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[Characterization of the content of polycyclic aromatic hydrocarbons in the cold- and hot-smoked fish].
The carcinogenic danger of the commercial smoked herring was assessed. The edible part of the smoked herring contains 16 polycyclic aromatic hydrocarbons whose bulk consists of phenanthrene, pyrene, floranthene, and benzo(b)fluoranthene. The content of benzo(a)pyrene (BP) in the cold and hot smoked herring are 189 and 291 ng/kg, respectively. It is lower than the present standard values. The proportion of carcinogenic danger of BP is 32% for cold smoked herring and 34% for hot smoked herring. PMID:10465871
Kim, I N; Kim, G N; Krivosheeva, L V; Khitrovo, I A
[Polycyclic aromatic hydrocarbons content in Antarctica soils as exemplified by the Russian polar stations].
The comprehensive study of the qualitative and quantitative composition of polycyclic aromatic hydrocarbons (PAHs) in soils of Antarctica (reference landscapes--mountains Hudson, Haswell Archipelago contaminated soil--Mirny, Druznaya-4, Bellingshausen--and imported soils) was performed with the use of HPLC in a gradient mode. A characteristic feature of the studied PAHs content of soils is the predominance of low-molecular polyarenes in them. Due to anthropogenic pollution the quantitative accumulation of both light and heavy PAHs occurs under the qualitative increase in the proportion of heavy polyarenes. Polyarenes pool in the studied soils is represented mainly by light PAHs: naphthalene, phenanthrene, fluoranthene, pyrene, etc. The content of benzo(a)pyrene does not exceed the MCL (adopted in the Russian Federation) for this ecotoxicant. Performed primary factual and statistical analysis of data permitted to reveal that heavy PAH pollution of Antarctica soils is in the most initial stage, there is no sustained and statistically significant accumulation of PAHs in soils of maritime as well as continental Antarctica. There are established the levels of the actual content of various PAHs in soils of different regions of the Antarctica, which is the basic data for further comparative analysis of data of geochemical studies. PMID:24749277
Abakumov, E V; Lodygin, E D; Gabov, D A; Krylenkov, V A
Impact of oxidation process on polycyclic aromatic hydrocarbon (PAH) content in bitumen.
This study investigated the impact of the oxidation process on the concentration of polycyclic aromatic hydrocarbons (PAH) in blown bitumen and identified some key contributing parameters. The U.S. Environmental Protection Agency's PAH list was used for this study. PAHs are considered a good toxicological marker, and measurement of PAHs in bitumen can be performed easily. The results of PAH content in blown bitumen and the corresponding feedstock was determined from the limit of detection up to 120 mg/kg for 24 samples. Compared to PAH levels in coal tar pitch, PAH levels in bitumen are very low. Measurements were performed by three laboratories using different methods to allow robust conclusions. The results highlight the difficulties in measuring PAHs in bitumen with accuracy for values below 30 mg/kg; therefore the discussion is based on summary statistics by adding concentrations of PAHs with common ring sizes. Incorporation of flux oil in the feed of the blowing bitumen unit tends to increase PAH content in feed stock and in blown bitumen, particularly the 4- to 6-ring PAHs, which are the most carcinogenic as identified by an animal skin painting test. The amount of PAH content from blown bitumen with flux oil can be at least three times higher than the amount in blown bitumen without flux oil, depending on the quality and quantity of the flux oil used. This study shows that the blowing process does not produce PAHs in bitumen. Conversely, it appears to reduce them in the final product. Close to 10 to 30% of PAHs are probably stripped from the liquid phase of bitumen during the blowing operation. PMID:23767962
Bolliet, Christophe; Juery, Catherine; Thiebaut, Benoit
Factors affecting the polycyclic aromatic hydrocarbon content of cereals, fats and other food products
Microsoft Academic Search
Factors affecting polycyclic aromatic hydrocarbon (PAH) concentrations in oils and fats, cereals and related foodstuffs have been investigated. Levels of PAHs were low in retail fish and animal?derived oils and fats, such as butter, where the mean benzo(a)pyrene concentration was 0.06 ?g\\/kg. Higher and more variable amounts were present in retail vegetable oils for which the mean level of benzo(a)pyrene
M. J. Dennis; R. C. Massey; G. Cripps; I. Venn; N. Howarth; G. Lee
Biodegradation of polycyclic aromatic hydrocarbons
The intent of this review is to provide an outline of the microbial degradation of polycyclic aromatic hydrocarbons. A catabolically diverse microbial community, consisting of bacteria, fungi and algae, metabolizes aromatic compounds. Molecular oxygen is essential for the initial hydroxylation of polycyclic aromatic hydrocarbons by microorganisms. In contrast to bacteria, filamentous fungi use hydroxylation as a prelude to detoxification rather
Carl E. Cerniglia
Impact of using fishing boat fuel with high poly aromatic content on the emission of polycyclic aromatic hydrocarbons from the diesel engine
NASA Astrophysics Data System (ADS)
Because of the fishery subsidy policy, the fishing boat fuel oil (FBFO) exemption from commodity taxes, business taxes and air pollution control fees, resulted in the price of FBFO was �50% lower than premium diesel fuel (PDF) in Taiwan. It is estimated that �650,000 kL FBFO was illegally used by traveling diesel-vehicles (TDVs) with a heavy-duty diesel engine (HDDE), which accounted for �16.3% of the total diesel fuel consumed by TDVs. In this study, sulfur, poly aromatic and total-aromatic contents in both FBFO and PDF were measured and compared. Exhaust emissions of polycyclic aromatic hydrocarbons (PAHs) and their carcinogenic potencies (BaP eq) from a HDDE under transient cycle testing for both FBFO and PDF were compared and discussed. Finally, the impact caused by the illegal use of FBFO on the air quality was examined. Results show that the mean sulfur-, poly aromatic and aromatic-contents in FBFO were 43.0, 3.89 and 1.04 times higher than that of PDF, respectively. Emission factors of total-PAHs and total-BaP eq obtained by utilizing FBFO were 51.5 and 0.235 mg L -1-Fuel, which were 3.41 and 5.82 times in magnitude higher than obtained by PDF, respectively. The estimated annual emissions of total-PAHs and total-BaP eq to the ambient environment due to the illegally used FBFO were 23.6 and 0.126 metric tons, respectively, which resulted in a 17.9% and a 25.0% increment of annual emissions from all mobile sources, respectively. These results indicated that the FBFO used illegally by TDVs had a significant impact on PAH emissions to the ambient environment.
Lin, Yuan-Chung; Lee, Wen-Jhy; Li, Hsing-Wang; Chen, Chung-Ban; Fang, Guor-Cheng; Tsai, Perng-Jy
Nitro-polycyclic aromatic hydrocarbon contents of fumes from heated cooking oils and prevention of mutagenicity by catechin
According to earlier studies, fumes from cooking oils were found to be mutagenic and several polycyclic aromatic hydrocarbons (PAHs), (benzo(a)pyrene (B(a)P), benz(a)antracene (B(a)A), and dibenz(a,h)anthracene (DB(ah)A)) were identified. Fume samples from three different commercial cooking oils frequently used in Taiwan were collected and nitro-polycyclic aromatic hydrocarbons (NPAHs) were extracted from the samples and identified by HPLC chromatography. Extracts from three
Pei-Fen Wu; Tai-An Chiang; Li-Fang Wang; Chia-Shiung Chang; Ying-Chin Ko
Polycyclic Aromatic Hydrocarbon Structure Index.
National Technical Information Service (NTIS)
The Structure Index presents a compilation of names, structures, and related data for 660 aromatic hydrocarbons. The publication consists of two parts: (1) chemical structures including ring numbering, name(s), Chemical Abstract Service (CAS) Registry num...
L. C. Sander S. A. Wise
Polycyclic Aromatic Hydrocarbons
NASA Technical Reports Server (NTRS)
Carbonaceous materials play an important role in space. Polycyclic Aromatic Hydrocarbons (PAHs) are a ubiquitous component of the carbonaceous materials. PAHs are the best-known candidates to account for the IR emission bands. They are also thought to be among the carriers of the diffuse interstellar absorption bands (DIBs). PAH ionization states reflect the ionization balance of the medium while PAH size, composition, and structure reflect the energetic and chemical history of the medium. A major challenge is to reproduce in the laboratory the physical conditions that exist in the emission and absorption interstellar zones. The harsh physical conditions of the ISM -low temperature, collisionless, strong UV radiation fields- are simulated in the laboratory by associating a molecular beam with an ionizing discharge to generate a cold plasma expansion. PAH ions and radicals are formed from the neutral precursors in an isolated environment at low temperature and probed with high-sensitivity cavity ringdown spectroscopy in the NUV-NIR range. Carbon nanoparticles are also formed during the short residence time of the precursors in the plasma and are characterized with time-offlight mass spectrometry. These experiments provide unique information on the spectra of large carbonaceous molecules and ions in the gas phase that can now be directly compared to interstellar and circumstellar observations (IR emission bands, DIBs, extinction curve). These findings also hold great potential for understanding the formation process of interstellar carbonaceous grains. We will review recent progress in the experimental and theoretical studies of PAHs, compare the laboratory data with astronomical observations and discuss the global implications.
Salama, Farid
Infrared Properties of Molecular Cirrus. II. Cloud-to-Cloud Variations in Graphite and Polycyclic Aromatic Hydrocarbon Content
We have conducted a photometric survey of translucent molecular clouds in the four IRAS wave bands. We find notable cloud-to-cloud variations in mid-IR emission, with the ratio I12/I25 varying by up to 1 order of magnitude and often above unity. Because the clouds in our sample are nearby and translucent, the cloud heating is well constrained, so that the observed differences in infrared emission must represent differences in grain content. We show from first principles that a dust model containing only two components, Mathis-Rumpl-Nordsieck (MRN) grains in thermal equilibrium and very small grains undergoing stochastic heating, can never produce I12/I25>=1 under the conditions that prevail in the cloudy interstellar medium. We fit the clouds in this sample with a three-component model which contains continuum emission from both MRN grains and very small graphite grains, plus emission features from a mixture of polycyclic aromatic hydrocarbon (PAH). The cloud-to-cloud variations in mid-IR emission require significant differences in their composition of small grains and PAH molecules. Models which describe the formation and evolution of these particles in the interstellar medium must explain the presence of these variations in a cloud sample which is located in the solar neighborhood.
Verter, Frances; Magnani, Loris; Dwek, Eli; Rickard, Lee J.
Contents and sources of polycyclic aromatic hydrocarbons and organochlorine pesticides in vegetable soils of Guangzhou, China
We investigated contents, distribution and possible sources of PAHs and organochlorine pesticides (Ops) in 43 surface and subsurface soils around the urban Guangzhou where variable kinds of vegetables are grown. The results indicate that the contents of PAHs (16 US EPA priority PAHs) range from 42 to 3077?g\\/kg and the pollution extent is classified as a moderate level in comparison
Laiguo Chen; Yong Ran; Baoshan Xing; Bixian Mai; Jianghua He; Xiuguo Wei; Jiamo Fu; Guoying Sheng
EPA Science Inventory
Aromatic hydrocarbons have a ubiquitous distribution in nature. he majority of these compounds are formed through the pyrolysis of organic matter. yrolysis at high temperatures leads to the information of unsubstituted polycyclic aromatic hydrocarbons (1). yrolysis at low tempera...
Stabilization of sewage sludge by different biochars towards reducing freely dissolved polycyclic aromatic hydrocarbons (PAHs) content.
The objective of the study was to identify the effect of various biochars on the content of freely dissolved (Cfree) PAHs in sewage sludge. Apart from the evaluation of biochars obtained from various materials, the study also included the determination of the effects of biochar particle sizes and biochar production temperature on their ability to bind PAHs in sewage sludge. Increase in biochar dose caused a gradual reduction of Cfree PAHs content, but only up to the biochar dose of 5%. Depending on the kind of initial material from which the biochar was produced, the reduction of Cfree PAHs content in sewage sludge varied from 17.4% to 58.0%. Both the temperature and the particle size of biochar had an effect on PAH free concentration reduction. Biochars characterised by a low polarity index (O/C or (O+N)/C) reduced the level of Cfree PAHs better than biochars with a higher polarity index value. PMID:24495539
Oleszczuk, Patryk; Zieli?ska, Anna; Cornelissen, Gerard
Contents and sources of polycyclic aromatic hydrocarbons and organochlorine pesticides in vegetable soils of Guangzhou, China.
We investigated contents, distribution and possible sources of PAHs and organochlorine pesticides (Ops) in 43 surface and subsurface soils around the urban Guangzhou where variable kinds of vegetables are grown. The results indicate that the contents of PAHs (16 US EPA priority PAHs) range from 42 to 3077 microg/kg and the pollution extent is classified as a moderate level in comparison with other investigations and soil quality standards. The ratios of methylphenanthrenes to phenanthrene(MP/P), anthracene to anthracene plus phenanthrene (An/178), benz[a]anthracene to benz[a]anthracene plus chrysene (BaA/228), indeno[1,2,3-cd]pyrene to indeno[1,2,3-cd]pyrene plus benzo[ghi]perylene (In/In+BP) suggest that the sources of PAHs in the soil samples are mixed with a dominant contribution from petroleum and combustion of fossil fuel. The correlation analysis shows that the PAHs contents are significantly related to total organic carbon contents (TOC) (R2=0.75) and black carbon contents (BC) (R2=0.62) in the soil samples. Dichlorodiphenyltrichloroethane and metabolites (DDTs) and hexachlorocyclohexanes and metabolites (HCHs) account largely for the contaminants of OPs. The concentrations of DDTs range from 3.58 to 831 microg/kg and the ratios for DDT/(DDD+DDE) are higher than 2 in some soil samples, suggesting that DDT contamination still exists and may be caused by its persistence in soils and/or impurity in the pesticide dicofol. The concentrations of HCHs are 0.19-42.3 microg/kg. PMID:15992594
Chen, Laiguo; Ran, Yong; Xing, Baoshan; Mai, Bixian; He, Jianghua; Wei, Xiuguo; Fu, Jiamo; Sheng, Guoying
Polycyclic Aromatic Hydrocarbon Structure Index
NSDL National Science Digital Library
The Polycyclic Aromatic Hydrocarbon (PAH) Index, a special publication from the National Institute of Standards and Technology, provides the structures of a large number of PAHs. In addition to the structure, the Index lists other names for the compound, CAS number, molecular weight, length-to-breadth ratio, width, length, and thickness. Users can search the PAH Index via compound name and molecular weight, browse alphabetically, or scan cover to cover. An introduction to the Index is available in [.pdf] format.
Sander, Lane C.; Wise, Stephen A. (Stephen Albert), 1949-.
Aromatic hydrocarbon degradation: A molecular approach
SciTech Connect
Aromatic hydrocarbons have a ubiquitous distribution in nature. The majority of these compounds are formed through the pyrolysis of organic matter. Pyrolysis at high temperatures leads to the formation of unsubstituted polycyclic aromatic hydrocarbons. Pyrolysis at low temperatures, such as those at which crude petroleum is formed, leads to the formation of alkyl-substituted aromatic hydrocarbons. Many of these compounds are suspected carcinogens. Increased use of petrochemicals by modern society has increased the amount of aromatic hydrocarbons found in air and soil samples. It is not surprising then that due to the ubiquitous nature and increasing concentrations of aromatic hydrocarbons microorganisms can be found that have the ability to degrade these compounds. The varied mechanisms by which microorganisms utilize aromatic hydrocarbons as carbon and energy sources have been the focus of several reviews.
Zylstra, G.J.; Gibson, D.T.
Quantitative data concerning photoreactions of aromatic hydrocarbons were obtained in distilled water and several natural water samples. The reactions were studied at concentrations lower than the solubility limits of the aromatics, which in some cases were less than 1 microgram ...
Nitro-polycyclic aromatic hydrocarbon contents of fumes from heated cooking oils and prevention of mutagenicity by catechin.
According to earlier studies, fumes from cooking oils were found to be mutagenic and several polycyclic aromatic hydrocarbons (PAHs), (benzo(a)pyrene (B(a)P), benz(a)antracene (B(a)A), and dibenz(a,h)anthracene (DB(ah)A)) were identified. Fume samples from three different commercial cooking oils frequently used in Taiwan were collected and nitro-polycyclic aromatic hydrocarbons (NPAHs) were extracted from the samples and identified by HPLC chromatography. Extracts from three cooking oil fumes contained 1-nitropyrene (1-NP) and 1,3-dinitropyrene (1,3-DNP). Concentrations of 1-NP and 1,3-DNP were 1.1 +/- 0.1 and 0.9 +/- 0.1 micrograms/m3 in fumes from lard oil, 2.9 +/- 0.3 and 3.4 +/- 0.2 micrograms/m3 in soybean oil, 1.5 +/- 0.1 and 0.4 +/- 0.1 micrograms/m3 in peanut oil, respectively. The preventive effect of three natural antioxidants (gamma-tocopherol (TOC), lecithin (LEC), and catechin (CAT)) for the reduction of mutagenicity and amounts of PAHs and NPAHs of fumes from cooking oils were evaluated. Mutagenicity of cooking oil fumes occurred, and the concentration of B(a)P were significantly reduced (p < 0.05), by adding CAT into cooking oils before heating. B(a)A, DB(ah)A, and two NPAHs were not detected when the concentration of CAT was 500 ppm in all three cooking oil fumes. These results indicate that fumes of cooking oils contained PAHs and NPAHs that may be a risk factor for lung cancer among cooks and the carcinogens could be reduced by adding the natural antioxidant, catechin. PMID:9726003
Wu, P F; Chiang, T A; Wang, L F; Chang, C S; Ko, Y C
Sedimentary polycyclic aromatic hydrocarbons: the historical record
Polycyclic aromatic hydrocarbons in three sections of a dated sediment core from Buzzards Bay, Massachusetts, have been analyzed by gas chromatographic mass spectrometry. This historical information suggests that sedimentary polycyclic aromatic hydrocarbons, at least at this location, result primarily from the anthropogenic combustion of fossil fuels.
R. A. Hites; R. E. LaFlamme; J. W. Farrington
Effect of roasting conditions on the polycyclic aromatic hydrocarbon content in ground Arabica coffee and coffee brew.
Roasting is a critical process in coffee production as it enables the development of flavor and aroma. At the same time, roasting may lead to the formation of nondesirable compounds, such as polycyclic aromatic hydrocarbons (PAHs). In this study, Arabica green coffee beans from Cuba were roasted under controlled conditions to monitor PAH formation during the roasting process. Roasting was performed in a pilot spouted bed roaster, with the inlet air temperature varying from 180 to 260 degrees C, using both dark (20 min) and light (5 min) roasting conditions. Several PAHs were determined in both roasted coffee samples and green coffee samples. Also, coffee brews, obtained using an electric coffee maker, were analyzed for final estimation of PAH transfer coefficients to the infusion. Formation of phenanthrene, anthracene, and benzo[a]anthracene in coffee beans was observed at temperatures above 220 degrees C, whereas formation of pyrene and chrysene required 260 degrees C. Low levels of benzo[g,h,i]perylene were also noted for dark roasting under 260 degrees C, with simultaneous partial degradation of three-cycle PAHs, suggesting that transformation of low molecular PAHs to high molecular PAHs occurs as the roasting degree is increased. The PAH transfer to the infusion was quite moderate (<35%), with a slightly lower extractability for dark-roasted coffee as compared to light-roasted coffee. PMID:17941690
Houessou, Justin Koffi; Maloug, Saber; Leveque, Anne-Sophie; Delteil, Corine; Heyd, Bertrand; Camel, Val�rie
Shallow sublittoral meiofauna communities and sediment polycyclic aromatic hydrocarbons (PAHs) content on the Galician coast (NW Spain), six months after the Prestige oil spill.
The aim of this work was to detect the impact of Prestige oil spill on meiobenthic community structure at higher levels of taxonomic aggregation. In addition, the relationship between sediment individual polycyclic aromatic hydrocarbon (PAH) concentration and meiofauna community structure was investigated. Six months after the Prestige oil spill, meiobenthos community and sediment PAHs content from seven shallow subtidal localities along the Galician coast were studied. Two sites presented differences in community structure, characterized by high densities of nematodes, gastrotrichs and turbellarians, and low densities of copepods. Chrysene and triphenylene were only found at these two disturbed sites and could be responsible for differences of meiobenthos community structure. However, differences in community structure of sites could be linked with sedimentary parameters, and discrimination between the effect of PAHs and sedimentary parameters was impossible due to the lack of baseline studies on meiobenthos and PAHs contents in this area. PMID:19091356
Veiga, P; Rubal, M; Besteiro, C
Birds and polycyclic aromatic hydrocarbons
USGS Publications Warehouse
Polycyclic aromatic hydrocarbons (PAH) are present throughout the global environment and are produced naturally and by activities of humans. Effects of PAH on birds have been determined by studies employing egg injection, egg immersion, egg shell application, single and multiple oral doses, subcutaneous injection, and chemical analysis of field-collected eggs and tissue. The four-to six-ring aromatic compounds are the most toxic to embryos, young birds, and adult birds. For embryos, effects include death, developmental abnormalities, and a variety of cellular and biochemical responses. For adult and young birds, effects include reduced egg production and hatching, increased clutch or brood abandonment, reduced growth, increased organweights, and a variety of biochemical responses. Trophic level accumulation is unlikely. Environmental exposure to PAH in areas of high human population or habitats affected by recent petroleum spills might be sufficient to adversely affect reproduction. Evidence of long-term effects of elevated concentrations of environmental PAH on bird populations is very limited and the mechanisms of effect are unclear.
Albers, P. H.
High temperature chemistry of aromatic hydrocarbons.
We have not only gained new insight into the mechanism and generality of Polycyclic Aromatic Hydrocarbon (PAH) thermal automerization reactions, we have also uncovered several new high temperature reactions and added a third dimension to our program by ap...
L. T. Scott
Polycyclic Aromatic Hydrocarbon Analysis Round Robin Study.
The polycyclic aromatic hydrocarbon round robin study was conducted using an analytical procedure developed by IIT Research Institute. The method involves the fractionation of a representative diesel extract by high performance liquid chromatography (HPLC...
W. C. Eisenberg
Infrared Spectra of Polycyclic Aromatic Hydrocarbons (PAHs)
We have computed the synthetic infrared spectra of some polycyclic aromatic hydrocarbons containing up to 54 carbon atoms. The species studied include ovalene, circumcoronene, dicoronylene, and hexabenzocoronene. We report spectra for anions, neutrals, cations, and multiply charged cations.
Bauschlicher, Charles W., Jr.; Bakes, E. L. O.
Ethane to Aromatic Hydrocarbons: Past, Present, Future
Ranking high in the current challenges of catalysis, direct transformations of lower saturated hydrocarbons (alkanes) have been investigated for a long time. However, unsaturated hydrocarbons (e.g., aromatics and olefins) have always been the more important feedstocks to produce basic and intermediate chemicals because of their wide variety of possible reaction pathways. This article focuses on the conversion of one representative
Comparison of Polycyclic Aromatic Hydrocarbons and Nitropolycyclic Aromatic Hydrocarbons in Airborne and Automobile Exhaust Particulates
Polycyclic aromatic hydrocarbons (PAH) and nitropolycyclic aromatic hydrocarbons (NPAH) in airborne particulates collected simultaneously at downtown and suburban sites and in exhaust particulates from diesel and gasoline engine vehicles were determined. The mean concentrations of all compounds in the atmosphere were lower at the suburban site. The differences between the two sites were smaller in airborne particulates than in the
Kazuichi Hayakawa; Tsuyoshi Murahashi; Kazuhiko Akutsu; Tetsuo Kanda; Ning Tang; Hitoshi Kakimoto; Akira Toriba; Ryoichi Kizu
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
PubMed Central
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.
Distribution of polycyclic aromatic hydrocarbons in lime spray dryer ash
Four lime spray dryer (LSD) ash samples were collected from a spreader stoker boiler and measured for their concentrations of 16 U.S. EPA specified polycyclic aromatic hydrocarbons (PAHs). Results showed that the total measured PAH concentration correlated with the organic carbon content of the LSD ash. Each LSD ash sample was then separated using a 140 mesh sieve into two
Ping Sun; Panuwat Taerakul; Linda K. Weavers; Harold W. Walker
Microbial Degradation of Aromatic Hydrocarbons in Marine Sediments.
This study examined how adsorption to marine sediments affects the bioavailability of aromatic hydrocarbons. Sediment slurries were used to study microbial mineralization of the aromatic hydrocarbons, phenanthrene and naphthalene, added at low concentrati...
J. F. Braddock Z. Richter
This report identifies the origins, applications, environmental effects, and health effects of polynuclear aromatic hydrocarbons. Ways to reduce polynuclear aromatic hydrocarbons (PNA) emissions and problems associated with PNA derived effluents in the dye industry are discussed....
Aromatic Hydrocarbons in Generator Shale Resin (Aromaticheskie Uglevodorody v Generatornoi Slantsevoi Smole).
The group composition and content of aromatic hydrocarbons of shale oil generator resin which boil at temperatures above 300C have been determined previously and the aromatic hydrocarbons of this resin have been analyzed in more detail in other works. In ...
L. Lakhe O. Eizen
Detection of Polycyclic Aromatic Hydrocarbons (PAHs) in Human Breast Milk
Exposure to polycyclic aromatic hydrocarbons can result from numerous sources including dietary as well as environmental. Exposure to polycyclic aromatic hydrocarbons has been well-established through combustion sources, particularly coal-fired power plants, automobile and diesel exhaust emissions, and the burning of fossil fuels. In addition, exposure to polycyclic aromatic hydrocarbons occurs through the intake of tobacco smoke, both mainstream and sidestream,
S. Hunter; S. Myers; P. Radmacher; C. Eno
On the aromatic stabilization of benzenoid hydrocarbons.
A general scheme for estimation of aromatic stabilization energies of benzenoid hydrocarbons based on selected topological features has been presented. The reactions have been applied to benzene, naphthalene, anthracene, phenanthrene, pyrene, tetracene, benz[a]anthracene, chrysene, [4]-helicene, anthanthrene and coronene. PMID:22962659
Ciesielski, Arkadiusz; Stepie?, Dorota K; Dobrowolski, Micha? A; Dobrzycki, ?ukasz; Cyra?ski, Micha? K
Analysis of nitrated polycyclic aromatic hydrocarbons
Many nitrated polycyclic aromatic hydrocarbons (NPAH) that are present in low concentrations in the environment and in emission\\u000a sources have been shown to be mutagenic and\\/or carcinogenic. This paper reviews the current methods of analysis of these compounds\\u000a with the emphasis on NPAH measurements in ambient particulate matter samples.
Barbara Zielinska; Shar Samy
Polynuclear aromatic hydrocarbons: Chemistry, characterization and carcinogenesis
This book contains 75 selections. Some of the titles are: Polycyclic Aromatic Hydrocarbons in Cancer Research, Photolysis of PAH Absorbed on Silica Gel and Fly ASh, Phenotyping Cytochromes P-450 with Monoclonal Antibodies, Leaching of PAH from Industrial Wastes with Municipal Waste Leachate, and Determinants of the Potencies of Carcinogenic Mineral Oils.
Cooke, M.; Dennis, A.J.
Polycyclic aromatic hydrocarbons in the bakery chain.
The level of polycyclic aromatic hydrocarbons occurrence and the possibility of their formation in the bakery chain, its raw materials and final products, were examined. Experimental bread baking, with different baking temperatures, was performed in the Warsaw bakery, using cyclothermic deck ovens. PAHs determination was performed by high-pressure liquid chromatography with fluorescent and diode array detectors (HPLC-FLD/DAD) and confirmed by gas chromatography coupled with mass spectrometry (GC/MS). Total content of 19 PAHs in the grain, flour and bran varied from 1.07 to 3.65 ?g/kg and, in bread, from 1.59 to 13.6 ?g/kg depending on the part of bread and baking temperature. Based on the dough's contamination level and the influence of the baking temperature on the bread's PAHs content, it was confirmed that PAHs are formed during baking. Considering the results of the average dietary exposure to PAHs and the MOE (Margin of Exposure) analysis, it could be concluded that analysed bread and cereal products constitute little concern for consumer health. PMID:23768318
Ciecierska, M; Obiedzi?ski, M W
Dihydrodiol dehydrogenase and polycyclic aromatic hydrocarbon metabolism
Carcinogenic activation of polycyclic aromatic hydrocarbons by microsomal monoxygenases proceeds through trans-dihydrodiol metabolites to diol-epoxide ultimate carcinogens. This thesis directly investigated the role of dihydrodiol dehydrogenase, a cytosolic NAD(P)-linked oxidoreductase, in the detoxification of polycyclic aromatic trans-dihydrodiols. A wide variety of non-K-region trans-dihydrodiols were synthesized and shown to be substrates for the homogeneous rat liver dehydrogenase, including several potent proximate carcinogens derived from 7,12-dimethylbenz(a)anthracene, 5-methylchrysene, and benzo(a)pyrene. Since microsomal activation of polycyclic aromatic hydrocarbons is highly stereospecific, the stereochemical course of enzymatic trans-dihydrodiol oxidation was monitored using circular dichroism spectropolarimetry. The major product formed from the dehydrogenase-catalyzed oxidation of the trans-1,2-dihydrodiol of naphthalene was characterized using UV, IR, NMR, and mass spectroscopy, and appears to be 4-hydroxy-1,2-naphthoquinone. Mass spectral analysis suggests that an analogous hydroxylated o-quinone is formed as the major product of benzo(a)pyrene-7,8-dihydrodiol oxidation. Enzymatic oxidation of trans-dihydrodiols was shown to be potently inhibited by all of the major classes of the nonsteroidal antiinflammatory drugs. Enhancement of trans-dihydrodiol proximate carcinogen oxidation may protect against possible adverse effects of the aspirin-like drugs, and help maintain the balance between activation and detoxification of polycyclic aromatic hydrocarbons.
Smithgall, T.E.
Polycyclic aromatic hydrocarbons and olive pomace oil.
The occurrence of polycyclic aromatic hydrocarbons (PAHs) in five samples of olive pomace oil has been studied to determine the contamination degree of this type of oil and to evaluate if specific purification steps must be introduced during its manufacture. The PAHs present have been determined by gas chromatography-mass spectrometry. A high number of PAHs, with a wide range of molecular weights and in very high concentrations, have been found in four of the samples studied. A very high number of alkyl derivatives and, in many cases, in higher concentrations than their respective parent PAHs, have also been identified. One of the samples, however, presents a more reduced number of PAHs and in significantly lower concentrations than the others. These findings reveal that it is necessary to introduce adequate cleanup steps in the manufacturing process of olive pomace oil, which can give rise to oils with a relatively low content of PAHs. Some carcinogenic PAHs have also been identified, both unalkylated and alkylated. PMID:15053562
Guill�n, Mar�a D; Sopelana, Patricia; Palencia, Gemma
Origins of polycyclic aromatic hydrocarbons in estuarine sediments
In order to determine the origin of polycyclic aromatic hydrocarbons (PAHs) in sediments from Narragansett Bay, Rhode Island, the PAH assemblages from the sediments and from possible origin materials were analyzed by gas Chromatographic and gas chromatographic-mass spectrometric techniques. Analyses included determinations of: 1. (1) the relative content of non-alkylated PAH parent molecules i.e. parent compound distributions (PCDs); 2. (2)
James L. Lake; Curtis Norwood; Crandall Dimock; Robert Bowen
Detoxification of polycyclic aromatic hydrocarbons by fungi
Summary The polycyclic aromatic hydrocarbons (PAHs) are a group of hazardous environmental pollutants, many of which are acutely toxic, mutagenic, or carcinogenic. A diverse group of fungi, includingAspergillus ochraceus, Cunninghamella elegans, Phanerochaete chrysosporium, Saccharomyces cerevisiae, andSyncephalastrum racemosum, have the ability to oxidize PAHs. The PAHs anthracene, benz[a]anthracene, benzo[a]pyrene, fluoranthene, fluorene, naphthalene, phenanthrene, and pyrene, as well as several methyl-, nitro-,
John B. Sutherland
Arenium acid catalyzed deuteration of aromatic hydrocarbons.
The arenium acid [mesitylene-H](+) has been shown to be an extraordinarily active H/D exchange catalyst for the perdeuteration of polycyclic aromatic hydrocarbons. The reactions take place under ambient conditions in C6D6 as an inexpensive deuterium source. High isolated yields and excellent degrees of deuterium incorporation were achieved using the substrates p-terphenyl, fluoranthene, pyrene, triphenylene, and corannulene. PMID:23163918
Duttwyler, Simon; Butterfield, Anna M; Siegel, Jay S
Polycyclic aromatic hydrocarbon emissions from motorcycles
Emissions of polycyclic aromatic hydrocarbons (PAHs, 2�7 ring) and regulated air pollutants (CO, HC, NOx, PM) from 2-stroke carburetor (2-Stk\\/Cb), 4-stroke carburetor (4-Stk\\/Cb) and 4-stroke fuel injection (4-Stk\\/FI) motorcycles were investigated by testing these vehicles on a chassis dynamometer. Exhaust samplings were carried out on diluted exhausts in a dilution tunnel connected to a constant volume sampling system. Measurements were
Hsi-Hsien Yang; Lien-Te Hsieh; Hsu-Chung Liu; Hsiao-Hsuan Mi
Polycyclic aromatic hydrocarbons in the diet
Polycyclic aromatic hydrocarbons (PAHs), of which benzo[a]pyrene is the most commonly studied and measured, are formed by the incomplete combustion of organic matter. They are widely distributed in the environment and human exposure to them is unavoidable. A number of them, such as benzo[a]pyrene, are carcinogenic and mutagenic, and they are widely believed to make a substantial contribution to the
David H Phillips
Atmospheric polycyclic aromatic hydrocarbons in Seoul, Korea
Daily particulate- and vapor-phase polycyclic aromatic hydrocarbons (PAH) samples were collected at an urban site in Seoul, Korea, during five intensive sampling campaigns between October 1998 and December 1999. PAH samples collected on quartz fiber filters and PUF plugs were first extracted using dichloromethane with ultrasonication and supercritical fluid extraction methods, respectively, and then analyzed by GC\\/MSD\\/SIM. Seasonal trends in
Seung S. Park; Young J. Kim; Chang H. Kang
Analysis of nitrated polynuclear aromatic hydrocarbons
A derivatization-gas chromatography\\/electron capture detector (GC\\/ECD) method has been developed for the measurement of trace nitrated polynuclear aromatic hydrocarbons (NPAHs) in air. The method involves first the derivatization of parent nitro-PAHs to their corresponding fluorinated derivatives, followed by GC\\/ECD analysis. The sensitivity of the method is an order of magnitude higher than those of direct GC\\/ECD analysis of NPAHs themselves.
Xu Jinhui; Frank S. C Lee
Fungi growing on aromatic hydrocarbons: biotechnology's unexpected encounter with biohazard?
The biodegradation of aromatic hydrocarbons by fungi has traditionally been considered to be of a cometabolic nature. Recently, however, an increasing number of fungi isolated from air biofilters exposed to hydrocarbon-polluted gas streams have been shown to assimilate volatile aromatic hydrocarbons as the sole source of carbon and energy. The biosystematics, ecology, and metabolism of such fungi are reviewed here,
Richard Summerbell; G. Sybren de Hoog
Polycyclic Aromatic Hydrocarbons in Soils and Recent Sediments
Soils and recent marine sediments contain a complex polycyclic aromatic hydrocarbon assemblage. There is a high degree of similarity in the molecular weight distribution of the many series of alkyl homologs of these aromatic hydrocarbons, and this distribution varies little over a wide range of depositional environments. The evidence suggests that these hydrocarbons are formed in natural fires, are dispersed
M. Blumer; W. W. Youngblood
The Uptake of Aromatic and Branched Chain Hydrocarbons by Yeast.
Studies of the hydrocarbon utilizing yeasts, Candida maltosa and C. lipolytica, have shown that both were capable of reducing recoverable amounts of branched chain and aromatic hydrocarbons in a mixture of naphthalene, tetradecane, hexadecane, pristane (t...
S. A. Crow S. L. Bell D. G. Ahearn
A method of trace analysis of volatile aromatic hydrocarbons in natural water is described. The method is based on sparging water samples with nitrogen, adsorption of hydrocarbons on activated charcoal, followed by desorption into carbon disulfide and gas chromatographic analysis...
Studies of the hydrocarbon utilizing yeasts, Candida maltosa and C. lipolytica, have shown that both were capable of reducing recoverable amounts of branched chain and aromatic hydrocarbons in a mixture of naphthalene, tetradecane, hexadecane, pristane (tetra-methylpentadecane). ...
Polynuclear aromatic hydrocarbons (PNAs), formed in combustion processes with liquid hydrocarbon fuels, contribute to mobile source exhaust emissions. Because correlation between PNA levels in automobile exhaust and pre-existent PNAs in fuel has been demonstrated in previous work...
Potency Equivalency Factors for Some Polycyclic Aromatic Hydrocarbons and Polycyclic Aromatic Hydrocarbon Derivatives
Potency equivalency factors (PEFs) for cancer induction relative to benzo[a]pyrene have been derived for 21 polycyclic aromatic hydrocarbons (PAHs) and PAH derivatives based on a data preference scheme. PEFs have been derived only for PAHs with demonstrated carcinogenicity in bioassays. Cancer potency values and inhalation unit risks are presented for four additional carcinogenic PAHs based on expedited risk assessments conducted
J. F. Collins; J. P. Brown; G. V. Alexeeff; A. G. Salmon
Recent Changes in Atmospheric Polycyclic Aromatic Hydrocarbons (PAHs) and Nitropolycyclic Aromatic Hydrocarbons (NPAHs) in Shenyang, China
Airborne particulates were collected in three size fractions by using Anderson low-volume air samplers in Shenyang, China, in winter and summer in 2007. Compared with data obtained in 2001 at the same sites, the total concentrations of nine polycyclic aromatic hydrocarbons (PAHs) in winter decreased by 67% at one site and decreased by 40% at the other site, while the
Ning Tang; Takahiro Tokuda; Akihiko Izzaki; Kenji Tamura; Ruonan Ji; Xuemei Zhang; Lijun Dong; Takayuki Kameda; Akira Toriba; Kazuichi Hayakawa
Biomarkers of Exposure to Polycyclic Aromatic Hydrocarbons and Related Compounds
Polycyclic aromatic hydrocarbons (PAHs) and nitropolycyclic aromatic hydrocarbons (NPAHs) are widespread carcinogenic compounds that arise from occupational, environmental and dietary sources. The metabolites of PAHs and NPAHs in biological fluids have been investigated as potential biomarkers for assessing human exposure to them, and, particularly, urinary metabolites are the excelle nt candidates due to the non-invasiveness and convenience of collecting the
Akira Toriba; Kazuichi Hayakawa
Polycyclic aromatic hydrocarbons in soils of Vasilievsky Island (St. Petersburg)
The composition and accumulation patterns of priority polycyclic aromatic hydrocarbons (PAHs) in soils of Vasilievsky Island in Saint Petersburg were studied. Concentrations of benzo[a]pyrene were found to exceed maximum permissible concentrations in all the samples, and the maximum recorded concentration exceeded the MPC by 50 times. Concentrations of other PAHs also exceeded the background values. The main soil pollutants were found to be fluoranthene, pyrene, benzo[b]fluoranthene, benzo[a]pyrene, and benzo[g, h, i] perylene, the part of which in the total content of PAHs was 65-80%.
Lodygin, E. D.; Chukov, S. N.; Beznosikov, V. A.; Gabov, D. N.
Mechanisms for polycyclic aromatic hydrocarbon degradation by ligninolytic fungi
Ligninolytic fungi accomplish the partial degradation of numerous aromatic organopollutants. Their ability to degrade polycyclic aromatic hydrocarbons (PAHs) is particularly interesting because eukaryotes were previously considered to be unable to cleave fused-ring aromatics. Recent results indicate that extracellular peroxidases of these fungi are responsible for the initial oxidation of PAHs. Fungal lignin peroxidases oxidize certain PAHs directly, whereas fungal manganese
Kenneth E. Hammel
Considerations of Atmospheric Behaviors of Polycyclic Aromatic Hydrocarbons, Nitropolycyclic Aromatic Hydrocarbons and Inorganic Pollutants Based on Their Interrelationships
Airborne particulates were collected during the same periods in downtown Kanazawa, Sapporo and Tokyo and polycyclic aromatic hydrocarbons (PAHs) and nitropolycyclic aromatic hydrocarbons (NPAHs) were determined together with several heavy metal elements and water-soluble inorganic ions. The mean concentrations of metal elements and inorganic ions were the highest in Tokyo, followed by Sapporo and the lowest in Kanazawa both in
Hitoshi Kakimoto; Hitoshi Yokoe; Yutaka Matsumoto; Shigekatsu Sakai; Fumio Kanoh; Tsuyoshi Murahashi; Kazuhiko Akutsu; Akira Toriba; Ryoichi Kizu; Kazuichi Hayakawad
Coumarin, Naphthalene, and Additional Polycyclic Aromatic Hydrocarbons
The featured molecules this month are drawn from two papers. The first, "One-Pot Synthesis of 7-Hydroxy-3-carboxycoumarin in Water", is a Green Chemistry feature by Fringuelli, Piermatti, and Pizzo. The three-dimensional versions of the molecules in the synthesis of the coumarin derivative are directly tied to the reaction scheme included in the paper, opening the possibility of showing large numbers of complex synthetic pathways in this manner.The second paper is "Determining the Carbon-Carbon Distance in an Organic Molecule with a Ruler" by Simoni, Tubino, and Ricchi. This article describes an experiment to determine the size of a naphthalene molecule, using an extension of classic experiments for determining molecular size and Avogadro's number. While the structure of naphthalene will come as no surprise to most students, the molecule collection also includes additional polycyclic aromatic hydrocarbons (PAHs) that can be used to introduce students to the environmental and health issues related to these molecules.
Analysis of nitrated polynuclear aromatic hydrocarbons.
A derivatization-gas chromatography/electron capture detector (GC/ECD) method has been developed for the measurement of trace nitrated polynuclear aromatic hydrocarbons (NPAHs) in air. The method involves first the derivatization of parent nitro-PAHs to their corresponding fluorinated derivatives, followed by GC/ECD analysis. The sensitivity of the method is an order of magnitude higher than those of direct GC/ECD analysis of NPAHs themselves. The method is simple and robust and thus ideally suited for the routine monitoring of NPAHs in air samples. The sensitivity and reproducibility of GC/negative ion chemical ionization MS (NICIMS) for the measurement of NPAHs after derivatization has been evaluated. The method has sensitivity comparable to GC/ECD, but is less reproducible in quantification. The method is therefore suitable for method validation and NPAHs peak confirmation rather than routine operations. PMID:11100923
Jinhui, X; Lee, F S
Partially oxidized polycyclic aromatic hydrocarbons show an increased bioavailability and biodegradability
Polycyclic aromatic hydrocarbons have a low water solubility and tend to adsorb on soil particles, which both result in slow bioremediation processes. Many microorganisms, known for their ability to degrade polycyclic aromatic hydrocarbons, only partially oxidize these compounds. White rot fungi, for instance, convert polycyclic aromatic hydrocarbons to more water soluble and bioavailable products. Polycyclic aromatic hydrocarbon metabolites were more
Rogier Meulenberg; Huub H. M Rijnaarts; Hans J Doddema; Jim A Field
Degradation of polycyclic aromatic hydrocarbons by manganese peroxidase of Nematoloma frowardii
The degradation of polycyclic aromatic hydrocarbons by a manganese peroxidase crude preparation of Nematoloma frowardii was demonstrated for a mixture of eight different polycyclic aromatic hydrocarbons, and the five individual polycyclic aromatic hydrocarbons phenanthrene, anthracene, pyrene, fluoranthene, and benzo[a]pyrene. Oxidation of polycyclic aromatic hydrocarbons was enhanced by the addition of glutathione, a mediator substance, able to form reactive thiyl radicals.
Ute Sack; Martin Hofrichter; Wolfgang Fritsche
Selection of ionic liquids for the extraction of aromatic hydrocarbons from aromatic\\/aliphatic mixtures
The separation of aromatic hydrocarbons (benzene, toluene, ethyl benzene and xylenes) from C4 to C10 aliphatic hydrocarbon mixtures is challenging since these hydrocarbons have boiling points in a close range and several combinations form azeotropes. In this work, we investigated the separation of toluene from heptane by extraction with ionic liquids.Several ionic liquids are suitable for extraction of toluene from
G. Wytze Meindersma; Andr� B. de Haan
In order to determine the origin of polycyclic aromatic hydrocarbons (PAHs) in sediments from Narragansett Bay, Rhode Island, the PAH assemblages from the sediments and from possible origin materials were analyzed by gas chromatographic and gas chromatographic-mass spectrometric ...
Infrared Spectroscopy of Matrix-Isolated Polycyclic Aromatic Hydrocarbon Cations.
Gaseous, ionized polycyclic aromatic hydrocarbons (PAHS) are thought to be responsible for a very common family of interstellar infrared emission bands. Here the near- and mid-infrared spectra of the cations of the five most thermodynamically favored PAHs...
D. M. Hudgins L. J. Allamandola
Gaseous, ionized polycyclic aromatic hydrocarbons (PAHs) are thought to be responsible for a very common family of interstellar infrared emission bands. Here the near- and mid-infrared spectra of the cations of the five most thermodynamically favored PAHs...
The book chapter examines methods that have been used to isolate and to construct bacteria capable of growing aerobically with chlorinated aromatic compounds, including chlorinated hydrocarbons. It also describes some recent work in this area of research....
The ability of the white rot fungus Phanerochaete chrysosporium to degrade polycyclic aromatic hydrocarbons (PAHS) that are present in anthracene oil (a distillation product obtained from coal tar) was demonstrated. nalysis by capillary gas chromatography and high-performance liq...
The objective of this multidisciplinary project is to use molecular biological techniques to derive a set of antibodies with useful affinities and selectivities for recovery and detection of polynuclear aromatic hydrocarbons (PAHs) in environmental and biological samples. The lon...
Polycyclic Aromatic Hydrocarbons and the Diffuse Interstellar Bands: A Survey.
We discuss the proposal relating the origin of some of the diffuse interstellar bands (DIBs) to neutral and ionized polycyclic aromatic hydrocarbons (PAHs) present in interstellar clouds. Laboratory spectra of several PAHs, isolated at low temperature in ...
F. Salama G. A. Galazutdinov J. Krelowski L. J. Allamandola F. A. Musaev
Double photoionization of pyrene and other aromatic hydrocarbons
We have measured the ratio of doubly to singly charged parent ions of pyrene, an aromatic hydrocarbon, for photon energies ranging from threshold to the carbon K edge. Monochromatized synchrotron radiation of the Synchrotron Radiation Center has been used in combination with an ion time-of-flight spectrometer for this investigation. We compared these results with our previous measurements on benzene, coronene and pyrrole. We will discuss differences and similarities in the double photoionization for these aromatic hydrocarbons.
Wehlitz, R.; Hartman, T.
Determination of aromatic hydrocarbons in urban air of Rome
Aromatic hydrocarbons were measured in Rome during 1992�1993 by means a differential optical absorption spectrometer (DOAS) and an automatic gas chromatograph (VOC analyzer). The mean distribution of aromatic hydrocarbons was: benzene 12.6%, toluene 35.4%, and remaining species 42%. The mean yearly concentrations of toluene (128 and 138 ?g m?3) were 2�3 times higher than those of benzene (40 and 47
D. Brocco; R. Fratarcangeli; L. Lepore; M. Petricca; I. Ventrone
Methane direct conversion to aromatic hydrocarbons at low reaction temperature
Conversion of pure methane and natural gas with different methane purity to aromatic hydrocarbons at. 773 and 873 K have been\\u000a investigated. Conversion of methane to aromatics under non-oxidizing conditions can be initiated by higher hydrocarbon mixtures\\u000a in the feed and, some special coke deposited on Mo\\/HZSM-5 catalyst at lower reaction temperature. Methane conversion of about\\u000a 10�20% is obtained at
Liliana B. Pierella; Linsheng Wang; Oscar A. Anunziata
The molecular biology of environmental aromatic hydrocarbons
The induction of mutations in living cells by polycyclic aromatic hydrocarbons (PAH) has been recognized for many years. Although the mechanism for this occurrence has been examined by numerous investigators, the precise nature and type of mutations induced is still unclear. Earlier investigations of DNA damage and repair were primarily examined by the random alkylation of bacterial and mammalian DNAs, in vivo, using a variety of different PAH agents. This procedure is still used today. Though informative, such studies have not offered any explanation of the mechanism by which PAH agents induce carcinogenesis. We have attempted to examine the repair of PAH-damaged DNA using small DNA oligomer constructs as targets for site-specific alkylation. DNA constructs containing a single BPDE alkylated site in each duplex strand were ligated into M13 RF DNA and used to transfect E. coli. Progeny M13 DNA was isolated from E. coli colonies grown on agar plates containing IPTG and Xgal. DNA sequence analysis of the isolated progeny M13 DNA, at the site of construct insertion, was found to contain large deletions and illegitimate recombinants. These sequence rearrangements occurred in either recA{sup +} or recA{sup -} host cells suggesting that SOS processing was not involved in the deletions and the recombinants observed. The mechanism by which BPDE induces illegitimate recombinants has not been resolved, however, it is possible that the closely spaced adducts activate the recombinant machinery in our DNA-damaged cells. 1 ref., 6 figs., 1 tab.
Weiss, S.B.
Porphyrins fused with unactivated polycyclic aromatic hydrocarbons.
A systematic study of the preparation of porphyrins with extended conjugation by meso,?-fusion with polycyclic aromatic hydrocarbons (PAHs) is reported. The meso-positions of 5,15-unsubstituted porphyrins were readily functionalized with PAHs. Ring fusion using standard Scholl reaction conditions (FeCl(3), dichloromethane) occurs for perylene-substituted porphyrins to give a porphyrin ?,meso annulated with perylene rings (0.7:1 ratio of syn and anti isomers). The naphthalene, pyrene, and coronene derivatives do not react under Scholl conditions but are fused using thermal cyclodehydrogenation at high temperatures, giving mixtures of syn and anti isomers of the meso,?-fused porphyrins. For pyrenyl-substituted porphyrins, a thermal method gives synthetically acceptable yields (>30%). Absorption spectra of the fused porphyrins undergo a progressive bathochromic shift in a series of naphthyl (?(max) = 730 nm), coronenyl (?(max) = 780 nm), pyrenyl (?(max) = 815 nm), and perylenyl (?(max) = 900 nm) annulated porphyrins. Despite being conjugated with unsubstituted fused PAHs, the ?,meso-fused porphyrins are more soluble and processable than the parent nonfused precursors. Pyrenyl-fused porphyrins exhibit strong fluorescence in the near-infrared (NIR) spectral region, with a progressive improvement in luminescent efficiency (up to 13% with ?(max) = 829 nm) with increasing degree of fusion. Fused pyrenyl-porphyrins have been used as broadband absorption donor materials in photovoltaic cells, leading to devices that show comparatively high photovoltaic efficiencies. PMID:22077105
Diev, Vyacheslav V; Schlenker, Cody W; Hanson, Kenneth; Zhong, Qiwen; Zimmerman, Jeramy D; Forrest, Stephen R; Thompson, Mark E
Emission of polycyclic aromatic hydrocarbons in China
Emission of 16 polycyclic aromatic hydrocarbons (PAHs) listed as U.S. Environmental Protection Agency (U.S. EPA) priority pollutants from major sources in China were compiled. Geographical distribution and temporal change of the PAH emission, as well as emission profiles, are discussed. It was estimated that the total PAH emission in China was 25,300 tons in 2003. The emission profile featured a relatively higher portion of high molecular weight (HMW) species with carcinogenic potential due to large contributions of domestic coal and coking industry. Among various sources, biomass burning, domestic coal combustion, and the coking industry contributed 60%, 20%, and 16% of the total emission, respectively. Total emission, emission density, emission intensity, and emission per capita showed geographical variations. In general, the southeastern provinces were characterized by higher emission density, while those in western and northern China featured higher emission intensity and population-normalized emission. Although energy consumption in China went up continuously during the past two decades, annual emission of PAHs fluctuated depending on the amount of domestic coal consumption, coke production, and the efficiency of energy utilization. 47 refs., 6 figs.
Shanshan Xu; Wenxin Liu; Shu Tao [Peking University, Beijing (China). Laboratory for Earth Surface Processes, College of Environmental Sciences
Polynuclear aromatic hydrocarbons in the water environment*
Many polynuclear aromatic hydrocarbons (PAH) are known to be carcinogenic to animals and probably to man. This review is concerned with carcinogenic and non-carcinogenic PAH in the water environment, with emphasis on 3,4-benzpyrene (BP) because it is ubiquitous, is one of the most potent of the carcinogenic PAH and has been widely studied. Although PAH are formed in combustion and other high-temperature processes, there is also evidence for their endogenous formation in plants, which may explain their ubiquity therein. Although the solubility of these compounds in pure water is very low, they may be solubilized by such materials as detergents, or they may otherwise occur in aqueous solution associated with or adsorbed on to a variety of colloidal materials or biota, and thereby be transported through the water environment. A notable characteristic of PAH is their sensitivity to light. PAH have been found in industrial and municipal waste effluents, and occur in soils, ground waters and surface waters, and their sediments and biota. With the exception of filtration or sorption by activated carbon, conventional water treatment processes do not efficiently remove them, and they have been found in domestic water supplies. Because of the ubiquity of PAH in the environment, it is impossible to prevent completely man's exposure to them; nevertheless their surveillance should be continued and their concentrations in the environment should be reduced where practicable.
Andelman, Julian B.; Suess, Michael J.
Strong Correlation Physics in Aromatic Hydrocarbon Superconductors
We show, by means of ab-initio calculations, that electron-electron correlations play an important role in doped aromatic hydrocarbon superconductors, including potassium doped picene with Tc= 18K [1], coronene and phenanthrene [2]. For the case of picene the inclusion of exchange interactions by means of hybrid functionals reproduces the correct gap for the undoped compound and predicts an antiferromagnetic state for x=3, where superconductivity has been observed [3]. The latter finding is compatible with a sizable value of the correlation strength. The differences between the different compounds are analyzed and results of Dynamical Mean-Field Theory including both correlation effects and electron-phonon interactions are presented. Finally we discuss the consequences of strong correlations in an organic superconductor in relation to the properties of Cs3C60, in which electron correlations drive an antiferromagnetic state [4] but also lead to an enhancement of superconductivity [5]. 1. R. Mitsuhashi et al. Nature 464, 76 (2010)2. X.F. Wang et al, Nat. Comm. 2, 507 (2011)3. G. Giovannetti and M. Capone, Phys. Rev. B 83, 134508 (2011)4. Y. Takabayashi et al., Science 323, 1585 (2009)5. M. Capone et al. Rev. Mod. Phys. 81, 943 (2009
Capone, Massimo; Giovannetti, Gianluca
Ligninolytic fungi accomplish the partial degradation of numerous aromatic organopollutants. Their ability to degrade polycyclic aromatic hydrocarbons (PAHs) is particularly interesting because eukaryotes were previously considered to be unable to cleave fused-ring aromatics. Recent results indicate that extracellular peroxidases of these fungi are responsible for the initial oxidation of PAHs. Fungal lignin peroxidases oxidize certain PAHs directly, whereas fungal manganese peroxidases co-oxidize them indirectly during enzyme-mediated lipid peroxidation. 14 refs., 3 figs., 1 tab.
Hammel, K.E. [Dept. of Agriculture, Madison, WI (United States)
Comparison of polycyclic aromatic hydrocarbons and nitropolycyclic aromatic hydrocarbons in airborne particulates collected in downtown and suburban Kanazawa, Japan
In this study, airborne particulates were collected at three sites, two in a downtown area and the other in a suburban area of Kanazawa, Japan in each season for 7 years. Two polycyclic aromatic hydrocarbons (PAHs), pyrene (Py) and benzo[a]pyrene (BaP) and four nitropolycyclic aromatic hydrocarbons (NPAHs), 1-nitropyrene (NP) and 1,3-, 1,6-, and 1,8-dinitropyrenes (DNP) were determined by high-performance liquid
Kazuichi Hayakawa; Ning Tang; Kazuhiko Akutsu; Tsuyoshi Murahashi; Hitoshi Kakimoto; Ryoichi Kizu; Akira Toriba
Characteristics of Atmospheric Polycyclic Aromatic Hydrocarbons and Nitropolycyclic Aromatic Hydrocarbons in Hanoi-Vietnam, as a Typical Motorbike City
We investigated polycyclic aromatic hydrocarbons (PAHs) and nitropolycyclic aromatic hydrocarbons (NPAHs) in airborne particulates collected at two sites (I and T) in Hanoi city, a typical city where traffic jams were caused by many motorbikes. The mean total concentration of 10 PAHs having 4�6 rings at sites I and T ranged from 9.6�63.7 pmol m and from 24.8�41.9 pmol m,
Aliphatic and aromatic hydrocarbons in coastal caspian Sea sediments
This investigation represents the first extensive study of the spatial distribution and sources of aliphatic (n-alkanes and unresolved complex mixture of fossil hydrocarbons) and polycyclic aromatic hydrocarbons (PAHs) in coastal sediments from the Caspian Sea. PAH concentrations, n-alkanes and biomarker profiles all suggested that there was limited petrogenic contamination in the shallow North Caspian Sea sediments, which are coarse with
Imma Tolosa; Stephen de Mora; Mohammad Reza Sheikholeslami; Jean-Pierre Villeneuve; Jean Bartocci; Chantal Cattini
Rapid, microwave-assisted perdeuteration of polycyclic aromatic hydrocarbons.
A simple and convenient method for the perdeuteration of polycyclic aromatic hydrocarbons that does not require strong acid has been developed. Using commercially available reagents, the one-step procedure provides a new route to perdeuterated derivatives of both common and exotic polycyclic aromatic hydrocarbons. Microwave irradiation of the hydrocarbons in a solution of dimethylformamide-d7 containing potassium tert-butoxide affords rapid and essentially complete H/D exchange. For example, corannulene is converted to corannulene-d10 with >98% deuterium incorporation in just 1 h of microwave irradiation in a solution of t-BuOK/DMF-d7. PMID:23121393
Greene, Allison K; Scott, Lawrence T
Experimental and modeling investigation of aromatic and polycyclic aromatic hydrocarbon formation in a premixed ethylene flame.
Experimental and detailed chemical kinetic modeling has been performed to investigate aromatic and polyaromatic hydrocarbon formation pathways in a rich, sooting, ethylene-oxygen-argon premixed flame. An atmospheric pressure, laminar flat flame operated a...
M. J. Castaldi N. M. Marinov C. F. Melius
Biological and abiotic losses of polynuclear aromatic hydrocarbons (PAHs) from soils freshly amended with sewage sludge
Sewage sludge containing typical indigenous concentrations of polynuclear aromatic hydrocarbons (PAHs) was applied to several different soils in glass microcosms. Biologically active and sterilized soils were monitored for PAH content over a period of approximately 205 d. Agricultural soils with and without previous exposure to sewage sludge were tested, together with a forest soil and a soil from a major
S. R. Wild; K. C. Jones
Bioconcentration of polycyclic aromatic hydrocarbons in vegetables grown in an industrial area
The polycyclic aromatic hydrocarbon (PAH) content was determined in the inner tissue of various vegetable species and their growing environment (soil and atmosphere) in the greater industrial area of Thessaloniki, northern Greece. The lower molecular weight compounds dominated in both vegetable leaves and roots. Statistical analysis of variance showed that species and season are the factors that significantly affect PAH
A. M. Kipopoulou; E. Manoli; C. Samara
Polycyclic Aromatic Hydrocarbon Far-infrared Spectroscopy
The far-IR characteristics of astrophysically relevant polycyclic aromatic hydrocarbons (PAHs) averaging in size around 100 carbon atoms have been studied using the theoretical spectra in the NASA Ames PAH IR Spectroscopic Database. These spectra were calculated using density functional theory. Selections of PAH species are made, grouped together by common characteristics or trends, such as size, shape, charge, and composition, and their far-IR spectra compared. The out-of-plane modes involving the entire molecule are explored in detail, astronomical relevance is assessed, and an observing strategy is discussed. It is shown that PAHs produce richer far-IR spectra with increasing size. PAHs also produce richer far-IR spectra with increasing number of irregularities. However, series of irregular-shaped PAHs with the same compact core have common "Jumping-Jack" modes that "pile up" at specific frequencies in their average spectrum. For the PAHs studied here, around 100 carbon atoms in size, this band falls near 50 ?m. PAH charge and nitrogen inclusion affect band intensities but have little effect on far-IR band positions. Detailed analysis of the two-dimensional, out-of-plane bending "drumhead" modes in the coronene and pyrene "families" and the one-dimensional, out-of-plane bending "bar" modes in the acene "family" show that these molecular vibrations can be treated as classical vibrating sheets and bars of graphene, respectively. The analysis also shows that the peak position of these modes is very sensitive to the area of the emitting PAH and does not depend on the particular geometry. Thus, these longest wavelength PAH bands could provide a unique handle on the size of the largest species in the interstellar PAH family. However, these bands are weak. Observing highly excited regions showing the mid-IR bands in which the emission from classical dust peaks at short wavelengths offers the best chance of detecting PAH emission in the far-IR. For these regions sensitivity is not an issue, spectral contrast is maximized and the PAH population is only comprised of highly stable, compact symmetric PAHs, such as the members of the pyrene and coronene "families" discussed in detail here.
Boersma, C.; Bauschlicher, C. W., Jr.; Ricca, A.; Mattioda, A. L.; Peeters, E.; Tielens, A. G. G. M.; Allamandola, L. J.
Closed-Shell Polycyclic Aromatic Hydrocarbon Cations: A New Category of Interstellar Polycyclic Aromatic Hydrocarbons
Density functional theory has been employed to calculate the harmonic frequencies and intensities of a range of polycyclic aromatic hydrocarbon (PAH) cations that explore both size and electronic structure effects of the infrared spectroscopic properties of these species. The sample extends the size range of PAH species considered to more than 50 carbon atoms and includes several representatives from each of two heretofore unexplored categories of PAH cations: (1) fully benzenoid PAH cations whose carbon skeleton is composed of an odd number of carbon atoms (C(sub odd) PAHs); and (2) protonated PAH cations (HPAH+). Unlike the radical electronic structures of the PAH cations that have been the subject of previous theoretical and experimental work, the species in these two classes have a closed-shell electronic configuration. The calculated spectra of circumcoronene, C54H18 in both neutral and (radical) cationic form are also reported and compared with those of the other species. Overall, the C(sub odd) PAHs spectra are dominated by strong CC stretching modes near 1600 cm(exp -1) and display spectra that are remarkably insensitive to molecular size. The HPAH+ species evince a more complex spectrum consistent with the added contributions of aliphatic modes and their generally lower symmetry. Finally, for both classes of closed-shell cations, the intensity of the aromatic CH stretching modes is found to increase with molecular size far out of proportion with the number of CH groups, approaching a value more typical of neutral PAHs for the largest species studied.
Hudgins, Douglas M.; Bauschlicher, Charles W., Jr.; Allamandola, Louis J.; DeVincenzi, Donald (Technical Monitor)
The biodegradation of aromatic hydrocarbons by fungi has traditionally been considered to be of a cometabolic nature. Recently, however, an increasing number of fungi isolated from air biofilters exposed to hydrocarbon-polluted gas streams have been shown to assimilate volatile aromatic hydrocarbons as the sole source of carbon and energy. The biosystematics, ecology, and metabolism of such fungi are reviewed here, based in part on re-evaluation of a collection of published hydrocarbon-degrading isolates obtained from authors around the world. Incorrect or outdated identifications in original publications are corrected by ribosomal DNA sequence analysis. The data show that many volatile-hydrocarbon-degrading strains are closely related to, or in some cases clearly conspecific with, the very restricted number of human-pathogenic fungal species causing severe mycoses, especially neurological infections, in immunocompetent individuals. Neurochemistry features a distinctive array of phenolic and aliphatic compounds that are related to molecules involved in the metabolism of aromatic hydrocarbons. Hence, there may be physiological connections between hydrocarbon assimilation and certain patterns of mammalian infection. PMID:16438682
Prenafeta-Bold�, Francesc X; Summerbell, Richard; Sybren de Hoog, G
Determination of low concentrations of aromatic hydrocarbons in multicomponent mixtures with iso-octane and n-heptane
We have experimentally studied the absorption spectra of hydrocarbon mixtures based on n-heptane and isooctane with small (1%-2%) additions of aromatic hydrocarbons (benzene, toluene, xylene). The study was conducted in the region of the first overtones of the vibrational spectra for the hydrocarbon groups CH3, CH2, CH. We show that four-component modeling of the absorption spectrum of the hydrocarbon mixture and minimization of the deviation of the model spectrum from the experimental spectrum allow us to separately determine the content of the aromatic additives for concentrations from 1%.
Vesnin, V. L.; Muradov, V. G.
Comparative Molecular Analysis of Genes for Polycyclic Aromatic Hydrocarbon Degradation
\\u000a Aromatic hydrocarbons are found ubiquitously in nature. Their sources vary from biosynthesis de novo by organisms to abiotic reactions on naturally-occurring carbon deposits to chemical synthesis by man. It is generally accepted,\\u000a however, that the bulk of aromatic compounds found in the environment are not of biosynthetic origin but are produced through\\u000a the pyrolysis of organic materials such as the
Gerben J. Zylstra; Eungbin Kim; Anil K. Goyal
Assessment of Aliphatic and Polycyclic Aromatic Hydrocarbons and Trace Elements in Coastal Sediments of the Saronikos Gulf, Greece (Eastern Mediterranean)
Surface sediments from the Saronikos Gulf were analyzed for their aliphatic hydrocarbon (AHC) and polycyclic aromatic hydrocarbon (PAH) content by gas chromatography � mass spectrometry (GC\\/MS). The concentrations of Fe, Cr, As, Sb, Co and Sc were also determined by neutron activation analysis (NAA). The survey was performed at the beginning of the operation of Athens� sewage primary treatment unit
E. Sklivagou; S. P. Varnavas; I. Hatzianestis; G. Kanias
Micellar Extraction of Polycyclic Aromatic Hydrocarbons from Certified Marine Sediment
In the present study the extraction of polycyclic aromatic hydrocarbons from a certified marine sediment (SRM 1941a) with a micellar medium of polyoxyethylene 10 lauryl ether by micro-wave- and ultrasound-assisted method has been evaluated. The analysis of extracts has been carried out by HPLC with fluorimetric detection and wavelength programming. Hydrocarbons with more than three rings gave average recoveries of
Ver�nica Pino; Juan H. Ayala; Ana M. Afonso; Venerando Gonz�lez
Black carbon and polycyclic aromatic hydrocarbons (PAHs) in surface sediments of China�s marginal seas
This study investigates the distribution of black carbon (BC) and its correlation with total polycyclic aromatic hydrocarbons\\u000a (?PAH) in the surface sediments of China�s marginal seas. BC content ranges from <0.10 to 2.45 mg\\/g dw (grams dry weight)\\u000a in the sediments studied, and varied among the different coastal regions. The Bohai Bay sediments had the highest BC contents\\u000a (average 2.18
Yanju Kang; Xuchen Wang; Minhan Dai; Huan Feng; Anchun Li; Qian Song
The Concentration of Mild-Extracted Polycyclic Aromatic Hydrocarbons in Sewage Sludges
The present study evaluates the content of the mild-solvent extracted fraction of the polycyclic aromatic hydrocarbons. Ten compounds from the US EPA list (phenanthrene, anthracene, fluoranthene, pyrene, benzo[a]anthracene, chryzene, benzo[b]fluoranthene, benzo[a]pyrene, benzo[ghi]perylene oraz indeno[1,2,3-cd]pyrene) were chosen. The compounds were extracted with n-butanol from 11 sewage sludges that differed both in the total PAH content and in their physicochemical properties. On
Patryk Oleszczuk; Stanis?aw Baran
Experimental and modeling investigation of aromatic and polycyclic aromatic hydrocarbon formation in a premixed ethylene flame
Experimental and detailed chemical kinetic modeling has been performed to investigate aromatic and polyaromatic hydrocarbon formation pathways in a rich, sooting, ethylene-oxygen-argon premixed flame. An atmospheric pressure, laminar flat flame operated at an equivalence ratio of 2.5 was used to acquire experimental data for model validation. Gas composition analysis was conducted by an on-line gas chromatograph/mass spectrometer (GC/MS) technique. Measurements were made in the flame and post-flame zone for a number of low molecular weight species, aliphatics, aromatics and polycyclic aromatic hydrocarbons (PAHs) ranging from two to five-aromatic fused rings. The modeling results show the key reaction sequences leading to aromatic and polycyclic aromatic hydrocarbon growth involve the combination of resonantly stabilized radicals. In particular, propargyl and 1-methylallenyl combination reactions lead to benzene and methyl substituted benzene formation, while polycyclic aromatics are formed from cyclopentadienyl radicals and fused rings that have a shared C{sub 5} side structure. Naphthalene production through the reaction step of cyclopentadienyl self-combination and phenanthrene formation from indenyl and cyclopentadienyl combination were shown to be important in the flame modeling study. The removal of phenyl by O{sub 2} leading to cyclopentadienyl formation is expected to play a pivotal role in the PAH or soot precursor growth process under fuel-rich oxidation conditions.
Castaldi, M.J.; Marinov, N.M.; Melius, C.F. [and others
Effects of co-occurring aromatic hydrocarbons on degradation of individual polycyclic aromatic hydrocarbons in marine sediment slurries
Rates of polycyclic aromatic hydrocarbon (PAH) degradation and mineralization were influenced by preexposure to alternate PAHs and a monoaromatic hydrocarbon at relatively high (100 ppm) concentrations in organic-rich aerobic marine sediments. Prior exposure to three PAHs and benzene resulted in enhanced (¹⁴C)naphthalene mineralization, while (¹⁴C)anthracene mineralization was stimulated only by benzene and anthracene preexposure. Preexposure of sediment slurries to phenanthrene
J. E. Bauer; D. G. Capone
The report gives results of an evaluation of a fluorescent spot test for detecting the presence of polynuclear aromatic hydrocarbons (PAHs) as a screening technique for samples to be analyzed by Gas Chromatography/Mass Spectrometry (GC/MS). The test is based on the phenomenon of ...
In the last decade, several studies of polycyclic aromatic hydrocarbons (PAH) in ambient air in the U.S. specifically investigated (1) the sampling efficiency of two sorbents for PAH in air: XAD-2 and polyurethane foam (PUP); (2) the storage stability of PAH on quartz fiber fil...
Phytoremediation is a low-cost method of using plants to degrade, volatilize or sequester organic and metal pollutants that has been used in efforts to remediate sites contaminated with polycyclic aromatic hydrocarbon (PAH) refinery wastes. Non-native plant species aggressivel...
Polycyclic Aromatic Hydrocarbons in Maternal and Cord Blood Plasma
Polycyclic aromatic hydrocarbons (PAH) come from incomplete combustion of organic materials, including tobacco smoke. Some PAH are known to be mutagenic and carcinogenic and of concern for the fetus when women smoke during pregnancy. Known consequences of smoking during pregnancy include low birth weight (LBW) and preterm (PT) delivery. This study was designed to measure concentrations of 3 PAH: anthracene
Paula G. Radmacher; Stephen W. Looney; Steven R. Myers
The paper presents the results of experiments performed to determine the amounts of gas- and particle-phase polycyclic aromatic hydrocarbons (PAHS) in incense smoke. Ten brands of incense, 3 of stick, 2 of joss stick, and one each of cone, smudge bundle, rope, powder, and rock, w...
Microbial Degradation of Polycyclic Aromatic Hydrocarbons and Characterization of Bacteria
Biodegradation of polycyclic aromatic hydrocarbons was studied. Naphthalene was used as a model compound to represent these compounds. Low initial concentrations of naphthalene in a range of 30-60 mg/L were completely degraded after incubation for 15 hrs by consortia from a landfill soil while consortia from minewater took more that 29 hrs to reach complete degradation.
Tikilili, P. V.; Chirwa, E. M. N.
Polycyclic Aromatic Hydrocarbon Degrading Microorganisms in Great Lakes Sediments
Biodegradation is a chemical transformation process that may result in the decontamination of sediments. A criterion for the potential success of biode gradation is the ability of indigenous microorganisms to catabolize contaminants, such as polycyclic aromatic hydrocarbons (PAHs). The number of microorganisms displaying this ability may be influenced by the extent of their exposure to PAHs. In this study, microorganisms
Dan L. McNally; James R. Mihelcic; Donald R. Lueking
Phase distribution of polynuclear aromatic hydrocarbons in ambient air
The determination of concentrations of polynuclear aromatic hydrocarbons (PAH) in ambient air is of considerable importance to characterization of air quality. While these compounds are often found to be associated with airborne particulate matter, many PAH have sufficiently high vapor pressures that appreciable fractions of their total concentrations occur in the vapor phase. This is especially true when sampling is
R. G. Lewis; R. W. Coutant; P. J. Callahan; J. C. Chuang
Hydrogen Coverage of Interstellar PAHs (Polycyclic Aromatic Hydrocarbons).
The rate at which the CH bond in interstellar Polycyclic Aromatic Hydrocarbons (PAHs) rupture due to the absorption of a uv photon has been calculated. The results show that small PAHs (less than or equal to 25 carbon atoms) are expected to be partially d...
A. G. G. M. Tielens L. J. Allamandola J. R. Barker M. Cohen
Abiotic synthesis of polycyclic aromatic hydrocarbons on Mars
Thermochemical calculations of metastable equilibria are used to evaluate the stability of condensed polycyclic aromatic hydrocarbons (PAHs) in cooling thermal gases and hydrothermal fluids on ancient Mars, which are roughly similar to their terrestrial counterparts. The effects of temperature, pressure, the extent of PAH alkylation, and the relative stability of PAHs and alkanes are considered. Inhibition of methane and graphite
Mikhail Zolotov; Everett Shock
Biodegradation of Aliphatic vs. Aromatic Hydrocarbons in Fertilized Arctic Soils
The objectives of this study were to (1) test a simple bioremediation treatment strategy in the Arctic and (2) examine the effect of fertilization on the degradation of aliphatic and aromatic hydrocarbons. The site is a coarse sand pad that once supported fuel storage tanks. Concentrations of diesel-range organics at the beginning of the study (July 1996) ranged from 250
Joan F. Braddock; James L. Walworth; Kathleen A. McCarthy
Oxidation of polynuclear aromatic hydrocarbons in water. 1: Ozonation
The oxidation of three polynuclear aromatic hydrocarbons (PAHs), fluorene, phenanthrene, and acenaphthene, in aqueous solution with ozone has been studied. The influence of hydroxyl radical inhibitors, pH, ozone partial pressure, and temperature was investigated. All the PAHs studied show high oxidation rates with ozone. The ozonation of fluorene seems to be due to both direct and hydroxyl radical reactions while
Fernando J. Beltran; J. M. Encinar; J. Rivas; G. Ovejero
Polycyclic aromatic hydrocarbons in Estonian soil: contamination and profiles
The distribution and accumulation of polycyclic aromatic hydrocarbons (PAH) in soil as well as PAH profiles have been investigated in areas with different anthropogenic pollution such as the city of Tallinn, the towns of P�rnu and Kohtla-J�rve and some rural areas. PAH were identified in 147 soil samples (0�10 cm upper layer) collected in September 1996. The typical ? PAH
M Trapido
Woodburning as a source of atmospheric polycyclic aromatic hydrocarbons
Airborne particulate matter containing polycyclic aromatic hydrocarbons derived from burning natural vegetation and paper products in a variety of ways was collected and analyzed by HPLC. Similar profiles of compounds resulted from most of the combustion sources that do not involve fossil fuels and that are likely to contribute to Sydney's atmospheric particulates. In addition, the profiles did not change
Diana J. Freeman; Frank C. R. Cattell
Structure-biodegradability relationships of polycyclic aromatic hydrocarbons in soil
The potential of some polycyclic aromatic hydrocarbons (PAH) to be metabolized to mutagenic and\\/or carcinogenic compounds (Cerniglia 1984, Gibson & Subramanian 1984) has caused concern for environmental pollution by this class of residues. In industrialized countries, pollution by PAH is primarily associated with the processing, combustion and disposal of fossil fuels (Bartha & Bossert 1984, Hites& LaFlamme 1977), but low
Ingeborg D. Bossert; Richard Bartha
Emission factors for polycyclic aromatic hydrocarbons from biomass burning
Emission factors for 19 polycyclic aromatic hydrocarbons were measured during wind tunnel simulations of open burning for agricultural and forest biomass fuels including cereal grasses, agricultural tree prunings, and fir and pine wood (slash). Yields of total PAH varied from 5 to 683 mg kg⁻¹ depending principally on burning conditions and to a lesser extent on fuel type. Barley straw
Bryan M. Jenkins; A. Daniel Jones; Scott Q. Turn; Robert B. Williams
Consensus sediment quality guidelines for polycyclic aromatic hydrocarbon mixtures
Sediment quality guidelines (SQGs) for polycyclic aromatic hydrocarbons (PAHs) have been derived from a variety of laboratory, field, and theoretical foundations. They include the screening level concentration, effects ranges-low and -median, equilibrium partitioning concentrations, apparent effects threshold, ΣPAH model, and threshold and probable effects levels. The resolution of controversial differences among the PAH SQGs lies in an understanding of the
Richard C. Swartz
Sources of polycyclic aromatic hydrocarbons to the Hudson River Airshed
Sources of polycyclic aromatic hydrocarbons (PAHs) to the Hudson River Estuary Airshed were investigated using positive matrix factorization (PMF). A three-city dataset was used to obtain common factor profiles. The contributions of each factor on each sampling day and site were then determined, and a sensitivity analysis was conducted. A stable eight-factor solution was identified. PMF was able to identify
Jong Hoon Lee; Cari L. Gigliotti; John H. Offenberg; Steven J. Eisenreich; Barbara J. Turpin
Pressurised liquid extraction of polycyclic aromatic hydrocarbons from contaminated soils
The reliability and efficiency of the pressurised liquid extraction technique (PLE) for extracting polycyclic aromatic hydrocarbons (PAHs) from contaminated soil has been investigated. Experimental design was used to study the influence of seven extraction variables (sample load, solvents used, solvent ratios, pressure, temperature, extraction time, and rinse volume). The results show that large sample loads in combination with small solvent
Staffan Lundstedt; Bert van Bavel; Peter Haglund; Mats Tysklind; Lars �berg
Enhanced Bioremediation of Polycyclic Aromatic Hydrocarbons by Environmentally Friendly Techniques
Polycyclic aromatic hydrocarbons (PAHs) are recognized as a worldwide environmental contamination problem because of their intrinsic chemical stability, high resistance to various transformation processes, and toxicity property. Because of the wide distribution of the PAHs in the environment, human exposure to the PAHs is likely to occur from dermal contact, ingestion of particles, inhalation of airborne dust, or bioaccumulation in
Huey-Min Hwang; Xiaoke Hu; Xueheng Zhao
Dermal Exposure to Polycyclic Aromatic Hydrocarbons among Road Pavers
Objectives: Dermal exposure to polycyclic aromatic hydrocarbons (PAHs) and the role of an industrial by-product, coal fly ash, on workers' PAH exposure were investigated during stone mastic asphalt (SMA) paving and remixing. Methods: PAH exposure was measured at eight sites during the laying of SMA containing coal fly ash or limestone (conventional SMA) as the filler. Six of the surveys
Development of a Fluorescence Polarization Immunoassay for Polycyclic Aromatic Hydrocarbons
A fluorescence polarization immunoassay for detection of polycyclic aromatic hydrocarbons (PAHs) was developed. Fluorescein?labeled tracers based on different PAHs were synthesized and studied in order to achieve a high sensitivity using both monoclonal and polyclonal antibodies. The application of different combinations of antibody tracer pairs allows to separately determine groups of small and large PAHs or to realize a class?specific
Irina Yu Goryacheva; Sergei A. Eremin; Ekaterina A. Shutaleva; Miloslav Suchanek; Reinhard Niessner; Dietmar Knopp
Biodegradation of aromatic hydrocarbons by aquifer microorganisms under denitrifying conditions
A series of laboratory tests were conducted to evaluate whether denitrification would be a suitable alternative for biorestoration of an aquifer contaminated with JP-4 jet fuel. Microcosms were prepared from both uncontaminated and contaminated aquifer material from the site, in an anaerobic glovebox, amended with nitrate, nutrients, and aromatic hydrocarbons, and incubated under a nitrogen atmosphere at 12C. With uncontaminated
Stephen R. Hutchins; Guy W. Sewell; David A. Kovacs
Analysis of polycyclic aromatic hydrocarbons in cooking oil fumes
Various samples of cooking oil fumes were analyzed to an effort to study the relationship between the high incidence of pulmonary adenocarcinoma in Chinese women and cooking oil fumes in the kitchen. Polycyclic aromatic hydrocarbons (PAHs) in samples of cooking oil fumes were extracted, chromatographed, and measured by fluorescence spectrophotometer. The samples included oil fumes from three commercial cooking oils
Li Shuguang; Pan Dinhua; Wang Guoxiong
Analysis of Polycyclic Aromatic Hydrocarbons in Cooking Oil Fumes
Biomonitoring of polycyclic aromatic hydrocarbons in human urine
Measurement of polycyclic aromatic hydrocarbons (PAH) metabolites in human urine is the method of choice to determine occupational and\\/or environmental exposure of an individual to PAH, in particular, when multiple routes of exposure have to be taken into account. Requirements for methods of biomonitoring PAH metabolites in urine are presented. Studies using 1-hydroxypyrene or phenanthrene metabolites including its phenols and
J�rgen Jacob; Albrecht Seidel
Aromatic and polycyclic aromatic hydrocarbon formation in a laminar premixed n-butane flame
Experimental and detailed chemical kinetic modeling work has been performed to investigate aromatic and polycyclic aromatic hydrocarbon (PAH) formation pathways in a premixed, rich, sooting, n-butane-oxygen-argon burner stabilized flame. An atmospheric pressure, laminar flat flame operated at an equivalence ratio of 2.6 was used to acquire experimental data for model validation. Gas composition analysis was conducted by an on-line gas chromatograph/mass spectrometer technique. Measurements were made in the main reaction and post-reaction zones for a number of low molecular weight species, aliphatics, aromatics, and polycyclic aromatic hydrocarbons (PAHs) ranging from two to five-fused aromatic rings. Reaction flux and sensitivity analysis were used to help identify the important reaction sequences leading to aromatic and PAH growth and destruction in the n-butane flame. Reaction flux analysis showed the propargyl recombination reaction was the dominant pathway to benzene formation. The consumption of propargyl by H atoms was shown to limit propargyl, benzene, and naphthalene formation in flames as exhibited by the large negative sensitivity coefficients. Naphthalene and phenanthrene production was shown to be plausibly formed through reactions involving resonantly stabilized cyclopentadienyl and indenyl radicals. Many of the low molecular weight aliphatics, combustion by-products, aromatics, branched aromatics, and PAHs were fairly well simulated by the model. Additional work is required to understand the formation mechanisms of phenyl acetylene, pyrene, and fluoranthene in the n-butane flame. 73 refs.
Marinov, N.M.; Pitz, W.J.; Westbrook, C.K. [Lawrence Livermore National Lab., CA (United States)] [Lawrence Livermore National Lab., CA (United States); Vincitore, A.M.; Castaldi, M.J.; Senkan, S.M. [Univ. of California, Los Angeles, CA (United States)] [Univ. of California, Los Angeles, CA (United States); Melius, C.F. [Sandia National Labs., Livermore, CA (United States)] [Sandia National Labs., Livermore, CA (United States)
Analogs of solid nanoparticles as precursors of aromatic hydrocarbons
Context. Aromatic =CH and C=C vibrational bands have been observed within shocked interstellar regions, indicating the presence of aromatic emission carriers such as PAHs, which may have been created from adjacent molecular cloud material by interaction with a shock front. Aims: We investigate the evolution of the aromatic =CH and C=C vibrational modes at 3.3 and 6.2 ?m wavelength in heated HAC materials, PAHs and mixed PAHs and HACs, respectively, aiming at an explanation of the evolution of carbonaceous dust grains in the shocked regions. Methods: Materials used in these analogs (HAC and PAH materials) were prepared by the laser ablation and the laser pyrolysis methods, respectively. The transmission electron microscopy (TEM) in high-resolution mode was used as an analytical technique to characterize the aromatic layers in HACs. Spectroscopic analysis was prformed in the mid-IR range. Results: A remarkable destruction of aliphatic structures in HACs has been observed with the thermal processing, while aromatic structures become dominating by increasing the diameters of the graphene layers. The aromatic bands at 3.3 and 6.2 ?m, observed in the laboratory spectra of PAHs and of the combination of the PAHs and HAC materials, are also clearly observed in the spectrum of the heated HACs. These bands agree with those of aromatic bands observed in astronomical observations. Conclusions: Aromatization of HACs could be a pre-stage in the decomposition process of hydrocarbons that form PAH-clusters in such hot interstellar medium.
Gadallah, K. A. K.; Mutschke, H.; J�ger, C.
Effect of fluorine substitution on the aromaticity of polycyclic hydrocarbons.
The effect of fluorine substitution on the aromaticity of polycyclic hydrocarbons (PAH) is investigated. Magnetically induced current densities, current pathways, and current strengths, which can be used to assess molecular aromaticity, are calculated using the gauge-including magnetically induced current method (GIMIC). The degree of aromaticity of the individual rings is compared to those obtained using calculated nucleus-independent chemical shifts at the ring centers (NICS(0) and NICS(0)(zz)). Calculations of explicitly integrated current strengths for selected bonds show that the aromatic character of the investigated polycyclic hydrocarbons is weakened upon fluorination. In contrast, the NICS(0) values for the fluorinated benzenes increase noteworthy upon fluorination, predicting a strong strengthening of the aromatic character of the arene rings. The integrated current strengths also yield explicit current pathways for the studied molecules. The current pathways of the investigated linear polyacenes, pyrene, anthanthrene, coronene, ovalene, and phenanthro-ovalene are not significantly affected by fluorination. NISC(0) and NICS(0)(zz) calculations provide contradictory degrees of aromaticity of the fused individual ring. Obtained NICS values do not correlate with the current strengths circling around the individual rings. PMID:22994485
Kaipio, Mikko; Patzschke, Michael; Fliegl, Heike; Pichierri, Fabio; Sundholm, Dage
Vibrational Spectra of Polycyclic Aromatic Hydrocarbons Under Pressure
Polycyclic aromatic hydrocarbons are present in primitive meteorites, and hence their behavior under high-pressure conditions is relevant to carbon processing during planetary formation and accretion. Infrared and Raman spectra have been collected of the polycyclic aromatic hydrocarbons anthracene and pyrene under pressure, with the motivation being to understand how these two materials respond to compression, and ultimately how they form hydrogenated, dense, likely-amorphous carbon-rich materials at high pressures. Thus, our experiments are oriented towards providing data on the bonding within these materials to constrain their 300 K response to compression, and to provide a basis for comparison with shock data. Our infrared data on pyrene (which has four aromatic rings) under pressure show that most spectral features of low-pressure pyrene disappear above 18.0 GPa. The C-H bonding in this material becomes markedly disordered above ~2.0 GPa in the IR and ~3.0 GPa in the Raman. Most spectral features of low-pressure pyrene disappear above 10 GPa in the Raman spectra, in accord with previous studies. Our Raman data on anthracene (which has three aromatic rings) under pressure show that most spectral features disappear above 8.0 GPa and that the C-H bonding becomes markedly disordered above 6.0 GPa. Following decompression of anthracene from 10 GPa, most spectral features returned, including the C-H bands, which suggests that this material does not undergo an irreversible transformation up to this pressure. Comparison with prior work on benzene indicates that the onset of a high-density disordered material in aromatic hydrocarbons hinges on the number of rings present: fewer rings result in markedly greater stability on simple compression. This trend is likely associated with lower pressure onsets of strong intramolecular interactions in progressively larger aromatic hydrocarbons.
O'Bannon, E. F.; Williams, Q.
Aromatic and Polycyclic Aromatic Hydrocarbon Formation in a Laminar Premixed n-Butane Flame
Experimental and detailed chemical kinetic modeling work has been performed to investigate aromatic and polycyclic aromatic hydrocarbon (PAH) formation pathways in a premixed, rich, sooting, n-butane�oxygen�argon burner stabilized flame. An atmospheric pressure, laminar flat flame operated at an equivalence ratio of 2.6 was used to acquire experimental data for model validation. Gas composition analysis was conducted by an on-line gas
Nick M Marinov; William J Pitz; Charles K Westbrook; Antonio M Vincitore; Marco J Castaldi; Selim M Senkan; Carl F Melius
Growth of fungi on volatile aromatic hydrocarbons
The present study aimed the better understanding of the catabolism of monoaromatic hydrocarbons by fungi. This knowledge can be used to enhance the biodegradation of BTEX pollutants. Fungi with the capacity of using toluene as the sole source of carbon and energy were isolated by enriching environmental polluted soil and groundwater samples in solid state-like batches, air biofilters, and liquid
F. X. Prenafeta Bold�
Accumulation and release of petroleum-derived aromatic hydrocarbons by four species of marine animals
When exposed to oil-contaminated seawater, marine animals accumulate a wide variety of petroleum hydrocarbons in their tissues. Generally, the aromatic hydrocarbons are accumulated to a greater extent and are retained longer than the alkanes. In all species tested, accumulation of aromatic hydrocarbons appears to be dependent primarily on a partitioning of the hydrocarbons between the exposure water and the tissue
J. M. Neff; B. A. Cox; D. Dixit; J. W. Anderson
Biodegradation of Aromatic Hydrocarbons in an Extremely Acidic Environment
The potential for biodegradation of aromatic hydrocarbons was evaluated in soil samples recovered along gradients of both contaminant levels and pH values existing downstream of a long-term coal pile storage basin. pH values for areas greatly impacted by runoff from the storage basin were 2.0. Even at such a reduced pH, the indigenous microbial community was metabolically active, showing the ability to oxidize more than 40% of the parent hydrocarbons, naphthalene and toluene, to carbon dioxide and water. Treatment of the soil samples with cycloheximide inhibited mineralization of the aromatic substrates. DNA hybridization analysis indicated that whole-community nucleic acids recovered from these samples did not hybridize with genes, such as nahA, nahG, nahH, todC1C2, and tomA, that encode common enzymes from neutrophilic bacteria. Since these data suggested that the degradation of aromatic compounds may involve a microbial consortium instead of individual acidophilic bacteria, experiments using microorganisms isolated from these samples were initiated. While no defined mixed cultures were able to evolve 14CO2 from labeled substrates in these mineralization experiments, an undefined mixed culture including a fungus, a yeast, and several bacteria successfully metabolized approximately 27% of supplied naphthalene after 1 week. This study shows that biodegradation of aromatic hydrocarbons can occur in environments with extremely low pH values.
Stapleton, Raymond D.; Savage, Dwayne C.; Sayler, Gary S.; Stacey, Gary
Occupational exposure to Polycyclic Aromatic Hydrocarbons in wood dust
Sino-nasal cancer (SNC) represents approximately 3% of Oto-Rhino-Laryngology (ORL) cancers. Adenocarcinoma SNC is an acknowledged occupational disease affecting certain specialized workers such as joiners and cabinetmakers. The high proportion of woodworkers contracting a SNC, subjected to an estimated risk 50 to 100 times higher than that affecting the general population, has suggested various study paths to possible causes such as tannin in hardwood, formaldehyde in plywood and benzo(a)pyrene produced by wood when overheated by cutting tools. It is acknowledged that tannin does not cause cancer to workers exposed to tea dust. Apart from being an irritant, formaldehyde is also classified as carcinogenic. The path involving carcinogenic Polycyclic Aromatic Hydrocarbons (PAHs) emitted by overheated wood is attractive. In this study, we measured the particle size and PAHs content in dust emitted by the processing of wood in an experimental chamber, and in field situation. Quantification of 16 PAHs is carried out by capillary GC-ion trap Mass Spectrometric analysis (GC-MS). The materials tested are rough fir tree, oak, impregnated polyurethane (PU) oak. The wood dust contains carcinogenic PAHs at the level of ?g.g-1 or ppm. During sanding operations, the PU varnish-impregnated wood produces 100 times more PAHs in dust than the unfinished wood.
Huynh, C. K.; Sch�pfer, P.; Boiteux, P.
Adsorption and absorption of polycyclic aromatic hydrocarbons to rice roots.
Rice roots and surrounding air, soil and water samples were collected for polycyclic aromatic hydrocarbon (PAH) analysis. The rice roots were separated into lateral roots and nodal roots, and the PAH concentration in the former was found to be higher than that in the latter. In addition, root physiological characteristics including root biotic mass, root lipid content and specific surface area are also discussed. When normalizing the total, adsorption and absorption PAH fractions on a dry root weight basis to root biomass, root lipid, and surface area bases respectively, the differences between PAHs in the two types of roots diminished by 2 to 3 times on average. Results from sequential extraction indicated that PAHs were more easily absorbed by interior rice roots than adsorbed on the surface. In addition, more than 60% of total PAHs accumulated in root tissue for both lateral and nodal roots. However, the results were highly related to the solvent used, extraction time and methodology. Correlation analysis between bioconcentration factors (root over environment) and K(OA), K(OW) showed water to be more significant for PAH adsorption in rice roots than other environmental media. PMID:17182157
Jiao, X C; Xu, F L; Dawson, R; Chen, S H; Tao, S
Four lime spray dryer (LSD) ash samples were collected from a spreader stoker boiler and measured for their concentrations of 16 U.S. EPA specified polycyclic aromatic hydrocarbons (PAHs). Results showed that the total measured PAH concentration correlated with the organic carbon content of the LSD ash. Each LSD ash sample was then separated using a 140 mesh sieve into two fractions: a carbon-enriched fraction ({gt}140 mesh) and a lime-enriched fraction ({lt}140 mesh). Unburned carbon was further separated from the carbon-enriched fraction with a lithiumheteropolytungstate (LST) solution. PAH measurements on these different fractions showed that unburned carbon had the highest PAH concentrations followed by the carbon-enriched fraction, indicating that PAHs were primarily associated with the carbonaceous material in LSD ash. However, detectable levels of PAHs were also found in the lime-enriched fraction, suggesting that the fine spray of slaked lime may sorb PAH compounds from the flue gas in the LSD process. 37 refs., 5 figs., 4 tabs.
Ping Sun; Panuwat Taerakul; Linda K. Weavers; Harold W. Walker [Ohio State University, Columbus, OH (United States). Department of Civil and Environmental Engineering and Geodetic Science
Phototransformation of polycyclic aromatic hydrocarbons into stable, mutagenic components
This report compares the mutagenicity of photochemical products produced by exposure of the polycyclic aromatic hydrocarbons benzo(a)pyrene and 9,10-dimethylanthracene or the aromatic amines 2-aminofluorene, 2-aminoanthracene and 2-aminonaphthalene to sunlight or to ultraviolet light (UVA). 2-Aminofluorene, giving the most active products, was further investigated with respect to the mechanism of photoactivation and the chemical identity of the photochemical products. Screening of HPLC resolved photochemical products demonstrated that the majority of the mutagenicity was localized to one peak - which co-chromatographed with 2-nitrofluorene.
Okinaka, R.T.; Nickols, J.W.; Whaley, T.W.; Strniste, G.F.
Modeling of Aromatic and Polycyclic Aromatic Hydrocarbon Formation in Premixed Methane and Ethane Flames
Detailed chemical kinetic modeling has been performed to investigate aromatic and polyaromatic hydrocarbon formation pathways in rich, sooting, methane and ethane premixed flames. An atmospheric pressure, laminar flat flame operated at an equivalence ratio of 2.5 was used to acquire experimental data for model validation. Gas composition analysis was conducted by an on-line gas chromatograph \\/ mass spectrometer technique. Measurements
N. M. Marinov; W. J. Pitz; C. K. Westbrook; M. J. Castaldi; S. M. Senkan
Polycyclic aromatic hydrocarbons (PAHs), the real contaminants of petroleum, were detected in the surface seawater of Alexandria coastal area in winter and spring seasons of 1995. Their order of predominance, particularly for the individual components were principally due to the processes of input, transport and fluxes. Variation of PAHs was not following seasonal changes but it was slightly affected by
Polycyclic aromatic hydrocarbons degradation by composting in a soot-contaminated alkaline soil
This study deals with the biodegradation of the polycyclic aromatic hydrocarbons (PAH)s present in a soil contaminated by soot waste, characterised by a total PAHs content in the 200mgkg?1 range. A challenging characteristic of the waste soil treated was its high alkalinity, with a pH of about 12.8. The waste came from a soot-contaminated area located in the industrial zone
L. M. Moretto; S. Silvestri; P. Ugo; G. Zorzi; F. Abbondanzi; C. Baiocchi; A. Iacondini
Mineralization of sparsely water-soluble polycyclic aromatic hydrocarbons in a water table fluctuation zone
The mineralization potential of sparsely water-soluble polycyclic aromatic hydrocarbons (PAHs) within a highly diesel-contaminated water table fluctuation zone (WTFZ) was investigated using core-scale column microcosms. Experimental conditions mimicked overall seasonal changes in water and oxygen content at the site. During the first aerobic winter, PAH mineralization rates in the freshly contaminated soil were fastest for contaminant [¹⁴C]-naphthalene which was the
H.-Y. N. Holman; Y. W. Tsang; W. R. Holman
A simple and sensitive capillary electrophoretic method was developed for the separation and determination of selected carcinogenic amino derivatives of polycyclic aromatic hydrocarbons. The influence of pH and content of methanol in the background electrolyte on electrophoretic mobilities of 2-aminofluorene, 2,7-diaminofluorene, 1-aminonaphthalene, 1-aminopyrene and 6-aminochrysene was studied. The detection limits were estimated to be 2.5 � 10 mol.l for 2-aminofluorene,
Martin Pumera; Jan Muzik�?; Ji?� Barek; Ivan Jel�nek
Influence of humic substances on the formation of chlorinated polycyclic aromatic hydrocarbons during chlorination of polycyclic aromatic hydrocarbon polluted water
Chlorinated polycyclic aromatic hydrocarbons (PAH) are present at nanogram per liter levels in lake water. Some of these compounds are known to be mutagenic in the Ames Salmonella test. The PAH compounds fluorene, anthracene, fluoranthene, and benzo(a)pyrene were dissolved in lake water with low humus content and in humus water with 9.17 mg of total organic carbon/L, followed by sodium hypochlorite chlorination at different concentrations. Reaction of PAH and formation of chlorinated PAH were measured by cyclohexane extraction of the samples 3 days after chlorination and gas chromatography/mass spectrometry analyses of the extracts. The PAH-chlorine reaction was found to be dependent upon the concentration of free active chlorine in the water, and the presence of humic substances was found to affect the formation of chlorinated PAH. Chlorinated PAH were formed in the lake water samples of fluoranthene and benzo(a)pyrene, but no chlorinated PAH were detected in the presence of humic substances.
Johnsen, S.; Gribbestad, I.S.
Preferential utilization of petroleum oil hydrocarbon components by microbial consortia reflects degradation pattern in aliphatic�aromatic hydrocarbon binary mixtures
In this study, the abilities of two microbial consortia (Y and F) to degrade aliphatic�aromatic hydrocarbon mixtures were\\u000a investigated. Y consortium preferentially degraded the aromatic hydrocarbon fractions in kerosene, while F consortium preferentially\\u000a degraded the aliphatic hydrocarbon fractions. Degradation experiments were performed under aerobic conditions in sealed bottles\\u000a containing liquid medium and n-octane or n-decane as representative aliphatic hydrocarbons or
Hernando Pactao Bacosa; Koichi Suto; Chihiro Inoue
Direct photolysis of polycyclic aromatic hydrocarbons in drinking water sources.
The widely used low pressure lamps were tested in terms of their efficiency to degrade polycyclic aromatic hydrocarbons listed as priority pollutants by the European Water Framework Directive and the U.S. Environmental Protection Agency, in water matrices with very different compositions (laboratory grade water, groundwater, and surface water). Using a UV fluence of 1500 mJ/cm(2), anthracene and benzo(a)pyrene were efficiently degraded, with much higher percent removals obtained when present in groundwater (83-93%) compared to surface water (36-48%). The removal percentages obtained for fluoranthene were lower and ranged from 13 to 54% in the different water matrices tested. Several parameters that influence the direct photolysis of polycyclic aromatic hydrocarbons were determined and their photolysis by-products were identified by mass spectrometry. The formation of photolysis by-products was found to be highly dependent on the source waters tested. PMID:21784577
Sanches, S; Leit�o, C; Penetra, A; Cardoso, V V; Ferreira, E; Benoliel, M J; Crespo, M T Barreto; Pereira, V J
Oxidation of polycyclic aromatic hydrocarbons under sulfate-reducing conditions
[14C]naphthalene and phenanthrene were oxidized to 14CO2 without a detectable lag under strict anaerobic conditions in sediments from San Diego Bay, San Diego, Calif., that were heavily contaminated with polycyclic aromatic hydrocarbons (PAHs) but not in less contaminated sediments. Sulfate reduction was necessary for PAH oxidation. These results suggest that the self-purification capacity of PAH-contaminated sulfate-reducing environments may be greater than previously recognized.
Coates, J. D.; Anderson, R. T.; Lovley, D. R.
Polycyclic aromatic hydrocarbons in sediments of the Venice Lagoon
Three sediment cores were collected in the Venice Lagoon: two from mud flats (E, F) and one from the San Giuliano Canal (I1), which borders the industrial district. Samples were analysed for the 15 polycyclic aromatic hydrocarbons (PAHs) listed as priority pollutants by the U.S. EPA. Sediment chronologies were established using both 137Cs and 210Pb activity-depth profiles, and confirmed by
M. Frignani; L. G. Bellucci; M. Favotto; S. Albertazzi
Bioaccumulation and biomagnification of polycyclic aromatic hydrocarbons in aquatic organisms
Uptake and degradation of polycyclic aromatic hydrocarbons were studied in a laboratory scale food chain consisting of Dunaliella tertiolecta (microalga), Mytilus galloprovincialis (mussel) and Dicentrarchus labrax (fish), in tanks supplied with open water flow. The toxicants, benzo(a)pyrene and 7,12-dimethyl benz(a)anthracene, were added and samples were taken every ten days. Bioaccumulation of toxicants in the food chain steps and the physiological
R. D'Adamo; S. Pelosi; P. Trotta; G. Sansone
Polycyclic aromatic hydrocarbons in soils around Guanting Reservoir, Beijing, China
The concentrations of 16 polycyclic aromatic hydrocarbons (? 16PAHs) were measured by gas chromatography equipped with a mass spectrometry detector (GC-MS) in 56 topsoil samples around Guanting Reservior (GTR), which is an important water source for Beijing. Low to medium levels of PAH contamination (mean=394.2�580.7�ng�g dry weight (d.w.)) was evident throughout the region. In addition, localised areas of high PAH
Wentao Jiao; Yonglong Lu; Tieyu Wang; Jing Li; Jingyi Han; Guang Wang; Wenyou Hu
Direct arylation of polycyclic aromatic hydrocarbons through palladium catalysis.
We have discovered that the combination of Pd(OAc)(2)/o-chloranil can catalyze the direct C-H bond arylation of polycyclic aromatic hydrocarbons (PAHs) with arylboroxins that occurs selectively at the K-region. The sequential integration of Pd-catalyzed direct arylation of PAHs and FeCl(3)-mediated cyclodehydrogenation is effective in rapidly extending a parent PAH ?-system with high directionality. PMID:21699210
Mochida, Kenji; Kawasumi, Katsuaki; Segawa, Yasutomo; Itami, Kenichiro
Biodegradation of polycyclic aromatic hydrocarbons by a mixed culture
We investigated the potential biodegradation of polycyclic aromatic hydrocarbons (PAHs) by an aerobic mixed culture utilizing phenanthrene as its carbon source. Following a 3�5 h post-treatment lag phase, complete degradation of 5 mg\\/l phenanthrene occurred within 28 h (optimal conditions determined as 30�C and pH 7.0). Phenanthrene degradation was enhanced by the individual addition of yeast extract, acetate, glucose or
S. Y Yuan; S. H Wei; B. V Chang
Electron energy loss spectra of polycyclic aromatic hydrocarbons
A survey of the electron energy-loss spectroscopy is reported of gas-phase polycyclic aromatic hydrocarbon (PAH) molecules consisting of up to seven rings where the study is limited to the more thermodynamically stable pericondensed systems. The aim of this work is to obtain absorption profiles (proportional to the oscillator strengths) from the visible to the soft X-ray region near 30 eV.
Keller, John W.; Coplan, M. A.; Goruganthu, R.
Polycyclic aromatic hydrocarbons in U. K. Urban air
Polycyclic aromatic hydrocarbon (PAH) data for the first two years (January 1991-December 1992) of a national urban air monitoring scheme in the U.K. are presented. Urban sample sites were operated in the cities of London, Manchester, and Cardiff and in the light industrial town of Stevenage. Both the particulate and vapor phases of 15 PAHs were sampled using high-volume air
Crispin J. Halsall; V. Burnett; K. S. Waterhouse; K. C. Jones; P. J. Coleman; B. J. Davis; P. Harding-Jones
Vegetation-atmosphere partitioning of polycyclic aromatic hydrocarbons
The partitioning of polycyclic aromatic hydrocarbons (PAH) between vegetation and the atmosphere was studied throughout the growing season and under natural conditions. A vegetation-atmosphere partition coefficient (K[sub v]) was derived by analogy to partition coefficients for gas-particle partitioning and fish-water partitioning. K[sub v] is temperature dependent, and from this functional relationship we calculated PAH-vegetation binding energies. These energies were highly
Staci L. Simonich; Ronald A. Hites
Oxidation of Polycyclic Aromatic Hydrocarbons under Sulfate-Reducing Conditions
[(sup14)C]naphthalene and phenanthrene were oxidized to (sup14)CO(inf2) without a detectable lag under strict anaerobic conditions in sediments from San Diego Bay, San Diego, Calif., that were heavily contaminated with polycyclic aromatic hydrocarbons (PAHs) but not in less contaminated sediments. Sulfate reduction was necessary for PAH oxidation. These results suggest that the self-purification capacity of PAH-contaminated sulfate-reducing environments may be greater than previously recognized.
Photolysis of polycyclic aromatic hydrocarbons adsorbed on simulated atmospheric particulates
Fifteen polycyclic aromatic hydrocarbons (PAH) adsorbed on silica gel, alumina, fly ash, and carbon black were photolyzed in order to study their atmospheric fate. Photolytic half-lives for these particle-bound PAH were found to be highly dependent on the substrate to which they were adsorbed. On silica gel and alumina, PAH showed a wide range of photolytic half-lives, indicating a relationship
Thomas D. Behymer; Ronald A. Hites
Role of radical cations in aromatic hydrocarbon carcinogenesis
Carcinogenic activation of polycyclic aromatic hydrocarbons (PAH) involves two main pathways: one-electron oxidation and monooxygenation. One-electron oxidation produces PAH radical cations, which can react with cellular nucleophiles. Results from biochemical and biological experiments indicate that only PAH with ionization potentials below ca. 7.35 eV can be metabolically activated by one-electron oxidation. In addition, the radical cations of carcinogenic PAH must
E. Cavalieri; E. Rogan
Diversity and correlation of specific aromatic hydrocarbon biodegradation capabilities
This work investigated the biodegradation capabilitiesof indigenous microorganisms exposed to differentcombinations of aromatic hydrocarbons. Considerablediversity was found in the catabolic specificity of 55strains. Toluene was the most commonly degradedcompound, followed by p-xylene, m-xyleneand ethylbenzene. Strains capable of degradingo-xylene and benzene, which were theleast-frequently-degraded compounds, exhibited broaderbiodegradation capabilities. Kappa statistics showeda significant correlation between the abilities todegrade toluene and ethylbenzene, p-xylene
Nahide G�lensoy; Pedro J. J. Alvarez
This work investigated the biodegradation capabilities of indigenous microorganisms exposed to different com- binations of aromatic hydrocarbons. Considerable diversity was found in the catabolic specificity of 55 strains. Toluene was the most commonly degraded compound, followed byp-xylene,m-xylene and ethylbenzene. Strains capable of degrading o-xylene and benzene, which were the least-frequently-degraded compounds, exhibited broader biodegradation capabilities. Kappa statistics showed a significant
Chromatographic methods for carcinogenic/mutagenic nitropolycyclic aromatic hydrocarbons.
Nitropolycyclic aromatic hydrocarbons (NPAHs), which are known to be carcinogenic and/or mutagenic, are considered to be one of the air pollutants that cause lung cancer. In the last two decades, a number of sensitive and selective methods have been developed for the determination of NPAHs and related compounds in environmental and biological samples. This paper describes the state of the art of the methods and applications. PMID:11002277
Hayakawa, K
Quantification of nitrated polynuclear aromatic hydrocarbons in atmospheric particulate matter
A derivatization-GC\\/ECD analytical method has been developed. This method involves first the reduction of nitrated polynuclear aromatic hydrocarbons (NPAHs) to their corresponding amino-PAHs by NaBH4. This is followed by derivatization of the amino-PAHs with heptafluorobutyric anhydride (HFBA). Such derivatization provides a polyfluorinated tag to the NPAHs, which can then be detected and quantified at pg levels by GC\\/ECD. Using this
Reductive hydrogenation of polycyclic aromatic hydrocarbons catalyzed by metalloporphyrins
The hydrogenation of polycyclic aromatic hydrocarbons (PAHs) (naphthalene, anthracene, and phenanthrene) catalyzed by metalloporphyrins based on cobalt, nickel or iron was studied in aqueous solutions at room temperature and ambient pressure. Nickel porphyrin (P1) activated by nanosized zero-valent iron (nano-ZVI) and cobalt porphyrins (P2) and (P4) activated by titanium(III) citrate as the electron donor were demonstrated to be promising catalysts
Elza Nelkenbaum; Ishai Dror; Brian Berkowitz
Critically Evaluated Thermochemical Properties of Polycyclic Aromatic Hydrocarbons
Experimental thermochemical properties of benzene, toluene, and 63 polycyclic aromatic hydrocarbons, published within the period 1878-2008 (over 350 references), are reported. Available experimental data for the enthalpies of combustion used to calculate enthalpies of formation in the condensed state, combined with sublimation, vaporization, and fusion enthalpies, are critically evaluated. Whenever possible, recommended values for these thermochemical properties and for the enthalpies of formation in the gas state at T=298.15 K are provided.
Roux, Mar�a Victoria; Temprado, Manuel; Chickos, James S.; Nagano, Yatsuhisa
Modeling Galactic Extinction with Dust and "Real" Polycyclic Aromatic Hydrocarbons
We investigate the remarkable apparent variety of galactic extinction curves by modeling extinction profiles with core-mantle grains and a collection of single polycyclic aromatic hydrocarbons. Our aim is to translate a synthetic description of dust into physically well-grounded building blocks through the analysis of a statistically relevant sample of different extinction curves. All different flavors of observed extinction curves, ranging from the average galactic extinction curve to virtually "bumpless" profiles, can be described by the present model. We prove that a mixture of a relatively small number (54 species in 4 charge states each) of polycyclic aromatic hydrocarbons can reproduce the features of the extinction curve in the ultraviolet, dismissing an old objection to the contribution of polycyclic aromatic hydrocarbons to the interstellar extinction curve. Despite the large number of free parameters (at most the 54 � 4 column densities of each species in each ionization state included in the molecular ensemble plus the 9 parameters defining the physical properties of classical particles), we can strongly constrain some physically relevant properties such as the total number of C atoms in all species and the mean charge of the mixture. Such properties are found to be largely independent of the adopted dust model whose variation provides effects that are orthogonal to those brought about by the molecular component. Finally, the fitting procedure, together with some physical sense, suggests (but does not require) the presence of an additional component of chemically different very small carbonaceous grains.
Mulas, Giacomo; Zonca, Alberto; Casu, Silvia; Cecchi-Pestellini, Cesare
QSARs for aromatic hydrocarbons at several trophic levels.
Quantitative structure-activity relationships (QSARs) with aromatic hydrocarbons were obtained. Biological response was measured by acute toxicity of several aquatic trophic levels. The chemicals assayed were benzene, toluene, ethylbenzene, o-xylene, m-xylene, p-xylene, isopropylbenzene, n-propylbenzene, and butylbenzene. Acute toxicity tests were carried out with Scenedesmus quadricauda, as representative of primary producers; Daphnia spinulata, a zooplanctonic cladoceran; Hyalella curvispina, a benthic macroinvertebrate; and Bryconamericus iheringii, an omnivorous native fish. The EC50 or LC50 was calculated from analytical determinations of aromatic hydrocarbons. Nonlinear regression analysis between the logarithm of the octanol-water partition coefficient (log Kow) of each compounds and the toxicity end points was performed. QSARs were positively related to increases in log Kow at all trophic levels. Intertaxonomic differences were found in comparisons of algae with animals and of invertebrates with vertebrates. We observed that these differences were not significant with a log Kow higher than 3 for all organisms. Aromatic hydrocarbons with log Kow values of less than 3 showed different toxicity responses, with algae more resistant than fish and invertebrates. We concluded that this was a result of the narcotic mode of action related to liposolubility and the ability of the compound to reach its target site in the cell. The bioconcentration factor (BCF) achieved to start nonpolar narcosis fell almost 1 order of magnitude below the BCF expected from the log Kow. Predicted critical body residues for nonpolar narcosis ranged between 2 and 1 mM. PMID:16528686
Di Marzio, Walter; Saenz, Maria Elena
Occurrence of polycyclic aromatic hydrocarbons in smoked cheese.
The presence of polycyclic aromatic hydrocarbons (PAH) in smoked cheeses of different origin was studied. The samples were subjected to an initial extraction of fat and an alkaline treatment, extracted with cyclohexane, cleaned up by means of solid-phase extraction tubes, and analyzed by gas chromatography/mass spectrometry (GC/MS) operating in selective ion-monitoring mode (SIM). The results revealed the presence of numerous polycyclic aromatic hydrocarbons in the exterior zone of the samples, some of them with methyl groups. In all cases, the concentrations of compounds of low molecular weight were much higher than those of high molecular weight. Polycyclic aromatic hydrocarbons with varying degrees of carcinogenicity were identified, including benzo(a)pyrene in concentrations, which, although they did not exceed the limit established for this compound in the rind of ripened cheeses, do exceed the limit of 0.03 microg/kg fixed for other foods smoked with smoke flavorings. Significant differences in the number and concentration of PAH in smoked cheese also were observed from rind to interior, the rind being the most contaminated zone. PMID:15202639
Guill�n, Mar�a D; Sopelana, Patricia
Spectroscopic properties of polycyclic aromatic hydrocarbons (PAHs) and astrophysical implications.
PAHs (polycyclic aromatic hydrocarbons) are probably present as a mixture of neutral and ionized species and are responsible for the set of infrared emission bands in the 2-15 microns regions, which are observed in many different objects like reflection and planetary nebulae and external galaxies. PAHs are suggested to be the most abundant free organic molecules and ubiquitous in space. PAHs might also exist in the solid phase, included in interstellar ices in dense clouds. A complex aromatic network is expected on interstellar grains in the diffuse interstellar medium. The existence of an aromatic kerogen-like structure in carbonaceous meteorites and its similarity with interstellar spectra suggests a link between interstellar matter and primitive Solar System bodies. PMID:11541329
d'Hendecourt, L; Ehrenfreund, P
Fog processing of polycyclic aromatic hydrocarbons (PAH)
Polyaromatic hydrocarbons (PAHs) are a class of organic species of concern for environmental and human health. The present work will present initial finding of a comprehensive study on the fate of PAHs in multiphase fog/cloud systems and across consecutive fog/smog cycles. Field observations were conducted in Fresno, CA in Winter 2010. Simultaneous measurements of gas phase, aerosol and fog PAH allowed to gain insights on the partitioning of PAH in a multiphase fog system. Partitioning results as well as temporal evolution of PAH concentrations across different phases will be discussed. Select known degradation products (oxy-PAH) from the processing of PAHs were also analyzed in the fog systems, although frequently their concentrations were close to or below detection limits, even in the polluted urban study setting. The field observations are complemented by laboratory investigations on the reactivity of PAH in fog systems, both heterogeneously and in the aqueous phase. Heterogeneously a novel reactor design is being tested to simulate fog systems and allow for repeat fog/smog cycles. A separate series of measurements investigated the processing of PAH in the aqueous phase in a solar simulator set-up.
Wang, Y.; Khadapkar, K.; Ehrenhauser, F. S.; Hutchings, J. W.; Wornat, M. J.; Valsaraj, K. T.; Herckes, P.
Enzymatic and genetic profiles in environmental strains grown on polycyclic aromatic hydrocarbons
The possible generation of oxidative stress induced by aromatic hydrocarbon degradation suggests that ancillary enzyme activities\\u000a could facilitate the utilization of polycyclic aromatic hydrocarbons as sole carbon source. To investigate the metabolic profiles\\u000a of low molecular weight polycyclic aromatic hydrocarbon-degrading strains of Sphingobium chlorophenolicum, Rhodococcus\\u000a aetherovorans, Rhodococcus opacus and Mycobacterium smegmatis, the determination of the activity of putative detoxifying enzymes
Lucia Cavalca; Nicoletta Guerrieri; Milena Colombo; Silvia Pagani; Vincenza Andreoni
Atmospheric chlorinated polycyclic aromatic hydrocarbons in East Asia.
This study estimates atmospheric concentrations of chlorinated polycyclic aromatic hydrocarbons (ClPAHs) and polycyclic aromatic hydrocarbons (PAHs) in East Asia using a Gas Chromatograph with High Resolution Mass Spectrometer (GC-HRMS). ClPAHs are ubiquitously generated from PAHs through substitution, and some ClPAHs show higher aryl hydrocarbon receptor (AhR)-mediated activities than their parent PAHs. Atmospheric particles were collected using a high-volume air sampler equipped with a quartz-fiber filter. We determined the ClPAH concentrations of atmospheric particles collected in Japan (Sapporo, Sagamihara, Kanazawa, and Kitakyushu), Korea (Busan), and China (Beijing). The concentrations of ClPAHs were highest in the winter Beijing sample, where the total mean concentration was approximately 15-70 times higher than in the winter samples from Japan and Korea. The concentrations of ?19ClPAHs and ?9PAHs were significantly correlated in the Kanazawa and the Busan samples. This indicates that within those cities ClPAHs and PAHs share the same origin, implying direct chlorination of parent PAHs. Toxic equivalent concentrations (TEQs) of the total ClPAHs and PAHs were lowest in Kanazawa in the summer, reaching 1.18 and 2610fg-TEQm(-3) respectively, and highest in Beijing in the winter, reaching 627 and 4240000fg-TEQm(-3) respectively. PMID:24997898
Kakimoto, Kensaku; Nagayoshi, Haruna; Konishi, Yoshimasa; Kajimura, Keiji; Ohura, Takeshi; Hayakawa, Kazuichi; Toriba, Akira
Lymphocyte aromatic hydrocarbon responsiveness in acute leukemia of childhood
Aryl hydrocarbon hydroxylase (AHH) activity and inducibility were examined in mitogen-stimulated cultured lymphocytes from children with acute leukemia in remission, with nonleukemic malignancies, and with no family or personal history of malignant disease. Neither morphological differences nor differences in mitogen responsivelness were observed among the three sources of cells studied. Levels of constitutive and dibenzanthracene-induced AHH activity were found to be similar among the three groups by analysis of variance. However, when results were analyzed in terms of inducibility ratios, it was found that cells from leukemic children were significantly less inducible (p < 0.005) than cells from unaffected children or children with nonleukemic malignancies. The reason for this difference became apparent when statistical criteria were employed for the phenotypic separation of individuals who were highly aromatic hydrocarbon responsive and minimally responsive. A significantly larger proportion (p < 0.001) of leukemic children than unaffected children or children with nonleukemic malignancy were found to be minimally aromatic hydrocarbon responsive. Moreover, in patients with acute lymphoblastic leukemia relapsing while on therapy, longer durations of the first remission were correlated (r = 0.63, p < 0.05) with the highly inducible AHH phenotype.
Blumer, J.L. (Rainbow Babies and Children's Hospital, Cleveland, OH); Dunn, R.; Esterhay, M.D.; Yamashita, T.S.; Gross, S.
Thermochemical calculations of metastable equilibria are used to evaluate the stability of condensed polycyclic aromatic hydrocarbons (PAHs) in cooling thermal gases and hydrothermal fluids on ancient Mars, which are roughly similar to their terrestrial counterparts. The effects of temperature, pressure, the extent of PAH alkylation, and the relative stability of PAHs and alkanes are considered. Inhibition of methane and graphite formation favors synthesis of metastable mixtures of hydrocarbons from aqueous or gaseous CO, CO2, and H2 below 200�-300�C. High-temperature quenching of H2 and CO in volcanic and impact gases and dynamic hydrothermal fluids also favor the synthesis of hydrocarbons. In addition, an excess of CO in cooling systems relative to equilibrium makes the synthesis from CO and H2 more favorable energetically than from CO2 and H2. Both the CO-H2 reactions through Fischer-Tropsch (FT) type processes and the CO2-H2 reactions could be catalyzed by magnetite. Volcanic gases and hydrothermal fluids related to mafic and ultramafic magmas and rocks are more favorable for FT type synthesis than those associated with oxidized Fe2O3-bearing rocks and regolith. We conclude that PAHs and aliphatic hydrocarbons on Mars and Earth could be formed without the contribution of biogenic carbon. Some PAHs could be formed because of pyrolysis of other hydrocarbons formed earlier by the FT type synthesis or other processes. If the PAHs found in the ALH 84001 martian meteorite formed together with other hydrocarbons through FT type synthesis, it may be possible to bracket the temperature of the synthesis. The approach presented here can be generalized to study the synthesis of hydrocarbons in terrestrial volcanic and hydrothermal processes.
Zolotov, Mikhail; Shock, Everett
The high-temperature oxidation of aromatic hydrocarbons
Chemical mechanisms of the atmospheric pressure, high-temperature (875-1500 K) gas-phase oxidation of benzene, toluene, ethylbenzene, and propylbenzene are described and discussed. Oxidation trends evident from turbulent flow reactor experiments serve as the basis for the mechanisms of the oxidation of benzene and alkylated aromatics. The potential effects of very high temperatures and pressures on the chemistry of oxidation of aromatics are described. The oxidation of benzene and phenyl radical has been found to proceed in a stepwise C6-C5-C4 sequence. Species profiles obtained from flow-reactor experiments suggest that the oxidation of benzene and phenyl radical follows the generalized route via phenoxy, cyclopentadienyl and butadienyl radical. The oxidation of the C4 species branches into multiple pathways that yield copious amounts of ethylene and acetylene. Certain major trends are evident: the alkylated aromatics on initial attack either form styrene, benzyl radical or benzene. The styrene reacts further to produce a benzyl radical or benzene. The oxidation of an alkylated aromatic hydrocarbon appears eventually to reduce to the oxidation of either phenyl radical or benzene.
Brezinsky, K.
Fluorescence quenching studies of nitrated polycyclic aromatic hydrocarbons.
The analysis of nitrated polycyclic aromatic hydrocarbons (NPAHs) is of great importance because of the mutagenicity and possible carcinogenic activity of these compounds, which are distributed widely in the environment. Nitro-substituents in aromatic compounds are known to quench fluorescence and NPAHs have no intrinsic fluorescence, but they can be determined using their quenching effects on other fluorophores. The quenching effects of several important NPAHs on 1,2,3,4- tetrahydro-1-naphthol,5,6,7,8-tetrahydro-1-naphthol,4-(2-hydroxy-4-sulfo-1-naphthylazo)-2-naphthalene carboxylic acid and 7-amino-4-methyl coumarin have been studied. The singlet emission of these fluorophores is efficiently quenched by all the NPAHs, the quenching following the Stern-Volmer relationship. Quenching constants and the limits of detection and linear ranges of the quenchers have been determined in each case: the limits of detection are ca 1?�m. PMID:20354970
Al-Kindy, Salma M Z; Miller, James N
Stability of multiply charged clusters of polycyclic aromatic hydrocarbons
The stability of multiply charged clusters of polycyclic aromatic hydrocarbons (PAHs) is theoretically investigated. We propose a new model (stacked structure model) for fragmentation of PAH clusters. The appearance size, a minimum cluster size such that the cluster remains stable when multiply ionized, is calculated by our new model as well as by the conventional liquid drop model. The appearance sizes for doubly charged clusters of anthracene and coronene calculated by the two models are found to be much smaller than those observed in the experiments. Possible reasons for the discrepancy are discussed.
Nakamura, Masato; Ichimura, Atsushi
Polycyclic aromatic hydrocarbon-DNA adduct formation in prostate carcinogenesis
The evidence for polycyclic aromatic hydrocarbons (PAH) playing a role in prostate carcinogenesis comes mainly from associations between reported PAH exposures and prostate cancer in epidemiologic studies. Associations between prostate cancer and DNA repair genotypes and phenotypes have also been reported, lending further credence to a PAH-induced carcinogenesis pathway in prostate cancer. Recent work that demonstrates the human prostate has metabolic enzyme activity necessary for PAH activation and will form DNA adducts upon exposure to PAH further supports PAH carcinogenesis. We have demonstrated the presence of PAH-DNA adducts in prostate cancer cases, but further validation of this biomarker as a carcinogenic agent in human prostate is needed.
Rybicki, Benjamin A.; Nock, Nora L.; Savera, Adnan T.; Tang, Deliang; Rundle, Andrew
Extraction Techniques for Polycyclic Aromatic Hydrocarbons in Soils
This paper aims to provide a review of the analytical extraction techniques for polycyclic aromatic hydrocarbons (PAHs) in soils. The extraction technologies described here include Soxhlet extraction, ultrasonic and mechanical agitation, accelerated solvent extraction, supercritical and subcritical fluid extraction, microwave-assisted extraction, solid phase extraction and microextraction, thermal desorption and flash pyrolysis, as well as fluidised-bed extraction. The influencing factors in the extraction of PAHs from soil such as temperature, type of solvent, soil moisture, and other soil characteristics are also discussed. The paper concludes with a review of the models used to describe the kinetics of PAH desorption from soils during solvent extraction.
Lau, E. V.; Gan, S.; Ng, H. K.
Fragmentation dynamics of excited ionized polycyclic aromatic hydrocarbons
We have theoretically evaluated the fragmentation of excited and ionized polycyclic aromatic hydrocarbons (PAH) and clusters of PAHs. In particular the stability of neutral and positively charged coronene has been studied as a prototype of PAH. We present in this communication vertical and adiabatic ionization potentials with charge up to 6 and dissociation energies and fragmentation paths of several channels: H/H, H2, H+/H and H+/H+ loss. We present as well results corresponding to the fragmentation dynamics of singly-ionized clusters of pyrene.
Paris, C.; Silva, H., Jr.; D�az-Tendero, S.; Rapacioli, M.; Spiegelman, F.; Mart�n, F.; Alcam�, M.
Determination of polycyclic aromatic hydrocarbons in the lung
Polycyclie aromatic hydrocarbons (PAHs) accumulated in human lung samples from men (n = 236) and women (n = 128) were determined by high-performance liquid chromatography (HPLC) to examine their association with lung cancer. The mean values for benzo[a]pyrene (BaP), benzo[k]fluoranthene (BkF), and benzo[g,h,i]perylene (BghiP) in lungs (ng\\/g dry lung) of Japanese autopsied patients were 0.54, 0.44, and 0.87, respectively. The
Hiroshi Seto; Tomoko Ohkubo; Takako Kanoh; Morio Koike; Kyoji Nakamura; Yutaka Kawahara
Anharmonicity and the interstellar polycyclic aromatic hydrocarbon infrared emission spectrum
The hypothesis that interstellar infrared emission originates from vibrationally excited polycyclic aromatic hydrocarbons (PAHs) requires that emission can arise from all vibrational levels that are energetically accessible. Due to anharmonicity, the emission from the upper vibrational levels is shifted to longer wavelengths from that of the v = 1-0 transition. It is shown that structure in the 3-micron region is readily and quantitatively explained by emission from upper vibrational levels of excited PAHs that contain a maximum of 20-30 carbon atoms. The asymmetrical broadening of the 11.3-micron emission band may also be due to anharmonicity.
Barker, John R.; Allamandola, L. J.; Tielens, A. G. G. M.
Monocyclic Aromatic Hydrocarbons in Kathmandu During the Winter Season
Mixing ratios of seven monocyclic aromatic hydrocarbons, as well as NO2, SO2 and O3, were measured by long path differential optical absorption spectroscopy (DOAS) at a suburban site in Kathmandu, Nepal, during\\u000a Jan.�Feb. 2003. The results showed average benzene (3.9?�?1.8�ppbv), toluene (13.3?�?7.1�ppbv), and sum of xylene isomers\\u000a (42.2?�?15.7�ppbv) mixing ratios in Kathmandu. The xylenes concentrations were higher than in the
Yong Yu; Arnico Panday; Elke Hodson; Bo Galle; Ronald Prinn
Polycyclic aromatic hydrocarbons and the diffuse interstellar bands
This paper discusses some of the thermodynamic and spectroscopic properties of polycyclic aromatic hydrocarbons which make them attractive candidates as carriers of the Diffuse Interstellar Bands (DIBs). It is pointed out that, in the diffuse medium, many of these species will be partially hydrogenated and positively charged, and will absorb in the visible. The observed lineshapes and widths of the DIBs can be explained by rovibronic band contours and linebroadening due to internal conversion. Since little information is available concerning the spectroscopic properties of such species in the gas phase, a considerable amount of laboratory and theoretical work is needed.
Van Der Zwet, G. P.; Allamandola, L. J.
Polycyclic aromatic hydrocarbons residues in sandstorm depositions in Beijing, China.
This study was conducted to determine the concentration of 16 polycyclic aromatic hydrocarbons (PAHs) in sandstorm depositions in Beijing, China. The PAH concentrations in 13 samples collected in Beijing ranged from 0.18 to 3.52 microg g(-1). Analysis of the sources of contamination revealed that the PAHs were derived from a coal combustion source, although various effects of traffic emissions were also observed. Furthermore, the PAH levels in Beijing tended to be higher in the southeast. Finally, the nemerow composite index revealed that the degree of pollution in the sandstorm depositions varied widely among sampling sites. PMID:18773130
Fu, S; Li, K; Xia, X J; Xu, X B
Magnetic molecules created by hydrogenation of polycyclic aromatic hydrocarbons
Present routes to produce magnetic organic-based materials adopt a common strategy: the use of magnetic species (atoms, polyradicals, etc.) as building blocks. We explore an alternative approach which consists of selective hydrogenation of polycyclic aromatic hydrocarbons. Self-consistent-field (SCF) (Hartree-Fock and density-functional theory) and multiconfigurational (configuration interaction with single- and double-excitation and multiconfigurational SCF) calculations on coronene and corannulene, both hexahydrogenated, show that the formation of stable high spin species is possible. The spin of the ground states is discussed in terms of Hund�s rule and Lieb�s theorem for bipartite lattices (alternant hydrocarbons in this case). This proposal opens a door to magnetism in the organic world.
Verg�s, J. A.; Chiappe, G.; Louis, E.; Pastor-Abia, L.; Sanfabi�n, E.
Polycyclic aromatic hydrocarbons - Primitive pigment systems in the prebiotic environment
The chemical evolution of meteoritic organics in the primitive earth is examined experimentally with attention given to the photochemical effects of hydrocarbon/water mixtures. Also addressed are the generation of amphiphilic products by photochemical reactions and the transduction of light energy into potentially useful forms. Polycyclic aromatic hydrocarbons (PAHs) absorb light and exist in carbonaceous chondrites; PAHs are therefore examined as primitive pigments by means of salt solutions with pyrene, fluoranthene, and pyrene derivatives with hexadecane. The hexadecane undergoes photochemical oxidation and yields long-chain amphiphiles with oxygen supplied by water, and acid pH shifts also occur. PAHs are also tested in lipid bilayer membranes to examine light-energy transduction. Protons are found to accumulate within the membrane-bounded volume to form proton gradients, and this reaction is theorized to be a good model of primitive photochemical reactions that related to the transduction of light energy into useable forms.
Deamer, D. W.
Rates of polycyclic aromatic hydrocarbon (PAH) degradation and mineralization were influenced by preexposure to alternate PAHs and a monoaromatic hydrocarbon at relatively high (100 ppm) concentrations in organic-rich aerobic marine sediments. Prior exposure to three PAHs and benzene resulted in enhanced (/sup 14/C)naphthalene mineralization, while (/sup 14/C)anthracene mineralization was stimulated only by benzene and anthracene preexposure. Preexposure of sediment slurries to phenanthrene stimulated the initial degradation of anthracene. Prior exposure to naphthalene stimulated the initial degradation of phenanthrene but had no effect on either the initial degradation of mineralization of anthracene. For those compounds which stimulated (/sup 14/C)anthracene of (/sup 14/C)naphthalene mineralization, longer preexposures (2 weeks) to alternative aromatic hydrocarbons resulted in an even greater stimulation response. Enrichment with individual PAHs followed by subsequent incubation with one or two PAHs showed no alteration in degradation patterns due to the simultaneous presence of PAHs. The evidence suggests that exposure of marine sediments to a particular PAH or benzene results in the enhanced ability of these sediments to subsequently degrade that PAH as well as certain other PAHs. The enhanced degradation of a particular PAH after sediments have been exposed to it may result from the selection and proliferation of specific microbial populations capable of degrading it.
Bauer, J.E.; Capone, D.G.
Polycyclic aromatic hydrocarbons as plausible prebiotic membrane components.
Aromatic molecules delivered to the young Earth during the heavy bombardment phase in the early history of our solar system were likely to be among the most abundant and stable organic compounds available. The Aromatic World hypothesis suggests that aromatic molecules might function as container elements, energy transduction elements and templating genetic components for early life forms. To investigate the possible role of aromatic molecules as container elements, we incorporated different polycyclic aromatic hydrocarbons (PAH) in the membranes of fatty acid vesicles. The goal was to determine whether PAH could function as a stabilizing agent, similar to the role that cholesterol plays in membranes today. We studied vesicle size distribution, critical vesicle concentration and permeability of the bilayers using C(6)-C(10) fatty acids mixed with amphiphilic PAH derivatives such as 1-hydroxypyrene, 9-anthracene carboxylic acid and 1,4 chrysene quinone. Dynamic Light Scattering (DLS) spectroscopy was used to measure the size distribution of vesicles and incorporation of PAH species was established by phase-contrast and epifluorescence microscopy. We employed conductimetric titration to determine the minimal concentration at which fatty acids could form stable vesicles in the presence of PAHs. We found that oxidized PAH derivatives can be incorporated into decanoic acid (DA) vesicle bilayers in mole ratios up to 1:10 (PAH:DA). Vesicle size distribution and critical vesicle concentration were largely unaffected by PAH incorporation, but 1-hydroxypyrene and 9-anthracene carboxylic acid lowered the permeability of fatty acid bilayers to small solutes up to 4-fold. These data represent the first indication of a cholesterol-like stabilizing effect of oxidized PAH derivatives in a simulated prebiotic membrane. PMID:22798228
Groen, Joost; Deamer, David W; Kros, Alexander; Ehrenfreund, Pascale
Polycyclic Aromatic Hydrocarbons as Plausible Prebiotic Membrane Components
Aromatic molecules delivered to the young Earth during the heavy bombardment phase in the early history of our solar system were likely to be among the most abundant and stable organic compounds available. The Aromatic World hypothesis suggests that aromatic molecules might function as container elements, energy transduction elements and templating genetic components for early life forms. To investigate the possible role of aromatic molecules as container elements, we incorporated different polycyclic aromatic hydrocarbons (PAH) in the membranes of fatty acid vesicles. The goal was to determine whether PAH could function as a stabilizing agent, similar to the role that cholesterol plays in membranes today. We studied vesicle size distribution, critical vesicle concentration and permeability of the bilayers using C6-C10 fatty acids mixed with amphiphilic PAH derivatives such as 1-hydroxypyrene, 9-anthracene carboxylic acid and 1,4 chrysene quinone. Dynamic Light Scattering (DLS) spectroscopy was used to measure the size distribution of vesicles and incorporation of PAH species was established by phase-contrast and epifluorescence microscopy. We employed conductimetric titration to determine the minimal concentration at which fatty acids could form stable vesicles in the presence of PAHs. We found that oxidized PAH derivatives can be incorporated into decanoic acid (DA) vesicle bilayers in mole ratios up to 1:10 (PAH:DA). Vesicle size distribution and critical vesicle concentration were largely unaffected by PAH incorporation, but 1-hydroxypyrene and 9-anthracene carboxylic acid lowered the permeability of fatty acid bilayers to small solutes up to 4-fold. These data represent the first indication of a cholesterol-like stabilizing effect of oxidized PAH derivatives in a simulated prebiotic membrane.
Groen, Joost; Deamer, David W.; Kros, Alexander; Ehrenfreund, Pascale
Aromatic hydrocarbons in New York Bight polychaetes: ultraviolet fluorescence analyses and gas chromatography/gas chromatography-mass spectrometry analyses
Polychaetes collected from New York Bight sediments near sewage sludge and harbor dredge spoil drump sites contained a series of diaromatic-tetracyclic hydrocarbons of apparent triterpenoid origin. Microbial processes in sewage sludge are a likely source of these compounds. These octahydrochrysenes were much more abundant in the polychaetes than were the fossil fuel and combustion-derived polycyclic aromatic hydrocarbons which were found in the sediments, presumably because they are more available for biological uptake. If the polychaetes had been analyzed only by the spectrofluorometric techniques often used for screening samples for petroleum contamination, then grossly inaccurate results for aromatic hydrocarbon content would have been obtained. Therefore, UV fluorescence must be used in a hierarchical approach, with more sophisticated procedures available to verify the petrogenic nature of the hydrocarbons. 20 references, 4 figures, 2 tables.
Farrington, J.W.; Wakeham, S.G.; Livramento, J.B.; Tripp, B.W.; Teal, J.M.
MTBE and aromatic hydrocarbons in North Carolina stormwater runoff.
A total of 249 stormwater samples were collected from 46 different sampling locations in North Carolina over an approximate 1-year period and analyzed to identify land use types where fuel oxygenates and aromatic hydrocarbons may be present in higher concentrations and at greater frequency. Samples were analyzed by gas chromatography-mass spectrometry in ion selective mode to achieve a quantitation limit of 0.05 microg/l. m-,p-Xylene and toluene were detected in over half of all samples analyzed, followed by MTBE: o-xylene: 1,3,5-trimethylbenzene: ethylbenzene; and 1,2,4-trimethylbenzene. Benzene, DIPE, TAME and 1,2,3-trimethylbenzene were detected in < 10% of the samples analyzed. Median contaminant concentrations (when detected) varied from 0.07 microg/l for ethylbenzene to 0.11 microg/l for toluene. All of the locations with significantly higher contaminant concentrations were associated with direct runoff from a gas station or discharge of contaminated groundwater from a former leaking underground storage tank. For all of the aromatic hydrocarbons, the maximum observed contaminant concentrations were over an order of magnitude lower than current drinking water standards. PMID:11996377
Borden, Robert C; Black, David C; McBlief, Kathleen V
Formation of polycyclic aromatic hydrocarbons in circumstellar envelopes
Production of polycyclic aromatic hydrocarbons in carbon-rich circumstellar envelopes was investigated using a kinetic approach. A detailed chemical reaction mechanism of gas-phase PAH formation and growth, containing approximately 100 reactions of 40 species, was numerically solved under the physical conditions expected in cool stellar winds. The chemistry is based on studies of soot production in hydrocarbon pyrolysis and combustion. Several first-ring and second-ring cyclization processes were considered. A linear lumping algorithm was used to describe PAH growth beyond the second aromatic ring. PAH production using this mechanism was examined with respect to a grid of idealized constant velocity stellar winds as well as several published astrophysical models. The basic result is that the onset of PAH production in the interstellar envelopes is predicted to occur within the temperature interval of 1100 to 900 K. The absolute amounts of the PAHs formed, however, are very sensitive to a number of parameters, both chemical and astrophysical, whose values are not accurately known. Astrophysically meaningful quantities of PAHs require particularly dense and slow stellar winds and high initial acetylene abundance. It is suggested that most of the PAHs may be produced in a relatively small fraction of carbon-rich red giants.
Frenklach, Michael; Feigelson, Eric D.
Partition characteristics of polycyclic aromatic hydrocarbons on soils and sediments
The partition behavior was determined for three polycyclic aromatic hydrocarbons (PAHs), i.e., naphthalene, phenanthrene, and pyrene, from water to a range of soil and sediment samples. The measured partition coefficients of the individual PAHs between soil/sediment organic matter (SOM) and water (i.e., K(oc) values) are relatively invariant either for the 'clean' (uncontaminated) soils or for the clean sediments; however, the mean K(oc) values on the sediments are about twice the values on the soils. This disparity is similar to the earlier observation for other nonpolar solutes and reflects the compositional differences between soil and sediment organic matters. No significant differences in K(oc) are observed between a clean coastal marine sediment and freshwater sediments. The coastal sediments that are significantly impacted by organic contaminants exhibit higher K(oc) values. At given K(ow) values (octanol-water), the PAHs exhibit much higher K(oc) values than other relatively nonpolar solutes (e.g., chlorinated hydrocarbons). This effect is shown to result from the enhanced partition of PAHs to SOM rather than from lower K(ow) values of PAHs at given supercooled liquid solute solubilities in water. The enhanced partition of PAHs over other nonpolar solutes in SOM provides an account of the markedly different correlations between log K(oc) and log K(ow) for PAHs and for other nonpolar solutes. The improved partition of PAHs in SOM stems apparently from the enhanced compatibility of their cohesive energy densities with those of the aromatic components in SOM. The approximate aromatic fraction in soil/sediment organic matter has been assessed by solid-state 13C-NMR spectroscopy.The partition behavior was determined for three polycyclic aromatic hydrocarbons (PAHs), i.e., naphthalene, phenanthrene, and pyrene, from water to a range of soil and sediment samples. The measured partition coefficients of the individual PAHs between soil/sediment organic matter (SOM) and water (i.e., Koc values) are relatively invariant either for the `clean' (uncontaminated) soils or for the clean sediments; however, the mean Koc values on the sediments are about twice the values on the soils. This disparity is similar to the earlier observation for other nonpolar solutes and reflects the compositional differences between soil and sediment organic matters. No significant differences in Koc are observed between a clean coastal marine sediment and freshwater sediments. The coastal sediments that are significantly impacted by organic contaminants exhibit higher Koc values. At given Kow values (octanol-water), the PAHs exhibit much higher Koc values than other relatively nonpolar solutes (e.g., chlorinated hydrocarbons). This effect is shown to result from the enhanced partition of PAHs to SOM rather than from lower Kow values of PAHs at given supercooled liquid solute solubilities in water. The enhanced partition of PAHs over other nonpolar solutes in SOM provides an account of the markedly different correlations between log Koc and log Kow for PAHs and for other nonpolar solutes. The improved partition of PAHs in SOM stems apparently from the enhanced compatibility of their cohesive energy densities with those of the aromatic components in SOM. The approximate aromatic fraction in soil/sediment organic matter has been assessed by solid-state 13C-NMR spectroscopy.
Chiou, C. T.; Mcgroddy, S. E.; Kile, D. E.
Peat fires as source of polycyclic aromatic hydrocarbons in soils
Polycyclic aromatic hydrocarbons (PAHs) arrive from pyrogenic sources including volcanism and the combustion of oil products and plant materials. The production of PAHs during the combustion of plant materials was considered in a number of publications, but their results were mainly obtained in laboratory experiments. Insufficient data are available on the hightemperature production of PAHs in environmental objects. For example, natural fires are frequently related to the PAH sources in landscapes, but very little factual data are available on this topic. On Polistovskii reserve (Russia, Pskov region) the soil series were separated depending on the damage to the plants; these series included soils of plots subjected to fires of different intensities, as well as soils of the background plots. The series of organic and organomineral soils significantly differed in their PAH distributions. In this series, the concentration of PAHs in the upper horizons of the peat soils little varied or slightly decreased, but their accumulation occurred at a depth of 5-10 or 10-20 cm in the soils after the fires. For example, in the series of high moor soils, the content of PAHs in the upper horizons remained almost constant; significant differences were observed in the subsurface horizons: from 2 ng/g in the background soil to 70 ng/g after the fire. In the upper horizons of the oligotrophic peat soils under pine forests, the total PAH content also varied only slightly. At the same time, the content of PAHs in the soil series increased from 15 to 90 ng/g with the increasing pyrogenic damage to the plot. No clear trends of the PAH accumulation were recorded in the organomineral soils. The content of PAHs in the soddy-podzolic soil subjected to fire slightly decreased (from 20 to 10 ng/g) compared to the less damaged soil. In peat fires, the access of oxygen to the fire zone is lower than in forest fires. The oxygen deficit acts as a factor of the organic fragments recombination and PAH production; therefore, larger amounts of PAHs are formed in peat fires. In addition, the peat fires occur directly in the soil layer; therefore, larger amounts of the resulting polyarenes remain in the soils of the fire sites. PAHs also can be formed at the heating of organic matter on the areas adjacent to the fire sites. After the combustion of peat in fires, phenanthrene, chrysene, benz[a]pyrene, and tetraphene accumulate in soils. This is mainly the group of 4-nuclear compounds with the participation of 3-nuclear phenanthrene and 5-nuclear benz[a]pyrene. The formation of high-molecular weight compounds like benz[a]pyrene and, in some places, benzo[ghi]perylene is possible during smoldering under a low oxygen supply.
Tsibart, Anna
Polycyclic aromatic hydrocarbons: are they a problem in processed oil shales. [254 references
Organic residues from processed oil shales were characterized with specific attention to polycyclic aromatic hydrocarbons (PAH). Oil shale development in the White River Basin (Utah and Colorado) was projected and hydrological and geological parameters pertinent to estimations of polycyclic aromatic hydrocarbons (PAH) flux were focused. Oil shale samples from the Union B, Paraho, and Tosco II processes were extracted by
D. L. Maase; V. D. Adams
UV resonance Raman characterization of polycyclic aromatic hydrocarbons in coal liquid distillates
Ultraviolet resonance Raman spectroscopy has been used to characterize the polycyclic aromatic hydrocarbon composition of a series of distillates of coal-derived liquids. The UV Raman spectra easily monitor changes in the polycyclic aromatic hydrocarbon composition as a function of distillation temperature. Specific species, such as pyrene, can be determined by judicious choice of excitation wavelength.
Rumelfanger, R.; Asher, S.A.; Perry, M.B.
Polynuclear aromatic hydrocarbons (PAH) and nitro-substituted polynuclear aromatic hydrocarbons (NO2-PAH) have been identified in organic extracts of ambient air particulate matter. Many of the identified PAH and NO2-PAH are potent carcinogens and/or mutagens. Therefore the deter...
Non-aromatic hydrocarbons in surface sediments near the Pearl River estuary in the South China Sea.
Surface sediment samples at 4 sites along an offshore transect from outer continental shelf off the Pearl River estuary to the shelf slope region of the northern South China Sea, have been analyzed for total organic carbon (TOC), total nitrogen (TN), solvent extractable organic matter (EOM) and non-aromatic hydrocarbons. TOC, TN and EOM show distinct spatial variations. Their highest values are all recorded at the shelf slope region. EOM varies from 18.70-38.58 microgg(-1) dry sediment and accounts for 0.20-0.72% of the TOC contents. The non-aromatic hydrocarbons are an important fraction of EOM. Their contents range from 3.43-7.06 microgg(-1) dry sediment. n-Alkanes with carbon number ranging from 15-38 are identified. They derive from both biogenic and petrogenic sources in different proportions. Results of isoprenoid hydrocarbons, hopanes and steranes also suggest possible petroleum contamination. PMID:17240011
Gao, Xuelu; Chen, Shaoyong; Xie, Xueliang; Long, Aimin; Ma, Fujun
Polycyclic aromatic hydrocarbons and nitropolycyclic aromatic hydrocarbons in urban air particulates and their relationship to emission sources in the Pan�Japan Sea countries
Airborne particulates were collected in seven cities in the Pan�Japan Sea countries, Shenyang (China), Vladivostok (Russia), Seoul (South Korea), Kitakyushu, Kanazawa, Tokyo and Sapporo (Japan), in winter and summer from 1997 to 2002. In addition, particulates from domestic coal-burning heaters and diesel engine automobiles were collected in Shenyang and Kanazawa, respectively. Nine polycyclic aromatic hydrocarbons (PAHs) and four nitropolycyclic aromatic
Ning Tang; Tetsuyuki Hattori; Rina Taga; Kazuhiko Igarashi; Xiaoyang Yang; Kenji Tamura; Hitoshi Kakimoto; Vasiliy F. Mishukov; Akira Toriba; Ryoichi Kizu; Kazuichi Hayakawa
Contamination of soils in the urbanized areas of Belarus with polycyclic aromatic hydrocarbons
The content of polycyclic aromatic hydrocarbons (PAHs) in the soils of urbanized areas, including the impact zones of Belarus, were studied. The concentrations of 16 PAHs in the soils were determined for individual and high-rise building zones, forests, and forest parks of Belarus. The levels of the PAH accumulation in the soils of different industrial enterprises and boiler stations were analyzed. Possible sources of soil contamination with PAHs were considered, and the structure of the PAHs in the soils was shown. The levels of the soil contamination were determined from the regulated parameters for individual compounds and the sum of 16 PAHs.
Kukharchyk, T. I.; Khomich, V. S.; Kakareka, S. V.; Kurman, P. V.; Kozyrenko, M. I.
Formation of polycyclic aromatic hydrocarbons in an atmospheric pressure ethylene diffusion flame
The microstructure of an atmospheric pressure, counterflow, sooting, flat, laminar ethylene diffusion flame has been studied experimentally by withdrawing samples from within the flame using a heated quartz microprobe coupled to an online gas chromatograph\\/mass spectrometer (GC\\/MS). The identities and absolute concentrations of about 60 major, minor, and trace species, including aromatics, substituted aromatics, and polycyclic aromatic hydrocarbons (PAH) have
Nesrin Olten; Selim Senkan
Distribution, sources and ecological risks of polycyclic aromatic hydrocarbons in water-sediment system in Lake Small Baiyangdian
The contents of 15 priority polycyclic aromatic hydrocarbons (PAHs) in water, suspended particulate matter (SPM) and sediment from six sampling sites in Lake Small Baiyangdian nearby Duancun Village were measured by GC-MS. The PAHs distribution, composition, source and ecological risk were analyzed. The following results were obtained: (1) the total contents of 15 priority PAHs (PAH15) varied from 40.1 to
ZHU Ying; WU Wenjing; WANG Junjun; QIN Ning; WANG Yin; WANG Yan; XU Fuliu
Effects of sulfur and aromatic contents in gasoline on motorcycle emissions
By investigating the effect of sulfur and aromatic contents in gasoline on the criteria pollutant emissions [CO, total hydrocarbons (THCs), and NO x] and on air toxics in the exhaust from a non-catalyst four-stroke motorcycle engine, inferences can be made concerning the effect of fuel composition on motorcycle emissions. The fuels were blended with different contents of sulfur (40 and 150 ppmw) and aromatics (20 and 30 vol%). The data indicate that the sulfur content does not correlate with the emissions of the criteria pollutants from the catalyst free engine. Instead, lowering aromatic content in gasoline reduced the THC emission by over 30%, especially in the cruising test. The NO x emission, however, showed an inverse correlation with the aromatic content in gasoline. While a reduction of aromatic content in gasoline may decrease emissions of benzene and toluene, it will increase the emission of aldehyde. Since the percentage changes of emission factor of THC and air toxics in the motorcycle were larger than those in passenger cars, the benefit of emission reduction due to fuel composition changes in motorcycles may have significant impacts in health risk analysis.
Yao, Yung-Chen; Tsai, Jiun-Horng; Chang, An-Lin; Jeng, Fu-Tien
Assessment of Total Aromatic Hydrocarbons, Aliphatic and Polycyclic Aromatic Hydrocarbons in Surface Sediment and Fish from the Gulf of Tunis (Tunisia)
This investigation represents the extensive study of the spatial distribution and sources of hydrocarbons in the Gulf of Tunis. Sediments and fish were sampled within the open sea of the Gulf of Tunis during August 2004. All samples were extracted with organic solvents, separated by silica\\/alumina column chromatography, and analyzed by spectrofluorometry for the determination of total aromatic hydrocarbons (TAH)
Nadia Mzoughi; Lassaad Chouba; Ga�tane Lespes
Ultraviolet and photoelectron spectroscopic studies of aromatic hydrocarbons occurring in hydroformed fuel oil from coal
Ultraviolet spectra of fractions of hydroformed creosote oil boiling in the range 140-200�C are reproduced. The aromatic content is shown to consist predominantly of those hydrocarbons which might be expected to derive from the hydrogenation cracking of naphthalene such as indan and normal monoalkyl benzenes. The spectrum of indan has attracted discussion because of its relatively strong absorption in the 260 nm region compared to other polysubstituted alkyl aromatics. The possibility that this arises from the strained nature of the attached saturated five ring system is considered. The effects of increasing alkyl substitution on the excitation energies of the 260 nm transitions are compared with the associated ionization energies obtained by photoelectron spectroscopy. This has been done for the mono up to the completely substituted hexamethyl derivative and is illustrated graphically.
Drake, A. F.; Potts, A. W.; Price, W. C.
Magnetic instability and pair binding in aromatic hydrocarbon superconductors.
Understanding magnetism and electron correlation in many unconventional superconductors is essential to explore mechanism of superconductivity. In this work, we perform a systematic numerical study of the magnetic and pair binding properties in recently discovered polycyclic aromatic hydrocarbon (PAH) superconductors including alkali-metal-doped picene, coronene, phenanthrene, and dibenzopentacene. The ?-electrons on the carbon atoms of a single molecule are modelled by the one-orbital Hubbard model, and the energy difference [Formula: see text] between carbon atoms with and without hydrogen bonds is taking into account. We demonstrate that the spin polarized ground state is realized for charged molecules in the physical parameter regions, which provides a reasonable explanation of local spins observed in PAHs. In alkali-metal-doped dibenzopentacene, our results show that electron correlation may produce an effective attraction between electrons for the charged molecule with one or three added electrons. PMID:23213358
Huang, Zhongbing; Zhang, Chao; Lin, Hai-Qing
High-energy chemical processes: Laser irradiation of aromatic hydrocarbons
Recent studies of the high-energy photochemical degradation of polycyclic aromatic hydrocarbons (PAHs) in solution have furthered our fundamental understanding of the way in which radiation interacts with matter. A new comprehensive mechanism that unifies many of the seemingly contradictory observations in radiation and photochemistry has been proposed on basis of evidence gathered using specialized techniques such as transient optical spectroscopy and transient dc conductivity. The PAH molecules were activated by two-photon ionization, and behavior of the transient ions were monitored as a function of photon energy. It was found that a greater percentage of ions retain sufficient energy to decompose when higher energy light was used. When these cations decompose they leave a trail of products that establish a ``high-energy`` decomposition pathway that involves proton transfer from the ion, a mechanism hitherto not considered in photoionization processes.
Trifunac, A.D.; Liu, A.D.; Loffredo, D.M.
NMR shifts for polycyclic aromatic hydrocarbons from first-principles
We present first-principles, density-functional theory calculations of the NMR chemical shifts for polycyclic aromatic hydrocarbons, starting with benzene and increasing sizes up to the one- and two-dimensional infinite limits of graphene ribbons and sheets. Our calculations are performed using a combination of the recently developed theory of orbital magnetization in solids, and a novel approach to NMR calculations where chemical shifts are obtained from the derivative of the orbital magnetization with respect to a microscopic, localized magnetic dipole. Using these methods we study on equal footing the 1H and 13C shifts in benzene, pyrene, coronene, in naphthalene, anthracene, naphthacene, and pentacene, and finally in graphene, graphite, and an infinite graphene ribbon. Our results show very good agreement with experiments and allow us to characterize the trends for the chemical shifts as a function of system size.
Thonhauser, Timo; Ceresoli, Davide; Marzari, Nicola N.
Destruction and survival of polycyclic aromatic hydrocarbons in active galaxies
Infrared spectra of dusty galactic environments often contain emission features attributed to polycyclic aromatic hydrocarbons or PAHs, which can be considered to be very small grains or very large molecules. Although IR spectra of starburst galaxies almost always show these emission features, similar spectra of active galaxies are usually featureless. Even in those active galaxies that do exhibit PAH emission, the PAHs still appear to be eradicated from the nuclear region. This dichotomy suggests that PAHs are destroyed by the intense hard radiation field from an AGN. Laboratory experiments show that certain PAHs are, in fact, so effectively destroyed by individual EUV and X-ray photons that they cannot survive even at kiloparsec distances from active nuclei. Regions within active galaxies that do show PAH emission must therefore be shielded from the central X-ray source by a substantial column density of X-ray absorbing gas.
Voit, G. M.
Carcinogenic classification of polycyclic aromatic hydrocarbons through theoretical descriptors
Polycyclic aromatic hydrocarbons (PAHs) constitute an important family of molecules capable of inducing chemical carcinogenesis. In this work we report a comparative structure-activity relationship (SAR) study for 81 PAHs using different methodologies. The recently developed electronic indices methodology (EIM) with quantum descriptors obtained from different semiempirical methods (AM1, PM3, and PM5) was contrasted against more standard pattern recognition methods (PRMs), principal component analysis (PCA), hierarchical cluster analysis (HCA), Kth nearest neighbor (KNN), soft independent modeling of class analogies (SIMCA), and neural networks (NN). Our results show that PRMs validate the statistical value of electronic parameters derived from EIM analysis and their ability to identify active compounds. EIM outperformed more standard SAR methodologies and does not appear to be significantly Hamiltonian-dependent.
Troche, Karla S.; Braga, Scheila F.; Coluci, Vitor R.; Galv�o, Douglas S.
Magnetic instability and pair binding in aromatic hydrocarbon superconductors
Understanding magnetism and electron correlation in many unconventional superconductors is essential to explore mechanism of superconductivity. In this work, we perform a systematic numerical study of the magnetic and pair binding properties in recently discovered polycyclic aromatic hydrocarbon (PAH) superconductors including alkali-metal-doped picene, coronene, phenanthrene, and dibenzopentacene. The ?-electrons on the carbon atoms of a single molecule are modelled by the one-orbital Hubbard model, and the energy difference between carbon atoms with and without hydrogen bonds is taking into account. We demonstrate that the spin polarized ground state is realized for charged molecules in the physical parameter regions, which provides a reasonable explanation of local spins observed in PAHs. In alkali-metal-doped dibenzopentacene, our results show that electron correlation may produce an effective attraction between electrons for the charged molecule with one or three added electrons.
Determination of polycyclic aromatic hydrocarbons in Athens atmosphere.
Concentrations of total suspended particulates (TSP), benzene soluble fraction (BSF) and polycyclic aromatic hydrocarbons (PAH) have been determined in ambient air from four different sites in Athens, situated in urban, semi-industrial and industrial areas. GLC analysis has been applied for the determination of PAH, while the CGC/MS technique was used in order to confirm the obtained results. The same PAH pattern was observed for all stations. The identified PAH have been fluoranthene (FLA), pyrene (PYR), benzo(a)anthracene (BaA), chrysene (CHR), benzo(b)fluoranthene (BbF), benzo(k)fluoranthene (BkF), benzo(a)pyrene (BaP), benzo(e)pyrene (BeP) and benzo(ghi)perylene (B(ghi)P). The concentrations of individual PAH ranged from traces to 33 ng m-3 (e.g. same or lower comparing to other large cities). The higher values of PAH were found during adverse meteorological conditions. PMID:3557795
Viras, L G; Siskos, P A; Stephanou, E
Polycyclic aromatic hydrocarbon removal from water by natural fiber sorption.
The use of two natural sorbents, kapok and cattail fibers, were investigated for polycyclic aromatic hydrocarbon (PAH) removal from water. Naphthalene, acenaphthylene, acenaphthene, fluorene, phenanthrene, anthracene, and fluoranthene were the PAHs studied. For comparative purposes, a commercial polyester fiber sorbent was included in the investigation. The PAH sorption and retention capabilities of the three fibers were determined through batch and continuous-flow experiments under non-competitive and competitive conditions. In the batch experiments, cattail fiber was the most effective sorbent. Kapok fiber provided the lowest PAH retention, while cattail fiber had slightly less PAH retention than polyester fiber. When two PAHs were present in the same system, a competitive effect on the much less hydrophobic PAH was observed. Similar results were obtained in the column experiments, except that polyester fiber performed much poorer on naphthalene. Cattail fiber is a promising sorbent for treating PAH-contaminated water, such as urban runoff. PMID:17824537
Khan, Eakalak; Khaodhir, Sutha; Rotwiron, Paritta
Polycyclic Aromatic Hydrocarbons and Infrared Astrophysics with Spitzer
Over the past fifteen years, thanks to significant, parallel advancements in observational, experimental, and theoretical techniques, tremendous strides have been made in our understanding of the role that carbon-rich plays in the interstellar medium (ISM). Twenty years ago, the possible existence of an abundant population of large, carbon-rich molecules in the ISM was unthinkable. Today, the unmistakable spectroscopic signatures of polycyclic aromatic hydrocarbons (PAHs) - shockingly large molecules by the standards of traditional interstellar chemistry -are recognized throughout the Universe. In this presentation, we will examine the current state of the interstellar PAH model and explore how this data, in conjunction with the unparalleled observational data provided by the Spitzer Space Telescope, can be used to draw ever-deeper insights into the physical and chemical natures of a wide range of astrophysical environments.
Hudgins, Douglas M.; Allamandola, L. J.
Amperometric Immunosensors for screening of Polycyclic Aromatic Hydrocarbons in water
An amperometric immunosensor with low limit detection was developed for the screening of polycyclic aromatic hydrocarbons (PAHs) in water. The system was based on detecting the specific substance using an immunological reaction by measuring the chemical responses to specific antibodies. An integrated biochip with a three electrode system was fabricated. Gold was used as the working electrode with platinum was used as the counter electrode. A modified Ag/AgCl reference electrode was employed to enhance the stability of the immunosensors. Indirect competition enzyme-linked immunosorbent assay (ELISA) was carried out within the electrode using alkaline phosphatase (AP) as the labelled-enzyme. The system shows acceptable reproducibility and good stability. The immunosensor exhibited a wide linear response to PAHs. A limit of detection for this sensor was in the range of 1 to 10 ng ml-1 in aqueous sample.
Ahmad, A.; Paschero, A.; Moore, E.
Characterization of polycyclic aromatic hydrocarbons from the diesel engine by adding light cycle oil to premium diesel fuel.
Diesel fuels governed by U.S. regulations are based on the index of the total aromatic contents. Three diesel fuels, containing various fractions of light cycle oil (LCO) and various sulfur, total polyaromatic, and total aromatic contents, were used in a heavy-duty diesel engine (HDDE) under transient cycle test to assess the feasibility of using current indices in managing the emissions of polycyclic aromatic hydrocarbons (PAHs) from HDDE. The mean sulfur content in LCO is 20.8 times as much as that of premium diesel fuel (PDF). The mean total polyaromatic content in LCO is 28.7 times as much as that of PDF, and the mean total aromatic content in LCO is 2.53 times as much as that of PDF. The total polyaromatic hydrocarbon emission factors in the exhaust from the diesel engine, as determined using PDF L3.5 (3.5% LCO and 96.5% PDF), L7.5 (7.5% LCO and 92.5% PDF), and L15 (15% LCO and 85% PDF) were 14.3, 25.8, 44, and 101 mg L(-1), respectively. The total benzo(a)pyrene equivalent (BaPeq) emission factors in the exhaust from PDF, L3.5, L7.5, and L15 were 0.0402, 0.121, 0.219, and 0.548 mg L(-1), respectively. Results indicated that using L3.5 instead of PDF will result in an 80.4% and a 201% increase of emission for total PAHs and total BaPeq, respectively. The relationships between the total polyaromatic hydrocarbon emission factor and the two emission control indices, including fuel polyaromatic content and fuel aromatic content, suggest that both indices could be used feasibly to regulate total PAH emissions. These results strongly suggest that LCO used in the traveling diesel vehicles significantly influences PAH emissions. PMID:16805399
Lin, Yuan-Chung; Lee, Wen-Jhy; Chen, Chung-Bang
In this paper, we analyze the strong unidentified emission near 3.28 {mu}m in Titan's upper daytime atmosphere recently discovered by Dinelli et al. We have studied it by using the NASA Ames PAH IR Spectroscopic Database. The polycyclic aromatic hydrocarbons (PAHs), after absorbing UV solar radiation, are able to emit strongly near 3.3 {mu}m. By using current models for the redistribution of the absorbed UV energy, we have explained the observed spectral feature and have derived the vertical distribution of PAH abundances in Titan's upper atmosphere. PAHs have been found to be present in large concentrations, about (2-3) Multiplication-Sign 10{sup 4} particles cm{sup -3}. The identified PAHs have 9-96 carbons, with a concentration-weighted average of 34 carbons. The mean mass is {approx}430 u; the mean area is about 0.53 nm{sup 2}; they are formed by 10-11 rings on average, and about one-third of them contain nitrogen atoms. Recently, benzene together with light aromatic species as well as small concentrations of heavy positive and negative ions have been detected in Titan's upper atmosphere. We suggest that the large concentrations of PAHs found here are the neutral counterpart of those positive and negative ions, which hence supports the theory that the origin of Titan main haze layer is located in the upper atmosphere.
Lopez-Puertas, M.; Funke, B.; Garcia-Comas, M. [Instituto de Astrofisica de Andalucia (CSIC), E-18080 Granada (Spain); Dinelli, B. M. [ISAC-CNR, I-40129 Bologna (Italy); Adriani, A.; D'Aversa, E. [IAPS-INAF, I-00133 Rome (Italy); Moriconi, M. L. [ISAC-CNR, I-00133 Rome (Italy); Boersma, C.; Allamandola, L. J., E-mail: email@example.com [NASA Ames Research Center, Moffett Field, CA 94035-1000 (United States)
Chemical Kinetics of Polycyclic Aromatic Hydrocarbons in Comet Impacts
Polycyclic aromatic hydrocarbons (PAHs) are stable, robust organic compounds that would have been an important constituent of the early atmospheres of terrestrial planets. These strongly-bound molecules readily absorb ultraviolet light and may play a role in aerosol formation. PAHs are one of the predominant carriers of carbon in interstellar space, after CO. They are common in carbonaceous chondrites, and quite likely in comets as well. Impacts of volatile-rich planetesimals such as carbonaceous chondrites and comets would have been common during the late stages of planet formation. Theoretical studies of impact chemistry typically assume that the chemical composition of the post-impact material is given by thermodynamic equilibrium at 2000 K. These calculations also typically ignore the formation of aromatic compounds because the closure of the first aromatic ring is kinetically inhibited, although thermodynamically favorable at the temperatures and pressures of an impact fireball. Do the PAHs present in a comet or asteroid survive impact? If so, how are these PAHs modified during impact? To address these questions, we model the chemical kinetics of PAH survival, formation, growth and destruction within a parameter space consisting of impact fireball cooling timescales, pressures, temperatures, C/O ratios and other factors. The chemistry of PAHs has been well studied under conditions present in plug flow reactors and sooting flames (P ? 1atm, T? 1000 K). We hope that our results will motivate more experimental investigation of reaction mechanisms and rate coefficients for a broader range of temperatures and pressures than those heretofore studied for industrial applications. This work has been supported by the NASA Astrobiology Institute's Virtual Planetary Laboratory and the Institute for Geophysics and Planetary Physics at Lawrence Livermore National Laboratory.
Kress, M. E.; McKay, C.; Tielens, A. G.; Frenklach, M.
Autothermal reforming of aliphatic and aromatic hydrocarbon liquids
Results are presented from a study of the autothermal reforming of paraffins and aromatics over nickel catalysts. The trials were performed to examine the carbon products that appear when steam is passed over hydrocarbon liquids to form H2-rich gases, i.e., the autothermal process (ATR). Attention was given to n-hexane, n-tetradecane, benzene, and benzene solutions of naphthalene with reactant preheat to 1000-1150 F. The carbon-formation limit was sought as a function of the steam-to-carbon and oxygen to carbon molar ratios at constant pressure and the preheat temperatures. The catalyst bed was examined after each trial to identify the locations and types of carbon formed using SEM, thermal gravimetric analysis, and X ray diffraction techniques. The hydrocarbon fuels each had a separate temperature and reaction profile, as well as carbon formation characteristics. No carbon formation was observed in the upper layer of the reactor bed, while both gas phase and surface-grown deposits were present in the lower part. The results are concluded of use in the study of No. 2 fuel oil for ATR feedstock.
Flytzani-Stephanopoulos, M.; Voecks, G. E.
Effect of bioremediation on polycyclic aromatic hydrocarbon residues in soil
Soil contamination (60 mg/g of soil) by a diesel oil (DO) spill was simulated in outdoor lysimeter units and the effect of bioremediation treatment consisting of liming, fertilization, and tilling on the persistence of polycyclic aromatic hydrocarbon (PAH) components of DO was measured. After solvent extraction from soil and class separation on silica gel, PAH components were identified and partially quantified by GC-ITD analysis. Residual mutagenicity and acute toxicity of the contaminated soil was also assessed by Ames and Microtox tests. Bioremediation treatment, while increasing the rate of total hydrocarbon degradation, had an even greater effect on PAH persistence, almost completely eliminating these compounds in 12 weeks. Without bioremediation, 12.5-32.5% of the higher molecular weight PAH were still present at 12 weeks. Mutagenicity and toxicity tests corroborated the above results. After substantial initial mutagenicity and toxicity, the contaminated soil approached the background level of uncontaminated soil after 12 weeks of bioremediation. Detoxification was complete in 20 weeks.
Wang, Xiaoping; Yu, Xiaobing; Bartha, R. (Rutgers, The State Univ. of New Jersey, New Brunswick (USA))
Aliphatic and polycyclic aromatic hydrocarbons in the surface sediments from the Eastern Aegean: assessment and source recognition of petroleum hydrocarbons
Materials and methods��Aliphatic and polycyclic aromatic hydrocarbons (PAHs) were determined in surficial sediments from the Aegean Sea in the Eastern\\u000a Mediterranean in 2008.\\u000a \\u000a \\u000a \\u000a \\u000a Results��Total aliphatic hydrocarbons (n-C12 to n-C35) ranged from 330 to 2,660 ng g-1 dry weight (dwt), while aromatics (19 PAHs) varied between 73.5 and 2,170 ng g-1 dwt. Total concentrations of both aliphatic hydrocarbons and PAHs ranged
L. Tolga Gonul; Filiz Kucuksezgin
Polycyclic Aromatic Hydrocarbons in an industrialized urban area
Urbanization, agricultural intensification and industrialization are contributing to erosion, local and diffuse contamination and sealing of soil surfaces, resulting in soil quality degradation. Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous in urban environments and considered good markers of anthropogenic activities such as traffic, industry, domestic heating and agriculture. Although they are subject to biodegradation and photodegradation, once in the soil, they tend to bind to the soil organic fraction. Estarreja is a small coastal town in the Northwestern Portuguese coast, with a close relation with the lagoon of Aveiro which supports a variety of biotopes (channels, islands with vegetation, mudflats, salt marshes and agricultural fields) of important ecological value. It supports an intensive and diversified agriculture, a variety of heavy and light industries and a population of about half a million people which is dependent on this resource. This is a very industrialized area, due to its five decades of chemical industry. This study aims to assess the impact of the urbanization and of the chemical industry in PAHs distribution. The survey and sampling method were based on pre-interpreted maps, aerial photographs, and directly checked in the field, in order to get an overall characterization of the area. Topsoils were collected from 34 sites, considering different land uses. Five land uses were chosen: ornamental gardens, parks, roadsides, forest and agricultural. Parameters such as soil pH (ISO method 10390:1994), total C, N, H, S percentages (microanalyser LECO, CNHS-932), organic matter (LOI at 430�), particle size distribution (Micromeritics� Sedigraph 5100), cation exchange capacity and exchangeable bases, were determined in order to have a general characterization of soil. Determination of the 16 EPA PAHs in soils was performed by GC/MS after a Soxhlet extraction and an alumina clean-up of extracts. Procedure blanks, duplicates and reference material were used in each extraction batch for quality control assessment. In what concerns the general parameters, Estarreja soils were characterized as slightly acid, with a median pHCaCl2 of 5.15, ranging from 3.12 and 6.88. The content in organic matter observed was relatively high, with a median of 4.6% and ranging from 1.8 to 45%. The median concentration of PAHs was 98 �g kg-1, ranging from 27 to 2,016 �g kg-1. The former value was found in an agricultural area and, together with another agricultural soil (with 1121 �gPAHs/kg), were considered heavily contaminated according to the classification given by Maliszewska-Kordybach. Moreover, eight samples were classified as weakly contaminated (PAHs between 200 and 600 �g/kg) and the remaining ones were not contaminated. The relative abundance of individual PAHs in Estarreja soils was evaluated, being the most abundant Fluoranthene and Pyrene followed by Benzo(b)fluoranthene, Phenanthrene and Crysene. These PAHs are the ones usually associated with the combustion of fossil fuel and other burnable materials, being this composition is typical for topsoil of European industrialized countries. Geostatistical methods were used to show the spatial variability of contaminants and the probability of exceeding the risk-based standards. The plots of concentration of PAHs on GIS highlight areas where the highest elements concentrations occur and the land use associated. These soil maps assemble important information for decision-making, allowing identifying possible sources of contamination, assess the suitability of soil to its use and to contribute for land use planning in accordance to soil characteristics. Acknowledgements: This work was supported by the Portuguese Foundation for Science and Technology (SFRH/BD/38418/2007) and by CESAM
Cachada, A.; Pereira, R.; Ferreira da Silva, E.; Duarte, A. C.
ExBox: a polycyclic aromatic hydrocarbon scavenger.
A template-directed protocol, which capitalizes on donor-acceptor interactions, is employed to synthesize a semi-rigid cyclophane (ExBox(4+)) that adopts a box-like geometry and is comprised of ?-electron-poor 1,4-phenylene-bridged ("extended") bipyridinium units (ExBIPY(2+)). ExBox(4+) functions as a high-affinity scavenger of an array of different polycyclic aromatic hydrocarbons (PAHs), ranging from two to seven fused rings, as a result of its large, accommodating cavity (approximately 3.5 � in width and 11.2 � in length when considering the van der Waals radii) and its ability to form strong non-covalent bonding interactions with ?-electron-rich PAHs in either organic or aqueous media. In all, 11 PAH guests were observed to form inclusion complexes with ExBox(4+), with coronene being the largest included guest. Single-crystal X-ray diffraction data for the 11 inclusion complexes ExBox(4+)?PAH as well as UV/vis spectroscopic data for 10 of the complexes provide evidence of the promiscuity of ExBox(4+) for the various PAHs. Nuclear magnetic resonance spectroscopy and isothermal titration calorimetric analyses of 10 of the inclusion complexes are employed to further characterize the host-guest interactions in solution and determine the degree with which ExBox(4+) binds each PAH compound. As a proof-of-concept, a batch of crude oil from Saudi Arabia was subjected to extraction with the water-soluble form of the PAH receptor, ExBox�4Cl, resulting in the isolation of different aromatic compounds after ExBox�4Cl was regenerated. PMID:22928610
Barnes, Jonathan C; Jur�?ek, Michal; Strutt, Nathan L; Frasconi, Marco; Sampath, Srinivasan; Giesener, Marc A; McGrier, Psaras L; Bruns, Carson J; Stern, Charlotte L; Sarjeant, Amy A; Stoddart, J Fraser
Real-time characterization of particle-bound polycyclic aromatic hydrocarbons in ambient aerosols and from motor-vehicle exhaust
A photo-electric aerosol sensor, a diffusion charger, an Aethalometer, and a continuous particle counter were used along with other real-time instruments to characterize the particle-bound polycyclic aromatic hydrocarbon (p-PAH) content, and the physical\\/chemical characteristics of aerosols collected a) in Wilmington (CA) near the Los Angeles port and close to 2 major freeways, and b) at a dynamometer testing facility in
A. Polidori; S. Hu; S. Biswas; R. J. Delfino; C. Sioutas
Polycyclic aromatic hydrocarbons in recent sediments and mussels ( Mytilus edulis) from the Western Baltic Sea: occurrence, bioavailability and seasonal variations
Surface sediments and mussels, Mytilus edulis, collected in the Baltic Sea in March 1995, October 1995 and August 1996 have been analysed for polycyclic aromatic hydrocarbon (PAH) content. The analyses have been performed by gas chromatography coupled to mass spectrometry (GC�MS). Total sediment PAH concentrations range from 3 to about 30?000 ng\\/g while total mussel PAH concentrations range from 90
P Baumard; H Budzinski; P Garrigues; H Dizer; P. D Hansen
Emission characteristics of dioxins, furans and polycyclic aromatic hydrocarbons during fluidized-bed combustion of sewage sludge
Pre-dried sewage sludge with high sulfur content was combusted in an electrically heated lab-scale fluidized-bed incinerator. The emission characteristics of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and polycyclic aromatic hydrocarbons (PAHs) were studied. Coal and calcium oxide (CaO) were added during the sewage sludge combustion tests to optimize combustion conditions and control SO2 emission. The results indicated that the flue
Wenyi DENG; Jianhua YAN; Xiaodong LI; Fei WANG; Yong CHI; Shengyong LU
Origin of Polycyclic Aromatic Hydrocarbons (PAHs) in Coastal Marine Sediments: Case Studies in Cotonou (Benin) and Aquitaine (France) Areas
Polycyclic Aromatic Hydrocarbons (PAHs) were identified and quantified in recent sediments of the Cotonou coastal zones (Benin) in the total concentration range 25�1450 ng g?1, while the Aquitaine sediment samples (France) exhibited total PAH concentrations in the range 4�855 ng g?1. The highest contents of PAHs were found in the harbours, as well in Cotonou as in the Aquitaine region,
H. H Soclo; Ph Garrigues; M Ewald
Biodegradation kinetics were studied for binary and complex mixtures of nine polycyclic aromatic hydrocarbons (PAHs): naphthalene, 1-methylnaphthalene, 2-methylnaphthalene, 2-ethylnaphthalene, phenanthrene, anthracene, pyrene, fluorene and fluoranthene. Discrepancies between the ...
Chemical Characterization of Polynuclear Aromatic Hydrocarbon Degradation Products from Sampling Artifacts.
The objective of the study was to characterize the polar components, mainly polynuclear aromatic hydrocarbon (PAH) derivatives, in air samples and to determine whether these compounds are from sampling artifacts or from the sampled air. A literature surve...
J. C. Chuang S. W. Hannan L. E. Slivon
Microbial Degradation of Polycyclic Aromatic Hydrocarbons under Denitrification Conditions in Soil-Water Suspensions: Final Report.
The microbial degradation of polycyclic aromatic hydrocarbons (PAH) under different redox conditions was examined for soil-water suspensions, with particular emphasis on microbial degradation under denitrification conditions. Batch microbial degradation t...
J. R. Mihelcic R. G. Luthy
Degradation of Selected Polycyclic Aromatic Hydrocarbons in Coastal Sediments: Importance of Microbes and Polychaete Worms.
Rates of degradation of polycyclic aromatic hydrocarbons (PAH) were examined after addition of crude oil enriched with anthracene, fluoranthene, benz(a)anthracene, and benzo(a)pyrene to coastal sediments in a laboratory (20 degrees) flowing seawater syste...
W. S. Gardner R. F. Lee K. Tenore L. Smith
Biostabilization of Polycyclic Aromatic Hydrocarbons (PAHs) Under Denitrification Conditions in Sediments.
Carnegie Mellon University and Stanford University investigated the anaerobic biodegradation of polycyclic aromatic hydrocarbons (PAHs) in contaminated sediments under bioslurry denitrifying conditions. Samples from sediment bioslurry tests and toxicity b...
J. T. Bushey I. Ahn U. Ghosh R. G. Luthy T. Mahajan
Nitrated polycyclic aromatic hydrocarbons, including carcinogens, may be non-mutagenic in microorganisms because bacterial nitroreductases are unable to reduce their nitro function to proximate mutagenic hydroxylamines. The reduction of the nitro moiety can be accomplished chemic...
The mechanisms by which polycyclic aromatic hydrocarbons (PAHs) induce mutations and cancer have been the subject of considerable attention for several years. arious theoretical and experimental models have been advanced the effects of structural variations on mutagenicity and ca...
Fluorescence, phosphorescence, and heavy-metal activated room temperature phosphorescence spectra were obtained for ten polycyclic aromatic hydrocarbon (PAH) reference compounds individually and in mixtures on quartz plates and particulate matter. The results indicate that multic...
A selective list of polycyclic aromatic hydrocarbons (PAH) with varied carcinogenic and mutagenic potencies, which are identified as common contaminants at superfund clean up sites and neighboring ground water, are investigated for their ability to induce nuclear anomalies (NA) i...
Separation and Determination of Hydroxy-Functional Polycyclic Aromatic Hydrocarbons in Coal Liquefaction Materials.
Recently, an integrated multiple-stage chromatographic method was reported for reducing the chemical complexity of neutral polycyclic aromatic hydrocarbons (PAH) coal liquid isolates by sequentially using distillation, adsorption chromatography and revers...
R. B. Lucke D. W. Later E. K. Chess
Polycyclic Aromatic Hydrocarbon-DNAAdducts in Human Lung and Cancer Susceptibility Genes
Molecular dosimetry for polycyclic aromatic hydrocarbon-DNA ad- ducts, genetic predisposition to cancer, and their interrelationships are under study in numerous laboratories. This report describes a modified •�?\\
P. G. Shields; E. D. Bowman; A. M. Harrington; V. T. Doan; A. Weston
Investigators using models to determine the phototoxic effects of sunlight on polycyclic aromatic hydrocarbons (PAHS) have invoked the excited states of the molecule as important in elucidating the mechanism of these reactions. Energies of actual excited states were calculated fo...
Investigators using models to determine the phototoxic effects of sunlight on polycyclic aromatic hydrocarbons (PAHS) have invoked the excited states of the molecule as important in elucidating the mechanism of these reactions. Energies of actual excited states were calcu...
Evidence for the extraterrestrial origin of polycyclic aromatic hydrocarbons in the Martian meteorite ALH84001.
Possible sources of terrestrial contamination are considered for the observation of polycyclic aromatic hydrocarbons (PAHs) in the Martian meteorite ALH84001. Contamination is concluded to be negligible. PMID:9809015
Clemett, S J; Dulay, M T; Gillette, J S; Chillier, X D; Mahajan, T B; Zare, R N
Modeling electron and energy transfer processes in collisions between ions and Polycyclic Aromatic Hydrocarbon molecules
In this work we study collisions between ions and Polycyclic Aromatic Hydrocarbons with the aid of a novel over-the-barrier model and well-established models for nuclear and electronic stopping processes.
Chen, Tao; Alexander, John; Forsberg, Bj�rn; Pettersson, Alf; Gatchell, Michael; Cederquist, Henrik; Zettergren, Henning
Identification and Atmospheric Reactions of Polar Products of Selected Aromatic Hydrocarbons.
During this experimental program, we have used the facilities and expertise available at the Air Pollution Research Center, University of California, Riverside, to investigate the atmospheric chemistry of selected aromatic hydrocarbons found in California...
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 ...
Airborne particulate matter contains numerous organic species, including several polycyclic aromatic hydrocarbons (PAHs) that are known or suspected carcinogens. Existing methods for measuring airborne PAHs are complex and costly, primarily because they are designed to collect...
Sixteen laboratories participated in an interlaboratory study conducted to provide precision and accuracy statements for the proposed EPA Method 610 for 16 selected polynuclear aromatic hydrocarbons(PNA's) which may be present in municipal and industrial aqueous discharges. Metho...
Do lagoon area sediments act as traps for polycyclic aromatic hydrocarbons?
The coastal lagoons are vulnerable systems, located between the land and the sea, enriched by both marine and continental inputs and are among the most productive aquatic ecosystems. The purpose of this work is to understand the influence of the lagoon area sediments on the behaviour of polycyclic aromatic hydrocarbons, through the adsorption coefficient determination. In fact, the sorption of polycyclic aromatic hydrocarbons is an important process because it governs the fate, transport, bioavailability and toxicity of these compounds in sediments. It has been observed that the adsorption of polycyclic aromatic hydrocarbons in a transitional system is the outcome of different factors, such as their sources and physicochemical properties, salinity and sediment composition, hydrology and environmental conditions. The results showed that transitional areas contribute to the polycyclic aromatic hydrocarbon accumulation in the sediment turning it into a trap. PMID:24997903
Marini, Mauro; Frapiccini, Emanuela
Cytotoxicity in Human Skin Fibroblasts Induced by Photoactivated Polycyclic Aromatic Hydrocarbons.
Polycyclic aromatic hydrocarbons (PAH) require chemical modification in order to exert their mutagenic/carcinogenic activity on biological systems. The mode of activation which has been most extensively studied involves enzyme-catalyzed oxidation reaction...
G. F. Strniste R. J. Brake
Public Health Impacts of Secondary Particulate Formation from Aromatic Hydrocarbons in Gasoline
Background: Aromatic hydrocarbons emitted from gasoline-powered vehicles contribute to the formation of secondary organic aerosol (SOA), which increases the atmospheric mass concentration of fine particles (PM2.5). Here we estimate the public health burden associated w...
Modeling the Role of Alkanes, Polycyclic Aromatic Hydrocarbons, and Their Oligomers in Secondary Organic Aerosol Formation
A computationally efficient method to treat secondary organic aerosol (SOA) from various length and structure alkanes as well as SOA from polycyclic aromatic hydrocarbons (PAHs) is implemented in the Community Multiscale Air Quality (CMAQ) model to predict aerosol concentrations ...
The objective of this project was to evaluate polyurethane foam (PUF) cartridges as collection media for quantification of vapor phase polynuclear aromatic hydrocarbons (PAHs) in air. Two cleanup methods for PUF cartridges--compression rinsing and combined compression rinsing and...
Marine sediments around urban areas serve as catch basins for anthropogenic particles containing polycyclic aromatic hydrocarbons (PAHs). Using incubations with gut fluids extracted from a deposit-feeding polychaete (Arenicola marina), we determined the digestive bioavailability ...
Extraction and Determination of Selected Polycyclic Aromatic Hydrocarbons in Plant Tissues.
A procedure has been developed for analysis of plant material for polycyclic aromatic hydrocarbons (PAHs). Sonication is used to extract the PAHs from homogenized plant material into acetonitrile and then the PAHs are partitioned into pentane. The pentane...
J. T. Coates A. W. Elzerman A. W. Garrison
The Exobiological Role of Interstellar Polycyclic Aromatic Hydrocarbons and Ices
Tremendous strides have been made in our understanding of interstellar material over the past twenty years thanks to significant, parallel developments in observational astronomy and laboratory astrophysics. Before this time, the composition of interstellar dust was largely guessed-at, the presence of ices in interstellar clouds ignored, and the notion that large, gas phase, carbon rich molecules might be abundant and widespread throughout the interstellar medium (ISM) considered impossible. Today, the composition of dust in the ISM is reasonably well constrained to micron-sized cold refractory materials comprised of amorphous and crystalline silicates mixed with an amorphous carbonaceous material containing aromatic structural units and short, branched aliphatic chains. Shrouded within the protective confines of cold, opaque molecular clouds--the birthplace of stars and planets--these cold dust particles secrete mantles of mixed molecular ices whose compositions are also well constrained. Finally, amidst the molecular inventory of these ice mantles are likely to be found polycyclic aromatic hydrocarbons (PAHs), shockingly large molecules by the standards of interstellar chemistry, the telltale infrared spectral signature of which is now recognized throughout the Universe. In the first part of this talk, we will review the spectroscopic evidence that forms the basis for the currently accepted abundance and ubiquity of PANs in the ISM. We will then look at a few specific examples which illustrate how experimental and theoretical data can be applied to interpret the interstellar spectra and track how the PAN population evolves as it passes from its formation site in the circumstellar outflows of dying stars, through the various phases of the ISM, and into forniing planetary systems. Nevertheless, despite the fact that PANs likely represent the single largest molecular reservoir of organic carbon in evolving planetary systems, they are not what would be considered "biogenic" molecules. Although interesting from a chemical and astrophysical standpoint, in the absence of a mechanism by which this population can be dislodged from the precipitous thermodynamic well afforded by their extensive aromatic networks, they are of little Astrobiological significance. Consequently, for the remainder of the talk, we will consider the photochemical evolution of PANS under conditions similar to those found in the ISM and in proto-planetary systems with an eye toward means by which this rich repository of pre-biotic organic "ore" might be converted into materials of greater importance to Astrobiology.
Hudgins, Douglas M.; DeVincenzi, Donald (Technical Monitor)
Complications with remediation strategies involving the biodegradation and detoxification of recalcitrant contaminant aromatic hydrocarbons
Environmentally persistent aromatic hydrocarbons known as unresolved complex mixtures (UCMs) derived from crude oil can be accumulated by, and elicit toxicological responses in, marine organisms (e.g. mussels, Mytilus edulis). Comprehensive two-dimensional gas chromatography time-of-flight mass-spectrometry (GC�GC�ToF-MS) previously revealed that these UCMs included highly branched alkylated aromatic hydrocarbons. Here, the effects of biodegradation on the toxicity and chemical composition of an
Max Frenzel; Alan Scarlett; Steven J. Rowland; Tamara S. Galloway; Sara K. Burton; Hilary M. Lappin-Scott; Andy M. Booth
The aromatic hydrocarbon receptor, transcription, and endocrine aspects of dioxin action
The widespread and persistent environmental contaminant 2,3,7,8-tetrachlorodibenzo-p-dioxin elicits adaptive and adverse biological responses by inducing changes in gene transcription. Some of dioxin's effect reflect disruption of endocrine homeostatis. The aromatic hydrocarbon receptor protein, together with its heterodimerization partner, the aromatic hydrocarbon receptor nuclear translocator protein, mediates dioxin action. There are notable similarities between the mechanism of dioxin action and the
Steven T. Okino; James P. Whitlock
Characterization of the Aromatic Hydrocarbon Receptor Gene and Its Expression in Atlantic Tomcod
Cytochrome P4501A1 (CYP1A1) mRNA is not inducible in Atlantic tomcod from the Hudson River that are treated with halogenated aromatic hydrocarbons (HAHs). In contrast, CYP1A1 mRNA is inducible in Hudson River tomcod that are treated with polycyclic aromatic hydrocarbons (PAHs) and in tomcod that are collected from cleaner rivers and treated with HAHs or PAHs. We hypothesize that CYP1A1 transcription
Nirmal K. Roy; Isaac Wirgin
Electrochemiluminescence Determination of Nitro Polycyclic-Aromatic Hydrocarbons Using HPLC Separation
Summary In order to analyse nitro-polycyclic aromatic hydrocarbons (NPAHs), the NPAHs were reduced to amino-polycyclic aromatic hydrocarbons (APAHs), separated by HPLC and monitored with electrochemiluminescence detection (ECL). Based on a post-column reaction with bis(2,4,6-trichlorophenyl) oxalate, the ECL observations of APAHs were performed in hydrogen peroxide solution, which was electrogenerated from an electrolysis flow cell equipped with a reticulated vitreous carbon
X. Chen; M. J. Li; C. Q. Yi; Y. Tao; X. R. Wang
Aliphatic and Aromatic Hydrocarbons in Sediments of Santos and Canan�ia, SP, Brazil
Sediment samples from Santos and Canan�ia, S�o Paulo Brazil were analysed by GC�FID and GC�MS for aliphatic and aromatic hydrocarbons in order to gather information on the degree of contamination by oil and other biogenic contributions. Concentrations of total n-alkanes in Santos varied from 1.05 to 4.29?gg?1 and aromatic hydrocarbons from 0.08 to 42.39?gg?1. In Canan�ia total n-alkanes varied from
Fernando Noboru Nishigima; Rolf Roland Weber; M�rcia Caruso B??cego
Sequential accelerated solvent extraction of polycyclic aromatic hydrocarbons with different solvents: performance and implication.
Sixteen USEPA priority polycyclic aromatic hydrocarbons (PAHs) extracted by Soxhlet extraction (S-PAHs) with dichloromethane and routine accelerated solvent extraction (A-PAHs) with 1:1 toluene/methanol, respectively, were investigated in 24 soil samples from two cities in the center of the Pearl River Delta, South China. Polycyclic aromatic hydrocarbons, methylphenanthrene and perylene, in two soils, two sediments, and an immature oil shale were also sequentially extracted by accelerated solvent extraction (ASE) with each of four different organic solvents for three times. The A-PAHs' concentrations are 2.41 times the S-PAHs' concentrations. For sequential three ASEs, PAHs in the first extract account for 56 to 67% of their total concentrations in the sequential three extractions and toluene displays the best extraction performance among the four solvents. Diagnostic ratios of PAHs in Soxhlet extraction, routine ASE, and sequential ASE with each solvent for a given sample are very similar, suggesting their identical petrogenic and pyrogenic sources in the soils and sediments. But the PAH ratios for the shale have an obvious petrogenic origin. The perylene/5-ring PAH ratios indicate a diagenetic source, especially in the shale and sediments. The correlation analysis shows that A-PAHs/S-PAHs is better associated with the contents of total organic carbon (TOC) than those of black carbon (BC). The above results indicate the significant petrogenic origin of PAHs and the important effect of organic matter on their extraction and distribution in the investigated field soils/sediments. PMID:21284305
Ma, Xiaoxuan; Ran, Yong; Gong, Jian; Chen, Diyun
Polycyclic aromatic hydrocarbon exhaust emissions from different reformulated diesel fuels and engine operating conditions
The study of light-duty diesel engine exhaust emissions is important due to their impact on atmospheric chemistry and air pollution. In this study, both the gas and the particulate phase of fuel exhaust were analyzed to investigate the effects of diesel reformulation and engine operating parameters. The research was focused on polycyclic aromatic hydrocarbon (PAH) compounds on particulate phase due to their high toxicity. These were analyzed using a gas chromatography-mass spectrometry (GC-MS) methodology. Although PAH profiles changed for diesel fuels with low-sulfur content and different percentages of aromatic hydrocarbons (5-25%), no significant differences for total PAH concentrations were detected. However, rape oil methyl ester biodiesel showed a greater number of PAH compounds, but in lower concentrations (close to 50%) than the reformulated diesel fuels. In addition, four engine operating conditions were evaluated, and the results showed that, during cold start, higher concentrations were observed for high molecular weight PAHs than during idling cycle and that the acceleration cycles provided higher concentrations than the steady-state conditions. Correlations between particulate PAHs and gas phase products were also observed. The emission of PAH compounds from the incomplete combustion of diesel fuel depended greatly on the source of the fuel and the driving patterns.
Borr�s, Esther; Tortajada-Genaro, Luis A.; V�zquez, Monica; Zielinska, Barbara
Atmospheric concentrations of polycyclic aromatic hydrocarbons during chimney sweeping.
Air sampled from the breathing zone of chimney sweeps during "dirty work" and soot samples were analysed for polycyclic aromatic hydrocarbons (PAH). A total of 20 PAH were quantified by gas chromatography-mass spectrometry in 115 air samples and 18 soot samples. These included benzo(b)fluoranthene, benzo(a)pyrene (BaP), chrysene, dibenz(a,h)anthracene, and indeno (1,2,3-cd)pyrene, all of which are animal carcinogens. The summed atmospheric concentration of these compounds depended on the type of fuel used and averaged 2.27 micrograms/m3 for oil fuel. If a mixture of oil and solid fuel was used the concentration was 5.06 micrograms/m3; pure solid fuel heating yielded 5.08 micrograms/m3. The air concentrations of BaP were 0.36, 0.83, and 0.82 micrograms/m3 respectively. The soot samples recovered after using the three different fuel types were 10.50, 109.10, and 51.25 mg BaP/kg. The maximum total concentrations of the five carcinogenic PAH were 243.70, 691.06, and 213.94 mg/kg respectively. The time weighted, shift mean concentrations of 0.02 to 0.21 micrograms/m3 benzo(a)pyrene obtained on 11 days form the basis for the industrial medical estimation of risk.
Knecht, U; Bolm-Audorff, U; Woitowitz, H J
Recent observations have shown the presence of dust and molecular material in galactic winds, but relatively little is known about the distribution of these outflow components. To shed some light on this issue, we have used IRAC images from the Spitzer Space Telescope archive to investigate polycyclic aromatic hydrocarbon (PAH) emission from a sample of 16 local galaxies with known winds. Our focus on nearby sources (median distance 8.6 Mpc) has revealed detailed PAH structure in the winds and allowed us to measure extraplanar PAH emission. We have identified extraplanar PAH features on scales of {approx}0.8-6.0 kpc. We find a nearly linear correlation between the amount of extraplanar PAH emission and the total infrared flux, a proxy for star formation activity in the disk. Our results also indicate a correlation between the height of extraplanar PAH emission and star formation rate surface density, which supports the idea of a surface density threshold on the energy or momentum injection rate for producing detectable extraplanar wind material.
McCormick, Alexander; Veilleux, Sylvain [Department of Astronomy, University of Maryland, College Park, MD 20742 (United States); Rupke, David S. N., E-mail: email@example.com, E-mail: firstname.lastname@example.com, E-mail: firstname.lastname@example.com [Rhodes College, 2000 North Parkway, Memphis, TN 38112 (United States)
Aromatized arborane/fernane hydrocarbons as biomarkers for cordaites
Previous palaeobotanical and palynological studies on coals from Euramerican Pennsylvanian (? Late Carboniferous) coal basins indicate a major change in coal-swamp floras, especially at the Westphalian Stephanian (?Kasimovian Gzhelian, according to Geological Time Scale 2004) boundary. A flora dominated by arborescent lycophytes was replaced by a vegetation dominated by marattialean tree ferns in various Euramerican coal basins. Earlier combined palynological and organic geochemical studies on Westphalian/Stephanian coals and shales from the Saar-Nahe Basin (Germany) revealed that the distribution of aromatized arborane/fernane hydrocarbons in solvent extracts reflects the increasing importance of seed plants, especially cordaites (extinct group of gymnosperms), conifers and pteridosperms. However, the biological source of the precursor molecules could not be specified. To clarify if the arborane/fernane derivatives MATH, MAPH, DAPH 1, and DAPH 2 in Westphalian/Stephanian coals can be assigned to one of the three potential source plant groups, we analyzed coals, sediments and fossil plant remains from different Euramerican locations with respect to their biomarker composition and stable carbon isotopic composition. Thereby, stable carbon isotopic ratios showed only insignificant variations between Westphalian and Stephanian samples and proved to be an unsuitable tool to describe floral changes during the Westphalian/Stephanian of the Saar-Nahe Basin. In contrast, we were able to show for the first time that MATH, MAPH, DAPH 1 and DAPH 2 are prominent constituents only in extracts of cordaitean macrofossils and can therefore be regarded as biomarkers for this group of gymnosperms.
Auras, Stefan; Wilde, Volker; Scheffler, Kay; Hoernes, Stephan; Kerp, Hans; P�ttmann, Wilhelm
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.
Novel isoxazole polycyclic aromatic hydrocarbons as DNA-intercalating agents.
The third generation of isoxazole polycyclic aromatic hydrocarbons, acting as DNA-intercalator agents and possessing the binding constants in the range 10(4)-10(5)�M(-1), in order to easily diffuse targeting remotely implanted tumors, has been synthesized in good yields according to the 1,3-dipolar cycloaddition methodology. The structure of the obtained cycloadducts has been determined by NOE experiments and supported by computational studies at PM3 level. All the obtained compounds have been tested for their in�vitro cytotoxic activity and the most potent of them, (3RS,5SR)-2-benzyl-N,N-dimethyl-3-(pyren-1-yl)isoxazolidine-5-carboxamide (7d), showed an IC(50) of 4�?M upon the human lung cancer (A-549) cells. Moreover, compound 7d showed binding constant for the intercalation with calf thymus DNA, poly-d(AT)(2) and poly-d(GC)(2) of 1.7�נ10(5)�M(-1), 1.6�נ10(5)�M(-1) and 0.3�נ10(5)�M(-1), respectively. Biological and docking studies showed that, in�vitro, these compounds complex by intercalation between base pairs, approaching the DNA from its minor groove with a preference for the AT nucleobases pairs. PMID:22405647
Rescifina, Antonio; Varrica, Maria Giulia; Carnovale, Caterina; Romeo, Giovanni; Chiacchio, Ugo
The oxidation of three polynuclear aromatic hydrocarbons (PAHs), fluorene, phenanthrene, and acenaphthene, in aqueous solution with ozone has been studied. The influence of hydroxyl radical inhibitors, pH, ozone partial pressure, and temperature was investigated. All the PAHs studied show high oxidation rates with ozone. The ozonation of fluorene seems to be due to both direct and hydroxyl radical reactions while for the rest of the PAHs the ozonation develops only through direct reactions with ozone. Rate constants for the direct reaction between these PAHs and ozone have also been calculated. The reactivity with ozone goes in the following order: fluorene < phenanthrene < acenaphthene. The contribution of radical reactions represents more than 90% in the ozonation of fluorene in most cases except in the presence of hydroxyl radical inhibitors. In a standard agitated reactor the kinetic regime of the absorption of ozone corresponds to a slow reaction in the case of fluorene and phenanthrene and to a fast reaction in the case of acenaphthene.
Beltran, F.J.; Encinar, J.M.; Rivas, J. [Univ. de Extremadura, Badajoz (Spain). Dept. de Ingenieria Quimica y Energetica; Ovejero, G. [Univ. Complutense, Madrid (Spain). Dept. de Ingenieria Quimica
Particle-bound polycyclic aromatic hydrocarbon concentrations in transportation microenvironments
This study is one of the first case studies to characterize the exposure of urban residents to traffic-related air pollution across locations and transportation microenvironments during everyday activities. Twenty-four adult residents of Boyle Heights, a neighborhood near downtown Los Angeles, carried a portable air pollution monitor and a Global Positioning Systems (GPS) tracking device for a total of 96 days. We found significant spatial and temporal variation in the particle-bound polycyclic aromatic hydrocarbon (pPAH) concentrations in transportation microenvironments. Average pPAH concentrations were higher while walking outdoors (190 ng m-3) compared to traveling in private passenger vehicles (138-155 ng m-3) or traveling in public transportation (61-124 ng m-3). Although travel comprised 5% of participant days, it was associated with 27% of overall daily pPAH exposure. Regression models explained 40-55% of the variation in daily average pPAH concentrations, and 40-44% of the variation in 1-min interval concentrations. Important factors included time spent traveling, travel speed, meteorological and nearby land use factors, time of day, and proximity to roadways. Although future research is needed to develop stronger predictive models, our study demonstrates portable tracking devices can provide a more complete, diurnal characterization of air pollution exposures for urban populations.
Houston, Douglas; Wu, Jun; Yang, Dongwoo; Jaimes, Guillermo
Measurement of polycyclic aromatic hydrocarbon (PAHs) in interplanetary dust particles
We report here the first definitive measurements of specific organic molecules (polycyclic aromatic hydrocarbons (PAH's)) in interplanetary dust particles (IDP's). An improved version of the microbeam-two-step laser mass spectrometer was used for the analysis. Two IDP's gave similar mass spectra showing an abundance of PAH's. Control samples, including particles of probable terrestrial origin from the same stratospheric collector, gave either null results or quite different spectra. We conclude that the PAH's are probably indigenous to the IDP's and are not terrestrial contaminants. The instrument used to study the particles is a two-step laser mass spectrometer. Constituent neutral molecules of the sample are first desorbed with a pulsed infrared laser beam focussed to 40 micrometers. In the second step, PAH's in the desorbed plume are preferentially ionized by a pulsed UV laser beam. Resulting ions produced by resonant absorption are extracted into a reflectron time-of-flight mass spectrometer. This instrument has high spatial resolution, high ion transmission, unlimited mass range, and multichannel detection of all ion masses from a single laser shot.
Clemett, S. J.; Maechling, C. R.; Zare, R. N.; Swan, P. D.; Walker, R. M.
FT-IR spectroscopic studies of polycyclic aromatic hydrocarbons
Proper assessment of the hypothesis which correlates polycyclic aromatic hydrocarbons (PAHs) with the unidentified infrared emission bands requires additional experimental laboratory data. In order to address this need, thermal infrared emission studies were performed on a subset of PAHs suggested to be of astrophysical importance. It was proposed that infrared emission from interstellar PAHs occurs following absorption of an ultraviolet photon. Since energy transfer to the ground electronic state can be rapid for a species in which intersystem crossing is negligible, the emission spectrum may be viewed as resulting from an equilibrium vibrational temperature (Leger and d'Hendecourt, 1987). This has been the basis for using infrared absorption spectra to calculate the corresponding emission spectra at various temperatures. These calculations were made using room temperature infrared absorption coefficients instead of those at the temperature of interest because of the latter's unavailability. The present studies are designed to address the differences between the calculated and experimental thermal emission spectra and to provide information which will be useful in future ultraviolet induced infrared fluorescence studies. The emission spectra have been obtained for temperatures up to 825K using an emission cell designed to mount against an external port of an FT-IR spectrometer. These spectra provide information concerning relative band intensities and peak positions which is unavailable from previous calculations.
Salisbury, D. W.; Allen, J. E., Jr.; Donn, B.; Moore, W. J.; Khanna, R. K.
Determination of polycyclic aromatic hydrocarbons in the lung.
Polycyclic aromatic hydrocarbons (PAHs) accumulated in human lung samples from men (n = 236) and women (n = 128) were determined by high-performance liquid chromatography (HPLC) to examine their association with lung cancer. The mean values for benzo[a]pyrene (BaP), benzo[k]fluoranthene (BkF), and benzo[g,h,i]perylene (BghiP) in lungs (ng/g dry lung) of Japanese autopsied patients were 0.54, 0.44, and 0.87, respectively. The modal values were 0.3, 0.3 and 0.5, respectively. Each of the PAH concentrations was highly correlated with the others (r > 0.83). PAH concentrations in the lungs showed age-related increases with low correlation-coefficient values. BaP, BkF and BghiP concentrations in lungs of various subgroups were in the following order: male > female; and lung cancer > all cancers > non-cancer among male not female group. Only BghiP concentration in the lungs of the male smoker group is significantly higher (P < 0.10) than that of the male non-smoker group. Even among non-smoker groups, PAH concentrations in the lungs of male group were significantly higher than those of female group. In the male population, excess exposure to PAHs together with fine carbon particles, such as tobacco smoke or diesel exhaust, correlated with increased prevalence of lung cancer. PMID:8507106
Seto, H; Ohkubo, T; Kanoh, T; Koike, M; Nakamura, K; Kawahara, Y
Carcinogenic activation of polycyclic aromatic hydrocarbons (PAH) involves two main pathways: one-electron oxidation and monooxygenation. One-electron oxidation produces PAH radical cations, which can react with cellular nucleophiles. Results from biochemical and biological experiments indicate that only PAH with ionization potentials below ca. 7.35 eV can be metabolically activated by one-electron oxidation. In addition, the radical cations of carcinogenic PAH must have relatively high charge localization to react effectively with macromolecules in target cells. Metabolic formation of PAH quinones proceeds through radical cation intermediates. Binding of benzo(a)pyrene (BP) to mouse skin DNA occurs predominantly at C-6, the position of highest charge localization in the BP radical cation, and binding of 6-methylBP to DNA in mouse skin yields a major adduct with the 6-methyl group bound to the 2-amino group of deoxyguanosine. Studies of carcinogenicity by direct application of PAH to rat mammary gland indicate that only PAH with ionization potentials low enough for activation by one-electron oxidation produce tumors in this target tissue. These constitute some of the results which provide evidence for the involvement of one-electron oxidation in PAH carcinogenesis. 78 references.
Cavalieri, E.; Rogan, E.
Infrared Spectroscopy of Matrix-Isolated Polycyclic Aromatic Hydrocarbon Cations
Gaseous, ionized polycyclic aromatic hydrocarbons (PAHs) are thought to be responsible for a very common family of interstellar infrared emission bands. Here the near- and mid-infrared spectra of the cations of the five most thermodynamically favored PAHs up to coronene: phenanthrene, pyrene, benzo(e)pyrene, benzo-(ghi)perylene, and coronene, are presented to test this hypothesis. For those molecules that have been studied previously (pyrene, pyrene-d(sub 10), and coronene), band positions and relative intensities are in agreement. In all of these cases we report additional features. Absolute integrated absorbance values are given for the phenanthrene, perdeuteriophenanthrene, pyrene, benzo(ghi]perylene, and coronene cations. With the exception of coronene, the cation bands corresponding to the CC modes are typically 2-5 times more intense than those of the CH out-of-plane bending vibrations. For the cations, the CC stretching and CH in-plane bending modes give rise to bands that are an order of magnitude stronger than those of the neutral species, and the CH out-of-plane bends produce bands that are 5-20 times weaker than those of the neutral species. This behavior is similar to that found in most other PAH cations studied to date. The astronomical implications of these PAH cation spectra are also discussed.
Hudgins, D. M.; Allamandola, L. J.
Depletion of gaseous polycyclic aromatic hydrocarbons by a forest canopy
Rapid uptake of gaseous polycyclic aromatic hydrocarbons (PAHs) by a forest canopy was observed at Borden in Southern Ontario, Canada during bud break in early spring 2003. High volume air samples were taken on 12 individual days at three different heights (44.4, 29.1, and 16.7 m) on a scaffolding tower and on the forest floor below the canopy (1.5 m). Concentrations of PAHs were positively correlated to ambient temperature, resulting from relatively warm and polluted air masses passing over the Eastern United States and Toronto prior to arriving at the sampling site. An analysis of vertical profiles and gas/particle partitioning of the PAHs showed that gaseous PAHs established a concentration gradient with height, whereas levels of particulate PAHs were relatively uniform, implying that only the uptake of gaseous PAHs by the forest canopy was sufficiently rapid to be observed. Specifically, the gaseous concentrations of intermediate PAHs, such as phenanthrene, anthracene, and pyrene, during budburst and leaf emergence were reduced within and above the canopy. When a gradient was observed, the percentage of PAHs on particles increased at the elevations experiencing a decrease in gas phase concentrations. The uptake of intermediate PAHs by the canopy also led to significant differences in gaseous PAH composition with height. These results are the most direct evidence yet of the filter effect of forest canopies for gaseous PAHs in early spring. PAH deposition fluxes and dry gaseous deposition velocities to the forest canopy were estimated from the concentration gradients.
Choi, S.-D.; Li, H.; Su, Y.; Gevao, B.; Harner, T.; Staebler, R. M.; Wania, F.
Choi, S.-D.; Staebler, R. M.; Li, H.; Su, Y.; Gevao, B.; Harner, T.; Wania, F.
Fullerenes, fulleranes and polycyclic aromatic hydrocarbons in the Allende meteorite
In this paper, we confirm our earlier observations of fullerenes (C60 and C70) in the Allende meteorite (Becker et al., 1994a, 1995). Fullerene C60 was also detected in two separate C-rich (approximately 0.5-1.0%) dark inclusions (Heymann et al., 1987) that were hand picked from the Allende sample. The amounts of C60 detected were approximately 5 and approximately 10 ppb, respectively, which is considerably less than what was detected in the Allende 15/21 sample (approximately 100 ppb; Becker et al., 1994a, 1995). This suggests that fullerenes are heterogeneously distributed in the meteorite. In addition, we present evidence for fulleranes, (C60Hx), detected in separate samples by laser desorption (reflectron) time-of-flight (TOF) mass spectrometry (LDMS). The LDMS spectra for the Allende extracts were remarkably similar to the spectra generated for the synthetic fullerane mixtures. Several fullerane products were synthesized using a Rh catalyst (Becker et al., 1993a) and separated using high-performance liquid chromatography (HPLC). Polycyclic aromatic hydrocarbons (PAHs) were also observed ppm levels) that included benzofluoranthene and corannulene, a cup-shaped molecule that has been proposed as a precursor molecule to the formation of fullerenes in the gas phase (Pope et al., 1993).
Becker, L.; Bunch, T. E.
Aromatic hydrocarbons emissions in diesel and biodiesel exhaust
Regulated emissions of biodiesel blends are reasonably well documented in several works, non-regulated emissions, on the contrary, lack research. In this work, mono- and polycyclic aromatic hydrocarbons (MAHs and PAHs, respectively) emission tests were performed with a heavy-duty diesel engine, fueled with pure diesel (D) and biodiesel blends (v/v) of 2% (B2), 5% (B5) and 20% (B20%). The main objective of this study is to investigate the effect of the biodiesel addition on the emission profile of MAHs and PAHs. The tests were conducted using a six cylinder heavy-duty engine, typical of the Brazilian fleet of urban buses, in a steady-state condition under 1500 rpm. The PAHs were sampled with Teflon filters and XAD-2 cartridges and were identified by gaseous chromatograph coupled to a mass spectrometer (GC/MS) and quantified by flame ionization detection (GC/FID). The MAHs were sampled with active charcoal cartridges and analyzed by GC/FID. Both MAHs and PAHs filters and cartridges were extracted with dichloromethane in an ultrasonic bath. Ten PAHs and eight MAHs were identified and the average reduction of MAHs was 4.2% (B5), 8.2% (B5), and 21.1% (B20). The average reduction for PAHs was 2.7% (B2), 6.3% (B5), and 17.2% (B20). However, some PAHs and MAHs emissions increased because of/due to the biodiesel blends like phenanthrene, ethyl benzene, and trimethyl benzenes.
Corr�a, S�rgio Machado; Arbilla, Graciela
Polynuclear Aromatic Hydrocarbons Concentrations in Char-Broiled Meat Suya
Polynuclear aromatic hydrocarbons (PNAs) concentrations in char-broiled meat suya have been determined in samples obtained from four different selling points in Warri Metropolis of Nigeria. The sixteen EPA priority PNAs were detected using Gas Chromatography and Flame Ionization Detector. Concentrations of total PNAs determined in the four sampling points were: EF1 (134.82< �8.53 ?g kg-1), EF2 (113.83< �7.93 ?g kg-1), WR3 (115.14< �7.77 ?g kg-1), WR4 (81.95< �6.76 ?g kg-1). Benzo(a)pyrene, which is often used as a reference indicator for PNAs carcinogenicity, was determined at levels above 5 ?g kg-1 recommended as maximum limit by Commission of European Communities for smoked meat and smoked meat products. It was however, observed that the 2-3 rings PNAs including naphthalene, fluorene, acenaphthylene, acenaphthene, phenanthrene and anthracene were more abundant owing to their high percentage composition in the matrix of the charbroiled meat. Although the levels observed for benzo(a)pyrene in the beef suya exceeded standard guidelines of European Commission, it may take the diet to consist of frequent consumption of barbecued meat before a significant contributions of PNAs contaminant to the human system can be thoroughly assessed.
Duke, Okoro; Albert, Ikolo O.
Engineered Antibodies for Monitoring of Polynuclear Aromatic Hydrocarbons
Polynuclear aromatic hydrocarbons (PAHs) are a large class of structurally similar pollutants. Rapid, inexpensive, and high-throughput methods to identify and monitor PAHs are needed in several DOE focus areas, including human and ecosystem health effects, risk and exposure assessment, decontamination and decommissioning, and remediation. DOE has sponsored and participated in several demonstration projects in which commercial immunoassay kits proved useful and cost-effective for detection of PAHs and other pollutants. The emerging generation of sensors and residue recovery methods will require panels of antibodies with relatively subtle differences in cross-reactivity. This project is based on the premise that genetic engineering should be much more successful than conventional polyclonal and monoclonal antibody methods for developing these antibody panels. One objective of this project has been to define the structural basis and mechanisms by which antibodies bind and cross-react with various PAHs. A second objective has been to use this information to produce recombinant antibodies with improved performance in analytical procedures that DOE can use. A third objective has been development of PAH residue recovery and cleanup methods that will be compatible with immunoassays, and make instrumental analysis faster, more accurate, and less expensive.
Karu; Alexander E.; Roberts, Victoria A.; Li, Qing X.
Magnetic Beads-based Bioelectrochemical Immunoassay of Polycyclic Aromatic Hydrocarbons
A simple, rapid, and sensitive bioelectrochemical immunoassay method based on magnetic beads (MBs) has been developed to detect polycyclic aromatic hydrocarbons (PAHs). The principle of this bioassay is based on a direct competitive enzyme-linked immunosorbent assay using PAH-antibody-coated MBs and horseradish peroxidase (HRP)-labeled PAH (HRP-PAH). A magnetic process platform was used to mix and shake the samples during the immunoreactions and to separate free and unbound reagents after the liquid-phase competitive immunoreaction among PAH-antibody-coated MBs, PAH analyte, and HRP-PAH. After a complete immunoassay, the HRP tracers attached to MBs were transferred to a substrate solution containing 3, 3�, 5, 5�- tetramethylbenzidine (TMB) and hydrogen peroxide (H2O2) for electrochemical detection. The voltammetric characteristics of the substrate were investigated, and the reduction peak current of TMB was used to quantify the concentration of PAH. The different parameters, including the amount of HRP-PAH conjugates, the enzyme catalytic reaction time, and the pH of the supporting electrolyte that governs the analytical performance of the immunoassay have been studied in detail and optimized. The detection limit of 50 pg mL-1 was obtained under optimum experimental conditions. The performance of this bioelectrochemical magnetic immunoassay was successfully evaluated with tap water spiked with PAHs, indicating that this convenient and sensitive technique offers great promise for decentralized environmental applications.
Lin, Ying-Ying; Liu, Guodong; Wai, Chien M.; Lin, Yuehe
Detector for particulate polycyclic aromatic hydrocarbons in water.
It is estimated that most polycyclic aromatic hydrocarbons (PAHs) in environmental water are not dissolved but rather in particulate form. Nevertheless, the currently available optical detectors are not suited for proper sampling of solid PAHs. A new setup for direct sampling and quantification of suspended particulate PAHs in water is suggested. It is based on a polymeric film that has the capability of dissolving PAH particulates, coupled to a traditional laser-induced fluorescence probe. Kinetics and performance of two sampling modes have been studied: bulk sampling, by immersing the probe into the water, and surface sampling, by laying the film on the water surface. The latter method has proved to be more sensitive; however, it is diffusion-limited. Linear calibration plots have provided quantification over a wide concentration range with detection limits in the ppb range (these could be improved by using a modified probe). The effects due to other particulates in water have been studied and only little interferences have been observed. The possibility of analysis of PAH mixtures has been addressed and it has been concluded that multivariate analysis is needed. PMID:15789244
Levinson, Jane; Sluszny, Chanan; Yasman, Yakov; Bulatov, Valery; Schechter, Israel
Cardiac Autonomic Dysfunction from Occupational Exposure to Polycyclic Aromatic Hydrocarbons
Objectives Polycyclic aromatic hydrocarbons (PAHs) exposures have been associated with cardiopulmonary mortality and cardiovascular events. This study investigated the association between a biological marker of PAHs exposure, assessed by urinary 1-hydroxypyrene (1-OHP), and heart rate variability (HRV) in an occupational cohort of boilermakers. Methods Continuous 24-hour monitoring of the ambulatory electrocardiogram (ECG) and pre and post shift urinary 1-OHP were repeated over extended periods of the work week. Mixed effects models were fit for the 5-minute standard deviation of normal-to-normal intervals (SDNN) in relation to urinary 1-OHP levels pre and post workshift on the day they wore the monitor, controlling for potential confounders. Results We found a significant decrease in 5-min SDNN during work of ?13.6% (95% confidence interval, ?17.2% to ?9.8%) for every standard deviation (0.53 microgram/gram [?g/g] creatinine) increase in the next-morning pre-shift 1-OHP levels. The magnitude of reduction in 5-min SDNN were largest during the late night period after work and increased with every standard deviation (0.46 ?g/g creatinine) increase in post-shift 1-OHP levels. Conclusion This is the first report providing evidence that occupational exposure to PAHs is associated with altered cardiac autonomic function. Acute exposure to PAHs may be an important predictor of cardiovascular disease risk in the work environment.
Lee, Mi-Sun; Magari, Shannon; Christiani, David C.
Polycyclic Aromatic Hydrocarbon Ionization Energy Lowering in Water Ices
In studying various interstellar and solar system ice analogs, we have recently found that upon vacuum ultraviolet photolysis, polycyclic aromatic hydrocarbons (PAHs) frozen in water ice at low temperatures are easily ionized and indefinitely stabilized as trapped ions (Gudipati; Gudipati & Allamandola). Here we report the first experimental study that shows that PAH ionization energy is significantly lowered in PAH/H2O ices, in agreement with recent theoretical work (Woon & Park). The ionization energy (IE) of the PAH studied here, quaterrylene (C40H20, IE = 6.11 eV), is lowered by up to 2.11 eV in water ice. PAH ionization energy reduction in low-temperature water ice substantially expands the astronomical regions in which trapped ions and electrons may be important. This reduction in ionization energy should also hold for other types of trapped species in waterrich interstellar, circumstellar, and solar system ices. Subject headings: ISM: clouds - methods: laboratory - molecular processes - radiation mechanisms: nonthermal -ultraviolet: ISM - ultraviolet: solar system
Gudipati, Murthy S.; Allamandola, Louis J.
Polycyclic aromatic hydrocarbons in frying oils and snacks.
The high incidence of lung cancer observed among Chinese women has been associated with exposure to fumes from cooking oil. Polycyclic aromatic hydrocarbons (PAHs) are a class of potentially mutagenic substances emitted from cooking oils heated at high temperatures. The objective of this study was to investigate whether deep frying with different oils under different conditions leads to the development of PAHs either in the oil or in the fried product (snacks). PAH analysis was carried out with solid-phase extraction followed by reverse-phase high-performance liquid chromatography and spectrofluorometric detection. Different oils were used to fry chips and extruded snacks in different industrial plants (continuous frying) at temperatures between 170 and 205 degrees C, and peanut oil was used to fry French fries and fish (discontinuous frying) at temperatures between 160 and 185 degrees C. No appreciable differences in PAH load was observed in the same oil before and after frying. Both before and after frying, the benzo[a]pyrene concentration in oils ranged from trace to 0.7 ppb. All the analyzed samples, including oils from fried snacks, had benzo[a]pyrene concentrations well below the 2 ppb limit recently proposed by the European Community. PMID:16416919
Purcaro, Giorgia; Navas, Jos� A; Guardiola, Francesc; Conte, Lanfranco S; Moret, Sabrina
Accumulation of mutagenic polycyclic aromatic hydrocarbons in biological sludge
Research was conducted to study the lipophilic accumulation of mutagenic polycyclic aromatic hydrocarbons (PAH) in biological sludge produced during activated sludge treatment of fixed-bed coal-gasification wastewater. The activated sludge system was viewed as a two phase chemical system to model the PAH accumulation process, and PAH distribution in this system was quantified by an equilibrium distribution coefficient. A general equation was next developed from thermodynamic principles to predict a sludge lipid-gasifier wastewater distribution coefficient for any PAH of interest. Determination of the required parameters for this equation involved the use of a modified version of the UNIFAC method for calculating activity coefficients. PAH absorption isotherms for biological sludge in gasifier wastewater were determined by running a series of equilibrium absorption experiments. The results of these experiments indicated that the predictive equation accurately estimated distribution coefficients for most of the PAH tested. A bench scale activated sludge system treating gasifier wastewater was then operated to gather further data on PAH absorption.
Moretti, C.J.
Polycyclic aromatic hydrocarbons and the diffuse interstellar bands: a survey.
We discuss the proposal relating the origin of some of the diffuse interstellar bands (DIBs) to neutral and ionized polycyclic aromatic hydrocarbons (PAHs) present in interstellar clouds. Laboratory spectra of several PAHs, isolated at low temperature in inert gas matrices, are compared with the spectra of five reddened early-type stars selected from an extensive set of astronomical spectra. From this comparison, it is concluded that PAH ions are good candidates to explain some of the DIBS. Unambiguous assignments are difficult, however, because of the shift in wavelengths and the band broadening induced in the laboratory spectra by the solid matrix. This situation is illustrated by a comparison with the gas-phase spectra made available recently for two PAH ions. Definitive band assignments and, ultimately, the test of the proposal that PAH ions carry some of the DIBs must await the availability of a larger set of gas-phase measurements in the laboratory. The present assessment offers a guideline for future laboratory experiments by allowing the preselection of promising PAH molecules to be studied in jet expansions. PMID:11543306
Salama, F; Galazutdinov, G A; Krelowski, J; Allamandola, L J; Musaev, F A
Polycyclic aromatic hydrocarbon (PAH) ecotoxicology in marine ecosystems.
Low levels of oil and hence polycyclic aromatic hydrocarbons (PAHs) are naturally present in the marine environment, although levels have increased significantly following human extraction and use of oil and gas. Other major anthropogenic sources of PAHs include smelters, the use of fossil fuels in general, and various methods of waste disposal, especially incineration. There are two major sources for PAHs to marine ecosystems in Norway: the inshore smelter industry, and offshore oil and gas production activities. A distinction is generally made between petrogenic (oil-derived) and pyrogenic (combustion-derived) PAHs. Although petrogenic PAHs appear to be bioavailable to a large extent, pyrogenic PAHs are often associated with soot particles and less available for uptake into organisms. There is extensive evidence linking sediment-associated PAHs to induction of phase-I enzymes, development of DNA adducts, and eventually neoplastic lesions in fish. Most studies have focused on high-molecular-weight, carcinogenic PAHs such as benzo[a]pyrene. It is less clear how two- and three-ring PAHs affect fish, and there is even experimental evidence to indicate that these chemicals may inhibit some components of the phase I system rather than produce induction. There is a need for increased research efforts to clarify biological effects of two- and three-ring PAHs, PAH mixtures, and adaptation processes in marine ecosystems. PMID:16291565
Hylland, Ketil
Polycyclic aromatic hydrocarbon (PAH) emissions from charcoal grilling
The emission of polycyclic aromatic hydrocarbons (PAH) was quantitated in the smoke from the grilling of meat using hardwood charcoal as fuel in a table grill set. Smoke samples were collected with an ice-cooled condenser and subsequently cleaned up employing both open column- and high performance-liquid chromatography techniques. Using a PAH standard mixture, 23 PAH were identified in the smoke using gas chromatography-mass spectrometry. Emission levels of PAH ranged from several tens of ?g kg -1 meat for some 3- and 4-ringed PAH, to sub ?g kg -1 meat levels for the 5- and 6-ringed PAH (sum of PAH approximately 0.1 mg kg -1 meat), originating from a 10 min grilling of 0.33 kg minced lean pork. The major source of PAH emitted to the local air environment from charcoal grilling is from the combustion of the charcoal itself. The amount of PAH emitted from charcoal grilling in Sweden, time period June to August, is estimated to approximately 2 kg which is a minor source to the total emissions of PAH to the environment. However, relatively large peak exposures of PAH can be expected in a more local environment, e.g. during household grilling.
Dyremark, Anders; Westerholm, Roger; �vervik, Eva; Gustavsson, Jan-�ke
Generation of polycyclic aromatic hydrocarbons (PAHs) during woodworking operations.
Occupational exposures to wood dust have been associated with an elevated risk of sinonasal cancer (SNC). Wood dust is recognized as a human carcinogen but the specific cancer causative agent remains unknown. One possible explanation is a co-exposure to; wood dust and polycyclic aromatic hydrocarbons (PAHs). PAHs could be generated during incomplete combustion of wood due to heat created by use of power tools. To determine if PAHs are generated from wood during common wood working operations, PAH concentrations in wood dust samples collected in an experimental chamber operated under controlled conditions were analyzed. In addition, personal air samples from workers exposed to wood dust (n = 30) were collected. Wood dust was generated using three different power tools: vibrating sander, belt sander, and saw; and six wood materials: fir, Medium Density Fiberboard (MDF), beech, mahogany, oak and wood melamine. Monitoring of wood workers was carried out by means of personal sampler device during wood working operations. We measured 21 PAH concentrations in wood dust samples by capillary gas chromatography-ion trap mass spectrometry (GC-MS). Total PAH concentrations in wood dust varied greatly (0.24-7.95 ppm) with the lowest being in MDF dust and the highest in wood melamine dust. Personal PAH exposures were between 37.5-119.8 ng m(-3) during wood working operations. Our results suggest that PAH exposures are present during woodworking operations and hence could play a role in the mechanism of cancer induction related to wood dust exposure. PMID:23087908
Bruschweiler, Evin D; Danuser, Brigitta; Huynh, Cong Khanh; Wild, Pascal; Schupfer, Patrick; Vernez, David; Boiteux, Philippe; Hopf, Nancy B
Bioavailability of polycyclic aromatic hydrocarbons in the North Sea
Semipermeable membrane devices (SPMDs) and blue mussels (Mytilus edulis) were used to determine the bioavailable fraction of polycyclic aromatic hydrocarbons (PAHs) from oil field produced water in the North Sea. The SPMDs and mussels were deployed at 5, 10, and 50 m depth; 100 and 300 m downstream the discharge point; and at a reference site 16 km away. In both SPMDs and mussels, the concentration of PAHs increased significantly toward the discharge point, with the strongest contribution from the lower molecular weight compounds (naphthalene, phenanthrene, dibenzothiophene, and their C1-C3 alkyl homologues). The relative increase in PAH concentration from the reference site to the site at 100 m was higher for mussels than for the SPMDs. The SPMDs reflect the water-soluble fraction of the PAHs, which is probably the most important route of exposure for organisms at lower trophic levels and presumably also the fraction available for uptake by a respiratory route. Residues in the mussels represent both the water-soluble and particle-bound fraction and give information about bioavailability of the PAHs for organisms at higher trophic levels. The results of this study suggest that both techniques give important information about the bioavailability of PAHs to marine organisms.
Utvik, T.I.R. (Norsk Hydro E and P Operations, Bergen (Norway). Environmental Section); Johnsen, S. (Statoil R and D Centre, Trondheim (Norway))
Method of upgrading oils containing hydroxyaromatic hydrocarbon compounds to highly aromatic gasoline
The present invention is a multi-stepped method of converting an oil which is produced by various biomass and coal conversion processes and contains primarily single and multiple ring hydroxyaromatic hydrocarbon compounds to highly aromatic gasoline. The single and multiple ring hydroxyaromatic hydrocarbon compounds in a raw oil material are first deoxygenated to produce a deoxygenated oil material containing single and multiple ring aromatic compounds. Then, water is removed from the deoxygenated oil material. The next step is distillation to remove the single ring aromatic compouns as gasoline. In the third step, the multiple ring aromatics remaining in the deoxygenated oil material are cracked in the presence of hydrogen to produce a cracked oil material containing single ring aromatic compounds. Finally, the cracked oil material is then distilled to remove the single ring aromatics as gasoline.
Baker, Eddie G. (Richland, WA); Elliott, Douglas C. (Richland, WA)
Source identification of aromatic hydrocarbons in sediments using GC\\/MS
A method that may distinguish between input of polycyclic aromatic hydrocarbons (PAH) from petroleum and combustion sources is demonstrated on sediment samples. Selected series of aromatics (unsubstituted compounds and their C�-C� alkyl homologues) are quantified by computerized GC\\/MS. The alkyl homologue distribution (AHD) within each series and the sum of components in each series relative to the sum of all
S. Sporstoel; Nina Gjos; Rainer G. Lichtenthaler; Kay O. Gustavsen; Kjell Urdal; Froydis Oreld; J. Skel
Molecular cloning of novel genes for polycyclic aromatic hydrocarbon degradation from Commamonas testosteroni GZ39
The mechanisms by which bacteria degrade simple polycyclic aromatic compounds have been studied for some time. The genes for the initial steps in the degradation of maphthalene have been cloned from many different Pseudomonas stains. This study was undertaken to investigate the diversity of genes involved in phenanthrene degradation and to identify novel organisms and genes for polycyclic aromatic hydrocarbon
ANIL K. GOYAL; G. J. Zylstra
Biodegradation of High-Molecular-Weight Polycyclic Aromatic Hydrocarbons by Bacteria
Interest in the biodegradation mechanisms and environ- mental fate of polycyclic aromatic hydrocarbons (PAHs) is prompted by their ubiquitous distribution and their potentially deleterious effects on human health. PAHs constitute a large and diverse class of organic compounds and are generally de- scribed as molecules which consist of three or more fused aromatic rings in various structural configurations (5). The
Polycyclic aromatic hydrocarbon formation in carbon-rich stellar envelopes
A detailed chemical kinetic scheme is applied to stellar envelope profiles of gas density and temperature profiles in order to study the formation of PAH molecules in carbon-rich stellar outflows. Chemical concentration profiles are calculated for several envelope models by integrating the coupled continuity equations that include spherically expanding flows from an inner boundary at the shock formation radius. The influence of the 'inverse greenhouse' effect experienced by small PAHs is investigated and shown to increase the PAH yield by many orders of magnitude. It is shown that the route through propargyl radicals could be an important channel to produce benzene. PAH formation yields are found to be extremely sensitive to gas density and temperature and are much smaller than values inferred from the observed dust content of late-type carbon-rich stellar envelopes. It is therefore unlikely that aromatic molecules are generated in the stellar outflow itself.
Cherchneff, Isabelle; Barker, John R.; Tielens, Alexander G. G. M.
Polycyclic aromatic hydrocarbons in the environment: homologous series in soils and recent marine sediments
Soils and recent marine sediments contain a complex polycyclic aromatic hydrocarbon assemblage. The many series of alkylhomologs have a similar molecular weight distribution, and it varies little over a wide range of depositional environments. It is suggested that these hydrocarbons are formed in natural fires, are dispersed and mixed by air transport and eventually deposited into surface sediments. The analytical,
W. W. Youngblood; M. Blumer
Chlorinated and polycyclic aromatic hydrocarbons in riverine and estuarine sediments from Pearl River Delta, China
Spatial distribution of chlorinated hydrocarbons [chlorinated pesticides (CPs) and polychlorinated biphenyls (PCBs)] and polycyclic aromatic hydrocarbons (PAHs) was measured in riverine and estuarine sediment samples from Pearl River Delta, China, collected in 1997. Concentrations of CPs of the riverine sediment samples range from 12 to 158 ng\\/g, dry weight, while those of PCBs range from 11 to 486 ng\\/g. The
Bi-Xian Mai; Jia-Mo Fu; Guo-Ying Sheng; Yue-Hui Kang; Zheng Lin; Gan Zhang; Yu-Shuan Min; Eddy Y. Zeng
Atmospheric concentrations of saturated and aromatic hydrocarbons around a Greek oil refinery
Petroleum refineries are large industrial installations that are responsible for the emission of several pollutants into the atmosphere. Hydrocarbons are among the most important air pollutants that are emitted by petroleum refineries, since they are involved in almost every refinery process. The ambient air concentrations of many saturated and aromatic hydrocarbons were measured in several sites around an oil refinery,
P. D. Kalabokas; J. Hatzianestis; J. G. Bartzis; P. Papagiannakopoulos
Isolation, characterization of Rhodococcus sp. P14 capable of degrading high-molecular-weight polycyclic aromatic hydrocarbons and aliphatic hydrocarbons.
Rhodococcus sp. P14 was isolated from crude oil-contaminated sediments. This strain was capable of utilizing three to five rings polycyclic aromatic hydrocarbons (PAHs) including phenanthrene (Phe), pyrene (Pyr), and benzo[a]pyrene (BaP) as a sole carbon and energy source. After cultivated with 50mg/L of each PAH, strain P14 removed 43% Phe, 34% Pyr and 30% BaP in 30 d. Four different hydroxyphenanthrene products derived from Phe by strain P14 (1,2,3,4-hydroxyphenanthrene) were detected using SPME-GC-MS. Strain P14 also was capable of degrading mineral oil with n-alkanes of C17 to C21 carbon chain length. Compared with glucose-grown cells, PAHs-grown cells had decreased contents of shorter-chain length fatty acids (? C16:0), increased contents of C18:0, Me-C19:0 and disappeared odd-number carbon chain fatty acids. The contents of unsaturated C19:1, Me-C19:0 increased and C18:0 decreased in mineral oil-grown cells. At the same time, the strain P14 tended to float when cultivated in mineral oil-supplemented liquid medium. The degradation capability of P14 to alkane and PAHs and its floating characteristics will be very helpful for future's application in oil-spill bioremediation. PMID:21871639
Song, Xiaohui; Xu, Yan; Li, Gangmin; Zhang, Ying; Huang, Tongwang; Hu, Zhong
Vapor pressures and enthalpies of sublimation of polycyclic aromatic hydrocarbons and their derivatives
The vapor pressures of a series of polycyclic aromatic hydrocarbons (PAH) and heteroatom-containing PAH have been measured using the Knudsen effusion technique. Aromatic hydrocarbons examined included anthracene, phenanthrene, pyrene, 2,3-benzofluorene, naphthacene, perylene, pentacene, and coronene. Heteroatomic aromatic species examined included phenanthridine, perinaphthenone, 3-hydroxy-1-phenalen-1-one, benz[g]isoquinoline-5,10-dione, 1,2-benzodiphenylene sulfide, 1-hydroxypyrene, and 6,11-dihydroxy-5,12-naphthacenedione. The measurements were all made in the solid sublimation regime, and enthalpies of sublimation were calculated from the Clausius-Clapeyron equation.
Oja, V.; Suuberg, E.M. [Brown Univ., Providence, RI (United States). Div. of Engineering] [Brown Univ., Providence, RI (United States). Div. of Engineering
Aromatic hydrocarbon optrodes for groundwater monitoring applications. Final report, September 1988-February 1990
Research documented in this report produced a fiber-optic sensor utilizing a porous optical waveguide. This offered the advantage of improved sensitivity and specificity by impregnating fiber with a chemical indicator whose optical transmission properties change in the presence of aromatic species. The concept was adequately demonstrated the laboratory and a prototype optrode was developed which was sensitive for aromatic hydrocarbons to 50 ppb. The basic concept was proven. Fiber-optic sensor, Groundwater monitoring, Aromatic hydrocarbon optrodes, Porous glass xylene sensor, Chemical sensors, Evanescent fiber-optic sensor.
Tabacco, M.B.
Uptake, metabolism and discharge of polycyclic aromatic hydrocarbons by marine fish
The uptake, metabolism and discharge of two polycyclic aromatic hydrocarbons, 14C-naphthalene and 3H-3,4-benzopyrene, were studied in 3 species of marine fish (mudsucker or sand goby, Gillichthys mirabilis; sculpin, Oligocottus maculosus; sand dab, Citharichthys stigmaeus). The path of hydrocarbons through the fish included entrance through the gills, metabolism by the liver, transfer of hydrocarbons and their metabolites to the bile, and,
R. F. Lee; R. Sauerheber; G. H. Dobbs
Fluorescence Spectroscopy of Gas-phase Polycyclic Aromatic Hydrocarbons
The purpose of this investigation was to produce fluorescence spectra of polycyclic aromatic hydrocarbon (PAH) molecules in the gas-phase for comparison with blue luminescence (BL) emission observed in astrophysical sources te{ref2,ref3,ref4}. The BL occurs roughly from 350 to 450 nm, with a sharp peak near 380 nm. PAHs with three to four rings, e.g. anthracene and pyrene, were found to produce luminescence in the appropriate spectral region, based on existing studies. Relatively few studies of the gas-phase fluorescence of PAHs exist; those that do exist have dealt primarily with the same samples commonly available for purchase such as pyrene and anthracene. In an attempt to understand the chemistry of the nebular environment we also obtained several nitrogen substituted PAHs from our colleagues at NASA Ames. In order to simulate the astrophysical environment we also took spectra by heating the PAHs in a flame. The flame environment counteracts the formation of eximers and permits the spectroscopy of free-flying neutral molecules. Experiments with coal tar demonstrate that fluorescence spectroscopy reveals primarily the presence of the smallest molecules, which are most abundant and which possess the highest fluorescence efficiencies. One gas-phase PAH that seems to fit the BL spectrum most closely is phenanthridine. In view of the results from the spectroscopy of coal tar, a compound containing a mixture of PAHs ranging from small to very large PAH molecules, we can not preclude the presence of larger PAHs in interstellar sources exhibiting BL.
Thomas, J. D.; Witt, A. N.
STRONG POLYCYCLIC AROMATIC HYDROCARBON EMISSION FROM z {approx} 2 ULIRGs
Using the Infrared Spectrograph on board the Spitzer Space Telescope, we present low-resolution (64 < {lambda}/{delta}{lambda} < 124), mid-infrared (20-38 {mu}m) spectra of 23 high-redshift ULIRGs detected in the Booetes field of the NOAO Deep Wide-Field Survey. All of the sources were selected to have (1) f {sub {nu}}(24 {mu}m)>0.5 mJy; (2) R - [24]>14 Vega mag; and (3) a prominent rest frame 1.6 {mu}m stellar photospheric feature redshifted into Spitzer's 3-8 {mu}m IRAC bands. Of these, 20 show emission from polycyclic aromatic hydrocarbons (PAHs), usually interpreted as signatures of star formation. The PAH features indicate redshifts in the range 1.5 < z < 3.0, with a mean of (z) = 1.96 and a dispersion of 0.30. Based on local templates, these sources have extremely large infrared luminosities, comparable to that of submillimeter galaxies. Our results confirm previous indications that the rest-frame 1.6 {mu}m stellar bump can be efficiently used to select highly obscured star-forming galaxies at z {approx} 2, and that the fraction of starburst-dominated ULIRGs increases to faint 24 {mu}m flux densities. Using local templates, we find that the observed narrow redshift distribution is due to the fact that the 24 {mu}m detectability of PAH-rich sources peaks sharply at z = 1.9. We can analogously use observed spectral energy distributions to explain the broader redshift distribution of Spitzer-detected ULIRGs that are dominated by an active galactic nucleus (AGN). Finally, we conclude that z {approx} 2 sources with a detectable 1.6 {mu}m stellar opacity feature lack sufficient AGN emission to veil the 7.7 {mu}m PAH band.
Desai, Vandana; Soifer, B. T.; Melbourne, Jason [Division of Physics, Mathematics and Astronomy, California Institute of Technology, Pasadena, CA 91125 (United States); Dey, Arjun; Brand, Kate; Brodwin, Mark; Jannuzi, Buell T. [National Optical Astronomy Observatory, Tucson, AZ 85726-6732 (United States); Le Floc'h, Emeric [Institute for Astronomy, University of Hawaii, Honolulu, HI 96822 (United States); Armus, Lee; Teplitz, Harry [Spitzer Science Center, California Institute of Technology, Pasadena, CA 91125 (United States); Brown, Michael J. I. [School of Physics, Monash University, Clayton, Victoria 3800 (Australia); Houck, James R.; Weedman, Daniel W. [Astronomy Department, Cornell University, Ithaca, NY 14853 (United States); Ashby, Matthew L. N.; Huang Jiasheng; Smith, Howard A.; Willner, Steve P. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Gonzalez, Anthony [Department of Astronomy, University of Florida, Gainesville, FL 32611-2055 (United States)
Engineered antibodies for monitoring of polynuclear aromatic hydrocarbons
'The long-term goal of this project is to develop antibodies and antibody-based methods for detection and recovery of polynuclear aromatic hydrocarbons (PAHs) and PAH adducts that are potential biomarkers in environmental and biological samples. The inherent cross-reactivity will be exploited by pattern recognition methods. Dr. Karu''s laboratory uses new haptens representing key PAHs to derive recombinant Fab (rFab) and single-chain Fv (scFv) antibodies from hybridoma lines and combinatorial phage display libraries. Computational models of the haptens and combining sites made by Dr. Roberts''s group are used to guide antibody engineering by mutagenesis. Dr. Li''s laboratory develops enzyme immunoassays (EIAs), sensors, and immunoaffinity methods that make use of the novel haptens and antibodies for practical analytical applications in support of DOE''s mission. This report summarizes work completed in one and one-half years of a 3-year project, with close collaboration between the three research groups. Dr. Alexander Karu''s laboratory: the authors proceeded with the two strategies described in the original proposal. Site-directed mutagenesis was used to correct differences in the rFab N-terminal amino acids that were introduced by the degenerate PCR primers used for gene amplification. The binding constants of the rFabs with the corrected sequences will be compared with those of the parent MAbs, and should be very similar. The 4D5 and 10C10 heavy and light chain sequences are being moved to the pCOMB3H phagemid vector to facilitate selection of new engineered mutants.'
Karu, A.E. [Univ. of California, Berkeley, CA (US); Roberts, V.A. [Scripps Research Inst., La Jolla, CA (US); Li, Q.X. [Univ. of Hawaii, Honolulu, HI (US)
Polycyclic Aromatic Hydrocarbons in Residential Dust: Sources of Variability
Background: There is interest in using residential dust to estimate human exposure to environmental contaminants. Objectives: We aimed to characterize the sources of variability for polycyclic aromatic hydrocarbons (PAHs) in residential dust and provide guidance for investigators who plan to use residential dust to assess exposure to PAHs. Methods: We collected repeat dust samples from 293 households in the Northern California Childhood Leukemia Study during two sampling rounds (from 2001 through 2007 and during 2010) using household vacuum cleaners, and measured 12 PAHs using gas chromatography�mass spectrometry. We used a random- and a mixed-effects model for each PAH to apportion observed variance into four components and to identify sources of variability. Results: Median concentrations for individual PAHs ranged from 10 to 190 ng/g of dust. For each PAH, total variance was apportioned into regional variability (1�9%), intraregional between-household variability (24�48%), within-household variability over time (41�57%), and within-sample analytical variability (2�33%). Regional differences in PAH dust levels were associated with estimated ambient air concentrations of PAH. Intraregional differences between households were associated with the residential construction date and the smoking habits of residents. For some PAHs, a decreasing time trend explained a modest fraction of the within-household variability; however, most of the within-household variability was unaccounted for by our mixed-effects models. Within-household differences between sampling rounds were largest when the interval between dust sample collections was at least 6 years in duration. Conclusions: Our findings indicate that it may be feasible to use residential dust for retrospective assessment of PAH exposures in studies of health effects.
Metayer, Catherine; Petreas, Myrto; Does, Monique; Buffler, Patricia A.; Rappaport, Stephen M.
Neurotoxicity of polycyclic aromatic hydrocarbons and simple chemical mixtures.
Polycyclic aromatic hydrocarbons (PAHs) are a major class of environmental pollutants. These chemicals are the products of incomplete combustion and are present in every compartment of the environment. While the carcinogenic potential of these chemicals has been investigated in numerous studies, very little is known about the potential of these chemicals to produce damage to neural cells. The objective of this study was to investigate the toxicity of several model PAHs and binary mixtures of these chemicals in neural cells. Chemicals tested included benzo[a]pyrene (BaP), chrysene, anthracene, and pentachlorophenol (PCP). Four end points, including amino acid incorporation, total protein, total cell count, and viable cells (trypan dye exclusion), were measured in SY5Y human neuroblastoma cells and C6 rat glioma cells. The most sensitive measure of PAH toxicity in neural cells was amino acid incorporation into proteins. BaP was the most toxic of all PAHs tested, and anthracene failed to produce a toxic response at any concentration tested. Without metabolic activation, BaP induced a significant cytotoxic response at a concentration of 30 microM. With activation (0.25% S9), BaP induced a response at concentration levels of 3 microM and 30 microM. Minimal toxicity was observed with chrysene at the highest concentration tested, and anthracene failed to produce a toxic response at any concentration tested. With mixtures of PAHs the majority of samples induced additive responses. The minimum concentration required to induce a significant response was reduced for the mixture of chrysene and BaP when compared to BaP alone. In addition, PCP appeared to increase the inhibition of acetylcholinesterase by mipafox. The data suggest that PAHs are capable of producing damage to neural cells only at concentrations that are near their solubility limits. PMID:12825237
Tang, Y; Donnelly, K C; Tiffany-Castiglioni, E; Mumtaz, M M
Formation history of polycyclic aromatic hydrocarbons in galaxies
Polycyclic aromatic hydrocarbons (PAHs) are some of the major dust components in the interstellar medium (ISM). We present our evolution models for the abundance of PAHs in the ISM on a galaxy-evolution time-scale. We consider shattering of carbonaceous dust grains in interstellar turbulence as the formation mechanism of PAHs while the PAH abundance can be reduced by coagulation on to dust grains, destruction by supernova shocks, and incorporation into stars. We implement these processes in a one-zone chemical evolution model to obtain the evolution of the PAH abundance in a galaxy. We find that PAH formation becomes accelerated above certain metallicity where shattering becomes efficient. For PAH destruction, while supernova shock is the primary mechanism in the metal-poor environment, coagulation is dominant in the metal-rich environment. We compare the evolution of the PAH abundances in our models with observed abundances in galaxies with a wide metallicity range. Our models reproduce both the paucity of PAH detection in low-metallicity galaxies and the metallicity dependence of the PAH abundance in high-metallicity galaxies. The strong metallicity dependence of PAH abundance appears as a result of the strong metallicity dependence of the dust mass increase by the accretion of metals on to dust grains, which are eventually shattered into PAHs. We conclude that the observational trend of the PAH abundance can be a natural consequence of shattering of carbonaceous grains being the source of PAHs. To establish our scenario of PAH formation, observational evidence of PAH formation by shattering would be crucial.
Seok, Ji Yeon; Hirashita, Hiroyuki; Asano, Ryosuke S.
Degradation and transformation of polycyclic aromatic hydrocarbons in soil systems
Biodegradation of fourteen polycyclic aromatic hydrocarbon (PAH) compounds in two soils was studied by measuring parent compound disappearance and volatilization emission losses of these compounds from soil samples. Degradation kinetic rates using a first-order model were calculated as half-lives. Mean degradation half-lives corrected for volatilization varied from two days for two-ring PHAs to 59 days for three-ring PHAs to more than 300 days for PHAs with more than three rings. Volatilization corrected degradation of two-and three-ring PAH compounds in soil samples poisoned by 2% HgCl/sub 2/ was small but significant (p < 0.05). No significant degradation from poisoned soil was found for the PAH compound with more than three rings. RITZE (the Enhanced Regulatory and Investigative Treatment Zone) model was used to evaluate the treatment and leaching potential of PAH compounds in soil systems. All 12 PAH compounds evaluated were significantly assimilated in the soil system and no significant leaching of these compounds to ground water was predicted. Transformation of 7,12-dimethylbenz(a)anthracene was studied in a nonacclimated sandy loam soil at low and neutral pH soil conditions. Soil extracts containing transformation products were separated into three fractions based on HPLC retention time (polarity). Highly polar transformation products of 7,12-dimethylbenz(a)anthracene demonstrated a negative mutagenic response with the Ames mutagenicity assay, strain TA-100, for both low and neutral pH soils. Moderate and low polar fractions, however, induced mutagenicity for both soil samples with mutagenic ratios similar to those of the parent compound. Mutagenic responses for the metabolites formed from low and neutral pH soil were not different. Similar microbial distributions in the two pH soils contributed to this result.
Park, K.
Near Infrared Spectra of Large Polycyclic Aromatic Hydrocarbons.
The widespread, mid-IR interstellar emission features at 3.3, 6.2, 7.7, 8.6, and 11.2 microns are generally attributed to vibrationally excited polycyclic aromatic hydrocarbons (PAHs). Since these features typcially originate from radiation-rich regions, it has been generally thought that UV photons must dominate the interstellar excitation process since PAHs have very strong UV absorption bands. However, observations have shown that lower energy photons can also pump the emission (Aitken and Roche, Uchida and Sellgren), raising questions about the PAH model. Although it has long been known that larger PAHs should absorb at longer wavelengths (e.g. Schutte et. al., Salama et al., Li and Draine) data was not available for the isolated, neutral and ionized PAHs of sizes comparable to those thought responsible for the interstellar emission features. Here the matrix-isolated near-IR (NIR) spectra (from 0.7 to 2.5 microns) are presented for the anions and cations of PAHs ranging in size from C34H16 to C50H22. These molecules are characterized by strong absorption bands in this region, bands that can account for the emission of the interstellar features from UV poor regions. These NIR PAH transitions could also contribute to the extinction curve associated with the diffuse interstellar medium. For example, band overlap, as expected from a mixture of PAHs, can contribute to the continuum. Overlapping broad bands could lead to slight undulations in the continuum reminiscent of the Very Broad Structure (VBS, e.g. Hayes et al.). Furthermore, as previously pointed out, individual PAH bands may contribute to the diffuse interstellar band (DIB) spectrum (e.g. Romanini)
Mattioda, A. L.; Hudgins, D. M.; Bauschlicher, C. W.; Allamandola, L. J.
Polycyclic aromatic hydrocarbons in mountain soils of the subtropical Atlantic.
Surface soil samples from various altitudes on Tenerife Island, ranging from sea level up to 3400 m above mean sea level, were analyzed to study the distribution of 26 polycyclic aromatic hydrocarbons (PAHs) in a remote subtropical area. The stable atmospheric conditions in this island define three vertically stratified layers: marine boundary, trade-wind inversion, and free troposphere. Total PAH concentrations, 1.9 to 6000 microg/kg dry wt., were high when compared with those in tropical areas and in a similar range to those in temperate areas. In the marine boundary layer, fluoranthene (Fla), pyrene (Pyr), benz [a]anthracene (BaA), and chrysene (C + T) were largely dominant. The predominance of Fla over Pyr may reflect photo-oxidative processes during atmospheric transport, although coal combustion inputs cannot be excluded. The PAHs found in higher concentration in the soils from the inversion layer were benzo[b + j]fluoranthene (BbjF) + benzo[k]fluoranthene (BkF) > benzo[e]pyrene (BeP) approximately indeno[1,2, 3-cd]pyrene (Ind) > benzo[a]pyrene (BaP) approximately benzo[ghi]perylene (Bghi) > coronene (Cor) approximately dibenz[a,h]anthracene (Dib), reflecting that high temperatures and insolation prevent the accumulation of PAHs more volatile than BbjF in significant amounts. These climatic conditions involve a process of standardization that prevents the identification of specific PAH sources such as traffic, forest fires, or industrial inputs. Only soils with high total organic carbon (TOC) (e.g., 10-30%) preserve the more volatile compounds such as phenanthrene (Phe), methylphenanthrenes (MPhe), dimethylphenanthrenes (DMPhe), and retene (Ret). However, no relation between PAHs and soil TOC and black carbon (BC) was found. The specific PAH distributions of the free tropospheric region suggest a direct input from pyrolytic processes related to the volcanic emission of gases in Teide. PMID:12809298
Ribes, A; Grimalt, J O; Torres Garc�a, C J; Cuevas, E
Sorption characteristics of polycyclic aromatic hydrocarbons in aluminum smelter residues.
High temperature carbon oxidation in primary aluminum smelters results in the release of polycyclic aromatic hydrocarbons (PAH) into the environment. The main source of PAH are the anodes, which are composed of petroleum coke (black carbon, BC) and coal tar pitch. To elucidate the dominant carbonaceous phase controlling the environmental fate of PAH in aluminum smelter residues (coke BC and/or coal tar), the sorptive behavior of PAHs has been determined, using passive samplers and infinitesink desorption methods. Samples directly from the wet scrubber were studied as well as ones from an adjacent 20-year old storage lagoon and roof dust from the smelter. Carbon-normalized distribution coefficients of native PAHs were 2 orders of magnitude higher than expected based on amorphous organic carbon (AOC)/water partitioning, which is in the same order of magnitude as reported literature values for soots and charcoals. Sorption isotherms of laboratory-spiked deuterated phenanthrene showed strong (-100 times stronger than AOC) but nonetheless linear sorption in both fresh and aged aluminum smelter residues. The absence of nonlinear behavior typical for adsorption to BC indicates that PAH sorption in aluminum smelter residues is dominated by absorption into the semi-solid coal tar pitch matrix. Desorption experiments using Tenax showed that fresh smelter residues had a relatively large rapidly desorbing fraction of PAH (35-50%), whereas this fraction was strongly reduced (11-16%) in the lagoon and roof dust material. Weathering of the coal tar residue and/or redistribution of PAH between coal tar and BC phases could explain the reduced availability in aged samples. PMID:17438813
Breedveld, Gijs D; Pelletier, Emilien; St Louis, Richard; Cornelissen, Gerard
Temperature-Dependent Chemical-Specific Emission Rates of Aromatics and Polyaromatic Hydrocarbons (PAHs) in Bitumen Fume
Chemical-specific emission rates for simple aromatic and polycyclic aromatic hydrocarbon compounds (PAHs) from bitumens during hot mix asphalt (HMA) production and placement activities were evaluated using a headspace gas chromatography method. Temperature-dependent headspace concentrations of the EPA listed aromatic and polycyclic aromatic compounds were measured in the laboratory using headspace gas chromatographs equipped with a variety of detectors. The methodology
Clifford R. Lange; Mary Stroup-Gardiner
Determination of polycyclic aromatic hydrocarbons in fumes from fried chicken legs.
The amount and variety of polycyclic aromatic hydrocarbons (PAHs) in fumes during frying of chicken legs in edible oils were determined using a modified smoke collection device and a GC-MS technique. Chicken legs were fried in soybean oil, canola oil, or sunflower oil at 163 degrees C for 1-4 h. Results showed that most smoke (99%) was collected in the condensation apparatus, whereas the rest (1%) was adsorbed onto adsorption wool. A large proportion of PAHs in the smoke were detected in adsorption wool, whereas a small portion was found in the condensation apparatus. Canola oil generated the largest content (500.9 g for a frying time of 4 h) of smoke, followed by soybean oil, and sunflower oil. A similar trend was observed for PAH formation in fumes, with the exception that soybean oil produced a higher level than canola oil. PMID:12822962
Chen, Y C; Chen, B H
Nitrated polycyclic aromatic hydrocarbons and azaarenes induce cytochrome P4501A in a fish hepatoma cell line
Nitrated polycyclic aromatic hydrocarbons (NPAH) and N-heterocyclic aromatic hydrocarbons (azaarenes) are as ubiquitous in the environment as their parent polycyclic aromatic hydrocarbon (PAH) compounds, although concentrations are commonly lower. Some of the NPAH and azaarenes are carcinogenic in mammals. Little is known, however, about their carcinogenicity and cytochrome P4501A (CYP1A) induction potency in fish. In this study, CYP1A induction potencies,
K. Fent; D. K. J. Jung
Polycyclic aromatic hydrocarbons in harp seals (Phoca groenlandica) from the Northwest Atlantic.
There is virtually no information available on concentrations of polycyclic aromatic hydrocarbons (PAH) in seals from any of the world's oceans. The largest harp seal population in the world is found in Canadian waters of the Northwest Atlantic. Samples of muscle tissue obtained from twenty eight harp seals ranging in age from foetuses to animals 22 years old were analyzed for total PAH and lipid content. Concentrations were determined in terms of crude oil and chrysene equivalents in line with recommendations of the International Oceanographic Commission. Overall, relatively low concentrations were found, the highest values being less than 1 ppm (microgram/g) in terms of chrysene equivalents and 4 ppm (microgram/g) in terms of petroleum hydrocarbon equivalents. The lowest concentrations were observed in fetal tissue. There was no evidence of bioaccumulation with age, the concentrations in juvenile seals (1-5 years) being higher than concentrations in older animals (6-20 years). There was also no correlation between PAH concentration and fat content. There is a possibility that the animals having elevated levels of PAH are from the Gulf of St. Lawrence herd, indicating the importance of obtaining more information on PAH levels in marine mammals and other organisms from this and similar regionally contaminated seas. PMID:1898111
Hellou, J; Upshall, C; Ni, I H; Payne, J F; Huang, Y S
Distribution of aliphatic hydrocarbons, polycyclic aromatic hydrocarbons and organochlorinated pollutants in deep-sea sediments of the Southern Cretan margin, Eastern Mediterranean Sea: a baseline assessment.
Deep sediments from the southern Cretan margin were analyzed to establish baseline levels for various types of organic pollutants before the anticipated intensification of anthropogenic activities. The total concentration of aliphatic hydrocarbons (?AH:326-3758ngg(-1), dry weight) was similar to those reported for deep sediments of the western Mediterranean Sea, while considerably lower levels were measured for polycyclic aromatic hydrocarbons (?PAH:9-60ngg(-1)). Source-diagnostic ratios suggested that the aliphatic hydrocarbons in sediments were mainly of terrestrial biogenic origin, while polycyclic aromatic hydrocarbons stemmed from the deposition of long-range transported combustion aerosols. Among the organochlorinated compounds analyzed, ?-hexachlorocyclohexane (?-HCH:222-7052pgg(-1)), 1,1,1-trichloro-2,2-bis(4-chlorophenyl)ethane (p,p'-DDT:37-2236pgg(-1)) and polychlorinated biphenyls (?PCB:38-1182pgg(-1)) showed the highest abundance in sediments. The presence of HCHs and PCBs was attributed to historical inputs that have undergone extensive weathering, whereas an ongoing fresh input was suggested for p,p'-DDT. Multiple linear regression analysis revealed that the levels of the various pollutants in sediments were controlled by different factors, but with organic carbon content playing a prominent role in most cases. PMID:24447909
Mandalakis, Manolis; Polymenakou, Paraskevi N; Tselepides, Anastasios; Lampadariou, Nikolaos
Neurobehavioral performance in volunteers after inhalation of white spirits with high and low aromatic content.
The content of aromatic hydrocarbons in solvent mixtures, such as white spirits (WS), has been assumed a major contributor to the neurotoxic effects of these compounds. Hence, dearomatized WS have been introduced to the market rapidly in the last decade. Studies investigating other aromatic hydrocarbons (toluene) and animal models have supported the aforementioned assumption, but the current study is the first one to compare acute neurobehavioral effects of exposure to aromatic and dearomatized WS (aWS, daWS) content in human volunteers at current occupational exposure limit values. In a pseudo-randomized crossover design, six female and six male healthy volunteers were exposed to aWS and daWS at two concentrations (100 and 300�mg/m(3)) and to clean air for 4�h at rest. During each of the five exposure conditions, volunteers performed five neurobehavioral tasks that were selected following a multidisciplinary approach that accounted for findings from the cognitive neurosciences and mechanisms of solvent toxicity. Two of the tasks indicated performance changes during aromatic WS exposure, the working memory (WM) and the response shifting task, but both effects are difficult to interpret due to low mean accuracy in the WM task and due to a lack of dose-response relationship in the response shifting task. Healthy human volunteers showed weak and inconsistent neurobehavioral impairment after 4-h exposures to 100 and 300�mg/m(3) aromatic or dearomatized WS. Our multidisciplinary approach of selecting neurobehavioral test methods may guide the test selection strategies in future studies. PMID:24714767
Juran, S A; Johanson, G; Ernstg�rd, L; Iregren, A; van Thriel, C
Petroleum refineries are large industrial installations that are responsible for the emission of several pollutants into the atmosphere. Hydrocarbons are among the most important air pollutants that are emitted by petroleum refineries, since they are involved in almost every refinery process. The ambient air concentrations of many saturated and aromatic hydrocarbons were measured in several sites around an oil refinery, near the city of Corinth in Greece, during 1997. At the same time several meteorological parameters were also recorded. The seasonal, diurnal and spatial variations of the ambient air concentrations of these hydrocarbons were investigated and analyzed. An estimation of the contribution of the refinery to the measured atmospheric levels of hydrocarbons was also performed. The ambient air mixing ratios of the saturated and aromatic hydrocarbons in a large area outside the refinery were generally low, in ppbv range, much lower than the ambient air quality standards or the ambient air concentrations in the two largest urban centers in Greece, Athens and Thessaloniki.
Kalabokas, P. D.; Hatzianestis, J.; Bartzis, J. G.; Papagiannakopoulos, P.
Draft Genome Sequence of Marinomonas sp. Strain D104, a Polycyclic Aromatic Hydrocarbon-Degrading Bacterium from the Deep-Sea Sediment of the Arctic Ocean.
Marinomonas sp. strain D104 was isolated from a polycyclic aromatic hydrocarbon-degrading consortium enriched from deep-sea sediment from the Arctic Ocean. The draft genome sequence of D104 (approximately 3.83�Mbp) contains 62 contigs and 3,576 protein-encoding genes, with a G+C content of 44.8%. PMID:24459272
Dong, Chunming; Bai, Xiuhua; Lai, Qiliang; Xie, Yanrong; Chen, Xin; Shao, Zongze
Draft Genome Sequence of Marinomonas sp. Strain D104, a Polycyclic Aromatic Hydrocarbon-Degrading Bacterium from the Deep-Sea Sediment of the Arctic Ocean
Marinomonas sp. strain D104 was isolated from a polycyclic aromatic hydrocarbon-degrading consortium enriched from deep-sea sediment from the Arctic Ocean. The draft genome sequence of D104 (approximately 3.83�Mbp) contains 62 contigs and 3,576 protein-encoding genes, with a G+C content of 44.8%.
Dong, Chunming; Bai, Xiuhua; Lai, Qiliang; Xie, Yanrong; Chen, Xin
Potentiometric online detection of aromatic hydrocarbons in aqueous phase using carbon nanotube-based sensors.
Surfaces made of entangled networks of single-walled carbon nanotubes (SWCNTs) display a strong adsorption affinity for aromatic hydrocarbons. Adsorption of these compounds onto the walls of SWCNTs changes the electrical characteristics of the SWCNT-solution interface. Using these features, we have developed a potentiometric sensor to detect neutral aromatic species. Specifically, we can detect online aromatic hydrocarbons in industrial coolant water. Our chromatographic results confirm the adsorption of toluene onto the walls of carbon nanotubes, and our impedance spectroscopy data show the change in the double layer capacitance of the carbon nanotube-solution interface upon addition of toluene, thus confirming the proposed sensing mechanism. The sensor showed a toluene concentration dependent EMF response that follows the shape of an adsorption isotherm and displayed an immediate response to the presence of toluene with a detection limit of 2.1 ppm. The sensor does not respond to other nonaromatic hydrocarbons that may coexist with aromatic hydrocarbons in water. It shows a qualitative sensitivity and selectivity of 100% and 83%, respectively, which confirms its ability to detect aromatic hydrocarbons in aqueous solutions. The sensor showed an excellent ability to immediately detect the presence of toluene in actual coolant water. Its operational characteristics, including its fast response, low cost, portability, and easy use in online industrial applications, improve those of current chromatographic or spectroscopic techniques. PMID:20809625
Washe, Alemayehu P; Macho, Santiago; Crespo, Gast�n A; Rius, F Xavier
Chemical degradation of substituted aromatic hydrocarbon compounds in soil/sediment systems: Progress report
This project addresses the fate of organic contaminants in soil and sediment systems. The project is directed towards understanding some of the chemical pathways by which energy-related organic compounds may be oxidized in soils and sediments as a result of redox reaction with oxide minerals. Chemical degradation pathways may be an important mechanism for remediation of contaminated soils/sediments in the absence of microbial degradation. This project complements another research investigation which is investigating microbial degradation of unsubstituted polycyclic aromatic hydrocarbon compounds in different redox environments. The project is studying the chemical reactions of nitrogen-containing aromatic hydrocarbons with iron and manganese oxides. These oxides are likely to be the most prevalent oxidizing agents in soils and sediments in the absence of molecular oxygen and microbial activity. Previous screening studies in this laboratory have shown that unsubstituted PAH (e.g, naphthalene) are non-reactive with respect to redox reactions with manganese oxide, while hydroxy- and nitrogen-substituted aromatic hydrocarbon compounds undergo redox reaction with manganese oxide. The laboratory work for the near future will focus on understanding the reaction mechanisms of nitrogen-substituted aromatic hydrocarbon compounds with manganese oxide. The results of the study are expected to be useful in helping to develop basic knowledge on the fate and transport of aromatic hydrocarbon contaminants in subsurface environments.
Shanmuganantha, S.; Luthy, R.G.
Applications of electrochemically-modulated liquid chromatography (EMLC): Separations of aromatic amino acids and polycyclic aromatic hydrocarbons
The research in this thesis explores the separation capabilities of a new technique termed electrochemically-modulated liquid chromatography (EMLC). The thesis begins with a general introduction section which provides a literature review of this technique as well as a brief background discussion of the two research projects in each of the next two chapters. The two papers which follow investigate the application of EMLC to the separation of a mixture of aromatic amino acids and of a mixture of polycyclic aromatic hydrocarbons (PAHs). The last section presents general conclusions and summarizes the thesis. References are compiled in the reference section of each chapter. The two papers have been removed for separate processing.
Deng, L.
Biodegradation aspects of polycyclic aromatic hydrocarbons (PAHs): a review.
PAHs are aromatic hydrocarbons with two or more fused benzene rings with natural as well as anthropogenic sources. They are widely distributed environmental contaminants that have detrimental biological effects, toxicity, mutagenecity and carcinogenicity. Due to their ubiquitous occurrence, recalcitrance, bioaccumulation potential and carcinogenic activity, the PAHs have gathered significant environmental concern. Although PAH may undergo adsorption, volatilization, photolysis, and chemical degradation, microbial degradation is the major degradation process. PAH degradation depends on the environmental conditions, number and type of the microorganisms, nature and chemical structure of the chemical compound being degraded. They are biodegraded/biotransformed into less complex metabolites, and through mineralization into inorganic minerals, H(2)O, CO(2) (aerobic) or CH(4) (anaerobic) and rate of biodegradation depends on pH, temperature, oxygen, microbial population, degree of acclimation, accessibility of nutrients, chemical structure of the compound, cellular transport properties, and chemical partitioning in growth medium. A number of bacterial species are known to degrade PAHs and most of them are isolated from contaminated soil or sediments. Pseudomonas aeruginosa, Pseudomons fluoresens, Mycobacterium spp., Haemophilus spp., Rhodococcus spp., Paenibacillus spp. are some of the commonly studied PAH-degrading bacteria. Lignolytic fungi too have the property of PAH degradation. Phanerochaete chrysosporium, Bjerkandera adusta, and Pleurotus ostreatus are the common PAH-degrading fungi. Enzymes involved in the degradation of PAHs are oxygenase, dehydrogenase and lignolytic enzymes. Fungal lignolytic enzymes are lignin peroxidase, laccase, and manganese peroxidase. They are extracellular and catalyze radical formation by oxidation to destabilize bonds in a molecule. The biodegradation of PAHs has been observed under both aerobic and anaerobic conditions and the rate can be enhanced by physical/chemical pretreatment of contaminated soil. Addition of biosurfactant-producing bacteria and light oils can increase the bioavailability of PAHs and metabolic potential of the bacterial community. The supplementation of contaminated soils with compost materials can also enhance biodegradation without long-term accumulation of extractable polar and more available intermediates. Wetlands, too, have found an application in PAH removal from wastewater. The intensive biological activities in such an ecosystem lead to a high rate of autotrophic and heterotrophic processes. Aquatic weeds Typha spp. and Scirpus lacustris have been used in horizontal-vertical macrophyte based wetlands to treat PAHs. An integrated approach of physical, chemical, and biological degradation may be adopted to get synergistically enhanced removal rates and to treat/remediate the contaminated sites in an ecologically favorable process. PMID:19442441
Haritash, A K; Kaushik, C P
The Origins of Polycyclic Aromatic Hydrocarbons: Are They Everywhere?
During the past 15 years considerable progress in observational techniques has been achieved in the middle-infrared region (5000-500 per centimeter, 2-20 micron), the region where most diagnostic molecular vibrations occur. Spectra of many different astronomical infrared sources, some deeply embedded in dark molecular clouds and others at their edges, are now available. These spectra provide a powerful probe, not only for the identification of interstellar molecules in both the gas and solid phases, but also of the physical and chemical conditions which prevail in these two very different domains. The two lectures will focus on the evidence that polycyclic aromatic hydrocarbons (PAHs) are an important, ubiquitous and abundant interstellar species. PAHs are. extremely stable species which can range in size from a few angstroms across to several hundred angstroms (PAHs are also the building blocks of amorphous carbon particles). This identification rests on the suggestive agreement between the laboratory spectra of PAHs with a set of IR emission bands which emanate from many different sources where ultraviolet starlight impinges on a "dusty" region. The picture is that individual PAHs are first pumped into highly vibrationally excited states and relax by fluorescence at their fundamental vibrational frequencies. That PAHs are a ubiquitous interstellar component has serious ramifications in other spectral regions as well, including the strong extinction in the ultraviolet, and the classic visible diffuse interstellar bands discovered more than 50 years ago (but unexplained to this day) The first part of the course will focus on the interpretation of astronomical spectra. The second lecture will start by showing how recent laboratory data on PAHs taken under realistic interstellar conditions has con borated the PAH hypothesis and led to great insight into the conditions in the PAH containing regions. This lecture will end by reviewing the ever-increasing evidence for interstellar PAHs in meteorites and interplanetary dust particles. This in conjunction with the recent suggestion that PAHs are abundant in Jupiter's atmosphere will make the point that "PAHs are Everywhere".
Allamandola, L. J.; Morrison, David (Technical Monitor)
Exposure of firefighters to particulates and polycyclic aromatic hydrocarbons.
Firefighting continues to be among the most hazardous yet least studied occupations in terms of exposures and their relationship to occupational disease. Exposures are complex, involving mixtures of particles and chemicals such as polycyclic aromatic hydrocarbons (PAHs). Adverse health effects associated with these agents include elevated incidences of coronary heart disease and several cancers. PAHs have been detected at fire scenes, and in the firehouse rest area and kitchen, routinely adjoining the truck bay, and where firefighters spend a major part of each shift. An academic-community partnership was developed with the Cincinnati Fire Department with the goal of understanding active firefighters' airborne and dermal PAH exposure. PAHs were measured in air and particulates, and number and mass concentrations, respectively, of submicron (0.02-1�?m) and PM2.5 (2.5�?m diameter and less) particles during overhaul events in two firehouses and a University of Cincinnati administrative facility as a comparison location. During overhaul firefighters evaluate partially combusted materials for re-ignition after fire extinguishment and commonly remove Self-Contained Breathing Apparatus (SCBA). Face and neck wipes were also collected at a domestic fire scene. Overhaul air samples had higher mean concentrations of PM2.5 and submicron particles than those collected in the firehouse, principally in the truck bay and kitchen. Among the 17 PAHs analyzed, only naphthalene and acenaphthylene were generally detectable. Naphthalene was present in 7 out of 8 overhaul activities, in 2 out of 3 firehouse (kitchen and truck bay) samples, and in none collected from the control site. In firefighter face and neck wipes a greater number of PAHs were found, several of which have carcinogenic activity, such as benzofluoranthene, an agent also found in overhaul air samples. Although the concentration for naphthalene, and all other individual PAHs, was very low, the potential simultaneous exposure to multiple chemicals even in small quantities in combination with high ultrafine particle exposure deserves further study. It is recommended that personal respiratory and skin protection be worn throughout the overhaul process. PMID:24512044
Baxter, C Stuart; Hoffman, Joseph D; Knipp, Michael J; Reponen, Tiina; Haynes, Erin N
Polycyclic aromatic hydrocarbons in US and Swedish smokeless tobacco products
Background Debate about the health implications of using smokeless tobacco products (STPs) has prompted considerable interest in characterising their levels of toxic and carcinogenic components. In the present study seventy smokeless tobacco products from the US and Sweden, categorized as chewing tobacco, dry and moist snuff, hard and soft pellets, plug, and loose and portion snus, were analysed for twenty one polycyclic aromatic hydrocarbons (PAHs). The tested brands represented 80-90% of the 2008 market share for the major STP categories in these two countries. Results There were significant differences in the total and individual PAH concentrations in the different styles of product. Substantially higher levels of total PAHs (10�60 fold) were found in moist and dry snuff and soft pellets than in the other smokeless tobacco styles. The individual PAH concentrations followed the same patterns as total PAHs except for naphthalene, for which the highest concentrations were found in snus and moist snuff. Good correlations were obtained between benzo[a]pyrene (B[a]P) and all the other PAHs except naphthalene, 1-methylnaphthalene and 2-methylnaphthalene, providing evidence for the first time that it can be used as a good marker for PAHs in STPs. Results were generally in good agreement with two previous studies of PAHs in STPs, except for naphthalene for which significantly lower concentrations were found than previously reported. Analysis of the ratios of different PAHs confirmed that the use of fire-cured tobaccos in the snuffs and soft pellet were the major source of PAHs in these product styles, and provided, for the first time, some indications as to the source of PAHs in the other STP styles, including petrogenic and other combustion sources. Conclusions This study confirms the presence of PAHs in STPs, and identifies substantial differences between the levels in different STP categories. Since previous studies of naphthalene concentrations in STPs differed so markedly from those found in this study, it is recommended that further work on PAH determination is undertaken to investigate the source of this discrepancy.
Polycyclic aromatic hydrocarbons in the South American environment.
Pollution of the environment with polycyclic aromatic hydrocarbons (PAHs) should be a global concern, especially in urbanized areas. In South American countries, where notable increase in urban populations has been observed in the past few years, reliable information about the pollution status of these urban environments is not always easily accessible, and therefore an effort to collect updated information is required. This review attempts to contribute by analyzing the existing information regarding environmental levels of PAHs in some South American countries. A regional trend for environmental PAH information is an uneven contribution, because some countries, such as Bolivia, Peru, Paraguay, and Ecuador, have reported no information at all in the scientific literature, reflecting to a certain extent the different patterns of economic, technical, and scientific development. PAH air monitoring is one of the areas that has received the most attention during the last few years, mainly in Brazil, Chile, and Argentina, where data represent a few geographical areas within the region. PAH levels in air from some urban areas in Argentina, Brazil, and Chile, considered moderate to high (100-1000ng/m3), are probably among the highest values reported in the open literature. Urbanization, vehicle pollution, and wood fires are the principal contributors to the high reported levels. In more temperate areas, a clear distinction is observed between summer and winter levels. PAH monitoring in soils is very limited within the region, with few data available, and most information indicates widespread pollution. In Brazil, values for many representative ecosystems were found. In Chile, data from forestry and agricultural areas indicate in general low concentrations, in spite of a relatively high detection frequency. Pollution levels in soils are highly dependent on their closeness to PAH sources and certain cultural practices (agricultural burnings, forest fires, etc.). Water PAH levels are rarely reported in the scientific literature for South American countries. Few data were available, even though many regulatory agencies perform routine analysis of hydrocarbons in waters. No information was found specifically related to PAH compounds, which could indicate generally low PAH levels in waters. Regional PAH information for sediments also indicates higher levels. Overall, as observed for water, sediment data indicate a complex situation in densely populated areas affected by urban-industrial inputs where high PAH levels are found. In contrast, in remote areas a typical profile of diagenetic PAHs dominates. Concentrations are greatly variable and are principally related to several highly contaminated sites in Argentina and Brazil (hot spots) with levels four to five orders of magnitude higher. Even though PAHs have carcinogenic properties, little attention has been paid to the analysis of aquatic organisms except in the case of bivalves. As observed for other environmental receptors, the regional data distribution is uneven and is heavily centered in coastal environments and in a few countries (Argentina, Brazil, Chile, and Peru). The most comprehensive PAH monitoring program in the South American coastal environment is the Mussel Watch. Baseline PAH concentrations range from 200 to 700 microg kg(-1) lipids in unpolluted sites; from 1,000 to 3,000 microg kg(-1) in moderately contaminated sites; and from 4,000 to 13,000 microg/kg lipids in the most affected bivalves that come from areas of R�o de la Plata (Argentine side), Recife (Brazil), and Punta Arenas (Chile). Critical data gaps exist with respect to PAH analysis in biota, including humans, in foodstuffs, and subsequent effects. Considering the high levels reported in the air compartment, risk assessment procedures in highly populated areas need to be performed. Additionally, few countries within the region have information on PAH levels. In these countries, this type of analysis needs to be performed, and the laboratory capacity needs to be built to assure the accomplishment of these
Barra, Ricardo; Castillo, Caroline; Torres, Joao Paulo Machado
Headspace solid-phase microextraction as a tool to estimate the contamination of smoked cheeses by polycyclic aromatic hydrocarbons.
Headspace solid-phase microextraction (HS-SPME) was used to study polycyclic aromatic hydrocarbons (PAH) in smoked cheeses. Two types of fiber coatings and different extraction conditions were tested. The results reveal that the use of an 85-microm polyacrylate fiber immersed in the headspace of the samples at 70 degrees C for 60 min is suitable for the detection of PAH with no more than 4 aromatic rings. To determine if a relationship can be established between the results obtained using a solvent extraction technique and HS-SPME, 6 samples of smoked cheese previously studied by a solvent extraction method were analyzed by HS-SPME, and the results obtained by both methodologies were compared. Polycyclic aromatic hydrocarbons were identified and quantified by gas chromatography-mass spectrometry operating in selective ion monitoring mode. Among the PAH determined by the solvent extraction method, only those with 4 aromatic rings or less were detected by HS-SPME and, consequently, this technique does not allow one to determine the PAH content of smoked cheese samples under the conditions of the study. Nevertheless, the relationship between the results obtained by both techniques for some PAH revealed that HS-SPME could be useful as a screening method to distinguish among samples with different degrees of PAH contamination. PMID:15591362
Guill�n, M D; Sopelana, P
Polycyclic aromatic hydrocarbons in sediments and mussels of the western Mediterranean Sea
The distribution of polycyclic aromatic hydrocarbons (PAHs) has been investigated in superficial sediments and mussels (Mytilus galloprovincialis) of the western Mediterranean sea. The analyses were performed by gas chromatography coupled to mass spectrometry (GC-MS). The PAH concentrations ranged from 1 to 20,500 ng/g in the sediments. Different molecular indices allowed differentiation between the different pollutant sources. On the French coast, PAHs originated mainly from incomplete combustion of organic matter (pyrolytic origin), whereas for some sites in Corsica and Sardinia an overimposition of petrogenic PAHs occurred. The mussel PAH concentrations ranged from 25 to 390 ng/g. The total and individual PAH bioaccumulation factors were calculated. The correlation between sediment and mussel PAH content was discussed in terms of bioavailability. It was possible to distinguish different absorption routes for the xenobiotics according to their physicochemical properties. Because the mussel distribution of phenanthrene and anthracene seems to be governed by their water solubility, these compounds were probably mainly absorbed as the water-dissolved form, whereas the heavier molecular weight PAHs (more than four aromatic rings), whose sediment and mussel concentrations are correlated with higher correlation coefficients than for phenanthrene and anthracene, were probably mainly absorbed as adsorbed on particles. Furthermore, a possible preferential biotransformation of benzo[a]pyrene over benzo[e]pyrene is discussed.
Baumard, P.; Budzinski, H.; Garrigues, P. [Univ. Bordeaux I, Talence (France)
Influence of the bioaccessible fraction of polycyclic aromatic hydrocarbons on the ecotoxicity of historically contaminated soils.
Sequential supercritical fluid extraction together with a two-site desorption model were employed to estimate the bioaccessible fraction of polycyclic aromatic hydrocarbons (PAHs) in four historically contaminated soils. The ecotoxicity of the soils was assayed by four different contact tests. The same soils were exposed to exhaustive extraction and the extracts were returned to the soils to ensure total 100% bioaccessibility of the pollutants. Then the soils were assayed again. Statistical evaluation revealed that the predicted bioaccessible PAHs generally correlated with the ecotoxicity responses of the tests. The estimated bioaccessible fractions varied from 10 to 98%. This value increased for PAHs with higher lipophilicity and showed no correlation with the organic carbon content in the soils. The ecotoxicity tests in the study indicated different sensitivity toward PAHs and the tests employing Heterocypris incongruens and Eisenia fetida were found to be more suitable than Lemna minor and Vibrio fischeri. Mortality and growth inhibition of ostracods correlated with all the types of PAHs and earthworm growth inhibition and mortality were preferentially sensitive to PAHs with only 3-4 aromatic rings. Determination of the biota-soil accumulation factors indicated that the earthworm growth inhibition corresponded to increased accumulation of PAHs in the earthworm tissue. PMID:23611796
?van?arov�, Monika; K?esinov�, Zdena; Cajthaml, Tom�
The bioaccumulation of polynuclear aromatic hydrocarbons by benthic invertebrates in an intertidal marsh
Biota-sediment accumulation factors (BSAF; concentration in organism lipid/concentration in sediment on an organic carbon basis) of polyaromatic hydrocarbons varied with season and along an intertidal gradient in a coastal marsh in San Francisco Bay. The BSAFs were lowest during the local rainy season. During the dry season, BSAFs were lowest in the high intertidal zone closest to shore. Significant differences among species groups were also observed; BSAFs were lowest in polychaetes and highest in the Asian clam (Potamocorbula amurensis), varying over almost three orders of magnitude. The BSAFs decreased with increasing percent fines in the sediments and with PAH concentrations on an organic carbon basis. The authors suggest that a determining variable is the content of highly aromatic soot particles, which increases during periods of surface runoff and which is expected in the dry season to be highest in the high intertidal zone where these finer particles preferentially accumulate. Correlations of BSAFs with the ratio of the logarithm of the activity coefficients in porewaters to those in sediments were generally stronger than with log K{sub ow}, indicating a limitation of octanol as a surrogate for sediment organic carbon or organism lipid. These observations qualify but also strengthen the concept of equilibrium partitioning as the determining factor in bioaccumulation by benthic organisms of nonpolar organic compounds for sediments; the assumption that organic carbon can be considered in generic terms without allowance for aromaticity and probably other factors as well, must, however, be reconsidered.
Maruya, K.A.; Risebrough, R.W.; Horne, A.J. [Univ. of California, Berkeley, CA (United States). Dept. of Civil and Environmental Engineering
Analysis of Atmospheric Polycyclic Aromatic Hydrocarbons and Nitropolycyclic Aromatic Hydrocarbons in Gas\\/Particle Phases Separately Collected by a High-volume Air Sampler Equipped with a Column Packed with XAD-4 Resin
We developed a sampler for collecting atmospheric polycyclic aromatic hydrocarbons (PAHs) and nitropoly- cyclic aromatic hydrocarbons (NPAHs) by attaching a glass column packed with XAD-4 resin to the gas sampling port of a high-volume air sampler equipped with a filter. When the upper and bottom layers of the column were packed with 64 g and 32 g of XAD-4 resin,
Yuki Araki; Ning Tang; Michihiro Ohno; Takayuki Kameda; Akira Toriba; Kazuichi Hayakawaa
Formation mechanism of polycyclic aromatic hydrocarbons beyond the second aromatic ring.
The formation mechanism of polycyclic aromatic hydrocarbons (PAH) with three fused aromatic rings starting from naphthalene has been studied using accurate ab initio G3(MP2,CC)//B3LYP/6-311G** calculations followed by the kinetic analysis of various reaction pathways and computations of relative product yields. The results reveal new insights into the classical hydrogen abstraction-C2H2 addition (HACA) scheme of PAH growth. The HACA mechanism has been shown to produce mostly cyclopentafused PAHs instead of PAHs with six-member rings only, in contrast to the generally accepted view on this mechanism. Considering naphthalene as the initial reactant, the HACA-type synthesis of higher PAHs with all six-member rings, anthracene and phenanthrene, accounts only for 3-6% of the total product yield at temperatures relevant to combustion (1000-2000 K), whereas cyclopentafused PAHs, including acenaphthalene (41-48%), 4-ethynylacenaphthalene (?14%), 3-ethynylacenaphthalene (?7.5%), 1-methylene-1H-cyclopenta[b]naphthalene (?6%), and 3-methylene-3H-cyclopenta[a]naphthalene (?5%), account for another ?75%. It has been shown that acetylene addition to the radical site adjacent to the bay region in naphthalene (as in 1-naphthyl radical) or other similar PAH with a bay region is highly unlikely to be followed by the addition of a second acetylene molecule; alternatively, the bay region closure with a buildup of a new five-member ring occurs. Acetylene addition to a nonbay carbon atom (as in 2-naphthyl radical) can be followed by the second acetylene addition only at T < 1000 K, producing anthracene and phenanthrene. However, at temperatures relevant to combustion, such pathways give negligible contributions to the total product yield, whereas the dominant reaction product, 2-ethynylnaphthalene, is formed by simple hydrogen atom elimination from the attached ethenyl group. An additional six-member ring buildup may occur only after intermolecular hydrogen abstraction from ethynyl-substituted PAH (2-ethynylnaphthalene), in particular, from the carbon atoms adjacent to the existing ethynyl (C2H) fragment, followed by C2H2 addition producing adducts with two ethynyl C2H and ethenyl C2H2 groups next to each other, which then undergo a fast six-member ring closure. Nevertheless, this process has been shown to be relatively minor (?25%), whereas the major process is a five-member ring closure involving the same C2H and C2H2 groups and leading to a cyclopentafused PAH molecule. Although the computed product yields show a good agreement with experimentally observed concentrations of acenaphthalene and anthracene in various aliphatic and aromatic flames, the yield of phenanthrene, which exhibits an order of magnitude higher concentration than anthracene both in combustion flames and environmental mixtures, via the considered pathways is significantly underpredicted. This result points at the possible existence of another mechanism responsible for the formation of phenanthrene and other all-six-member-ring PAHs. The overall kinetic scheme for the HACA buildup process leading to various three-ring PAHs (both with six-member rings only and cyclopentafused) from naphthalene, which can be included in flame kinetic models, has been constructed, with rate constants for all individual reaction steps provided. PMID:23672431
Kislov, V V; Sadovnikov, A I; Mebel, A M
The mechanisms by which bacteria degrade simple polycyclic aromatic compounds have been studied for some time. The genes for the initial steps in the degradation of maphthalene have been cloned from many different Pseudomonas stains. This study was undertaken to investigate the diversity of genes involved in phenanthrene degradation and to identify novel organisms and genes for polycyclic aromatic hydrocarbon degradations. 53 refs., 5 figs., 1 tab.
Goyal, A.K.; Zylstra, G.J. [Rutgers Univ., New Brunswick, NJ (United States)
Genomic analysis of polycyclic aromatic hydrocarbon degradation in Mycobacterium vanbaalenii PYR-1
Mycobacterium vanbaalenii PYR-1 is well known for its ability to degrade a wide range of high-molecular-weight (HMW) polycyclic aromatic hydrocarbons\\u000a (PAHs). The genome of this bacterium has recently been sequenced, allowing us to gain insights into the molecular basis for\\u000a the degradation of PAHs. The 6.5�Mb genome of PYR-1 contains 194 chromosomally encoded genes likely associated with degradation\\u000a of aromatic
Seong-Jae Kim; Ohgew Kweon; Richard C. Jones; Ricky D. Edmondson; Carl E. Cerniglia
Molecular characterization of dioxygenases from polycyclic aromatic hydrocarbon-degrading Mycobacterium spp
Polycyclic aromatic hydrocarbon (PAH)-degrading genes nidA and nidB that encode the ? and ? subunits of the aromatic ring-hydroxylating dioxygenase have been cloned and sequenced from Mycobacterium vanbaalenii PYR-1 [Khan et al., Appl. Environ Microbiol. 67 (2001) 3577�3585]. In this study, the presence of nidA and nidB in 12 other Mycobacterium or Rhodococcus strains was investigated. Initially, all strains were
Barbara Brezna; Ashraf A. Khan; Carl E. Cerniglia
A novel integrative technique for locating and monitoring polynuclear aromatic hydrocarbon discharges to the aquatic environment
A simple integrative technique for locating and monitoring polynuclear aromatic hydrogen discharges to aquatic environments is described. The technique involves anchoring artificial substrates cut from a commercial oil-adsorbant cloth (3M Co.) near suspected sources of contamination. Analytical methodology involves mild ethanolic extraction and liquid-liquid partitioning to isolate a polynuclear aromatic hydrocarbon containing fraction that is amenable to analysis by high-pressure liquid chromatography.
Black, J.J.; Hart, T.F. Jr.; Black, P.J.
Polycyclic aromatic hydrocarbons in asteroid 2008 TC3: Dispersion of organic compounds inside asteroids
Ureilites are carbon-bearing ultramafic rocks characterized by partial melt depletion and a violent disruption resulting in graphitic carbon and diamonds. Among the predominantly polymict ureilite meteorites collected from the impact of asteroid 2008 TC3 on October 7, 2008�the first time an asteroid was spotted in space and subsequently recovered in the form of meteorites�were many fresh-looking chondrites. Four were classified as EH6 (#16), H5 (sample #25), EL6 (#41), and L4 (#A100) chondrites. All are called "Almahata Sitta," named after the nearby inhabited outpost of Station 6. Six hundred meteorites were collected, which show a wide range of densities, textures, reflection properties, and elemental compositions. In this study, we employ laser desorption laser ionization mass spectrometry to analyze the polycyclic aromatic hydrocarbon (PAH) contents of six meteorites from 2008 TC3 that are ureilites (sample #1, #4, #7, #15, #27, and #47) and three anomalous fragments (sample #25, #16, and #41). Numerous organic compounds were detected with a PAH signature that has not been observed in the carbonaceous chondrites previously studied by our experimental apparatus. Specifically, the Almahata Sitta spectra lack the diversity of alkylation series of parent PAHs commonly observed in Murchison and other carbonaceous chondrites. Spatial mappings of aromatic species across the surface of a fragment of sample #4 are presented including detection of what appears to be the aromatic amino acid tyrosine. Potential sources of terrestrial organic contamination are discussed and ruled out as a source of our observations. Meteorites #25 and #16 are found to have the same distribution of PAHs as the Almahata Sitta meteorites. Other chondrites have much different organic fingerprints. We conclude that both an H5 and E chondrite were included in asteroid 2008 TC3 as foreign clasts and that organic compounds contained in ureilites can spread into other parts of an asteroid.
Sabbah, Hassan; Morrow, Amy L.; Jenniskens, Peter; Shaddad, Muawia H.; Zare, Richard N.
Polycyclic aromatic hydrocarbons (PAH) and phenolic substances in meat products smoked with different types of wood and smoking spices.
The contents of polycyclic aromatic hydrocarbons (15+1 EU PAH) and phenolic substances (guaiacol, 4-methylguaiacol, syringol, eugenol, and trans-isoeugenol) were investigated in smouldering-smoked Frankfurters and mini-salamis. For the 51 smoking experiments wood chips of oak, poplar, hickory, spruce, fir, alder, beech, and beech with an apple-smoking spice mix, cherry-smoking spice mix, and a mix of juniper berries and bay leaves were tested. The use of poplar and hickory led to a decrease in the PAH contents in the range of 35-55% compared to the commonly used beech wood. Higher PAH contents by using softwood were not observed. The use of the rapidly growing poplar seems to be a reasonable approach for reducing the PAH contents in smoked meat products. Furthermore, the sum contents of the five phenolic substances in sausages smoked with poplar were higher, or only slightly lower, when compared to the use of beech. PMID:23561196
Hitzel, Alexander; P�hlmann, Margarete; Schw�gele, Fredi; Speer, Karl; Jira, Wolfgang
Indirect- and direct-acting mutagenicity of diesel, coal and wood burning-derived particulates and contribution of polycyclic aromatic hydrocarbons and nitropolycyclic aromatic hydrocarbons.
Particulates exhausted from two types of diesel engines (DEPs), burning-derived particulates from three types of coal (CBPs) and burning-derived particulates from three types of wood (WBPs) were separated into four fractions by silica-gel column chromatography using n-hexane, n-hexane-dichloromethane (3:1, v/v), dichloromethane and methanol, as the corresponding eluents. The indirect-acting mutagenicity of each fraction was assayed by the Ames test using the Salmonella typhimurium TA100 strain with S9 mix and the direct-acting mutagenicity was assayed using the S. typhimurium TA98 strain without S9 mix. The polycyclic aromatic hydrocarbons (PAHs) and nitropolycyclic aromatic hydrocarbons (NPAHs) of each fraction were determined by high-performance liquid chromatography (HPLC). Both direct- and indirect-acting of mutagenicities were the highest in samples of DEPs. The contributions of PAHs in samples of WBPs and NPAHs in DEPs were the largest, respectively. PMID:19896557
Yang, Xiao-Yang; Igarashi, Kazuhiko; Tang, Ning; Lin, Jin-Ming; Wang, Wei; Kameda, Takayuki; Toriba, Akira; Hayakawa, Kazuichi
Biodegradation of volatile aromatic hydrocarbons by native soil and groundwater microorganisms: Microcosm studies
The goal of this project was twofold: to develop and test strategies for enhancing the microbial degradation of hydrocarbon contaminants in subsurface soil and groundwater, and to understand why and under what conditions these strategies can be successful. The work deals primarily with what are generally considered the highest priority contaminants, from a toxicological point of view, in a typical hydrocarbon remediation site -- the aromatic fraction, including benzene and related compounds. The work involved the determination of the relative degradation rates of aromatic, as well as several nonaromatic constituents, in conjunction with an analysis of the effect of oxygen concentration and with an extensive microbiological characterization.
Rai, D.N.; Dasch, J.M.; Gibson, T.L.; Ang, C.C.; Abdul, A.S.
Sources and distribution of aliphatic and polycyclic aromatic hydrocarbons in Yellow River Delta Nature Reserve, China
Sediment samples collected from the Core Area, Experimental Area and Buffer Area of Yellow River Delta National Nature Reserve (YRDNNR), China, were analyzed by GC�MS in order to determine the degree of hydrocarbon contamination, and identify the sources of aliphatic hydrocarbons and PAHs. The total petroleum hydrocarbon contents of sediments were relatively low or moderate compared to world-wide locations reported
Chuanyuan Wang; Wanchun Wang; Shijie He; Jianguo Du; Zhigao Sun
Supercritical carbon dioxide extraction of polychlorinated biphenyls, polycyclic aromatic hydrocarbons, heteroatom-containing polycyclic aromatic hydrocarbons, and n-alkanes from polyurethane foam sorbents
Supercritical fluid extraction (SFE) with CO� is a rapid alternative to liquid solvent extraction for the recovery of organic air pollutants collected on polyurethane foam (PUF) sorbent plugs. Quantitative recovery (> 95%) of polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs) ranging from naphthalene to perylene, several heteroatom-containing PAHs, and n-alkanes ranging from C�� to C�� was achieved with 10-20 min
Steven B. Hawthorne; Mark S. Krieger; David J. Miller
Source determination of polynuclear aromatic hydrocarbons in water and sediment of a creek in the Niger Delta region
Polynuclear aromatic hydrocarbons in surface water and sediment of Ekpan Creek of the Warri River were determined with GC Perkin-Elmer\\/Clarius 500. Compositional patterns of the PAHs were used to distinguish their sources in the aquatic system. The three diagnostic selected concentration ratios of polynuclear aromatic hydrocarbon isomer pairs confirmed that the PAHs concentrations in sediment of Ekpan Creek were from
Okoro Duke
Biological and environmental monitoring of exposure to airborne benzene and other aromatic hydrocarbons in Milan traffic wardens
Environmental and biological monitoring of airborne aromatic hydrocarbons has been performed in 20 policemen working as traffic wardens exposed to motor vehicle exhausts and in 19 peers employed as clerks. Airborne benzene toluene, ethylbenzene and xylene concentrations, measured during the workshift, resulted in significantly higher out door than indoor concentrations (benzene and related aromatic hydrocarbons mean values, respectively of 53
S. Fustinoni; M. Buratti; R. Giampiccolo; A. Colombi
Polycyclic Aromatic Hydrocarbons and Hopane in Malacca Coastal Water: 130 Years of Evidence for Their Land-Based Sources
Massive development over the past century has led to environmental oil-related pollution around the Malaysian city of Malacca. To characterize the concentration, sources, and origins of polycyclic aromatic hydrocarbons in Malacca�s coastal water in the Strait of Malacca, sediment cores from near shore and offshore were collected and analyzed. The highest concentration of total polycyclic aromatic hydrocarbons (PAHs) in the
Mahyar Sakari; Mohamad Pauzi Zakaria; Che Abd Rahim Mohamed; Nordin Haj Lajis; Mohd Harun Abdullah; Azadeh Shahbazi
BN-Dibenzo[a,o]picenes: analogues of an unknown polycyclic aromatic hydrocarbon.
Reflecting on synthetic pinnacles: Whereas the parent hydrocarbon is not readily accessible, several examples of BN substituted-dibenzo[a,o]picenes can be prepared in two steps from known starting materials. These non-linear heptacene analogues are water-stable materials. Their preparation utilizes a potentially general method for preparing extended BN analogues of difficult-to-synthesize polycyclic aromatic hydrocarbon frameworks. PMID:23897598
Neue, Benedikt; Araneda, Juan F; Piers, Warren E; Parvez, Masood
Health Hazard Evaluation Report: HETA-2010-0156-3196, December 2013. Evaluation of Dermal Exposure to Polycyclic Aromatic Hydrocarbons in Fire Fighters.
The Health Hazard Evaluation Program carried out a study at a fire service training facility to assess exposures to airborne polycyclic aromatic hydrocarbons (PAHs) and other aromatic hydrocarbons. The purpose was to learn whether these substances pass th...
C. Mueller C. Striley D. Evans D. Sammons G. P. Horn J. Eisenberg J. Pleil J. Snawder K. W. Fent M. Stiegel S. Robertson V. Kochenderfer
Identification and Comparative Genotoxicity of Polycyclic Aromatic Hydrocarbons and Related Nitrogen-Containing Heteroatomic Species in Products from Coal Liquefaction Processes.
A series of process distillation cuts from a solvent refined coal process were separated into polycyclic aromatic hydrocarbons (PAH) and nitrogen-containing polycyclic aromatic hydrocarbons (N-PAC) chemical classes and the fractions tested for biological ...
D. W. Later R. A. Pelroy D. D. Mahlum C. W. Wright M. L. Lee
Aromatic hydrocarbons as indicators of origin and maturation for light oils from Panyu lower uplift in Pearl River Mouth basin
Aromatic fractions of six light oils and two source rock samples from Panyu (??) lower uplift of Pearl River Mouth basin were\\u000a analyzed using GC-MS (gas chromatography-mass spectrometric) technique. Thirteen aromatic series of hydrocarbons detected\\u000a such as biphenyls, naphthalenes, phenanthrenes, dibenzothiophenes (more than two hundred aromatic hydrocarbon compounds) were\\u000a used to analyze the origin and maturity of the light oils.
Xiaowen Guo; Sheng He
Oxidation of polycyclic aromatic hydrocarbons by fungal isolates from an oil contaminated refinery soil
Background and Objective��Indigenous soil microorganisms are used for the biodegradation of petroleum hydrocarbons in oily waste residues from the petroleum\\u000a refining industry. The objective of this investigation was to determine the potential of indigenous strains of fungi in soil\\u000a contaminated with petroleum hydrocarbons to bio-degrade polycyclic aromatic hydrocarbons (PAH).\\u000a \\u000a \\u000a \\u000a Materials and Methods��Twenty one fungal strains were isolated from a soil
Zhongming Zheng; Jeffrey P. Obbard
Vertical fluxes of aromatic and aliphatic hydrocarbons in the Northwestern Mediterranean Sea
Aliphatic and aromatic hydrocarbon fluxes were measured in time series sediment trap samples at 200m and at 1000m depths in the open Northwestern Mediterranean Sea, from December 2000 to July 2002. Averaged fluxes of n-alkanes, UCM and T-PAH35 were 2.96�2.60?gm?2d?1, 64�60?gm?2d?1 and 0.68�0.59?gm?2d?1, respectively. Molecular compositions of both hydrocarbon classes showed a contamination in petrogenic hydrocarbons well above the background
R�mi Deyme; Ioanna Bouloubassi; Marie-H�l�ne Taphanel-Valt; Juan-Carlos Miquel; Anne Lorre; Jean-Claude Marty; Laurence M�janelle
Enumeration and characterization of the soil microflora from hydrocarbon-contaminated soil sites able to mineralize polycyclic aromatic hydrocarbons (PAH)
The use of a plate screening technique allowed the direct isolation and quantification of polycylic aromatic hydrocarbon (PAH)-degrading bacteria from different soil sites. Bacteria that were able to grow on anthracene, phenanthrene, fluoranthene or pyrene as a sole carbon source were found with numbers between 103 and 105 colony-forming units (cfu)\\/g of soil dry weight, but only in samples that
M. K�stner; M. Breuer-Jammali; B. Mahro
Hydrogen solubility in a chemical hydrogen storage medium, aromatic hydrocarbon, cyclic hydrocarbon, and their mixture for fuel cell systems
A synthetic type apparatus was designed to measure hydrogen solubility in four pure aromatic or cyclic hydrocarbons, benzene, cyclohexane, toluene, and methylcyclohexane, and two equimolar binary mixtures, benzene + cyclohexane, and methylcyclohexane + toluene. The experimental temperature was 303.15K, and the pressure range from 0.887 to 4.827MPa. The hydrogen solubility increased linearly with the pressure following the Henry's law. The
Tomoya Tsuji; Yoshiko Shinya; Toshihiko Hiaki; Naotsugu Itoh
Isolation, characterization of Rhodococcus sp. P14 capable of degrading high-molecular-weight polycyclic aromatic hydrocarbons and aliphatic hydrocarbons
Rhodococcus sp. P14 was isolated from crude oil-contaminated sediments. This strain was capable of utilizing three to five rings polycyclic aromatic hydrocarbons (PAHs) including phenanthrene (Phe), pyrene (Pyr), and benzo[a]pyrene (BaP) as a sole carbon and energy source. After cultivated with 50mg\\/L of each PAH, strain P14 removed 43% Phe, 34% Pyr and 30% BaP in 30 d. Four different
Xiaohui Song; Yan Xu; Gangmin Li; Ying Zhang; Tongwang Huang; Zhong Hu
Effect of condensed organic matter on solvent extraction and aqueous leaching of polycyclic aromatic hydrocarbons in soils and sediments.
The contents of nonhydrolyzable organic matter (NHC) and black carbon (BC) were measured in soils and sediments from the Pearl River Delta, South China. Polycyclic aromatic hydrocarbons (PAHs) were extracted respectively by Soxhlet and an accelerated solvent extraction device (ASE) using different solvents. In addition, sequential aqueous leaching at different temperatures was carried out. The PAH content extracted with the sequential three solvent ASE is two times higher than that using the Soxhlet extraction method. The relationship of the PAH content with the NHC content is very significant. The PAH concentrations measured at various temperature steps fit well to the Van't Hoff equation and the enthalpy was estimated. The investigation indicates that condensed organic matter such as kerogen carbon, aged organic matter, and BC is relevant for the extraction and distribution of native PAHs in the investigated field soils and sediments. PMID:17257721
Ran, Yong; Sun, Ke; Ma, Xiaoxuan; Wang, Guohui; Grathwohl, Peter; Zeng, Eddy Y
In computational studies to understand the interaction of polycyclic aromatic hydrocarbons (PAHS) with biomolecular systems, the semi-empirical method AM1 has been used to determine the geometry of the PAH, its metabolites and relevant intermediates. umber of studies have shown t...
Characterization of subsurface polycyclic aromatic hydrocarbons at the Deepwater Horizon site
Here, we report the initial observations of distributions of polycyclic aromatic hydrocarbons (PAH) in subsurface waters near the Deepwater Horizon oil well site (also referred to as the Macondo, Mississippi Canyon Block 252 or MC252 well). Profiles of in situ fluorescence and beam attenuation conducted during 9-16 May 2010 were characterized by distinct peaks at depths greater than 1000 m,
Arne-R. Diercks; Raymond C. Highsmith; Vernon L. Asper; DongJoo Joung; Zhengzhen Zhou; Laodong Guo; Alan M. Shiller; Samantha B. Joye; Andreas P. Teske; Norman Guinasso; Terry L. Wade; Steven E. Lohrenz
This report summarizes the results of a spiking study performed on a sanitary landfill leachate matrix. Fifteen polynuclear aromatic hydrocarbons (PNAs) were dosed into the landfill leachate and analyzed using EPA Method 610. The results show that the PNAs containing two, three, ...
Polycyclic Aromatic Hydrocarbon-Induced Cytotoxicity in Cultured Rat Sertoli Cells Involves Differential Apoptotic Response
Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous and persistent environmental contami- nants. Some PAHs are carcinogens and may affect the male reproductive system. Therefore, we exposed cultured rat Sertoli cells to a variety of PAHs to determine possible direct toxic effects on the cells of the seminiferous epithelium. Sertoli cells were chosen because they support germ cell development and maintain spermatogenesis.
Samir S. Raychoudhury; Dana Kubinski
Characterization of polycyclic aromatic compounds in diesel exhaust particulate extract responsible for aryl hydrocarbon receptor activity
Chemical fractions of a model diesel exhaust particulate extract, notably the fraction containing polycyclic aromatic hydrocarbons (PAH) (Fraction II), mono-nitro PAH (Fraction III), and dinitro-PAH (Fraction IV) have been shown to displace binding of 2,3,7,8-tetrachloro[1,6-[ 3H
Soontjens, Carol D.; Holmberg, Kristina; Westerholm, Roger N.; Rafter, Joseph J.
Development of a catabolically significant genetic probe for polycyclic aromatic hydrocarbon-degrading Mycobacteria in soil
A gene probe for the detection of polycyclic aromatic hydrocarbon (PAH) induced nidB and nidA dioxygenase genes has been designed from Mycobacteria JLS, KMS, and MCS. The probe detects a catabolic gene involved in the initial steps of PAH biodegradation in mycobacteria. The gene probe is comprised of three PCR primer sets designed to detect the genes that code for
Kevin Hall; Charles D. Miller; Darwin L. Sorensen; Anne J. Anderson; Ronald C. Sims
Genotypic and phenotypic responses of a riverine microbial community to polycyclic aromatic hydrocarbon contamination
The phenotypic and genotypic adaptation of a freshwater sedimentary microbial community to elevated levels of polycyclic aromatic hydrocarbons (PAHs) was determined by using an integrated biomolecular approach. Central to the approach was the use of phospholipid fatty acid (PLFA) profiles to characterize the microbial community structure and nucleic acid analysis to quantify the frequency of degradative genes. The study site
DONALD E. LANGWORTHY; R. H. Findlay; R. D. Stapleton; G. S. Sayler
Toxicity of polycyclic aromatic hydrocarbons. (Latest citations from Pollution abstracts). Published Search
The bibliography contains citations concerning the toxicity and biochemical effects of aromatic polycyclic hydrocarbons. Citations discuss air, water, soil, and sediment pollution and control. Topics include vehicle emissions and control, pollutant pathways, carcinogens and mutagenic activity, and photoinduced toxicity. Food contamination, environmental monitoring, and soil contamination along highways are examined. (Contains 50-250 citations and includes a subject term index and title list.)
Distribution, sources and potential toxicological significance of polycyclic aromatic hydrocarbons (PAHs) in Taihu Lake sediments, China
Taihu Lake is one of the largest freshwater lakes in China. The lake is very shallow with a mean depth of 1.9 m and an area of 2428 km2. This is the first time that polycyclic aromatic hydrocarbon concentrations in the surface sediments of Taihu Lake have been analyzed. A distinctive spatial distribution of PAHs was observed. Sediments from Lake
Qu Wenchuan; Mike Dickman; Fan Chengxin; Wang Sumin; Su Chenwei; Zhang Lu; Zou Huixian
Interaction of multiply charged ions with isolated polycyclic aromatic hydrocarbon molecules
The interaction of multiply charged ions (He2+, O3+, and Xe20+, v <= 0.6 a.u.) with gas phase pericondensed polycyclic aromatic hydrocarbon (PAH) molecules (pyrene and coronene) was studied. Positively charged ionic products were analyzed with a linear time-of-flight mass spectrometer.
?awicki, A.; Capron, M.; Maisonny, R.; Maclot, S.; Lattouf, E.; M�ry, A.; Rangama, J.; Holm, A. I. S.; Zettergren, H.; Seitz, F.; Johansson, H. A. B.; Ros�n, S.; Schmidt, H. T.; Cederquist, H.; Manil, B.; Adoui, L.; Rousseau, P.; Huber, B. A.
Field comparison of polyurethane foam and XAD-2 resin for air sampling for polynuclear aromatic hydrocarbons
A study of the sampling efficiency for polynuclear aromatic hydrocarbons (PAH) in air of two adsorbents, XAD-2 resin and polyurethane foam (PUF), was performed under summer and winter ambient conditions. Two aspects were investigated: (1) collection efficiency for ambient PAH vapor and (2) retention efficiency for native and perdeuteriated PAH spiked onto the adsorbents before sampling. The XAD-2 resin had
Jane C. Chuang; Steve W. Hannan; Nancy K. Wilson
Negative-ion chemical-ionization mass spectrometry (NICI MS) has the potential to be a very useful technique in identifying various polycyclic aromatic hydrocarbons (PAHs) in soil and sediment samples. Some PAHs give much stronger signals under NICI MS conditions than others. On ...
For a series of cyclopenta-polynuclear aromatic hydrocarbons, epoxidated in the cyclopenta ring, semi-empirical AM1 calculations, and single point ab initio calculations using the 3-21g split valence basis set, have been performed for the each carbocation that might be formed by ...
Health risk assessment for traffic policemen exposed to polycyclic aromatic hydrocarbons (PAHs) in Tianjin, China
In China, traffic policemen have to stand for several hours a day at the road intersections with high vehicle flows. To assess their exposure to airborne carcinogenic polycyclic aromatic hydrocarbons (PAHs) during their working time, a preliminary study was conducted to measure the personal exposure level to PAHs. And a probabilistic incremental lifetime cancer risk (ILCR) model together with the
Yandi Hu; Zhipeng Bai; Liwen Zhang; Xue Wang; Li Zhang; Qingchan Yu; Tan Zhu
Minimal clean-up and rapid determination of polycyclic aromatic hydrocarbons in instant coffee
The essential aim of this work is the development of a simple, fast, quantitative and economic method for polycyclic aromatic hydrocarbons (PAHs) potentially generated by roasting coffee beans, which is the most important process in the coffee industry for the development of the characteristic flavour of the bean mix. The PAHs were chosen because they differed in the number of
Mercedes Sonia Garc??a-Falc�n; Beatriz Cancho-Grande; Jes�s Simal-G�ndara
Diversity of ndo Genes in Mangrove Sediments Exposed to Different Sources of Polycyclic Aromatic Hydrocarbon Pollution
Polycyclic aromatic hydrocarbon (PAH) pollutants originating from oil spills and wood and fuel combustion are pollutants which are among the major threats to mangrove ecosystems. In this study, the composition and relative abundance in the sediment bacterial communities of naphthalene dioxygenase (ndo) genes which are important for bacterial adaptation to environmental PAH contamination were investigated. Three urban mangrove sites which
Newton C. Marcial Gomes; Ludmila R. Borges; Rodolfo Paranhos; Fernando N. Pinto; Ellen Krogerrecklenfort; Leda C. S. Mendonca-Hagler; Kornelia Smalla
Polycyclic aromatic hydrocarbons in water and sediment of the Baltic Sea
Between 1992 and 1994, the distribution of 15 polycyclic aromatic hydrocarbons (PAHs) was investigated in seawater and surface sediments of the Baltic Sea. The analysis of PAHs in seawater is very difficult due to the low concentration. High separation capability is required. A method for analysing very low concentrations of PAHs is presented. The method is based on the high-performance
G. Witt
Characterization of a Polycyclic Aromatic Hydrocarbon�Degrading Microbial Consortium from a Petrochemical Sludge Landfarming Site
Anthracene, phenanthrene, and pyrene are polycyclic aromatic hydrocarbon (PAHs) that display both mutagenic and carcinogenic properties. They are recalcitrant to microbial degradation in soil and water due to their complex molecular structure and low solubility in water. This study presents the characterization of an efficient PAH (anthracene, phenanthrene, and pyrene)-degrading microbial consortium, isolated from a petrochemical sludge landfarming site. Soil
Rodrigo J. S. Jacques; Benedict C. Okeke; Fatima M. Bento; Maria C. R. Peralba; Fl�vio A. O. Camargo
Comparative studies on lignin and polycyclic aromatic hydrocarbons degradation by basidiomycetes fungi
A total of 130 wild basidiomycetes fungi were collected and identified. The polycyclic aromatic hydrocarbons (PAHs) degradation by the potential Phellinus sp., Polyporus sulphureus (in liquid state fermentation (LSF), solid state fermentation (SSF), in soil) and lignin biodegradation were compared with those of a bacterial isolate and their corresponding cocultures. The PAHs degradation was higher in LSF and the efficiency
A. Arun; M. Eyini
Products from the Incomplete Metabolism of Pyrene by Polycyclic Aromatic Hydrocarbon-Degrading Bacteria
Pyrene is a regulated pollutant at sites contaminated with polycyclic aromatic hydrocarbons (PAH). It is mineralized by some bacteria but is also transformed to nonmineral products by a variety of other PAH- degrading bacteria. We examined the formation of such products by four bacterial strains and identified and further characterized the most apparently significant of these metabolites. Pseudomonas stutzeri strain
Numerical and Genetic Analysis of Polycyclic Aromatic Hydrocarbon-Degrading Mycobacteria
Ability to degrade high molecular weight polycyclic aromatic hydrocarbons (PAHs) has been found in diverse species of fast-growing mycobacteria. This study included several PAH-degrading mycobacteria from heavily contaminated sites and an uncontaminated humus soil in the Natural Park, Schw�bische Alb, Germany. The numerical analysis with a total of 131 tests showed that isolates from humus soil and contaminated sites had
Yong-Hak Kim; Karl-H. Engesser; Carl E. Cerniglia
Enumeration and phylogenetic analysis of polycyclic aromatic hydrocarbon-degrading marine bacteria from Puget Sound sediments
Polycyclic aromatic hydrocarbons (PAHs) are primarily released into the environment through anthropomorphic sources. PAH degradation has been known to occur in marine sediments. This paper describes the enumeration, isolation, and preliminary characterization of PAH-degrading strains from Puget Sound sediments. 38 refs., 3 figs., 3 tabs.
A. D. Geiselbrecht; R. P. Herwig; J. W. Deming; J. T. Staley
Enrichment, Isolation, and Phylogenetic Identification of Polycyclic Aromatic Hydrocarbon-Degrading Bacteria from Elizabeth River Sediments
The diversity of indigenous bacteria in sediments from several sites in the Elizabeth River (Virginia) able to degrade multiple polycyclic aromatic hydrocarbons (PAHs) was investigated by the use of classical selective enrichment and molecular analyses. Enrichment cultures containing naphthalene, phenan- threne, fluoranthene, or pyrene as a sole carbon and energy source were monitored by denaturing gradient gel electrophoresis (DGGE) to
Edward J. Hilyard; Joanne M. Jones-Meehan; Barry J. Spargo; Russell T. Hill
Products from the incomplete metabolism of pyrene by polycyclic aromatic hydrocarbon-degrading bacteria
Pyrene is a regulated pollutant at sites contaminated with polycyclic aromatic hydrocarbons (PAH). It is mineralized by some bacteria but is also transformed to nonmineral products by a variety of other PAH-degrading bacteria. The authors examined the formation of such products by four bacterial strains and identified and further characterized the most apparently significant of these metabolites. Pseudomonas stutzeri strain
C. Kazunga; M. D. Aitken
A theoretical analysis was performed to examine the role of naphthalene dioxygenase (NDO) enzymes in determining differences in biodegradability and biodegradation rates of two- to four-ring polycyclic aromatic hydrocarbons (PAHs) via oxy- genation and desaturation reactions. Investigation of the thermodynamics of PAH biodegradation reactions catalyzed by NDO revealed that enthalpies of reaction can explain reaction patterns or regioselectivity of the
Kristine H. Wammer; Catherine A. Peters
Determination of polycyclic aromatic hydrocarbons in alcoholic drinks and the identification of their potential sources
Some polycyclic aromatic hydrocarbons (PAHs), particularly those with a high molecular mass, have been classified as probably being carcinogenic to humans by the International Agency for Research on Cancer (IARC). The significance of the determination of PAHs is reflected by the special attention the European Union is paying to regulating their maximum allowed levels in various types of foodstuffs. Like
M. S. Garc�a-Falc�n; J. Simal-G�ndara
The paper gives results of measuring polycyclic aromatic hydrocarbons (PAHs) in ambient air particulates in Northern New England. Standard high-volume filter samples of ambient-air particulates were collected during several heating seasons in a semi-rural village, a rural area, a...
Evidence for polynuclear aromatic hydrocarbons in the diet of bottom-feeding fish
Among environmental pollutants, polynuclear aromatic hydrocarbons (PAH) are of interest because of their widespread occurrence and the human carcinogenicity of their metabolic products. Most PAH are relatively water insoluble and ultimately are deposited in sediments. In localized areas of eastern Lake Erie, sediments have been shown to have high concentrations of PAH. As a part of an ongoing research on
A. E. Maccubbin; P. Black; L. Trzeciak; J. J. Black
Photoinduced toxicity of the polycyclic aromatic hydrocarbon, fluoranthene, on the coral, Porites divaricata
The synergistic effect of ultraviolet radiation (UVR) and a polycyclic aromatic hydrocarbon (PAH) was tested on the coral Poritesdivaricata. Small branches were incubated in different concentrations of fluoranthene followed by exposure to ecologically relevant levels of natural solar radiation, with and without UVR. Exposure to the highest concentration of fluoranthene (60 ? g L) resulted in decreased photochemical efficiency of
Mar�a Del Carmen Guzm�N Mart�nez; Patricia Ram�rez Romero; Anastazia T. Banaszak
Effect of irradiance spectra on the photoinduced toxicity of three polycyclic aromatic hydrocarbons
Photoinduced toxicity of polycyclic aromatic hydrocarbons (PAHs) is dependent on the concentration of compounds present and the dose of light received. Of the light present, only those wavelengths absorbed by the compound have the potential to initiate the photochemical events underlying phototoxicity. This suggests that variation in light spectra present in natural waters, arising from variation in dissolved organic carbon
S. A. Diamond; D. R. Mount; L. P. Burkhard; G. T. Ankley; E. A. Makynen; E. N. Leonard
U.S. EPA's Integrated Risk Information System (IRIS) Program has initiated a health assessment for polycylic aromatic hydrocarbon (PAH) mixtures. Currently, the IRIS database contains entries developed in the early 1990s for 15 non-methylated PAHs with three or more rings. These...
Personal exposure monitoring for select polycyclic aromatic hydrocarbons (PAHs) was performed as part of the National Human Exposure Assessment Survey (NHEXAS) Pilot Study in Baltimore, MD. Twenty-four hour PM10 sample collections (~5.7 m3) were performed using personal envi...
Cancer risk from occupational and environmental exposure to polycyclic aromatic hydrocarbons
Epidemiologic evidence on the relationship between polycyclic aromatic hydrocarbons (PAH) and cancer is reviewed. High occupational exposure to PAHs occurs in several industries and occupations. Covered here are aluminum production, coal gasification, coke production, iron and steel foundries, tar distillation, shale oil extraction, wood impregnation, roofing, road paving, carbon black production, carbon electrode production, chimney sweeping, and calcium carbide production.
Paolo Boffetta; Nadia Jourenkova; Per Gustavsson
Anaerobic Degradation of Polycyclic Aromatic Hydrocarbons and Alkanes in Petroleum-Contaminated Marine Harbor Sediments
Although polycyclic aromatic hydrocarbons (PAHs) have usually been found to persist under strict anaer- obic conditions, in a previous study an unusual site was found in San Diego Bay in which two PAHs, naphthalene and phenanthrene, were oxidized to carbon dioxide under sulfate-reducing conditions. Further investigations with these sediments revealed that methylnaphthalene, fluorene, and fluoranthene were also anaerobically oxidized to
Polycyclic Aromatic Hydrocarbons in Surface Sediments Around England and Wales, and Their Possible Biological Significance
Concentrations of polycyclic aromatic hydrocarbons (PAH) were determined in sediments taken at offshore, coastal and estuarine sites around the UK during the period 1993�1996. In all, 99 samples were taken from 80 locations, including 48 of the stations established under the UK National Monitoring Programme. Fifteen individual parent PAH compounds were determined using a method incorporating an ultrasonication extraction step,
R. J. Woodhead; R. J. Law; P. Matthiessen
Estimation of individual dermal and respiratory uptake of polycyclic aromatic hydrocarbons in 12 coke oven workers
Twelve workers from a coke plant in The Netherlands participated in an intensive skin monitoring programme combined with personal air sampling and biological monitoring during five consecutive eight hour workshifts. The purpose of the study was to make a quantitative assessment of both the dermal and respiratory intake of polycyclic aromatic hydrocarbons (PAHs). Pyrene was used as a marker compound
J G VanRooij; M M Bodelier-Bade; F J Jongeneelen
Sedimentary record of anthropogenic and biogenic polycyclic aromatic hydrocarbons in San Francisco Bay, California
Dated sediment cores collected from Richardson and San Pablo Bays in San Francisco Bay were used to reconstruct a history of polycyclic aromatic hydrocarbon (PAH) contamination. The sedimentary record of PAHs in Richardson Bay shows that anthropogenic inputs have increased since the turn of the century, presumably as a result of increasing urbanization and industrialization around the Bay Area. Concentrations
Wilfred E. Pereira; Frances D. Hostettler; Samuel N. Luoma; Alexander van Geen; Christopher C. Fuller; Roberto J. Anima
Urban runoff as a source of polycyclic aromatic hydrocarbons to coastal waters
Urban runoff samples collected from four storm drains, each serving a different land use, were analyzed for selected polycyclic aromatic hydrocarbons (PAHs) by gas chromatography. The PAH concentrations varied widely during the history of each storm and appeared to be most concentrated in first or second flushes. Higher molecular weight PAHs were mostly found associated with the particulates and were
Eva J. Hoffman; Gary L. Mills; James S. Latimer; James G. Quinn
One-electron oxidation in the degradation of creosote polycyclic aromatic hydrocarbons by Phanerochaete chrysoporium
The abilities of whole cultures of Phanerochaete chrysosporium and P. chrysosporium manganese peroxidase-mediated lipid peroxidation reactions to degrade the polycyclic aromatic hydrocarbons (PAHs) found in creosote were studied. The disappearance of 12 three- to six-ring PAHs occurred in both systems. Both in vivo and in vitro, the disappearance of all PAHs was found to be very strongly correlated with ionization
Bill W. Bogan; R. T. Lamar
Dissipation of 3�6-ring polycyclic aromatic hydrocarbons in the rhizosphere of ryegrass
Plants may contribute to the biodegradation of polycyclic aromatic hydrocarbons (PAHs) in contaminated soils. Different mechanisms have been proposed, such as an increase in microbial numbers, but are not clearly elucidated. This study investigates the dissipation of a mixture of eight PAHs, ranging from 3 to 6 rings, in the rhizosphere of ryegrass (Lolium perenne L.). Two pot experiments were
P Binet; J. M Portal; C Leyval
Dry deposition of particulate polychlorinated biphenyls and polycyclic aromatic hydrocarbons to Lake Michigan
Dry deposition was collected from November 1993 to October 1995 at multiple sites within the Lake Michigan basin to estimate fluxes of particulate polychlorinated biphenyls (PCBs) and polycyclic aromatic hydrocarbons (PAHs) as part of the Lake Michigan Mass Balance Study (LMMBS). Samples were also collected during the Atmospheric Exchange over Lakes and Oceans (AEOLOS) project to estimate fluxes to coastal
Thomas P. Franz; Steven J. Eisenreich; Thomas M. Holsen
New SERS Substrates For Polycyclic Aromatic Hydrocarbon (PAH) Detection: Towards Quantitative SERS Sensors For Environmental Analysis
In the investigation of chemical pollutions, such as PAHs (Polycyclic Aromatic Hydrocarbons) at low concentration in aqueous medium, surface-enhanced Raman scattering (SERS) stands for an alternative to the inherent low cross-section of normal Raman scattering. Indeed, SERS is a very sensitive spectroscopic technique due to the excitation of the surface plasmon modes of the nanostructured metallic film.
Peron, O. [Service Interfaces et Capteurs, Departement Recherches et Developpements Technologiques, IFREMER, BP70, 29280 Plouzane (France); Laboratoire de Nanotechnologie et d'instrumentation Optique, Institut Charles Delaunay, FRE 2848, Universite de technologie de Troyes, 12 rue Marie Curie, 10010 Troyes (France); Rinnert, E.; Compere, C. [Service Interfaces et Capteurs, Departement Recherches et Developpements Technologiques, IFREMER, BP70, 29280 Plouzane (France); Toury, T. [Laboratoire de Nanotechnologie et d'instrumentation Optique, Institut Charles Delaunay, FRE 2848, Universite de technologie de Troyes, 12 rue Marie Curie, 10010 Troyes (France); Lamy de la Chapelle, M. [Laboratoire CSPBAT (FRE 3043), UFR SMBH, Universite Paris XIII, 74 rue Marcel Cachin, 93017 Bobigny (France)
Sediment porewater partitioning of polycyclic aromatic hydrocarbons in three cores from Boston Harbor, Massachusetts
Polycyclic aromatic hydrocarbon (PAH) concentrations were measured in sediments and porewaters isolated from three cores from Boston Harbor, MA. Measured porewater PAH concentrations were significantly lower than the concentrations predicted by two- and three-phase equilibrium partitioning models. We hypothesize that only a fraction of the measured sediment PAH concentrations was available to partition rapidly into sediment porewaters. ?? 1995 American Chemical Society.
Mcgroddy, S. E.; Farrington, J. W.
Influence of ultraviolet light on the toxicity of sediments contaminated with polycyclic aromatic hydrocarbons
Standard 10-d toxicity tests were conducted with freshwater benthic invertebrates using sediments containing a range of concentrations of polycyclic aromatic hydrocarbons (PAHs). The assays were performed both under normal laboratory fluorescent light and ultraviolet (UV) light, which mimicked wavelengths present in sunlight, at about 10% of ambient solar intensity. In sediments with elevated PAH concentrations, tests conducted with UV light
Gerald T. Ankley; Scott A. Collyard; Philip D. Monson; Patricia A. Kosian
Microbial degradation of polycyclic aromatic hydrocarbons: effect of substrate availability on bacterial growth kinetics
It is demonstrated that bacterial growth on crystalline or adsorbed polycyclic aromatic hydrocarbons can result in a linear increase in biomass concentration. A simple mathematical approach is presented, showing that under these circumstances mass transfer from the solid phase to the liquid phase is rate-limiting for growth.
F. Volkering; A. M. Breure; A. Sterkenburg; J. G. van Andel
Effects of aqueous chemistry on the binding of polycyclic aromatic hydrocarbons by dissolved humic materials
The influence of solution chemistry on the binding of three polycyclic aromatic hydrocarbons (PAHs) by well-characterized humic material (Suwannee River humic and fulvic acid) was examined by using fluorescence quenching techniques. The experiments show that binding is complete within 3 min and that the fluorescence of PAH compounds associated with the humic substances is fully quenched as evidenced by quantum
Mark A. Schlautman; James J. Morgan
A review of atmospheric polycyclic aromatic hydrocarbons: Sources, fate and behavior
A review has been written to assess the sources, fate and behavior of polycyclic aromatic hydrocarbons (PAH) in the atmosphere. PAH are formed mainly by anthropogenic processes, especially the combustion of organic fuels. PAH concentration in air will reflect the location of source emitters, with high concentrations corresponding with urban and industrial areas. PAH are however ubiquitous contaminants of the
S. O. Baek; R. A. Field; M. E. Goldstone; P. W. Kirk; J. N. Lester; R. Perry
Ambient and biological monitoring of cokeoven workers: determinants of the internal dose of polycyclic aromatic hydrocarbons
Polycyclic aromatic hydrocarbons (PAH) were measured in the breathing zone air of 56 battery workers at two cokeovens during three consecutive days. The concentration of total PAH ranged up to 186 micrograms\\/m3. Preshift and end of shift urine samples were collected to determine 1-hydroxypyrene, a metabolite of pyrene. Control urine samples were available from 44 workers in the shipping yard
F J Jongeneelen; F E van Leeuwen; S Oosterink; R B Anzion; F van der Loop; R P Bos; H G van Veen
Characterization of polycyclic aromatic hydrocarbons in motor vehicle fuels and exhaust emissions
Motor vehicles are a significant source of polycyclic aromatic hydrocarbon (PAH) emissions. Improved understanding of the relationship between fuel composition and PAH emissions is needed to determine whether fuel reformulation is a viable approach for reducing PAH emissions. PAH concentrations were quantified in gasoline and diesel fuel samples collected in summer 1997 in northern California. Naphthalene was the predominant PAH
Linsey C. Marr; Thomas W. Kirchstetter; Robert A. Harley; S. K. Hammond; A. H. Miguel
Polycyclic aromatic hydrocarbons in soil and air: statistical analysis and classification by the SIMCA method
Soil samples from 12 locations in Norway have been analyzed for 9 polycyclic aromatic hydrocarbons (PAH). The same unsubstituted PAH have been determined in air samples collected near an aluminum reduction plant. Analysis by high-resolution gas chromatography-mass spectroscopy in the selected ion mode showed concentrations in soil ranging from less than 1 ppb (detection limit) to 993 ppb for individual
Nils B. Vogt; Frode Brakstad; Karin Thrane; Svein Nordenson; Jostein Krane; Eli Aamot; Knut Kolset; Kim Esbensen; Eiliv Steinnes
Kinetics of urea adduct formation in the presence of aromatic hydrocarbons
Here, we are reporting on studies of the influence of aromatic hydrocarbons on adduct formation, with a view toward establishing the relationship between their adsorption interaction and their inhibiting properties. In forming the adducts we used n-heptadecane as the starting material; the urea was crystalline material in \\
�. L. Borovneva; A. N. Belousov; A. G. Martynenko; R. A. Martirosov
Black Carbon in Marine Sediments: Quantification and Implications for the Sorption of Polycyclic Aromatic Hydrocarbons.
Sorption is a key factor in determining the fate of polycyclic aromatic hydrocarbons (PAHs) in the environment. Here, PAH sorption is proposed as the sum of two mechanisms: absorption into a biogenic, organic carbon (OC) fraction and adsorption onto a com...
A. Accardi-Dey
A procedure has been developed for analysis of plant material for polycyclic aromatic hydrocarbons (PAHs). Sonication is used to extract the PAHs from homogenized plant material into acetonitrile and then the PAHs are partitioned into pentane. The pentane extract is fractionated ...
A method for concentration of trace quantities of the six representatives of polynuclear aromatic hydrocarbon (PAH) family has been developed and successfully applied to PAH monitoring in finished and raw waters. PAH are collected by passing water through polyurethane foam plugs....
Comparative studies of the effect of polycyclic aromatic hydrocarbon geometry on the hydrolysis of diol epoxides The interaction of the diol epoxides (DEs) of both planar and non-planar PAHs with water have been examined using quantum mechanical and molecular dynamics. Th...
Immunological disorders associated with polychlorinated biphenyls and related halogenated aromatic hydrocarbon compounds
This review characterizes immunological disorders in fish associated with the widespread environmental contaminants, polychlorinated biphenyls (PCBs), and related halogenated aromatic hydrocarbons (HAHs). Special attention is devoted to comparing the sensitivity of fish species, identifying sensitive immunological endpoints and postulating mechanisms of action.
Noguchi, G. E.
Characterization of polycyclic aromatic hydrocarbons (PAHs) on lime spray dryer (LSD) ash using different extraction methods
In this study, traditional Soxhlet, automatic Soxhlet and ultrasonic extraction techniques were employed to determine the speciation and concentration of polycyclic aromatic hydrocarbons (PAHs) on lime spray dryer (LSD) ash samples collected from the baghouse of a spreader stoker boiler. To test the efficiencies of different extraction methods, LSD ash samples were doped with a mixture of 16 US EPA
Ping Sun; Linda K. Weavers; Panuwat Taerakul; Harold W. Walker
Occurrence of Polycyclic Aromatic Hydrocarbons in Artisanal Palmero Cheese Smoked with Two Types of Vegetable Matter
Palmero cheese is a fresh smoked cheese from the Isle of Palma (Canary Islands), manufactured with goat's milk. To guarantee its safety, the occurrence of polycy- clic aromatic hydrocarbons (PAH) in artisanal Palmero cheese smoked with 2 types of vegetable matter (almond shells and dry prickly pear) was studied. The determi- nation of PAH includes extraction and clean-up steps, followed
M. D. Guill�n; G. Palencia; P. Sopelana; M. L. Ibargoitia
Measurement of Short and Long-Term Toxicity of Polycyclic Aromatic Hydrocarbons Using Luminescent Bacteria
Growing concern over environmental contamination has stimulated rigorous efforts to establish reliable biological monitoring assays. Methodology was developed for measuring photoinduced short- and long-term toxicity of an important group of contaminants, polycyclic aromatic hydrocarbons (PAHs), using the luminescent bacterium Vibrio fischeri. The toxicity of most PAHs can be greatly enhanced on exposure of a living organism and\\/or the chemicals to
Yousef S. El-Alawi; Brendan J. McConkey; D. George Dixon; Bruce M. Greenberg
This research project was conducted to test the hypothesis that fates of polycyclic aromatic hydrocarbons (PAH) in ecosystems can be predicted by mechanistic simulation models based on easily measured properties of the compounds in this homologous series. To accomplish this goal ...
Empirical modeling of soot formation in shock-tube pyrolysis of aromatic hydrocarbons
A method for empirical modeling of soot formation during shock-tube pyrolysis of aromatic hydrocarbons is developed. The method is demonstrated using data obtained in pyrolysis of argon-diluted mixtures of toluene behind reflected shock waves. The developed model is in good agreement with experiment.
Frenklach, M.; Clary, D. W.; Matula, R. A.
Measurement of Polycyclic Aromatic Hydrocarbons in Diesel Exhaust Gas by a Part Flow Process.
A new process for the quantitative analysis of polycyclic aromatic hydrocarbons is described in this report, where the samples are collected by extracting a part flow from the diluted exhaust gas. The important advantage of this method is that apart from ...
A. Hartung J. Kraft J. Schulze H. Hartwig K. H. Lies
Examination of Apollo 17 surface fines for porphyrins and aromatic hydrocarbons
An Apollo 17 surface fines sample 75081,78, collected from Station 5, was extracted and examined fluorometrically. No porphyrins were found with fluorometric methods capable of detecting 2 times 10 to the minus 14th moles/g of Ni-mesoporphyrin IX in the sample. Also aromatic hydrocarbons were undetected.
Rho, J. H.
Dioxins, furans and polycyclic aromatic hydrocarbons emissions from a hospital and cemetery waste incinerator
An experimental campaign was carried out on a hospital and cemetery waste incineration plant in order to assess the emissions of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and polycyclic aromatic hydrocarbons (PAHs). Raw gases were sampled in the afterburning chamber, using a specifically designed device, after the heat recovery section and at the stack. Samples of slags from the combustion
Giuseppe Mininni; Andrea Sbrilli; Camilla Maria Braguglia; Ettore Guerriero; Dario Marani; Mauro Rotatori
Growth characteristics of polycyclic aromatic hydrocarbons in dimethyl ether diffusion flame
The growth characteristics of polycyclic aromatic hydrocarbons (PAHs) in laminar dimethyl ether (DME) diffusion flame were investigated experimentally, and we assumed that the growth of PAHs within the flame was predominantly due to methyl addition\\/cyclization (MAC) mechanism. Methane and propane laminar diffusion flames were also investigated for comparison, and their PAHs growth characteristics had been explained by reactions concerning acetylene
Kazuhiro Hayashida; Toshio Mogi; Kenji Amagai; Masataka Arai
The synthesis and/or purification of a group of polynuclear aromatic (PNA) hydrocarbons, commonly found as pollutants in the environment, are described. The steps used in a given synthesis, the experiments carried out, and a presentation of some instrumental data obtained in esta...
Phototoxicity of individual polycyclic aromatic hydrocarbons and petroleum to marine invertebrate larvae and juveniles
Phototoxicity resulting from photoactivated polycyclic aromatic hydrocarbons (PAHs) has been reported in the literature for a variety of freshwater organisms. The magnitude of increase in PAH toxicity often exceeds a factor of 100. In the marine environment phototoxicity to marine organisms has not been reported for individual or complex mixtures of PAHs. In this study, larvae and juveniles of the
Marguerite C. Pelletier; Robert M. Burgess; Kay T. Ho; Anne Kuhn; Richard A. McKinney; Stephan A. Ryba
Modeling of nitro-polycyclic aromatic hydrocarbon formation and decay in the atmosphere
A reaction mechanism of polycyclic aromatic hydrocarbons (PAH) and nitro-PAH (NPAH) in the gas and particle phase in the atmosphere has been further evaluated and modified using outdoor smog chamber experimental results. Diesel exhaust emissions were added to a 190 m3 outdoor smog chamber and permitted to age under conditions of daylight and darkness. A sampling train consisting of an
Zhihua Fan; Danhua Chen; Parag Birla; Richard M. Kamens
Sampling precautions for the measurement of nitrated polycyclic aromatic hydrocarbons in ambient air
Because of the toxicity of polycyclic aromatic hydrocarbons (PAHs) and of their oxidation products, such as nitrated and oxygenated PAHs (NPAHs and OPAHs), the determination of their concentrations is of great interest in terms of atmospheric pollution control. Then, normalisation of sampling procedures appears essential. In this context, this paper presents a comparison of particulate PAH, OPAH and NPAH concentrations
A. Albinet; E. Leoz-Garziandia; H. Budzinski; E. ViIlenave
Atmospheric concentrations of polycyclic aromatic hydrocarbons and selected nitrated derivatives in Greater Cairo, Egypt
Polycyclic aromatic hydrocarbons (PAHs) and selected nitrated derivatives (NPAHs) in air were determined at two sites, El Dokki (a traffic site) and El Teppen (an industrial site) in Greater Cairo, Egypt, during the winter and summer seasons. The sites were selected to represent areas with different activities of Greater Cairo. The concentrations of fifteen PAHs having two to six rings
Hossam F. Nassar; Ning Tang; Takayuki Kameda; Akira Toriba; Mamdouh I. Khoder; Kazuichi Hayakawa
This paper focuses on the removal of nitro substituted polycyclic aromatic hydrocarbon compounds (NPAHs) from water using low cost synthesized zirconium phosphate mesoporous materials. These materials are lamellar type incorporating n-alkyl-(n = 12 and n = 16) trimethylamonium bromide molecules with different concentrations. For comparison of their performance as adsorbents and in the recovery of NPAH, their results were compared
M. Algarra; M. V. Jim�nez; F. G. S�nchez; J. Soto; J. J. Jim�nez; Joaquim C. G. Esteves da Silva
The objective of the project was to evaluate a potential collection medium, XAD-4 resin, for collecting nicotine and polynuclear aromatic hydrocarbon (PAH) and to determine whether one collection system and one analytical method will allow quantification of both compound classes ...
Photoinduced Toxicity to Lake Erie Phytoplankton Assemblages from Intact and Photomodified Polycyclic Aromatic Hydrocarbons
Pulse amplitude modulated (PAM) chlorophyll-a fluorescence is a simple, rapid technique for measuring photosynthetic efficiency in plants and algae that could be a useful biomarker of toxicity in the aquatic environment. PAM Chlorophyll fluorescence was used to detect inhibition of photosynthesis in natural assemblages of Lake Erie phytoplankton incubated with both intact and photomodified polycyclic aromatic hydrocarbons. The maximum efficiency
Christopher A. Marwood; Ralph E. H. Smith; Murray N. Charlton; Keith R. Solomon; Bruce M. Greenberg
Toxicity of aromatic polycyclic hydrocarbons. (Latest citations from the Life Sciences Collection database). Published Search
The bibliography contains citations concerning the toxicity and biochemical effects of aromatic polycyclic hydrocarbons. Topics include effects on metabolism and liver activity, cellular responses, binding characteristics, and the occurrence and path of the compounds in food chains. Bioaccumulation studies in specific areas, and isolation and detection techniques are also considered. (Contains 250 citations and includes a subject term index and title list.)
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Toxicity of aromatic polycyclic hydrocarbons. (Latest citations from the Life Sciences Collection data base). Published Search
Distribution of Petroleum and Aromatic Hydrocarbons at a Former Crude Oil and Natural Gas Production Facility
Site characterization and remediation activities were performed at a former crude oil and natural gas production facility prior to redevelopment of the site. Field activities included delineation, excavation and segregation of approximately 1,250,000 m of soil impacted by total petroleum hydrocarbons (TPH) and the aromatic volatile organic compounds (VOCs) benzene, toluene, ethylbenzene, and xylenes (hereafter, collectively referred to as BTEX).
D. A. Soukup; A. L. Ulery; Steve Jones
The relationship between biomass growth and degradation of polynuclear aromatic hydrocarbons (PAHs) in soil, and subsequent toxicity reduction, was evaluated in 10 in-vessel, bench-scale compost units. Field soil was aquired from the Reilly Tar and Chemical Company Superfund site...
Polycyclic aromatic hydrocarbon burden in ambient air in selected Niger Delta communities in Nigeria
The Niger Delta area in Nigeria has major oil producing and refining centers that characterized enormous industrial activities, especially in the petroleum sector. These industrial processes release different kinds of atmospheric pollutants, of which there is paucity of information on their levels and health implications. The objective of this study was to determine the ambient levels of polycyclic aromatic hydrocarbons
G. R. E. E. Ana; M. K. C. Sridhar; G. O. Emerole
Fluorescence, Absorption, and Excitation Spectra of Polycyclic Aromatic Hydrocarbons as a Tool for Quantitative Analysis
ERIC Educational Resources Information Center
A quantitative and qualitative study of the interplay between absorption, fluorescence, and excitation spectra of pollutants called polycyclic aromatic hydrocarbons (PAHs) is conducted. The study of five PAH displays the correlation of the above-mentioned properties along with the associated molecular changes.
Rivera-Figueroa, A. M.; Ramazan, K. A.; Finlayson-Pitts, B. J.
A pilot-scale study was conducted at a primary aluminum plant to evaluate the removal of benzo(a)pyrene and other polynuclear aromatic hydrocarbons (PAH's) from potline scrubber wastewater. Specific objectives included determining the need for granular activated carbon to remove ...
Exposure to polycyclic aromatic hydrocarbons (PAHs), mutagenic aldehydes and particulate matter during pan frying of beefsteak
ObjectivesCooking with gas or electric stoves produces fumes, especially during frying, that contain a range of harmful and potentially mutagenic compounds as well as high levels of fine and ultrafine particles. The aim of this study was to see if polycyclic aromatic hydrocarbons (PAHs) and higher mutagenic aldehydes which were collected in the breathing zone of the cook, could be
Ann Kristin Sjaastad; Rikke Bramming J�rgensen; Kristin Svendsen
Coal-tar-based pavement sealcoat, polycyclic aromatic Hydrocarbons (PAHs), and environmental health
Studies by the U.S. Geological Survey (USGS) have identified coal-tar-based sealcoat-the black, viscous liquid sprayed or painted on asphalt pavement such as parking lots-as a major source of polycyclic aromatic hydrocarbon (PAH) contamination in urban areas for large parts of the Nation. Several PAHs are suspected human carcinogens and are toxic to aquatic life.
Mahler, B.J.; Van Metre, P.C.
Polycyclic aromatic hydrocarbons affect survival and development of common snapping turtle ( Chelydra serpentina) embryos and hatchlings
Polycyclic aromatic hydrocarbons (PAHs) are toxic compounds found in the John Heinz National Wildlife Refuge in Philadelphia, Pennsylvania. We assessed the impact of PAHs and crude oil on snapping turtle development and behavior by exposing snapping turtle eggs from the Refuge and from three clean reference sites to individual PAHs or a crude oil mixture at stage 9 of embryonic
Robin J. Van Meter; James R. Spotila; Harold W. Avery
A study of the sampling efficiency of two adsorbents, XAD-2 resin and polyurethane foam (PUF), for polynuclear aromatic hydrocarbons (PAH) in air, was performed under summer and winter ambient conditions. Two aspects were investigated: the collection efficiency for ambient PAH va...
A study was conducted to determine whether the High Volume Small Surface Sampler (HVS3) can quantitatively collect polycyclic aromatic hydrocarbons (PAH) will polychlorinated biphenyls (PCB) adsorbed onto house dust from nine houses in Seattle, Washington. In two of the houses, a...
Habitat function of agricultural soils as affected by heavy metals and polycyclic aromatic hydrocarbons contamination
Ecotoxic activity of soils polluted with polycyclic aromatic hydrocarbon (PAH) and heavy metals (HM) was evaluated in pot and laboratory experiments. Plants and soil microorganisms were chosen as test organisms and six different soil materials were used in the study. The applied levels of HM and PAH were aimed to reflect environmental conditions in the �worst case� situation. Zn2+, Pb2+
Barbara Maliszewska-Kordybach; Bo?ena Smreczak
Laboratory tests were conducted to determine the effect of soil gas oxygen concentration on the degradation and mineralization of spiked 14C-pyrene and nonspiked 16 priority pollutant polycyclic aromatic hydrocarbons (PAH) present in the soil. The soil used for the evaluation was...
Photoinduced toxicity of polycyclic aromatic hydrocarbons (PAHs) is dependent on the concentration of compounds present and the dose of light recieved. Of the light present, only those wavelengths absorbed by the compound have the potential to initiate the photochemical events un...
Photoinduced toxicity of polycyclic aromatic hydrocarbons (PAHs) is dependent on the concentration of compounds present and the dose of light received. Of the light present, only those wavelengths absorbed by the compound have the potential to initiate the photochemical events un...
Spatial and temporal variability of particulate polycyclic aromatic hydrocarbons in Mexico City
As part of the Megacities Initiative: Local and Global Research Observations (MILAGRO) study in the Mexico City Metropolitan Area in March 2006, we mea- sured particulate polycyclic aromatic hydrocarbons (PAHs) and other gaseous species and particulate properties, includ- ing light absorbing carbon or effective black carbon (BC), at six locations throughout the city. The measurements were intended to support the
D. A. Thornhill; B. de Foy; S. C. Herndon; T. B. Onasch; E. C. Wood; M. Zavala; L. T. Molina; J. S. Gaffney; N. A. Marley; L. C. Marr
Biodegradation of polycyclic aromatic hydrocarbons in sediments from the Daliao River watershed, China
The Daliao River, as an important water system in Northeast China, was reported to be heavily polluted by polycyclic aromatic hydrocarbons (PAHs). Aerobic biodegradations of four selected PAHs (naphthalene, phenanthrene, fluorene and anthracene) alone or in their mixture in river sediments from the Daliao River water systems were studied in microcosm systems. Effects of additional carbon source, inorganic nitrogen and
Xiangchun QUAN; Qian TANG; Mengchang HE; Zhifeng YANG; Chunye LIN; Wei GUO
Phototoxic response of Lumbriculus variegatus to sediments contaminated by polycyclic aromatic hydrocarbons
The toxicity of certain polycyclic aromatic hydrocarbons (PAHs) to aquatic organisms can be greatly increased upon exposure of the organisms to ultraviolet (UV) radiation present in sunlight. The phenomenon of photoactivation of PAHs had received some attention in the laboratory; however, evaluation of the photoinduced toxicity of PAHs in field settings has been limited. In these studies, in situ chambers
Philip D. Monson; Gerald T. Ankley; Patricia A. Kosian
Additive Toxicity of Binary Mixtures of Phototoxic Polycyclic Aromatic Hydrocarbons to the Oligochaete Lumbriculus variegatus
Toxicity of some polycyclic aromatic hydrocarbons (PAHs) can increase by an order of magnitude, or more, in the presence of solar ultraviolet (UV) radiation. In the environment, PAHs exist as complex mixtures, which generally would include multiple PAHs that could cause photoinduced toxicity. Hence, to accurately predict the potential ecological risk of phototoxic PAHs, it is critical to understand their
Russell J. Erickson; Gerald T. Ankley; David L. DeFoe; Patricia A. Kosian; Elizabeth A. Makynen
Polycyclic aromatic hydrocarbons in soil and plant samples from the vicinity of an oil refinery
Soil samples, and samples of leaves of Plantago major (great plantain) and grass (mixed species) were collected from the vicinity of an oil refinery in Zelzate, Belgium, and analysed for seven polycyclic aromatic hydrocarbons (PAHs). The samples from the site adjacent to the refinery (site 1) contained very high total PAH-concentrations: namely 300, 8 and 2 ?g\\/g dry wt. for
Martine I. Bakker; Berta Casado; Judith W. Koerselman; Johannes Tolls; Chris Koll�ffel
Polycyclic Aromatic Hydrocarbons in stalagmites: Occurrence and use for analyzing past environments
This article presents a preliminary investigation into the value of Polycyclic Aromatic Hydrocarbons (PAHs) as markers for interpreting past environments in karst areas. We analyzed a core sample representing the last 400�years' growth from a massive stalagmite in the Chevaline Cave (Vercors, France), together with the soil overlying the karst directly above the stalagmite. During the last millennium, this area
Yves Perrette; J�r�me Poulenard; Abdel-Ilah Saber; Bernard Fanget; Sylvie Guittonneau; Bassam Ghaleb; Sandrine Garaudee
Influence of volatility on the collection of polycyclic aromatic hydrocarbon vapors with polyurethane foam
Polycyclic aromatic hydrocarbon (PAH) vapor penetration through thin sections of polyurethane foam (PUF) was studied to determine the relationships between sample breakthrough, PAH vapor pressure, and total air volume. Frontal chromatographic movement of fluorene, phenanthrene, anthracene, and pyrene vapors through a PUF bed at high volume airflow was examined. From these fronts, the thickness of foam corresponding to 50% breakthrough
Feng You; Terry F. Bidleman
Locally Aromatic Polycyclic Hydrocarbons as Potential Carriers of Infrared Emission Features
We report B-LYP/6-31G* and B3-LYP/6-31G* density functional theory calculations on a set of polycyclic hydrocarbons, ranging in size from C19H22 to C36H32, combining aromatic (unsaturated) and aliphatic (saturated, sp3-hybridized carbon) ring systems. These locally aromatic polycyclic hydrocarbons (LAPHs), generally exhibiting large deviations from planarity, may be considered as intermediate structures between polycyclic aromatic hydrocarbons (PAHs) and nanodiamonds. Calculated infrared vibrational frequencies are found to be similar to those observed experimentally in spectra of hydrogenated amorphous carbon (HAC) and other carbonaceous solids. In the C-H stretching region (~3.1-3.6 ?m) these species are characterized by strong absorption/emission within both the aliphatic and aromatic C-H bands. They also show spectral features associated with tertiary C-H. Similar features are evident in calculated spectra of the corresponding ions, which we have characterized in some cases. Ionization results in the particular enhancement of a spectral feature typically seen at ~6.4 ?m, in the aromatic C-C stretching region. In keeping with previous experimental and theoretical studies on the spectra of neutral and cationic PAHs, we find that the influence of ionization on the relative intensities of C-C and C-H stretching features is much greater than the influence of molecular structure. We suggest that LAPHs may be significant contributors to emission in Type B unidentified infrared emission sources.
Petrie, Simon; Stranger, Robert; Duley, Walter W.
Laboratory studies of the remediation of polycyclic aromatic hydrocarbon contaminated soil by in-vessel composting.
The biodegradation of 16 polycyclic aromatic hydrocarbons (PAHs), listed as priority pollutants by the USEPA, present in a coal-tar-contaminated soil from a former manufactured gas plant site was investigated using laboratory-scale in-vessel composting reactors to determine the suitability of this approach as a bioremediation technology. Preliminary investigations were conducted over 16 weeks to determine the optimum soil composting temperature (38, 55 and 70 degrees C). Three tests were performed; firstly, soil was composted with green-waste, with a moisture content of 60%. Secondly, microbial activity was HgCl2-inhibited in the soil green-waste mixture with a moisture content of 60%, to evaluate abiotic losses, while in the third experiment only soil was incubated at the three different temperatures. PAHs and microbial populations were monitored. PAHs were lost from all treatments with 38 degrees C being the optimum temperature for both PAH removal and microbial activity. Calculated activation energy values (E(a)) for total PAHs suggested that the main loss mechanism in the soil-green waste reactors was biological, whereas in the soil reactors it was chemical. Total PAH losses in the soil-green waste composting mixtures were by pseudo-first order kinetics at 38 degrees C (k = 0.013 day(-1), R2 = 0.95), 55 degrees C (k = 0.010 day(-1), R2 = 0.76) and at 70 degrees C (k = 0.009 day(-1), R2 = 0.73). PMID:15823743
Antizar-Ladislao, Blanca; Lopez-Real, Joseph; Beck, Angus J
Desorption of polycyclic aromatic hydrocarbons (PAH`s) from calcite and quartz sediments to seawater
Polycyclic aromatic hydrocarbons (PAH`s) are ubiquitous hydrophobic organic pollutants in the marine environment. Many of the PAM`s are classified as possible carcinogens or mutagens, therefore they are of considerable concern to human and environmental health. The highest concentrations are found in coastal regions due to anthropogenic activities including oil spills, tanker operations, incomplete fossil fuel combustion and runoff. The sources and distribution of PAM`s in sediments are fairly well known, while the fate and transport of PAH`s in the marine environment are less known. Desorption is an important factor influencing the fate and transport of hydrophobic molecules at the seawater/sediment interface. The desorption of PAH`s from contaminated marine sediments to the water column/pore water affects the availability of the pollutant to biota. The sorption of PAH`s is determined in part by the organic carbon content of the sediments. The presence of dissolved organic carbon (DOC) in the water column may also influence sorption of hydrophobic molecules. DOC may play an important role in the fate and transport of PAH`s in coastal regions where DOC concentrations are highest. This study presents the results of the desorption of nine PAHs from sediments to seawater. Factors observed included carbon content of sediments, sediment mineralogy, fulvic acid addition to seawater and dissolved organic carbon in seawater.
Sutton, P.L.; Van Vleet, E.S. [Univ. of South Florida, St. Petersburg, FL (United States)
Factors affecting elimination of polycyclic aromatic hydrocarbons from smoked meat foods and liquid smoke flavorings.
This review deals with effects of environmental and physicochemical factors affecting polyaromatic hydrocarbon (PAH) elimination from smoked meat products and liquid smoke flavoring (LSF). In the introductory part, some essential information are aimed at principles of food smoking and PAH formation during smoke generation as a result of incomplete wood combustion. Also, an application of alternative technology for food aromatization using LSF is briefly mentioned. Similarly, latest European legislation, biological effects, and analytical aspects of PAHs are mentioned concisely. The main part is devoted to physicochemical factors affecting the PAH content in smoked meat products, such as light, additional cooking, and packaging, which are able to decrease considerably PAH content in some meat products. The most important effect on PAH concentration decrease in LSF has low-density polyethylene (LDPE) package due to sorption processes on a surface of the plastic with subsequent diffusion into the plastic bulk. A less effective material is polyethylene terephthalate (PET), when only a surface adsorption process comes into account. Moreover, this process is affected also by other compounds presented in liquid media able to compete for the adsorption center on the PET surface. PMID:15945119
Simko, Peter
Monocyclic aromatic hydrocarbons measured by differential optical absorption spectroscopy in urban areas (China)
Monocyclic aromatic hydrocarbons are regarded as one of the most important classes of hydrocarbons in the atmosphere since they are a potential risk for human health and play a key role for photochemical smog formation. Differential Optical Absorption Spectroscopy (DOAS) has been widely used for many trace gases monitoring in the atmosphere however he analysis of aromatic compounds is difficult and the spectral structures from interfering absorbers (e.g. O2) should be very careful to separate correctly. This paper describes a spectral evaluation technique of aromatic compounds from DOAS measurement and summarizes the results of field measurements of benzene toluene xylene (BTX) in Chinese cities Beijing (2000) Shanghai (2001) and Hefei (2002). High concentrations of BTX were observed in Beijing and Shanghai whereas low concentrations in Hefei. This study will provide useful information to help understanding air pollution and atmospheric chemistry processes in urban areas ofChina and thereby contributes towards an improved pollution control strategy in Chinese cities.
Xie, Pinhua; Liu, Wenqing; Liu, Cheng; Yu, Yong; Volkerman, Rainer; Fu, Qiang; Mettendorf, Kai U.; Platt, Ulrich
Environmental assessment of aromatic hydrocarbons-contaminated sediments of the Mexican Salina Cuz Bay.
Concentrations of total aromatic hydrocarbons and extractable organic matter in the water column and sediment were determined in samples collected in the course of the last 20 years from the Salina Cruz Harbor, M�xico, to assess the degree of organic contamination. In sediments, organic compounds accumulate in shallow areas mostly associated with extractable organic matter and fine fractions. Calculated geocumulation index and enrichment factors suggest that contamination could be derived from anthropogenic activities attributed to harbor and ship scrapping activities, as well as transboundary source. Concentration of total aromatic hydrocarbons (as chrysene equivalents) ranged from 0.01 to 534 microg l(-1) in water, and from 0.10 to 2,160 microg g(-1) in sediments. Total aromatic concentration of 5 microg g(-1) is proposed as background concentration. PMID:17295107
Gonz�lez-Mac�as, C; Schifter, I; Lluch-Cota, D B; M�ndez-Rodr�guez, L; Hern�ndez-V�zquez, S
Characterization of polycyclic aromatic hydrocarbons and metals in ashes released from a forest fire
Wildfires have become a permanent source of environmental and societal concerns. Whilst the impacts of wildfire on hydrological and erosion processes are well documented, the stocks and export of polycyclic aromatic hydrocarbons (PAHs) and heavy metals have received considerably less research attention. The ashes produced by wildfires, which include polluting substances such as PAHs and metals, are subject to transport processes by wind and especially by overland flow and water infiltrating into the soil and possibly reaching ground water bodies. In the framework of the FIRECNUTS project, we are studying the stocks of PAHs and selected metals in recently burnt forest stands in north-central Portugal, and their subsequent export by overland flow. The present work, however, will focus on the stocks in the ashes, both immediately after wildfire and three months later. These ashes were collected at two burnt slopes with contrasting forest types, i.e. a eucalypt and a maritime pine stand, the two pre-dominant forest types in the study region. The sixteen PAHs identified by US EPA as priority contaminants were analysed by gas chromatograph, after extraction and column clean up. The contents of vanadium (V), chromium (Cr), cobalt (Co), nickel (Ni), copper (Cu), zinc (Zn), arsenic (As), cadmium (Cd) and lead (Pb) were analysed by inductively coupled plasma- mass spectrometry (ICP-MS), after an acid digestion, while mercury (Hg) was analysed by pyrolysis atomic absorption spectrometry with gold amalgamation. The total concentration of PAHs immediately after the wildfire ranged from 314 ng/g dry weight in the maritime pine stand to 597 ng/g dry weight in the eucalypt stand. Three months later, the total concentration has decreased with 33% in the pine stand but only half (16%) in the eucalypt stand. The composition the PAHs by ring size was dominated by three-rings PAHs. This was true for all samples. The concentrations of various metals differed for the two sampling occasions but not in straightforward manners. Some metals (Co, Ni, Cu, Zn, Cd, Pb and Hg) revealed higher contents immediately after the fire, whereas others (V, Cr and As) did three months later. The present results underline the importance of furthering the knowledge about contamination of soil and water by ashes from wildfires and the associated risks in terms of ecotoxicological effects, both in-situ and in downstream aquatic systems. Keywords: Polycyclic aromatic hydrocarbons (PAH); heavy metals; stocks; ash; wildfires
Campos, I.; Abrantes, N.; Pereira, P.; Vale, C.; Ferreira, A.; Keizer, J. J.
SPITZER'S VIEW ON AROMATIC AND ALIPHATIC HYDROCARBON EMISSION IN HERBIG Ae STARS
The chemistry of astronomical hydrocarbons, responsible for the well-known infrared emission features detected in a wide variety of targets, remains enigmatic. Here we focus on the group of young intermediate-mass Herbig Ae stars. We have analyzed the aliphatic and polycyclic aromatic hydrocarbon (PAH) emission features in the infrared spectra of a sample of 53 Herbig Ae stars, obtained with the Infrared Spectrograph aboard the Spitzer Space Telescope. We confirm that the PAH-to-stellar luminosity ratio is higher in targets with a flared dust disk. However, a few sources with a flattened dust disk still show relatively strong PAH emission. Since PAH molecules trace the gas disk, this indicates that gas disks may still be flared, while the dust disk has settled due to grain growth. There are indications that the strength of the 11.3 {mu}m feature also depends on dust disk structure, with flattened disks being less bright in this feature. We confirm that the CC bond features at 6.2 and 7.8 {mu}m shift to redder wavelengths with decreasing stellar effective temperature. Moreover, we show that this redshift is accompanied by a relative increase of aliphatic CH emission and a decrease of the aromatic 8.6 {mu}m CH feature strength. Cool stars in our sample are surrounded by hydrocarbons with a high aliphatic/aromatic CH ratio and a low aromatic CH/CC ratio, and vice versa for the hot stars. We conclude that, while the overall hydrocarbon emission strength depends on the dust disk's geometry, the relative differences seen in the IR emission features in disks around Herbig Ae stars are mainly due to chemical differences of the hydrocarbon molecules induced by the stellar UV field. Strong UV flux reduces the aliphatic component and emphasizes the spectral signature of the aromatic molecules in the IR spectra.
Acke, B.; Waters, L. B. F. M. [Instituut voor Sterrenkunde, K.U. Leuven, Celestijnenlaan 200D, B-3001 Leuven (Belgium); Bouwman, J.; Juhasz, A.; Henning, Th. [Max-Planck-Institute for Astronomy, Koenigstuhl 17, D-69117 Heidelberg (Germany); Van den Ancker, M. E. [European Southern Observatory, Karl-Schwarzschild-Strasse 2, D-85748 Garching (Germany); Meeus, G. [Departamento de Fisica Teorica C-XV, Universidad Autonoma de Madrid, 28049 Madrid (Spain); Tielens, A. G. G. M., E-mail: email@example.com [Leiden Observatory, P.O. Box 9513, NL-2300 RA Leiden (Netherlands)
Effect of three aromatic hydrocarbons on respiration and heart rates of the mussel, mytilus californianus
The effects of petroleum derivatives on morality of marine invertebrates is now well established. Aromatics are considered to be the most toxic of all oil fractions. Recent studies of marine invertebrates have focused mainly upon respiration, locomotion, and growth. The filter feeding marine bivalves have received primary attention due to their proximity to coastal oil spills, importance in human food consumption and possible role in petroleum hydrocarbon bioconcentration. If these organisms are to be used as monitors in the future, then it is important to learn something of how quickly the bivalve responds metabolically to changes in ambient levels of petroleum hydrocarbons. Respiration and heart activity reveal a great deal of information concerning the physiological state of the bivalve. We report measrements of these two variables in the mussel, Mytilus californianus (Conrad), under conditions of exposure to, and recovery from, three aromatic hydrocarbons.
Sabourin, T.D.; Tullis, R.E.
The photocatalytic degradation of a mixture of 16 polyaromatic hydrocarbons (PAHs) was investigated in aqueous suspensions of high surface area TiO2 illuminated with 310?380 nm ultraviolet light. Triethylamine was utilized for extraction of PAH compounds from motor oil...
[Study on size distribution of 8 polycylic aromatic hydrocarbons in airborne suspended particulates indoor and outdoor].
During Jan. 20-27, 1992, the size distribution of 8 polycyclic aromatic hydrocarbons (PAHs) in airborne suspended particulates in Tokyo, Japan was studied. The results showed that PAHs, 79.0%-94.5% in indoor air and 65.4%-90.4% in outdoor air, were associated with aerodynamic diameter less than 2.5 microns particles. The contents of these PAHs in indoor air were: pyrene (Py) 1.98, benzo (a) anthracene (BaA) 0.92, benzo (k) fluoranthene (BkF) 0.91, benzo (a) pyrene (BaP) 2.13, dibenzo (a,h) anthracene (dBahA) 0.30, benzo (b) chrysene (BbC) 0.15, benzo (g,h,i) perylene (BghiP) 2.56, dibenzo (a,e) pyrene (dBaeP) 0.23 ng/m3 and in outdoor air 3.93, 2.01, 1.41, 2.91, 0.40, 0.19, 3.65 and 0.30 ng/m3 respectively. The indoor/outdoor ratios for these PAHs ranged from 0.46 to 0.79. These PAHs contents were significantly correlative with one another and so were between the PAHs contents and the concentrations of airborne particulates both indoor and outdoor (the correlation coefficients ranged from 0.774 to 0.999). The PAHs contents (excluding Py) and the concentrations of airborne particulates between outdoor and indoor samples also correlated well with each other (correlation coefficients ranged from 0.821 to 0.944). PMID:7744392
Sun, C; Tanabe, K; Koyano, M; Yang, Z; Li, Y; Zhang, J
Aromatic as well as aliphatic hydrocarbon solvent axonopathy.
Superfund sites that contain mixtures of aromatic and aliphatic solvents represent an undefined health hazard. After prolonged exposure to relatively high levels of certain aliphatic solvents (e.g. n-hexane, 2-hexanone), humans and animals develop a dose-dependent neurodegeneration that occurs clinically as a symmetrical peripheral neuropathy. This is triggered by the action of 2,5-hexanedione (1,2-diacetylethane), a 1,4-diketone (gamma-diketone) metabolite that targets proteins required for the maintenance of neuronal (and testicular Sertoli cell) integrity. Certain aromatic solvents (1,2-diethylbenzene, 1,2,4-triethylbenzene) cause electrophysiological changes consistent with sensorimotor neuropathy in rodents, but the underlying mechanisms and pathogenesis are unclear. Our recent studies show that the o-diacetyl derivative and likely metabolite of 1,2-diethylbenzene, 1,2-diacetylbenzene, behaves as a neurotoxic (aromatic) gamma-diketone of high neurotoxic potency. Rats treated with 1,2-diacetylbenzene develop limb weakness associated with proximal, neurofilament-filled giant axonal swellings comparable to those seen in animals treated with the potent 3,4-dimethyl derivative of 2,5-hexanedione. The blue chromogen induced by treatment with 1,2-diacetylbenzene is under study as a possible urinary biomarker of exposure to aromatic solvents (e.g. 1,2-diethylbenzene, tetralin) with neurotoxic potential. Development and validation of sensitive new biomarkers, especially for non-cancer endpoints, will aid in assessing the health risk associated with exposure to hazardous substances at Superfund sites. PMID:12018006