision of minor home repairs, home cleaning using special vacuuming and wet washing, and integrated pest management. Dust vacuum samples were collected from measured surface areas of floors in the TV room, kitchen, and child's bedroom at baseline and at three-, six-, and 12-month follow-up visits. Dust loading (mass per surface area) is a means of measuring total dust and the total amount of allergen present. Results For the intervention group, geometric mean dust loadings declined significantly from baseline (39 milligrams per square foot [mg/ft2]) to post-intervention (11 mg/ft2) (p<0.001). Baseline dust loading, treatment group, visit, and season were significant predictors of follow-up dust loadings. Mean post-intervention dust loadings were 72% higher in the control group. The total amount of allergen in settled house dust declined significantly following the intervention because total dust loading declined; the concentration of allergens in settled dust did not change significantly. Conclusion The combination of nurse case management and home environmental interventions promotes collaboration between health and housing professionals and is effective in reducing exposures to allergens in settled dust.
Breysse, Jill; Wendt, Jean; Dixon, Sherry; Murphy, Amy; Wilson, Jonathan; Meurer, John; Cohn, Jennifer; Jacobs, David E.
Development and field trial of a household surface lead loading rate sampling device in a lead-contaminated community of southern Thailand.
A new dust-collecting device was developed to assess surface lead loading rates in houses in communities contaminated with lead oxide dust used for caulking in nearby boat-repair yards. The device consists of two small glass sheets with total area of 1,200 cm(2) placed in two plastic trays suspended from the ceiling in the house for 3 months before wiping and sending the dust specimen for determination of lead content using flame atomic absorption spectrophotometry. After a pilot trial in four households, further data were collected from 43 matched pairs of boat-caulkers' and neighboring control households. All devices were retained in the house for 3 months without any complaint. Static measurements of lead dust levels were also assessed in all households. The values significantly discriminated high from low lead exposure households (p = 0.015) and provided good correlations with floor lead loading (Spearman rank correlation coefficient, r = 0.39 to 0.62) and dust lead content (r = 0.53 to 0.64). This sampling method is an alternative to others which consume more household space or require a longer collection period. PMID:19415518
Untimanon, Orrapan; Geater, Alan; Chongsuvivatwong, Virasakdi; Thoumsang, Somkiat; Verkasalo, Pia K; Saetia, Wiyada
Multiple Metal Contamination from House Paints: Consequences of Power Sanding and Paint Scraping in New Orleans
Power sanding exterior paint is a common practice during repainting of old houses in New Orleans, Louisiana, that triggers lead poisoning and releases more than Pb. In this study we quan- tified the Pb, zinc, cadmium, manganese, nickel, copper, cobalt, chromium, and vanadium in exterior paint samples collected from New Orleans homes (n = 31). We used interior dust wipes
Howard W. Mielke; Eric T. Powell; Aila Shah; Christopher R. Gonzales; Paul W. Mielke
Health complaints and annoyances after moving into a new office building: a multidisciplinary approach including analysis of questionnaires, air and house dust samples.
After moving into a new office building, employees complained about eye irritations, sore throats and unspecific symptoms. They were concerned about visible dust as a potential cause of adverse health effects. An external working group was appointed to investigate indoor air pollution and health complaints and to suggest measures to improve the situation. Air samples and floor dust samples for analysis of organic compounds were collected in three offices. Bimonthly during 8 months, measurement campaigns were conducted to assess the trend of air pollutants. A questionnaire was administered concerning environmental conditions at the work place and complaints before and after moving into the new office building. Overall the concentrations of volatile organic compounds (VOC) and formaldehyde were fairly low. However, initially high concentrations (4300-7800 mg/kg) of tris-(2-butoxyethyl)-phosphate (TBEP) and diethylhexylphthalate (DEHP: 980-3000 mg/kg) were found in dust samples. The coating of the rubber floor was identified as the source of TBEP, while no single predominant source of DEHP was found. Results of the questionnaire demonstrated an increased irritation of the mucous membranes and a reduction of well-being after the employees had moved into the new building. Perception of low relative humidity and high temperature as well as unpleasant odors were associated with respiratory complaints. After removal of the coating of the rubber floor throughout the whole building, a reduction up to 90% of TBEP in the dust samples was found. In spite of several attempts, no such marked reduction was achieved with the concentration of phthalates. Although there was no significant association between visible dust exposure and increase of complaints after moving in, room climate conditions that could increase the deposition of dust in the airways were associated with the complaints. Hence it cannot be ruled out that fine dust containing TBEP together with unfavorable indoor factors were responsible for the development of the complaints. PMID:16373203
Hutter, Hans-Peter; Moshammer, Hanns; Wallner, Peter; Damberger, Bernhard; Tappler, Peter; Kundi, Michael
Roadside dusts and soils contamination in Cincinnati, Ohio, USA
NASA Astrophysics Data System (ADS)
Roadside dusts and soils were collected from various nonindustrial districts in Cincinnati, Ohio, USA, and analyzed for lead and copper contents. Results showed that the recent lead phase-down action has reduced the level of lead, but the concentrations of both metals are still higher than the background levels for normal soil. Elevated concentrations of copper in heavily traveled highways were noted, suggesting that much of the copper pollutants is probably of automotive origin. The concentration of lead was found to vary with housing age, and higher levels of contamination in the older neighborhoods were observed. This result is probably ascribable to the accumulation of residues from leaded gasoline and lead-based paint in the past and the use of coal fire for space heating in older houses.
Tong, Susanna T. Y.
Silica-dust inhalation and resistance to infections. Progress report
To determine the effects of silica-dust inhalation on the immunological defense mechanisms which are involved in pulmonary resistance to infection, mice were housed in exposure chambers and subjected to various concentrations of silica dust for various lengths of time; control mice were similarly housed without exposure to silica dust. These exposures were followed by examination of a variety of immunologic
A. Zarkower; F. G. Ferguson
Bioaccessibility, release kinetics, and molecular speciation of arsenic and lead in geo-dusts from the Iron King Mine Federal Superfund site in Humboldt, Arizona.
Abstract Mine tailings contain multiple toxic metal(loid)s that pose a threat to human health via inhalation and ingestion. The goals of this research include understanding the speciation and molecular environment of these toxic metal(loid)s (arsenic and lead) as well as the impacts particle size and residence time have on their bioaccessibilty in simulated gastric and lung fluid. Additionally, future work will include smaller size fractions (PM10 and PM2.5) of surface mine tailings, with the goal of increasing our understanding of multi-metal release from contaminated geo-dusts in simulated bio-fluids. This research is important to environmental human health risk assessment as it increases the accuracy of exposure estimations to toxic metal(loid)s. PMID:24552959
Menka, Nazune; Root, Rob; Chorover, Jon
Experimentally increased in ovo testosterone leads to increased plasma bactericidal activity and decreased cutaneous immune response in nestling house wrens.
Maternally derived testosterone in the eggs of birds may benefit nestlings by increasing various aspects of their growth, condition and behavioral development, but these benefits may come at a cost, including suppression of immune responsiveness. Experiments on a variety of species in which in ovo levels of testosterone have been experimentally increased have produced mixed results; some have found increased growth and suppressed immune function of nestlings whereas others have found the opposite. In an attempt to clarify the relationship between in ovo testosterone and nestling size, mass, health state and immune responsiveness, we experimentally increased levels of testosterone in the eggs of house wrens (Troglodytes aedon). We simultaneously determined the size, mass, hematocrit (a measure of health state), cutaneous immune response to phytohaemagglutinin and plasma bactericidal activity of nestlings near the time of fledging. We predicted that nestlings hatching from testosterone-injected eggs would exhibit lower immune responsiveness, but achieve greater mass, size and condition, than nestlings hatching from vehicle-injected control eggs. Instead, we found that nestlings hatching from testosterone-injected eggs had a weaker cutaneous immune response but greater bactericidal activity than those hatching from control eggs. They did not, however, differ significantly in mass, size or hematocrit from controls. These results suggest that experimentally increased in ovo testosterone induced a trade-off between bactericidal activity and the cutaneous immune response. The opposite responses by two different measures of immune function to experimentally increased in ovo testosterone underscore the importance of including multiple immune assays when investigating the potential for trade-offs with the immune system and other physiological functions. PMID:21795576
Clairardin, Sandrine G; Barnett, Craig A; Sakaluk, Scott K; Thompson, Charles F
Lead in drinking water and human blood lead levels in the United States.
Lead is a pervasive environmental contaminant. The adverse health effects of lead exposure in children and adults are well documented, and no safe blood lead threshold in children has been identified. Lead can be ingested from various sources, including lead paint and house dust contaminated by lead paint, as well as soil, drinking water, and food. The concentration of lead, total amount of lead consumed, and duration of lead exposure influence the severity of health effects. Because lead accumulates in the body, all sources of lead should be controlled or eliminated to prevent childhood lead poisoning. Beginning in the 1970s, lead concentrations in air, tap water, food, dust, and soil began to be substantially reduced, resulting in significantly reduced blood lead levels (BLLs) in children throughout the United States. However, children are still being exposed to lead, and many of these children live in housing built before the 1978 ban on lead-based residential paint. These homes might contain lead paint hazards, as well as drinking water service lines made from lead, lead solder, or plumbing materials that contain lead. Adequate corrosion control reduces the leaching of lead plumbing components or solder into drinking water. The majority of public water utilities are in compliance with the Safe Drinking Water Act Lead and Copper Rule (LCR) of 1991. However, some children are still exposed to lead in drinking water. EPA is reviewing LCR, and additional changes to the rule are expected that will further protect public health. Childhood lead poisoning prevention programs should be made aware of the results of local public water system lead monitoring measurement under LCR and consider drinking water as a potential cause of increased BLLs, especially when other sources of lead exposure are not identified. PMID:22874873
Brown, Mary Jean; Margolis, Stephen
... house built before 1978, especially when using power sanders or other work practices that generate lead-contaminated ... www.ehow.com . Accessed April 2012. Wengrovitz, Anne M. and Brown, Mary Jean. Recommendations for Blood Lead ...
Three widely used commercially available portable X-ray fluorescence spectrometers were evaluated for precision and accuracy of measurement of lead in paint. ncluded were two direct reading instruments and one spectrum analyzer. est materials were prepared by spiking oil-based an...
House dust mite allergens induce proinflammatory cytokines from respiratory epithelial cells: the cysteine protease allergen, Der p 1, activates protease-activated receptor (PAR)-2 and inactivates PAR-1.
In previous studies, we demonstrated that allergenic house dust mite proteases are potent inducers of proinflammatory cytokines from the respiratory epithelium, although the precise mechanisms involved were unclear. In this study, we investigated whether this was achieved through activation of protease-activated receptor (PAR)-1 or -2. Pretreatment of A549 respiratory epithelial cells with the clinically important cysteine protease allergen, Der p 1, ablated subsequent PAR-1, but not PAR-2 agonist peptide-induced IL-6 and IL-8 release. HeLa cells transfected with the plasmid coding for PAR-2, in contrast to PAR-1, released significant concentration of IL-6 after exposure to Der p 1. Exposure of HeLa cells transfected with either PAR-1/enhanced yellow fusion protein or PAR-2/enhanced yellow fusion protein to Der p 1 caused receptor internalization in the latter cells only, as judged by confocal microscopy with re-expression of the receptor within 120-min postenzyme exposure. Der p 1-induced cytokine release from both A549 and transfected HeLa cells was accompanied by changes in intracellular Ca(2+) concentrations. Desensitization studies showed that Der p 1 pretreatment of the A549 cells resulted in the abolition of both trypsin- and PAR-2 agonist peptide-induced Ca(2+) release, but not that induced by subsequent exposure to either thrombin or PAR-1 agonist peptide. These data indicate for the first time that the house dust mite allergen Der p 1-induced cytokine release from respiratory epithelial cells is, in part, mediated by activation of PAR-2, but not PAR-1. PMID:12370395
Asokananthan, Nithiananthan; Graham, Peter T; Stewart, David J; Bakker, Anthony J; Eidne, Karin A; Thompson, Philip J; Stewart, Geoffrey A
Measurement of nicotine in household dust
An analytical method of measuring nicotine in house dust was optimized and associations among three secondhand smoking exposure markers were evaluated, i.e., nicotine concentrations of both house dust and indoor air, and the self-reported number of cigarettes smoked daily in a household. We obtained seven house dust samples from self-reported nonsmoking homes and 30 samples from smoking homes along with the information on indoor air nicotine concentrations and the number of cigarettes smoked daily from an asthma cohort study conducted by the Johns Hopkins Center for Childhood Asthma in the Urban Environment. House dust nicotine was analyzed by isotope dilution gas chromatography-mass spectrometry (GC/MS). Using our optimized method, the median concentration of nicotine in the dust of self-reported nonsmoking homes was 11.7 ng/mg while that of smoking homes was 43.4 ng/mg. We found a substantially positive association (r=0.67, P<0.0001) between house dust nicotine concentrations and the numbers of cigarettes smoked daily. Optimized analytical methods showed a feasibility to detect nicotine in house dust. Our results indicated that the measurement of nicotine in house dust can be used potentially as a marker of longer term SHS exposure.
Kim, Sungroul [Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Institute for Global Tobacco Control, 627 N. Washington Street, 2nd Floor Baltimore, MD 21205 (United States); Department of Environmental Health Sciences, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205 (United States)], E-mail: email@example.com; Aung, Ther; Berkeley, Emily [Department of Environmental Health Sciences, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205 (United States); Diette, Gregory B. [Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205 (United States); Department of Medicine, Johns Hopkins University School of Medicine (United States); Breysse, Patrick N. [Department of Environmental Health Sciences, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205 (United States)
... are exposed through lead-contaminated household dust or soil that gets into their mouths. � Homes that were ... out of areas in the yard with bare soil. o Wash children�s hands and toys with soap ...
Exposure to Beta-(1,3)-D-Glucan in House Dust at Age 7-10 Is Associated with Airway Hyperresponsiveness and Atopic Asthma by Age 11-14
Background Mould exposure has been linked to childhood asthma and bronchial hyper-responsiveness. Few studies have assessed beta-(1,3)-d-glucan (beta-glucan), a significant fungal cell wall constituent, in relation to asthma in adolescence. Objective To determine whether house dust-derived beta-glucan exposure at age 7�10 is associated with the development and persistence of atopic and non-atopic asthma, and bronchial hyper-responsiveness (BHR) by age 11�14. Methods Dust samples were collected from the 1995 Study of Asthma, Genes, and Environment (SAGE) birth cohort. This cohort was derived from Manitoba provincial healthcare administrative records of children high and low risk for asthma. Samples were collected from the homes of 422 children at age 7�10 and analyzed using beta-glucan and endotoxin-specific Limulus Amoebocyte Lysate assays. Asthma, atopy, and BHR status of each child were also assessed at ages 7�10 and 11�14. Results At age 7�10, beta-glucan dust levels in the home were associated with persistent atopic asthma at age 11�14 (OR 1.79 for each unit increase in levels, 95% CI 1.14�2.81), independent of endotoxin exposure, and Alternaria or Cladosporium sensitization. The likelihood of BHR almost doubled with unit increases in dust beta-glucan in asthmatic children. In children without asthma, exposure to high beta-glucan levels at age 7�10 also elevated risk for BHR in adolescence (OR 1.74, 95% CI 1.05�2.89). New-onset atopic asthma was twice more likely following high beta-glucan exposure in children without asthma but the association did not reach statistical significance. No associations were evident with concurrent asthma phenotype at age 7�10 or non-atopic asthma at age 11�14. Conclusion These findings implicate home beta-glucan exposure at school-age as a risk factor for persistent atopic asthma and new-onset BHR. The higher prevalence of BHR in urban adolescents may be propagated by this home exposure.
Maheswaran, Dharini; Zeng, Yiye; Chan-Yeung, Moira; Scott, James; Osornio-Vargas, Alvaro; Becker, Allan B.; Kozyrskyj, Anita L.
Multiple metal contamination from house paints: consequences of power sanding and paint scraping in New Orleans.
Power sanding exterior paint is a common practice during repainting of old houses in New Orleans, Louisiana, that triggers lead poisoning and releases more than Pb. In this study we quantified the Pb, zinc, cadmium, manganese, nickel, copper, cobalt, chromium, and vanadium in exterior paint samples collected from New Orleans homes (n = 31). We used interior dust wipes to compare two exterior house-painting projects. House 1 was measured in response to the plight of a family after a paint contractor power sanded all exterior paint from the weatherboards. The Pb content (approximately 130,000 microg Pb/g) was first realized when the family pet died; the children were hospitalized, the family was displaced, and cleanup costs were high. To determine the quantity of dust generated by power sanding and the benefits of reducing Pb-contaminated dust, we tested a case study house (house 2) for Pb (approximately 90,000 microg/g) before the project was started; the house was then dry scraped and the paint chips were collected. Although the hazards of Pb-based paints are well known, there are other problems as well, because other toxic metals exist in old paints. If house 2 had been power sanded to bare wood like house 1, the repainting project would have released as dust about 7.4 kg Pb, 3.5 kg Zn, 9.7 g Cd, 14.8 g Cu, 8.8 g Mn, 1.5 g Ni, 5.4 g Co, 2.4 g Cr, and 0.3 g V. The total tolerable daily intake (TTDI) for a child under 6 years of age is 6 microg Pb from all sources. Converting 7.4 kg Pb to this scale is vexing--more than 1 billion (10(9)) times the TTDI. Also for perspective, the one-time release of 7.4 x 10(9) microg of Pb dust from sanding compares to 50 x 10(9) microg of Pb dust emitted annually per 0.1 mile (0.16 km) from street traffic during the peak use of leaded gasoline. In this paper, we broaden the discussion to include an array of metals in paint and underscore the need and possibilities for curtailing the release of metal dust.
Mielke, H W; Powell, E T; Shah, A; Gonzales, C R; Mielke, P W
NASA Astrophysics Data System (ADS)
We examine dust formation in macronovae (as known as kilonovae), which are the bright ejecta of neutron star binary mergers and one of the leading sites of r-process nucleosynthesis. In light of information about the first macronova candidate associated with GRB 130603B, we find that dust grains of r-process elements have difficulty forming because of the low number density of the r-process atoms, while carbon or elements lighter than iron can condense into dust if they are abundant. Dust grains absorb emission from ejecta with an opacity even greater than that of the r-process elements, and re-emit photons at infrared wavelengths. Such dust emission can potentially account for macronovae without r-process nucleosynthesis as an alternative model. This dust scenario predicts a spectrum with fewer features than the r-process model and day-scale optical-to-ultraviolet emission.
Takami, Hajime; Nozawa, Takaya; Ioka, Kunihito
Vacuum Head Removes Sanding Dust
NASA Technical Reports Server (NTRS)
Vacuum sander prevents sanding dust from entering a work area, since dust particles are drawn off as quickly as they are produced. Tool is useful where dust presents health hazards, interferes with such processes as semiconductor manufacture, or could destroy wet paint or varnish finishes. Could be used to sand such materials as lead paint.
Bengle, C. G.; Holt, J. W.
A coordinated relocation strategy for enhancing case management of lead poisoned children: outcomes and costs.
Controlling residential lead hazards is critical for case management of lead poisoned children. To attain this goal, permanent relocation of the family is sometimes necessary or advisable for many reasons, including poor housing conditions; extensive lead hazards; lack of abatement resources, landlord compliance and local enforcement capacity; and family eviction. During 1996-1998, the Kennedy Krieger Institute implemented a unique capitated program for case management of Baltimore City children with blood lead concentrations (PbB) >19 microg/dL. The Program provided financial, housing, and social work assistance to facilitate relocation as a means of providing safer housing. Nearly half of the Program families relocated with direct assistance, and 28% relocated on their own. The Program evaluation examined the costs and benefits of relocation. Average relocation cost per child was relatively inexpensive (<1,500 dollars). Average relocation time of 5 months (range <2 months to >12 months) was less than the 8-month average time to complete lead hazard control work in 14 city and state programs funded by U.S. HUD. Relocation was associated with (1) a statistically significant decrease in dust lead loadings on floors, windowsills and window troughs that persisted for one year, and (2) statistically significantly greater decreases in children's PbB compared to children who did not relocate from untreated homes. Children relocated to housing that met current Federal residential dust lead standards had statistically significant decreases in blood lead levels. Visual inspection did not consistently identify relocation houses with dust lead levels below current Federal standards, indicating that dust testing should be an essential component of future programs. This will require additional resources for dust testing and possibly cleaning and repairs but is expected to yield additional benefits for children. The findings support recent U.S. CDC case management recommendations suggesting that permanent relocation to safer housing is a viable means to reduce children's lead exposure. The benefits of relocation notwithstanding, 40% of families moved at least twice. Research is needed to better understand how to expedite relocation and encourage families to remain in safe housing. Relocation does not negate owners' and health authorities' responsibilities to address lead hazards in the child's original house in order to protect future occupants. PMID:16736359
McLaine, Pat; Shields, Wendy; Farfel, Mark; Chisolm, J Julian; Dixon, Sherry
Environmental and potential human health legacies of non-industrial sources of lead in a Canadian urban landscape � the case study of St John's, Newfoundland
Residential soil and house dust were collected in St John's to assess the levels of lead exposure and potential human health risk. Although St John's does not have an identified, major point source for lead, nor is it a heavily industrialized or populated city, 51% of all analysed soil samples (n = 1231) exceeded the Canadian Council of Ministers of
Trevor Bell; Stacy Campbell; David G. E. Liverman; David Allison; Paul Sylvester
Origin of lead in the United States diet.
We report 208Pb/207Pb and 206Pb/207Pb ratios for 1001 duplicate diets collected from mothers and children, 1304 samples of house dust and hand wipes, and 64 samples of aerosols that were taken in Omaha, Nebraska, during the period from 1990 to 1997. A plot of 208Pb/207Pb versus 206Pb/ 207Pb for the dust and hand wipes indicates that they contain lead from ores mined in Idaho, Missouri, and Mexico. The absence of lead from Utah suggests that this mixture is not representative of the whole country. The lead in the aerosols has a narrower range of isotope ratios and resembles aerosols collected elsewhere in the United States. Most dietary collections contain a large component of house dust. Some, especially those from infants, are dominated by uranogenic lead with high 206Pb/207Pb ratios. Its source is taken to be calcium-supplemented food where the calcium is derived from limestone. Another source of lead is thorogenic and is ascribed to lead in tin coatings. Agricultural lead, whether from soil (estimated from recently published analyses of sedimentary materials), fertilizer, or agricultural lime, could not be unambiguously identified in the diets. Lead derived from aerosols, if present at all, is insignificant. PMID:16329199
Manton, William I; Angle, Carol R; Krogstrand, Kaye L Stanek
Migration of contaminated soil and airborne particulates to indoor dust.
We have developed a modeling and measurement framework for assessing transport of contaminated soils and airborne particulates into a residence, their subsequent distribution indoors via resuspension and deposition processes, and removal by cleaning and building exhalation of suspended particles. The model explicitly accounts for the formation of house dust as a mixture of organic matter (OM) such as shed skin cells and organic fibers, soil tracked-in on footwear, and particulate matter (PM) derived from the infiltration of outdoor air. We derived formulas for use with measurements of inorganic contaminants, crustal tracers, OM, and PM to quantify selected transport parameters. Application of the model to residences in the U.S. Midwest indicates that As in ambient air can account for nearly 60% of the As input to floor dust, with soil track-in representing the remainder. Historic data on Pb contamination in Sacramento, CA, were used to reconstruct sources of Pb in indoor dust, showing that airborne Pb was likely the dominant source in the early 1980s. However, as airborne Pb levels declined due to the phase-out of leaded gasoline, soil resuspension and track-in eventually became the primary sources of Pb in house dust. PMID:19924944
Layton, David W; Beamer, Paloma I
Migration of Contaminated Soil and Airborne Particulates to Indoor Dust
We have developed a modeling and measurement framework for assessing transport of contaminated soils and airborne particulates into a residence, their subsequent distribution indoors via resuspension and deposition processes, and removal by cleaning and building exhalation of suspended particles. The model explicitly accounts for the formation of house dust as a mixture of organic matter (OM) such as shed skin cells and organic fibers, soil tracked-in on footwear, and particulate matter (PM) derived from the infiltration of outdoor air. We derived formulas for use with measurements of inorganic contaminants, crustal tracers, OM, and PM to quantify selected transport parameters. Application of the model to residences in the U.S. Midwest indicates that As in ambient air can account for nearly 60% of the As input to floor dust, with soil track-in representing the remainder. Historic data on Pb contamination in Sacramento, CA, was used to reconstruct sources of Pb in indoor dust, showing that airborne Pb was likely the dominant source in the early 1980s. However, as airborne Pb levels declined due to the phase out of leaded gasoline, soil resuspension and track-in eventually became the primary sources of Pb in house dust.
Layton, David W.; Beamer, Paloma I.
Influence of nutrient intake on blood lead levels of young children at risk for lead poisoning.
Although removal of lead paint hazards from at-risk houses remains the primary means of preventing elevated blood lead among young children, reduction of risk through nutritional factors has also been of interest. In this study we evaluated the effect of nutrient intake on blood lead levels by analyzing whether the intakes of certain dietary components a) were associated with blood lead levels independent of lead exposure or b) modified the effect of lead exposure on blood lead. Subjects were 205 children from low-income families who were approximately 1 year of age and living in old, urban houses. The data collected for each child included blood lead level, nutritional status, and amount of lead exposure, which was assessed from samples of household dust. Multiple linear regression analyses showed a statistically significant positive association between lead exposure and blood lead. Statistically significant positive associations were found between blood lead and total fat as well as blood lead and saturated fat, independent of lead exposure and age of the child. Regression modeling and stratified analysis showed that mean blood lead increased with increasing lead exposure as well as with increasing caloric intake, suggesting that caloric intake modifies the association between lead exposure and blood lead. The findings from this study, if replicated in other studies, support a dietary intervention to reduce the amount of total calories, total fat, and saturated fat among children 1 year of age at risk for lead exposure, while maintaining adequate intake of these dietary components. Our results also reinforce recommendations that removal of lead paint hazards from at-risk houses should be the primary means of preventing lead exposure.
Gallicchio, Lisa; Scherer, Roberta W; Sexton, Mary
Pilot investigation of a model for canine atopic dermatitis: environmental house dust mite challenge of high-IgE-producing beagles, mite hypersensitive dogs with atopic dermatitis and normal dogs.
Although canine atopic dermatitis (cAD) is common, few models are available. The aim of this study was to evaluate high-IgE beagles epicutaneously sensitized to house dust mite (HDM) as a possible model for cAD. Six high-IgE beagles were environmentally challenged with HDM using various doses and protocols. Similar challenge protocols were used in positive and negative control dogs: three dogs with naturally occurring cAD and positive intradermal skin test (IDT) to HDM and three normal dogs without history of skin disease and negative IDT to HDM. All high-IgE beagles and all atopic dogs developed severe cutaneous lesions and pruritus after challenge. Lesions were erythematous papules and macules in contact areas such as face, ears, ventral abdomen, groin, axillae and feet. They were first visible after 6 h and increased in severity over time. No normal dog developed pruritus or lesions. Biopsies of representative lesions in the high-IgE beagles were taken for histopathology and immunohistochemistry. There was superficial perivascular dermatitis with mononuclear infiltrates and spongiosis. Lymphocytes and eosinophils accumulated in small epidermal micro-abscesses with hyperplasia of epidermal IgE-bearing dendritic cells. These findings suggest that this colony of high-IgE beagles develops a dermatitis that clinically, histopathologically and immunologically resembles the naturally occurring canine disease. It is also concluded that this modality of challenge is not irritating to normal dogs but induces flare-ups in hypersensitive atopic dogs. PMID:16412117
Marsella, Rosanna; Olivry, Thierry; Nicklin, Connie; Lopez, Jennifer
Lead in the Japanese living environment.
Lead has long been known to be a neurotoxic heavy metal, particularly in the context of occupational health. However, its adverse effect on the cognitive development of children at lower exposure levels has only recently received attention. Although the exposure level of contemporary Japanese children is among the lowest in the world, it is desirable to reduce exposure as much as reasonably possible due to the absence of a threshold of exposure for adverse effects. In this review, information on lead levels in milieus of our proximate environment, such as the atmosphere, drinking water, soil, house dust, diet and others, of contemporary Japan was compiled with the aim of updating our knowledge on lead distribution. Monitoring data demonstrates that lead concentrations in the atmosphere and lead intake from food consumption have decreased substantially from the 1970s. Lead was hardly detectable in tap water in a recent nation-wide monitoring survey. To the contrary, elevated lead concentrations were detected in surface soil and house dust in one of the studies on daily exposure to lead from all potential sources, and both of these sources were regarded by the authors as significant contributors of lead exposure to general Japanese children. A similar study indicated that diet is the sole major source of lead for Japanese children. A significant difference was present in the estimated dietary lead intake levels in different studies, resulting in significant discrepancies in the current knowledge on lead in our environment. Further studies are warranted to identify the major source(s) of lead exposure in Japanese children in order to establish an effective countermeasure to reduce lead exposure to children. PMID:22528209
Yoshinaga, Jun
The effect of House Market downturn on House Price Index
Downturn of housing markets is a fact leading to falling prices and lower volume of sales. In the Icelandic case this has led to problem because of fewer contracts and missing prices. This has caused difficult measurement problems that are outlined. This paper descripes also the Icelandic house price index, the development of housing sales and prices 2000-2009 and falling
Gu�r�n R. J�nsd�ttir; L�ra G. J�nasd�ttir
Ceiling (attic) dust: A �museum� of contamination and potential hazard
Ceiling or attic dusts provide an indirect measure of air pollution integrated over varying time periods. We undertook an investigation into the particle-size distributions and sources and exposure pathways of metals in ceiling dusts from 38 houses in the city of Sydney, Australia. The houses ranged in age from 4 to 106 years and were grouped into three settings: industrial,
Jeffrey J. Davis; Brian L. Gulson
Geographic patterns of non-carpeted floor dust loading in Syracuse, New York (USA) homes
Residential floor dust loading was measured on the smooth floor surface of 488 houses in Syracuse, New York, during the summers\\u000a of 2003 and 2004. Using U.S. Environmental Protection Agency (EPA) wipe methods, pre-weighed Ghost Wipes, Lead Wipes, or Whatman\\u000a Filters were employed to collect duplicate samples from (predominantly) kitchens. The collection efficiency of the various\\u000a media was determined from
D. L. Johnson; A. Hunt; D. A. Griffith; J. M. Hager; J. Brooks; H. StellaLevinsohn; A. Lanciki; R. Lucci; D. Prokhorova; S. L. Blount
Lead exposure assessment from study near a lead-acid battery factory in China.
The production of lead-acid battery in China covered about one-third of the world total output and there are more than 2000 lead-acid battery factories. They may cause the major environment lead pollution. Blood lead levels of several hundreds of residents were over 100 ?g/L due to the waste discharges from a lead-acid battery factory in Heyuan, Guangdong province. This study aimed to find out the environmental lead sources, the human lead exposure pathways, and the amplitudes from a lead-acid battery factory. The study results showed that lead levels in soil, dust, tree leaves and human blood declined with the distances increased from the production site. Twenty nine of 32 participants had blood lead levels of over 100 ?g/L with an exceptional high value of 639 ?g/L for one child. This result suggested that the lead-acid battery production from this factory has caused the elevated lead levels in its neighboring environment and residents. Dust intake was the dominant exposure pathway for humans (over 90%). The lead levels found in adult and toddler (6.19 and 50.1 ?g/kg/d, respectively) in the polluted area were far higher than the provisional tolerable weekly intake (PTWI) of 25 ?g/kg body weight (translated into 3.5 ?g/kg/d), which was established by the joint FAO/WHO Expert Committee. Blood lead levels within the family members were strongly correlated with the house dust lead levels. Our results in this study suggested that further studies in this area should be performed to assess human exposure and relevant human health risks from living close to lead-acid battery factories. PMID:22578522
Chen, Laiguo; Xu, Zhencheng; Liu, Ming; Huang, Yumei; Fan, Ruifang; Su, Yanhua; Hu, Guocheng; Peng, Xiaowu; Peng, Xiaochun
Health and environmental outcomes of traditional and modified practices for abatement of residential lead-based paint
We evaluated traditional and modified practices for abating lead-based paint in homes of children with blood-lead concentrations (PbB) greater than 1.4 mumol\\/L (greater than 29 micrograms\\/dl). Traditional abatement resulted in acute increases in: (1) lead contaminated house dust (generally 3 to 6-fold over pre-abatement levels, but at abated sites typically 10 to 100-fold); and (2) the PbBs of nearly half
M. R. Farfel; J. J. Jr. Chisolm
NSDL National Science Digital Library
Poets House is an organization that focuses on modern poetry and is a "national poetry library and literary center that invites poets and the public to step into the living tradition of poetry." The website of this New York-based treasure is now in Battery Park City, and houses a 50,000 volume poetry collection of varied media, including journals, audio, video, and digital media. The "News" tab offers a slideshow of "Poetry Hard-Hat Tours" that has almost two dozen photos of the progress of the building of the new Battery Park City location. The "Programs" tab on the left hand menu leads the visitors to a "Calendar of Events", as well as descriptions of the events on the calendar, such as "Seminars and Workshops", "Showcase Events" and "Conversations on Poetics". The "Directory" tab on the left hand menu offers a free 20,000 title online database of poetry titles published between 1990 and 2008, and is searchable by numerous criteria, as well as sortable by author, title, or publisher.
An evaluation of the effectiveness of lead paint hazard reduction when conducted by homeowners and landlords
This research project was conducted in collaboration with the Iowa Department of Public Health to evaluate whether property owners who follow recommended procedures for lead-based paint removal/repair can do the work safely and effectively. This study included 29 homes where a lead-based paint hazard had been identified and lead-based paint was removed or repaired (hazard reduction). Exposure evaluation included pre-project surface dust wipe sampling, air monitoring during lead-based paint removal, post-project surface dust wipe sampling, and pre- and post-project blood samples from adult study participants. The comparison of surface dust wipe samples taken before and after lead paint hazard reduction was used to evaluate the effectiveness of lead paint hazard reduction. The lead loadings on window sill surfaces in the work area were significantly lower after completion of the project, and the lead-based paint removal did not contaminate the adjoining living area. The proportion of homes with surface dust lead loading exceeding Department of Housing and Urban Development (HUD) clearance standard was 73% pre-project and 38% post-project. Personal airborne exposures during lead removal activities reinforce the need to respiratory protection and good hygiene. There was no difference in adult pre-/post-blood levels, indicating that participants die remove lead in a safe manner with respect to their own exposures. The results indicate that hazard reduction can be done effectively when recommended procedures for the removal of lead-based paint are followed.
Etre, L.A.; Reynolds, S.J.; Burmeister, L.F.; Whitten, P.S.; Gergely, R.
NASA Astrophysics Data System (ADS)
With plans for the United States to return to the moon, and establish a sustainable human presence on the lunar surface many issues must be successfully overcome. Lunar dust is one of a number of issues with the potential to create a myriad of problems if not adequately addressed. Samples of dust brought back from Apollo missions show it to be soft, yet sharp and abrasive. The dust consists of a variety of morphologies including spherical, angular blocks, shards, and a number of irregular shapes. One of the main issues with lunar dust is its attraction to stick to anything it comes in contact with (i.e. astronauts, equipment, habitats, etc.). Ionized radiation from the sun strikes the moon's surface and creates an electrostatic charge on the dust. Further, the dust harbors van der Waals forces making it especially difficult to separate once it sticks to a surface. During the Apollo missions, it was discovered that trying to brush the lunar dust from spacesuits was not effective, and rubbing it caused degradation of the suit material. Further, when entering the lunar module after moonwalks, the astronauts noted that the dust was so prolific inside the cabin that they inhaled and ingested it, causing at least one of them, Harrison "Jack" Schmidt, to report irritation of the throat and lungs. It is speculated that the dust could also harm an astronaut's nervous and cardiovascular systems, especially during an extended stay. In addition to health issues, the dust can also cause problems by scouring reflective coatings off of thermal blankets, and roughening surfaces of windows and optics. Further, panels on solar cells and photovoltaics can also be compromised due to dust sticking on the surfaces. Lunar dust has the capacity to penetrate seals, interfere with connectors, as well as mechanisms on digging machines, all of which can lead to problems and failure. To address lunar dust issues, development of electrostatic screens to mitigate dust on sur-faces is currently being developed in a collaborative effort between Langley Research Center and Kennedy Space Center. The screens typically consist of spiral shaped conductive traces patterned on high dielectric substrates (i.e. glass, quartz, polyimide film, etc.). Two broad categories of substrate materials are being investigated for the screens. One category consists of transparent substrates (i.e. glass, quartz, sapphire, etc.), and the other non-transparent sub-strates (Kapton, polyimide films, metals, etc.). The transparent screens utilize patterns made from indium tin oxide (ITO), a transparent conductive material, on clear substrates while the non-transparent screens use copper patterns on a transluscent or opaque substrates. Further, the screen is coated with a high dielectric polyimide cover layer to protect the screen pattern. One promising cover layer material that is currently being investigated is Langley Research Center-Soluble Imide (LaRC-SI), a NASA LaRC developed polyimide. Lastly, a top-coat of hard, inorganic material is evaporated onto the cover layer for protection from scratches due to abrasive nature of the dust. Of note, several top-coat materials are under investigation and include: aluminum oxide, silicon dioxide, titanium oxide, yttrium oxide, zirconium oxide, and zinc sulfide. The electrostatic dust mitigation screens function when a high voltage (700V or greater) is applied to the screen electrodes, thus creating an electromagnetic wave across the surface of the screen that repels the dust. Lunar dust typically contains a high positive charge; therefore, the screens are charged with a higher positive charge that effectively repels dust from the surface (i.e. like charges repel, unlike charges attract). It is anticipated that full development and maturation of this technology will enable humans to sustain a long term presence on the moon, and other planets where dust may have negative implications.
Knutson, Shawn; Holloway, Nancy
ERIC Educational Resources Information Center
Reviews some of the efforts of the Society for the Preservation of New England Antiquities (SPNEA) to preserve, conserve, and interpret historic houses to the public. Examines the history and some of the specific preservation problems concerning the Beauport Cottage, the Sayward-Wheeler House, and the Gropius House. (MJP)
Curtis, Nancy
NASA Astrophysics Data System (ADS)
Preface; 1. Planet formation and protoplanetary dust Daniel Apai and Dante Lauretta; 2. The origins of protoplanetary dust and the formation of accretion disks Hans-Peter Gail and Peter Hope; 3. Evolution of protoplanetary disk structures Fred Ciesla and Cornelius P. Dullemond; 4. Chemical and isotopic evolution of the solar nebula and protoplanetary disks Dmitry Semenov, Subrata Chakraborty and Mark Thiemens; 5. Laboratory studies of simple dust analogs in astrophysical environments John R. Brucato and Joseph A. Nuth III; 6. Dust composition in protoplanetaty dust Michiel Min and George Flynn; 7. Dust particle size evolution Klaus M. Pontoppidan and Adrian J. Brearly; 8. Thermal processing in protoplanetary nebulae Daniel Apai, Harold C. Connolly Jr. and Dante S. Lauretta; 9. The clearing of protoplanetary disks and of the protosolar nebula Ilaira Pascucci and Shogo Tachibana; 10. Accretion of planetesimals and the formation of rocky planets John E. Chambers, David O'Brien and Andrew M. Davis; Appendixes; Glossary; Index.
Apai, D.�niel; Lauretta, Dante S.
NASA Astrophysics Data System (ADS)
Preface; 1. Planet formation and protoplanetary dust Daniel Apai and Dante Lauretta; 2. The origins of protoplanetary dust and the formation of accretion disks Hans-Peter Gail and Peter Hope; 3. Evolution of protoplanetary disk structures Fred Ciesla and Cornelius P. Dullemond; 4. Chemical and isotopic evolution of the solar nebula and protoplanetary disks Dmitry Semenov, Subrata Chakraborty and Mark Thiemens; 5. Laboratory studies of simple dust analogs in astrophysical environments John R. Brucato and Joseph A. Nuth III; 6. Dust composition in protoplanetaty dust Michiel Min and George Flynn; 7. Dust particle size evolution Klaus M. Pontoppidan and Adrian J. Brearly; 8. Thermal processing in protoplanetary nebulae Daniel Apai, Harold C. Connolly Jr. and Dante S. Lauretta; 9. The clearing of protoplanetary disks and of the protosolar nebula Ilaira Pascucci and Shogo Tachibana; 10. Accretion of planetesimals and the formation of rocky planets John E. Chambers, David O'Brien and Andrew M. Davis; Appendixes; Glossary; Index.
Apai, D�niel; Lauretta, Dante S.
Does Housing Mobility Policy Improve Health?
This article summarizes the empirical evidence for the effect of housing mobility policies on health outcomes. Our focus derived from our interest in housing policies that might help reduce health disparities and our finding that, excluding policies concerned with the physical characteristics of housing (e.g., exposure to lead), only housing mobility has been evaluated for its effects on health.We reviewed
Theresa L. Osypuk; Rebecca E. Werbel; Ellen R. Meara; David M. Cutler; Lisa F. Berkman
... Crystal McIntyre email@example.com Compliance Assistance & Enforcement Lead-Based Paint Disclosure Rule Pre-Renovation Education ... EPA's Lead in Paint, Dust and Soil page . Enforcement 40 CFR Part 2 Confidential Business Information (PDF) ( ...
The connection between housing and health is well established. Physical, chemical, and biological aspects of the child's home, such as cleanliness, moisture, pests, noise, accessibility, injury risks, and other forms of housing environmental quality, all have the potential to influence multiple aspects of the health and development of children. Basic sanitation, reduced household crowding, other improvements in housing and expanded, and improved housing regulations have led to advances in children's health. For example, lead poisoning prevention policies have profoundly reduced childhood lead exposure in the United States. This and many other successes highlight the health benefits for families, particularly children, by targeting interventions that reduce or eliminate harmful exposures in the home. Additionally, parental mental health problems, food insecurity, domestic violence, and the presence of guns in children's homes all are largely experienced by children in their homes, which are not as yet considered part of the Healthy Homes agenda. There is a large movement and now a regulatory structure being put in place for healthy housing, which is becoming closely wedded with environmental health, public health, and the practice of pediatrics. The importance of homes in children's lives, history of healthy homes, asthma, and exposures to lead, carbon monoxide, secondhand/thirdhand smoke, radon, allergy triggers is discussed, as well as how changes in ambient temperature, increased humidity, poor ventilation, water quality, infectious diseases, housing structure, guns, electronic media, family structure, and domestic violence all affect children's health. PMID:23953987
Weitzman, Michael; Baten, Ahmareen; Rosenthal, David G; Hoshino, Risa; Tohn, Ellen; Jacobs, David E
Skin lead contamination of family members of boat-caulkers in southern Thailand.
Powdered lead oxide (Pb(3)O(4)) is used in the wooden-boat repair industry as a constituent of the caulking material. This study compared skin lead of household members of caulkers' and control homes, and examined the relationship of household member's skin lead with household floor lead loading (FLL) and dust lead content (DLC). FLL and DLC were measured in 67 caulkers' houses and 46 nearby houses with no known lead exposure. In each household, wipe specimens of skin lead were obtained from one selected family member. Hand lead loading (HdLL) and foot lead loading (FtLL) were significantly higher in family members of caulkers than controls (geometric mean 64.4 vs. 36.2 ?g m(-2); p = 0.002 and 77.8 vs 43.8 ?g m(-2); p = 0.002, respectively). This pattern mirrored FLL and DLC, which were also higher in caulkers' than in control houses (geometric mean 109.9 vs. 40.1 ?g m(-2); p<0.001 and 434.8 vs 80.8 ?g g(-1); p<0.001, respectively). Multiple linear regression modelling revealed FLL to be a better predictor than DLC for HdLL in all age groups and for FtLL in adult family members. In conclusion, skin lead levels are elevated in family members living in a lead-exposed worker's house and are related to the levels of household lead contamination. PMID:20823635
Untimanon, Orrapan; Geater, Alan; Chongsuvivatwong, Virasakdi; Saetia, Wiyada; Utapan, Sutida
Miners' Views about Personal Dust Monitors
oal Workers Pneumoconiosis is the leading cause of death due to occupational illness among coal Cminers. This disease is caused by miners' exposure to respirable coal mine dust. A Personal Dust Monitor has recently been developed to provide near real time feedback to miners regarding the number of milligrams of respirable coal mine dust in the air they breathe. This
Robert H. Peters; Charles Vaught; Erica E. Hall; Jon C. Volkwein