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Guidelines for safe recreational water environments
WHO Library Cataloguing-in-Publication Data World Health Organization. Guidelines for safe recreational water environments. Volume 2, Swimming pools and similar environments. 1.Swimming pools — standards 2.Water quality — analysis 3.Drowning — prevention and control 4.Wounds and injuries — prevention and control 5.Risk management 6.Reference values 7.Guidelines I.Title II.Title: Swimming pools and similar environments. ISBN 92 4 154680 8 (NLM classification: WA 820)
© World Health Organization 2006
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1 2.2 2.4.1 2.2 Outbreaks of viral illness associated with pools .1 1. other impact injuries.1.6 2.2.1 2.4.2 2.1 Hazard identification 3.7 General considerations Types of pools Types of users Hazard and risk Types of hazard encountered Assessment of hazard and risk Degree of water contact Measures to reduce risks Nature of the guidelines References vi viii x xiii 1 1 3 4 5 5 6 8 9 9 10 12 12 14 15 16 18 18 19 19 20 20 21 22 26 28 28 28 iii CHAPTER 2.1 1.4 2.1 Faecally-derived viruses 3.2.8 Drowning Contributory factors Preventive and management actions Spinal injury Contributory factors Preventive and management actions Brain and head injuries Fractures.1.2 1.5 2.5 1.Contents List of acronyms and abbreviations Preface Acknowledgements Executive summary CHAPTER 1.4.2 1.1. DROWNING AND INJURY PREVENTION 2.6 1.3 2. MICROBIAL HAZARDS 3.3 1. cuts and lesions Disembowelment Hazards associated with temperature extremes Injuries associated with 'feature pools' References CHAPTER 3. INTRODUCTION 1.3 1.2 2.7 2.1. dislocations.4 1.
2. CHEMICAL HAZARDS 184.108.40.206. Plasmodium spp.1 4.5 4.5.1 3.4 3.5 3.4 3.4 3.3 3.5.2 3.4.2. Pseudomonas aeruginosa Mycobacterium spp.4.5 3.3.3 3.3 3.3 4.2 3.3 3.1 126.96.36.199 4.4.4 3.2 4.1 3.2 3.2 184.108.40.206 4.7 Exposure Ingestion Inhalation Dermal contact Source water-derived chemicals Bather-derived chemicals Management-derived chemicals Disinfectants pH correction Coagulants Disinfection by-products (DBP) Exposure to disinfection by-products Risks associated with disinfection by-products Risks associated with plant and equipment malfunction References iv GUIDELINES FOR SAFE RECREATIONAL WATER ENVIRONMENTS . and Epidermophyton floccosum References 31 32 33 33 33 34 35 35 35 35 38 39 40 40 43 45 46 47 48 48 49 49 50 51 52 52 52 53 60 60 61 61 61 62 62 63 63 66 66 66 68 71 76 76 CHAPTER 4.2 3.3 4.4.2 3.4.1 3.4 3.3.1 4.2 4.1.1 4.4.3 3.2.6 3.1 3.6. Non-faecally-derived fungi Trichophyton spp.7 220.127.116.11.4.2 4.3 184.108.40.206. Staphylococcus aureus Leptospira interrogans sensu lato Non-faecally-derived viruses Molluscipoxvirus Papillomavirus Non-faecally-derived protozoa Naegleria fowleri Acanthamoeba spp.4 4.6 4.8 Risk assessment Risk management Faecally-derived bacteria Hazard identification Outbreaks of bacterial illness associated with pools Risk assessment Risk management Faecally-derived protozoa Hazard identification Outbreaks of protozoan illness associated with pools Risk assessment Risk management Non-faecally-derived bacteria Legionella spp.7.2 3.1 3.
2 6.2.4 Disinfectant dosing 5.3.1 Turbidity 5.5 Microbial quality 5.7 Bathing load 5.4 Filtration 5.3 6.10.5 184.108.40.206 6.3 pH 5.6 Design and construction Operation and management Pool safety plan Lifeguards Public education and information Signage Education Regulatory requirements Regulations and compliance Registration and certification schemes Conclusions References 80 81 82 82 82 83 87 87 88 88 89 90 90 91 92 93 94 94 94 95 96 99 98 98 99 100 100 103 103 105 105 108 109 110 111 112 113 113 114 APPENDIX 22.214.171.124 6.1 Choosing a disinfectant 5. GUIDELINE IMPLEMENTATION 6.9 Air quality 5.1 6. LIFEGUARDS CONTENTS v .1 Pre-swim hygiene 5.5 Dilution 5.8 Accidental release of faeces or vomit into pools 5.10.2 6.2 Residual disinfectant level 5.1 6.1 6.10.12 References CHAPTER 6.10.2 Coagulation 220.127.116.11 Oxidation–reduction potential (ORP) 5.3 Disinfection 5.3 Disinfection by-products (DBP) 5.11 Cleaning 5.1 Filter types 5.2 Characteristics of various disinfectants 18.104.22.168. MANAGING WATER AND AIR QUALITY 5.CHAPTER 126.96.36.199 Monitoring 5.4.6 Circulation and hydraulics 5.2 6.6 Other operational parameters 5.2 Turbidity measurement 5.1 6.
List of acronyms and abbreviations AFR AIDS BCDMH BDCM cfu CPR CPSC DBAA DBAN DBCM DBP DCAA DCAN DMH FAO GAE HAA HIV HPC HUS HVAC ID50 ILSF ISO JECFA LOAEL MBAA MCAA NOAEL NOEL NTU ORP PAM pfu QMRA TCAA vi accidental faecal release acquired immunodeficiency syndrome bromochlorodimethylhydantoin bromodichloromethane colony-forming unit cardiopulmonary resuscitation Consumer Product Safety Commission (USA) dibromoacetic acid dibromoacetonitrile dibromochloromethane disinfection by-products dichloroacetic acid dichloroacetonitrile dimethylhydantoin Food and Agriculture Organization of the United Nations granulomatous amoebic encephalitis haloacetic acid human immunodeficiency virus heterotrophic plate count haemolytic uraemic syndrome heating. ventilation and air conditioning infectious dose for 50% of the population International Life Saving Federation International Organization for Standardization Joint FAO/WHO Expert Committee on Food Additives and Contaminants lowest-observed-adverse-effect level monobromoacetic acid monochloroacetic acid no-observed-adverse-effect level no-observed-effect level nephelometric turbidity unit oxidation–reduction potential primary amoebic meningoencephalitis plaque-forming unit quantitative microbiological risk assessment trichloroacetic acid .
TCAN TDI TDS THM TOC UFF UV WHO trichloroacetonitrile tolerable daily intake total dissolved solids trihalomethane total organic carbon ultrafine filter ultraviolet World Health Organization LIST OF ACRONYMS AND ABBREVIATIONS vii .
and provides background information on the different types of recreational water activity (swimming. These include a number of normative "guidelines" documents. and activities available for their control through education of users. Excreta and Greywater. and good operation and management. They represent a consensus view among experts on the risk to health represented by various media and activities and on the effectiveness of control measures in protecting health. separate chapters address microbial hazards. The Guidelines for Safe Recreational Water Environments are published in two volumes: • Volume 1: Coastal and Fresh Waters provides an authoritative referenced review and assessment of the various health hazards encountered during recreational use of coastal and freshwater environments. etc. Documents of this type are intended to provide a basis for standard setting.Preface he World Health Organization (WHO) has been concerned with health aspects of the management of water resources for many years and publishes various documents concerning the safety of the water environment and its importance for health. marine algae and chemical aspects. It addresses a wide range of types of hazard. their monitoring and assessment. With regard to water quality. They address a wide range of types of hazard. such guideline documents also describe the principal characteristics of the monitoring and assessment of the safety of the medium under consideration as well as the principal factors affecting decisions to be made in developing strategies for the control of the health hazards concerned. Wherever possible and appropriate. It includes the derivation of guideline values or conditions and explains the basis for the decision to derive or not to derive them. water quality. They are based on critical review of the available evidence. and dangerous aquatic organisms. exposure to heat. such as the Guidelines for Drinking-water Quality and the Guidelines for the Safe Use of Wastewater. T viii . freshwater algae. surfing. cold and sunlight. The Guidelines include both specific guideline values and good practices. water quality. The volume describes prevention and management options for responding to identified hazards. including hazards leading to drowning and injury. • Volume 2: Swimming Pools and Similar Recreational Water Environments provides an authoritative referenced review and assessment of the health hazards associated with recreational waters of this type.) to enable informed readers to interpret the Guidelines in light of local and regional circumstances. good design and construction. including hazards leading to drowning and injury. contamination of associated facilities and air quality.
PREFACE ix . The work of the individuals concerned (see Acknowledgements) was central to the completion of the work and is much appreciated.The preparation of this volume of Guidelines for Safe Recreational Water Environments has covered a period of over a decade and has involved the participation of numerous institutions and more than 60 experts from 20 countries worldwide.
South Africa Brian Guthrie. International Life Saving Federation. The Netherlands Lucia Bonadonna. Geneva. Canada Marilyn L. USA Rudy Calders. Chris Brewster. Geneva. University of Modena. Japan Lothar Erdinger. National Center for Injury Prevention and Control. Istituto Superiore di Sanità. VU University Medical Centre. Alexandria. Germany x T . either in contribution of text or through provision of comments and constructive criticism. USA Joseph Cotruvo. Amsterdam. Switzerland Joost Bierens. National Spa and Pool Institute. University of Modena. Microdiagnostics. Washington. USA Carvin DiGiovanni. Bureau of Environmental and Occupational Epidemiology. Italy Paul C. Royal Tropical Institute (KIT). University of Wales. Spain Willie Grabow. VA. UK Rudy Hartskeerl. Oberschleißheim. DC. The Netherlands Christiane Höller. Norfolk. WHO Regional Office for the Eastern Mediterranean. Tokyo. Browne. is appreciated: Houssain Abouzaid. Antwerp. WHO. Troy. Health Canada. Fantuzzi. NSF International. Australia John Fawell. New York State Department of Health. Egypt Gabrielle Aggazzotti. Rome. University of Heidelberg. Ottawa. Pool Water Treatment Advisory Group.Acknowledgements he assistance of the following persons in the development of the Guidelines for Safe Recreational Water Environments. Flackwell Heath. USA Alfred P. MD. San Diego. National Exposure Research Laboratory. Volume 2: Swimming Pools and Similar Environments. Pretoria. GA. UK Lorna Fewtrell. Cairo. Azienda Comunale Energia e Ambiente (ACEA). Provinciaal Instituut voor Hygienne. CPF Associates. Cincinnati. National Institute of Infectious Diseases. US Environmental Protection Agency. Centre for Research into Environment and Health (CREH). Independent Consultant. NY. Switzerland Rodney Cartwright. Guildford. Aberystwyth. OH. University of Pretoria. Atlanta. Modena. Italy Norman Farmer. Dufour. Italy Jamie Bartram. USA Takuro Endo. Bavarian Health and Food Safety Authority. Rome. Modena. Tarragona-Reus. Amsterdam. Takoma Park. Chrostowski. Institute for Hygiene. Italy Christine Branche. Belgium Richard Carr. CA. Germany G. UK Maria Jose Figueras. US Centers for Disease Control and Prevention. WHO. UK Maurizio Cavalieri. USA B. University Rovira and Virgili. Melbourne. International Life Saving Federation. USA Teresa Brooks.
National Center for Environmental Assessment. New York. MD. Aberystwyth. Greece Charles Mbogo.G. USA Athena Mavridou. the States of Jersey.. Askham Bryan College. Mannings Heath. Switzerland Albrecht Wiedenmann.. United Kingdom. DC. Saltash. UK Laura Tew. USA Jeff Soller. Royal National Lifeboat Institution. Guildford. Washington. Swedish Institute for Infectious Disease Control. Stuttgart. UK M. the Ministry of Environment of Germany. Broxbourne. USA Ralph Riley. Hungary Simon Kilvington. UK Jeff Sloan. Rice. Independent Consultant. Kenya Medical Research Institute. USA Eric Mood. UK Kathy Pond. National Institute of Hygiene. UK Pranav Joshi. Lyon. Yale University. Budapest. Baden-Württemberg State Health Office. University of Surrey. WHO. NY. Arlington. York. Surrey. Canada Henry Salas. Institute of Sport and Recreation Management. France Art Mittelstaedt. Australia Ernst Stottmeister. Charleston. Cornwell. MI. Federal Environment Agency (UBA). Peru Ian Scott. VA. Salisbury. UK The preparation of these Guidelines would not have been possible without the generous support of the following. Devon. RICE International Consulting Enterprises. UK (formerly of WHO European Centre for Environment and Health. Recreational Safety Institute. Stockholm. USA Phil Penny. Arch Chemicals. Health Protection Agency. McGregor (formerly of International Programme on Chemical Safety). Leicester. University of East Anglia. UK Owen Hydes. TP Pool Water Treatment Services Ltd. National Environment Agency. Singapore Mihaly Kadar. the Department of the Environment. WHO. Robens Centre for Public and Environmental Health. Pan American Center for Sanitary Engineering and Environmental Science. USA Carolyn Vickers. Geneva. USA Gareth Rees. Sanget. Stevenson & Associates Pty Ltd. Norwich. Occidental Chemical Corporation. Loughborough. University of Leicester. UK Tom Kuechler. USA Thor-Axel Stenström. Rome.. Bad Elster. NSF International. UK (formerly of the Surf Life-Saving Association of Great Britain. Technological Educational Institution of Athens. Sweden Paul Stevenson. Switzerland Geoff Shute. New Haven.Paul Hunter. the Ministry of Health of Germany. Chlorine Chemistry Council. UK Will Robertson. Kenya Douglas B. University of Wales. Tintometer Ltd. Transport and the Regions of the United Kingdom. Health Canada. Italy) Terry Price. UK) Peter Wyn-Jones. which is gratefully acknowledged: the European Commission. ACKNOWLEDGEMENTS xi . Ottawa. Kilifi. London. IL. Ann Arbor. School of Medicine. Rayer. Sydney. Independent Consultant. CT. Plymouth. Geneva. US Environmental Protection Agency. UK R. Germany Adam Wooler. Ashton. Department of Microbiology and Immunology. TN. Lima. Taunton. Independent Consultant. Athens. the Ministry of Health of Italy. Germany Susanne Surman-Lee.
xii GUIDELINES FOR SAFE RECREATIONAL WATER ENVIRONMENTS . Thanks are also due to Lorna Fewtrell for editing the complete text of the Guidelines and overseeing the review process and finalization of the Guidelines. Windy Gancayo-Prohom and Evelyn Kortum-Margot for providing secretarial and administrative support. and the United States Environmental Protection Agency.the Swedish International Development Cooperation Agency. Penny Ward. Marla Sheffer for editing the initial draft and Grazia Motturi.
cleaned and refilled for each user) and natural spas (facilities using thermal and/or mineral water). or • a combination of the last two. Although bathing houses. When a guideline is exceeded. the principles outlined in the Guidelines should also be generally applicable to these environments. public. semi-public or domestic. for the purposes of these Guidelines. are often aerated and are not drained. is the term used to encompass a variety of facilities that are designed for sitting in. supervised or unsupervised. The primary aim of the Guidelines is the protection of public health. T xiii . • a concentration of a constituent that does not represent a significant risk to the health of members of significant user groups.Executive summary his volume of the Guidelines for Safe Recreational Water Environments describes the present state of knowledge regarding the impact of the recreational use of swimming pools and similar environments upon the health of users – specifically drowning and injury. microbial contamination and exposure to chemicals. whether they are indoors or outdoors. The preferred approaches adopted by national or local authorities towards implementation of guideline values and conditions may vary between these types of environment. semi-public and domestic hot tubs (which. Control and monitoring of the hazards associated with these environments are discussed. contain treated water usually above 32 °C. A guideline can be: • a level of management. this should be a signal to investigate the cause of the failure and identify the likelihood of future failure. marine or thermal water. such as hammams. The information provided is generally applicable to pools supplied with fresh. The purpose of the Guidelines is to ensure that swimming pools and similar recreational water facilities are operated as safely as possible in order that the largest possible population gets the maximum possible benefit and not to deter the use of these recreational water environments. are not specifically covered. • a condition under which exposures with a significant risk are unlikely to occur. to liaise with the authority responsible for public health to determine whether immediate action should be taken to reduce exposure to the hazard. Information also relates to public. and to determine whether measures should be put in place to prevent or reduce exposure under similar conditions in the future. The Guidelines are intended to be used as the basis for the development of approaches to controlling the hazards that may be encountered in recreational water environments.
Barrier fencing should be at least 1. It has been suggested that in terms of swimming pools and similar environments most drownings occur in domestic pools and hot tubs.or footholds that could enable a young child to climb it. many while the child's supervisor assumed the child was safely indoors. Of sports-related spinal cord injuries. hand. Injuries in diving incidents are almost exclusively located in the cervical vertebrae. The recovery rate from near-drowning may be lower among young children than among teenagers and adults. For domestic or outdoor hot tubs. Few preventive measures for drowning and near-drowning have been evaluated. Most studies of accidental drowning have focused on children. In swimming pools and similar environments. an accessible and/or pressure-activated emergency shut-off for the pump and the wearing of bathing caps. and in some countries drowning is the leading cause of injury deaths among younger age groups. Studies show that the prognosis for survival depends more on the effectiveness of the initial rescue and resuscitation than on the quality of subsequent hospital care. whereas lapses in parental supervision are most frequently cited for incidents involving children. Warnings displayed in the form of clear and simple signs as well as water safety instruction and adult supervision all may have value as preventive actions. running on decks. Above-ground pools should have steps or ladders leading to the pool that can be secured and locked to prevent access when the pool is not in use. Other injuries associated with the use of swimming pools and similar environments include brain and head injuries and arm. leg and foot/toe injuries. it is recommended that locked safety covers be used when the hot tub is not in use. Data suggest that diving into the upslope of a pool bottom or into the shallow portion of the pool is the most common cause of spinal injuries in pools. the majority appear to be associated with diving. although installation of isolation fencing around outdoor pools has been shown by some studies to decrease the number of pool immersion injuries by more than 50%.2 m high and have no hand. Causes include slippery decks.Drowning and injury prevention Drowning. Preventive measures for hair and body entrapment in pools and similar environments include the use of grilles on drain gates that prevent hair entrapment. alcohol consumption is one of the most frequently reported contributory factors associated with drownings and neardrownings for adults. Fence slats should be no more than 10 cm apart. Alcohol consumption may contribute significantly to the frequency of injury. resulting in quadriplegia (paralysis affecting all four limbs) or paraplegia (paralysis of both legs). reckless water entry. which is defined in these Guidelines as death arising from impairment of respiratory function as a result of immersion in liquid. is a major cause of death worldwide. Education and raising awareness appear to offer the most potential for diving injury prevention. uncovered drains. causing the victim's head to be held under water. xiv GUIDELINES FOR SAFE RECREATIONAL WATER ENVIRONMENTS . Expert opinion suggests that the latter are common and generally go unreported. Also of concern is the danger of drownings and near-drownings due to inlets and outlets where the suction is strong enough to cause entrapment of body parts or hair. Pool fences around domestic pools should have a self-closing and self-latching gate and should isolate the pool. tripping on swimming aids left on the poolside and stepping on glass (from broken bottles). Near-drowning is also a serious problem. dual drains. as it may have lifelong effects.
Where pools or spas are not disinfected. vomiting.Maintenance of surfaces (including appropriate waste disposal). muscle cramps and loss of consciousness. from birds and rodents). Symptoms associated with shigellosis include diarrhoea. Episodes of gross contamination of pool water due to an accidental faecal release. norovirus and echovirus have also been implicated in pool-related disease outbreaks. warnings from pool staff and regulations on time limits for use can reduce these adverse outcomes. Microbial hazards The risk of illness or infection associated with swimming pools and similar recreational water environments is primarily associated with faecal contamination of the water. may be the result of direct animal contamination (e. fever and abdominal cramps. whereas symptoms of cryptosporidiosis include diarrhoea. foul-smelling stools. however. They also both have high infectivity and are shed in high densities by infected individuals. bacteria. as well as vomiting and fever in more severe cases. loss of appetite. which are used in conjunction with saunas or steam baths. although hepatitis A. fatigue and vomiting. hypothermia. Many of the outbreaks related to pools and similar environments have occurred because disinfection was not applied or was inadequate. but have been linked to viruses. occurs most frequently in infants. HUS. ensuring good underwater visibility and pool safety education are among the actions that can reduce these incidents. loss of control of breathing. and it is recommended that water temperatures in hot tubs be kept below 40 °C. Exposure to low temperatures in plunge pools. supervision of pool users. Symptoms of E. can cause drowsiness.g. Temperature extremes should be avoided by users with medical problems. Educational displays and warning signs. for example. which may lead to loss of consciousness or to heat stroke and death. High temperatures in hot tubs. impaired coordination. in the case of outdoor pools. fever and nausea. characterized by haemolytic anaemia and acute renal failure. accidental EXECUTIVE SUMMARY xv . Shigella and Escherichia coli O157 are two related bacteria that have been linked to outbreaks of illness associated with swimming in pools. including filtration and the proper application of chlorine or other disinfectants. and the causative viruses have rarely been isolated from the water. Non-faecal human shedding into the pool water or surrounding area is also a potential source of pathogenic organisms. This may be due to faeces released by the bathers or contaminated source water or. It should be borne in mind that the evidence linking viral outbreaks to a pool is generally circumstantial. Viral outbreaks are most often attributed to adenovirus. coli O157 infection include bloody diarrhoea (haemorrhagic colitis) and haemolytic uraemic syndrome (HUS). Swimming pool-related outbreaks of illness are relatively infrequent. providing appropriate warnings. pregnant women and young children. young children and elderly people. The control of viruses and bacteria in swimming pool water is usually accomplished by appropriate treatment. These two organisms have a cyst or oocyst form that is highly resistant to both environmental stress and disinfectants. cannot all be effectively controlled by normal treatment and disinfectant levels. The risk of illness in swimming pools associated with faecally-derived protozoa mainly involves two parasites: Giardia and Cryptosporidium. Giardiasis is characterized by diarrhoea. cramps. may result in slowed heart beat. protozoa and fungi.
The only approach to maintaining public health protection under conditions of an accidental faecal release is to prohibit the use of the pool until the potential contaminants are inactivated. Most of the legionellosis. Pseudomonas aeruginosa is also frequently present in hot tubs. as it is able to withstand high temperatures and disinfectants and to grow rapidly in waters supplied with nutrients from users. where possible. daily). dermal or central nervous system infections or diseases. Thorough cleaning of the area surrounding the hot tub on a frequent basis (e. In addition. ventilation and air-conditioning systems) or on other wet surfaces within the facility to a point at which they may cause a variety of respiratory. Thus. including the importance of limiting contact between xvi GUIDELINES FOR SAFE RECREATIONAL WATER ENVIRONMENTS . nutrient-containing aerobic water) for the selection and proliferation of Legionella. Pool operators can help prevent faecal contamination of pools by encouraging preswim showering and toilet use and. Natural spas (especially thermal water) and hot tub water and the associated equipment create an ideal habitat (warm. and P. aeruginosa in hot tubs than in pools. papillomavirus (which causes benign cutaneous tumours – verrucae). Opportunistic pathogens (notably bacteria) can also be shed from users and be transmitted via both surfaces and contaminated water. an often serious infection caused by Legionella species. confining young children to pools small enough to drain in the event of an accidental faecal release. In addition. frequent backwashing and filter inspection and good ventilation are all recommended control measures. facility operators should require users to shower before entering the water and control the number of users and the duration of their exposure. the most important means of controlling the spread of the infections is educating the public about the diseases.faecal releases present an even greater problem. hot tub or natural spa waters. In hot tubs. Molluscipoxvirus (which causes molluscum contagiosum). Epidermophyton floccosum and various species of fungi in the genus Trichophyton (which cause superficial fungal infections of the hair. Infected users can directly contaminate pool waters and the surfaces of objects or materials at a facility with primary pathogens (notably viruses or fungi) in sufficient numbers to lead to skin and other infections in users who subsequently come in contact with the contaminated water or surfaces. through physical contact with contaminated surfaces. It is less easy to control the growth of Legionella spp. a number of infectious non-enteric organisms may be transferred through pool water and the surrounding environment via human shedding. in public and semi-public facilities. associated with recreational water use has been associated with public and semi-public hot tubs and natural spas. in pool or hot tub components or facilities (including heating.g. fingernails or skin) are spread by direct person-to-person contact or indirectly. as the design and operation of hot tubs can make it difficult to achieve adequate residual disinfection levels in these facilities. the primary health effect associated with the presence of P. aeruginosa is folliculitis. As the primary source of these viruses and fungi in swimming pools and similar environments is infected bathers. as are programmed 'rest periods' to allow disinfectant levels to 'recover'. an infection of the hair follicles that may result in a pustular rash. frequent monitoring and adjustment of pH and disinfectant levels are essential. It is recommended that people with gastroenteritis not use public or semi-public facilities while ill or for at least a week after their illness. complete draining and cleaning of the hot tub and pipework on at least a weekly basis. As well as pathogenic enteric organisms. certain free-living aquatic bacteria and amoebae can grow in pool.
12 mg/m3 is recommended in order to protect bathers and staff working in the pool building. but in public and semi-public pools these should not exceed 3 mg/l and in public and semi-public hot tubs should not exceed 5 mg/l. The amount of water ingested by swimmers and bathers will depend upon a range of factors. generally for outdoor pools. Dermal exposure depends upon the period of contact with the water.infected and non-infected people and medical treatment. Swimmers inhale from the atmosphere just above the water's surface. chlorinated isocyanurates). added to minimize the risk to pool users from microbial contaminants. age. inhalation of volatile or aerosolized solutes and dermal contact and absorption through the skin. Where ozone is used. known as disinfection by-products. skill and type of activity. soap residues. A number of disinfectants can react with other chemicals in the water to give rise to unwanted by-products. but there is evidence from model studies with amino acids that other organic substances will also give rise to a similar range of by-products. levels of cyanuric acid in pool water should not exceed 100 mg/l. including experience. and the volume of air inhaled is a function of the intensity of effort and time. deliberate additions such as disinfectants and pool users themselves (these include sweat. Practice varies widely around the world. Although there is potentially a large number of by-products. Experimental evidence suggests that water intake varies according to age and sex. the substances produced in the greatest quantities are trihalomethanes. hypochlorite or. urine. The principal management-derived chemicals are disinfectants. ozone and ultraviolet (UV) radiation (with ozone and UV usually being used in combination with a chlorineor bromine-based disinfectant). as do the levels of chemicals that are currently considered to be acceptable in order to achieve adequate disinfection while minimizing user discomfort. Chemical hazards Chemicals found in swimming pool water can be derived from a number of sources. Thorough frequent cleaning and disinfection of surfaces in facilities that are prone to contamination can also reduce the spread of the diseases. water temperature and the concentration of the chemical. Where chlorinated isocyanurates are used. Most is known about the by-products that result from the reaction of chlorine with humic and fulvic acids. Acids and alkalis may also be added to the water in order to maintain an appropriate pH for optimal water treatment and also the comfort of bathers. colloidal or suspended material. It is recommended that acceptable levels of free chlorine continue to be set at the local level. It is recommended that total bromine does not exceed 4 mg/l in public and semi-public pools and 5 mg/l in hot tubs. chlorine dioxide. an air quality guideline of 0. The chemical disinfectants that are used most frequently include chlorine (as a gas. Coagulants may be added as part of the water treatment process to enhance the removal of dissolved. Inhalation exposure will be largely associated with volatile substances that are lost from the water surface. with adult women ingesting the least and male children ingesting the most. within a hot tub (for example) or where there is significant splashing. There are three main routes of exposure to chemicals in swimming pools and similar environments: direct ingestion of the water. namely the source water. of which chloroform is generally present in the greatest EXECUTIVE SUMMARY xvii . but will also include some inhalation of aerosols. bromochlorodimethylhydantoin (BCDMH). cosmetics and suntan oil).
Although there are data to indicate that the concentrations of chlorination by-products in swimming pools and similar environments may exceed the concentrations proposed by WHO for drinking-water. reflecting the level of available information. cosmetics. of which di. The chloramines and bromamines. and adequate ventilation of indoor facilities. All of these challenges can be met through the combination of the following factors: treatment (to remove particulates.concentrations. addition of fresh water at frequent intervals (to dilute substances that cannot be removed from the water by treatment). controlling water quality to prevent the transmission of infectious disease and controlling potential hazards from disinfection by-products. pool water is cleaner. urine. faecal matter. particularly nitrogen trichloride and nitrogen tribromide. Pre-swim showering will help to remove traces of sweat. Trihalomethanes are volatile in nature and can be lost from the surface of the water. in typical order of public health priority. Trihalomethanes have been considered more than other chlorination by-products. easier to disinfect with smaller amounts of chemicals and thus more pleasant to swim in. All users should also be encouraged to use the toilets before bathing to minimize urination in the pool and accidental faecal releases. can give rise to significant eye and respiratory irritation in swimmers and pool attendants. dichloramine and nitrogen trichloride) and bromamines. competitive swimmers and pool attendants can experience substantial exposure to volatile disinfection by-products via inhalation and dermal absorption. sediments from the pool floor and particulates adsorbed to filter materials). including disinfection and filtration. The risks from exposure to chlorination by-products in reasonably well managed swimming pools would be considered to be small and must be set against the benefits of aerobic exercise and the risks of microbial disease in the absence of disinfection. cleaning (to remove biofilms from surfaces. expressed as nitrogen trichloride. so they are also found in the air above the pool. The provisional guideline value for chlorine species. pool hydraulics (to ensure effective distribution of disinfectant throughout the pool and removal of contaminated water). which are both volatile. chlorine dose. xviii GUIDELINES FOR SAFE RECREATIONAL WATER ENVIRONMENTS . Concentrations vary as a consequence of the concentration of precursor compounds. shorter exposure periods and non-ingestion exposure. while making appropriate allowance for the much lower quantities of water ingested. pollutants and microorganisms). Both chlorine and bromine will react with ammonia in the water (resulting from the presence of urine) to form chloramines (monochloramine. suntan oil and other potential water contaminants. Where pool users normally shower before swimming. concentrations less than the drinking-water guideline values can be consistently achieved. The guideline values in the WHO Guidelines for Drinking-water Quality can be used to screen for potential risks arising from swimming pools and similar environments. the evidence indicates that for reasonably well managed pools. and the haloacetic acids.5 mg/m3. controlling clarity to minimize injury hazard. in the atmosphere of swimming pools and similar environments is 0. temperature and pH. Managing water and air quality The primary water and air quality health challenges are. Nevertheless.and trichloroacetic acid are generally present in the greatest concentrations.
Particulate removal through coagulation and filtration is important for removing Cryptosporidium oocysts and Giardia cysts and some other protozoa that are resistant to chemical disinfection. it should be possible to see a small child at the bottom of the pool from the lifeguard position while the water surface is in movement. Accidental faecal releases may occur relatively frequently. based on risk assessment at each pool. disinfected water. If residual disinfectant levels are satisfactory. type. upper-limit guideline for turbidity is 0. which partially inactivates agents added to the pool by bathers. Coagulation. size and location of the pool. The concentration of disinfection by-products can be controlled to a significant extent by minimizing the introduction of precursors though source water selection. including safety. Circulating pool water is disinfected during the treatment process. Good circulation and hydraulics in the pool ensure that the whole pool is adequately served by filtered. Treated water must get to all parts of the pool. If filtration is poor. a universal turbidity value is not considered appropriate. and the entire water body is disinfected by the application of a residual disinfectant (chlorine. it should be retrieved quickly and discarded appropriately. with the remainder taken from the bottom of the pool. no further action is necessary. but it is recommended that. the addition of fresh water to disinfected pools should not be less than 30 litres per bather. that some volatile disinfection by-products (such as chloroform and nitrogen trichloride) may be produced in the pool water and escape into the air. Disinfection will also be compromised. The scoop used to retrieve the faeces should be washed carefully and disinfected after use. pre-swim showering). If the faecal release is solid. It is inevitable. filtration and disinfection will not remove all pollutants. as much depends on the characteristics of the specific pool. good bather hygienic practices (e. bathing load and the operation of the pool. Individual standards should be developed. chlorination) or physical (e. as a minimum. as particles associated with turbidity can surround microorganisms and shield them from the action of disinfectants.g.Disinfection is part of the treatment process whereby pathogenic microorganisms are inactivated by chemical (e. disinfection by-products and various other dissolved chemicals. a useful. constituents of sweat and urine).e. Dilution limits the build-up of pollutants from bathers (e. As a general rule. The choice of disinfectant depends upon a number of factors. compatibility with the source water. For identifying bodies at the bottom of the pool.or bromine-based). Swimming pool design should enable the dilution of pool water with fresh water. This hazard can be managed to some extent through good ventilation of indoor pool buildings.g.g. however.5 nephelometric turbidity units. although it is likely that most go undetected. water clarity will decline and drowning risks increase. A pool operator faced with an accidental faecal release or vomit in the pool water must act immediately. UV radiation) means such that they represent no significant risk of infection. maximizing their removal by well managed pool water treatment and replacement of water by the addition of fresh supplies (i. Pool operators should replace pool water as a regular part of their water treatment regime. It is recommended that 75–80% be taken from the surface (where the pollution is greatest). but not absolute. dilution of chemicals that cannot be removed). and polluted water must be removed – especially from areas most used and most polluted by bathers.g. Where the stool is runny (diarrhoea) or if EXECUTIVE SUMMARY xix . In terms of effective disinfection. Filtration is important in ensuring a safe pool.
including exercise and relaxation.2 and 7. It is suggested that the residual disinfectant concentration in domestic pools be determined before use.2 and 8. In indoor facilities.8 for chlorine disinfectants and between 7. as much of the material as possible should be collected. disinfectant residual and pH) should be monitored most frequently and in all pool types. samples of pool water from public and semi-public pools should be monitored at appropriate intervals for microbial parameters. The safest course of action in small pools or hot tubs is to evacuate users. experience has shown that adequate routine disinfection should be achieved with a free chlorine level of 1 mg/l throughout the pool. xx GUIDELINES FOR SAFE RECREATIONAL WATER ENVIRONMENTS . There is limited risk of significant microbial contamination and illness in a well managed pool or similar environment with an adequate residual disinfectant concentration. Lower free chlorine concentrations (0. Where draining is not possible. clean and refill. including heterotrophic plate count. well operated filters and frequent monitoring of non-microbial parameters. the situation should be assessed and action taken. The pH value of swimming pool water (and similar environments) must be controlled to ensure efficient disinfection and coagulation. Guideline implementation Recreational water activities can bring health benefits to users.5 mg/l or less) will be adequate when chlorine is used in combination with ozone or UV disinfection. residual disinfectant concentrations should be checked by sampling the pool before it opens and during the opening period (ideally during a period of high bathing load). and building code ventilation rates should be adhered to. because of higher bathing loads and higher temperatures. the pool should be cleared of people immediately. For a conventional public or semi-public swimming pool with good hydraulics and filtration. to avoid damage to the pool fabric and to ensure user comfort. This is important not only for staff and user health. the situation is likely to be more hazardous. thermotolerant coliforms or E. Effective management can control potential adverse health consequences that can be associated with the use of unsafe recreational water environments. removed and disposed of to waste. disinfectant levels should be maintained at the top of the recommended range or shock dosing used. drain. Higher concentrations (up to 2–3 mg/l) may be required for hot tubs. the water should be filtered for six turnover cycles. Nevertheless. using a coagulant (if appropriate). operating within its design bathing load. Total bromine concentrations should not exceed 4 mg/l in public and semi-public pools and 5 mg/l in hot tubs.there is vomit. If the routine test results are outside the recommended ranges. but also for their comfort and to avoid negative impacts on the building fabric. Parameters that are easy and inexpensive to measure and of immediate operational health relevance (such as turbidity. In public and semi-public pools.0 for bromine-based and other non-chlorine processes. The pH should be maintained between 7. Pseudomonas aeruginosa and Legionella. The frequency of monitoring and the guideline values vary according to microbial parameter and the type of pool. coli. it is important to manage air quality as well as water quality in swimming pools and similar recreational water environments. a pH value maintained at an appropriate level. and the filter should be backwashed.
possibly. its monitoring and maintenance. National legislation may include different sets of regulations that will apply to swimming pools and similar recreational environments. public health bodies. pool-based clubs and sports bodies can play an important role in ensuring pool safety through public education and providing appropriate and targeted information to pool users. although there may be overlap between these and stakeholders with responsibilities falling within more than one category: • Design and construction. Facility operators. which consists of a description of the system. should be aware of the requirements to ensure safe and enjoyable use of facilities. This should include the preparation of and compliance with a pool safety plan. • Public education and information. local authorities. a generic emergency plan and an emergency evacuation procedure. their operation and management and control of substances hazardous to health. the design and construction of pools. Many decisions taken at the design and construction phase will have repercussions on the ease with which safe operation can be ensured once the pool is in use. along with designers and contractors. Facility operators play a key role and are responsible for the good operation and management of the recreational water environment. • Operation and management. Local regulatory oversight can support the work of pool management and provide greater public health protection and public confidence. for example. Regulation may control. Inspections by the regulatory officials to verify compliance with the regulations are an important component of this oversight.Different stakeholders play different roles in the management of the recreational water environment for safety. staff registered to certain bodies. normal operating procedures. • Regulatory requirements (including compliance). People responsible for commissioning pools and similar environments. The typical areas of responsibility may be grouped into four major categories. EXECUTIVE SUMMARY xxi . Within regulations it is likely that there will be a requirement for the use of certified material and. Successful implementation of the Guidelines will also require development of suitable capacities and expertise and the elaboration of a coherent policy and legislative framework. procedures for specified incidents.
Managing water and air quality to minimize health risks is covered in Chapter 5. as well as the monitoring and control of the hazards associated with these environments. In general. pH control and disinfection with a range of disinfectants. as well as providing a framework for policymaking and local decision-taking.CHAPTER 1 Introduction his volume of the Guidelines for Safe Recreational Water Environments describes the present state of knowledge regarding the possible detrimental impacts of the recreational use of swimming pools and similar recreational water environments upon the health of users. The use of swimming pools and similar recreational water environments – and the resulting social interaction. These are covered in Chapters 2. including those posed by microbes and chemicals. all available information on the different uses of water and routes of exposure was taken into consideration. This chapter covers the structure of this volume of the Guidelines for Safe Recreational Water Environments and introduces definitions of pool types. pool users and so on. This can encompass filtration. respectively. In the development of these Guidelines. The hazards from drowning and injury are probably the most obvious hazards relating to pools and similar environments. although there are also less visible hazards. The Guidelines may also be used as reference material for industries and operators preparing to develop facilities containing swimming 1 . relaxation and exercise – is associated with benefits to health and well-being. Most pools and similar environments apply treatment in managing water quality to ensure that the water is of an acceptable clarity and microbial and chemical quality. The purpose of the Guidelines is to ensure that the pools and similar environments are operated as safely as possible in order that the largest possible population gets the maximum possible benefit. while the roles of various stakeholders.1 General considerations The hazards that are encountered in swimming pools and similar environments vary from site to site. The primary aim of the Guidelines for Safe Recreational Water Environments is the protection of public health. 3 and 4. This volume of the Guidelines for Safe Recreational Water Environments is structured as shown in Figure 1.1. most available information relates to health outcomes arising from exposure through swimming and ingestion of water. The Guidelines are intended to be used as the basis for the development of approaches to controlling the hazards that may be encountered in swimming pools and similar recreational water environments. regulatory measures and guideline implementation are dealt with in Chapter 6. T 1. as does exposure to the hazards.
for example) and domestic (private) facilities (see Section 1. Vol. Drowning and injury prevention 3. general educational activities to enhance awareness of health hazards and inform users on ways to avoid and respond to the hazards. Because hazards may give rise to health effects after short. These range from proper facility planning to good operation and management practices. are not specifically covered. and compliance with applicable regulatory requirements. the approaches outlined in these Guidelines should also be generally applicable to these environments. Managing water and air quality 6.2). monitoring and implementation enable preventive and remedial actions within real time frames. 2: Swimming Pools and Similar Environments pools and similar environments. hotels and schools. Chemical hazards 5. The information provided in this volume of the Guidelines is intended to be generally applicable to public. provision of appropriate levels of supervision (i. Structure of Guidelines for Safe Recreational Water Environments. and nongovernmental organizations – have diverse management interventions. Guideline implementation Design & construction Operation & management Public education & information Regulatory requirements Figure 1. semi-public (as encountered in clubs. Concerned bodies – including national and local agencies. as well as a checklist for understanding and assessing the potential health impacts of projects involving the development of such facilities.e. emphasis in the Guidelines is placed upon identifying circumstances and procedures that are likely to lead to a continuously safe environment for recreation. it is important that standards. lifeguards). such as hammams. Introduction 2. 2 GUIDELINES FOR SAFE RECREATIONAL WATER ENVIRONMENTS . For this reason. This approach emphasizes monitoring of both conditions and practices and the use of threshold values for key indicators assessed through programmes of monitoring and assessment. facility owners and operators. Although medical facilities (such as hydrotherapy pools) and bathing houses.as well as long-term exposures.1.1. The preferred approaches adopted by national or local authorities towards implementation of guideline values and conditions may vary between these types of environment. Microbial hazards 4.
Plunge pools are usually used in association with saunas. For the purposes of these Guidelines. outdoors (i. diving pools and pools with special features such as 'flumes' or water slides. competent government authorities should take into account social. In the case of swimming pools and similar environments. there are many specialist pools for a particular user type – for example. cleaned or refilled for each user. bubble baths and Jacuzzi (a term that is used generically but is in fact a trade name). including spa pools. These would deal with. These guidelines use a risk–benefit approach. health club. Swimming pools may be located indoors. school. safety of associated facilities and dissemination of information. and it is used by people of all ages and abilities. marine or thermal water (i. there are physical therapy pools.g. such as aqua-aerobics. In developing strategies for the protection of public health. with no extra water features (other than possible provision for diving).3). development of such an approach concerns not only health risks.2 Types of pools Swimming pools may be supplied with fresh (surface or ground).g. in which treatments for a variety of physical symptoms are performed by professionals on people with neurological. cruise ship) or public (e. semi-public (e. including the general education of adults and children as well as the efforts and initiatives of nongovernmental organizations and industry operators in this area. they are considered to be the same as swimming pools. They may be domestic. water quality. some of which may be perceived to have therapeutic value and because of certain water characteristics may receive minimal water quality treatment. economic and environmental factors. learner or teaching pools. but can be larger. In addition.6). scuba diving and so on (see Section 1. municipal). from natural hot springs). They are usually only large enough for a single person. are generally aerated. This approach can often lead to the adoption of standards that are measurable and can be implemented and enforced. Hot tubs. public or municipal pool. A broad-based policy approach is required that will include legislation enabling positive and negative incentives to alter behaviour and monitor and improve situations. for the purposes of these Guidelines. In addition. whirlpool spas. and successful implementation will require development of suitable capacities and expertise as well as the elaboration of a coherent policy and legislative framework. steam rooms or hot tubs and are designed to cool users by immersion in unheated water. numerical guideline values are presented as indicators of safety or good management (as described in Section 1.e. which are often used in the domestic setting. whirlpools. Such a broad base will require significant efforts in intersectoral coordination and cooperation at national and local levels. Although termed swimming pools. they may be heated or unheated. contain treated water and are not drained. Natural spa is the term used to refer to facilities containing thermal and/or mineral water. for example. contain water usually above 32 °C. and they may be supervised or unsupervised. hotel. semi-public or public and located indoors or outdoors. they are often used for a variety of recreational activities.Where possible. the conventional pool is often referred to as the main. In terms of structure. paddling pools. There are also temporary or portable pools.e. They may be domestic (private). CHAPTER 1. heated spas. but also the health benefits and well-being derived from the recreational use of these environments. open air) or both. is the term used to encompass a variety of facilities that are designed for sitting in (rather than swimming). INTRODUCTION 3 . 1. housing complex. It is by tradition rectangular. A wide range of names is used for them.
These types of therapy pools are not covered by the Guidelines. Each type of pool has potentially different management problems. microbial quality and disinfectant concentrations. GUIDELINES FOR SAFE RECREATIONAL WATER ENVIRONMENTS . They may also pose an increased risk of injury compared with land-based pools. Of importance to the type of pool and its management is identification of how the pool will be used: • • • • the daily opening hours. These are operated as drain and fill pools or baths and are not covered by these Guidelines. In many countries. A very high rate of water exchange is necessary (even if not completely effective) if there is no other way of preventing microbial contamination. Hot tubs. by recycling or disinfection) because the agents believed to be of benefit. Also. These are not specifically covered by the Guidelines.3 Types of users Users may include: • • • • 4 the general public. children/babies. such as sulfides. and special requirements.g. The type. 2005). may be subject to high bather loads relative to the volume of water. therefore. pools may include sudden changes in depth. hotel guests. Pools and hot tubs on ships are also a special case. lanes and equipment. such as temperature. There are also therapy pools containing small fish (Garra ruffa) that feed on the scaly skin lesions caused by psoriasis. require non-oxidative methods of water treatment (see Chapter 5). cardiac or other diseases. which must be anticipated and dealt with by pool managers. the peak periods of use. which may result in wading non-swimmers suddenly finding themselves out of their depth). in some natural spas utilizing thermal and mineral waters it may not be possible to treat the water in the usual way (i. In certain circumstances. would be eliminated or impaired. 1. circulation and treatment systems of the pool will necessitate a unique design in order to be able to deal with movement of the ship and the variable source water quality (outlined in more detail in WHO. The hydraulic. as the source water may be either seawater or from the potable water supply for the ship. chemical substances of geological origin in some types of deep thermal springs and artesian wells (such as humic substances and ammonium) may hamper the effect of disinfectants when these waters are used to fill pools without any pretreatment.e. These natural spas. the anticipated number and types of users.orthopaedic. although many of the same principles that apply to swimming pools and hot tubs will also apply to hydrotherapy pools. for example. design and use of a pool may present certain hazards (e. there are public hygiene facilities to enable individuals and families to bathe. these are termed 'hydrotherapy pools' and are defined as pools used for special medical or medicinal purposes. tourists. it may become difficult to maintain satisfactory pH. Where there are high water temperatures and rapid agitation of water. especially when used in heavy seas. where complete drain-down between users is not possible.
Strictly speaking. the terms hazard and risk are used interchangeably. trip and fall accidents. Correctly. competitive swimmers. clients of outdoor camping parks. hazard is the potential for harm. The rate of incidence or attack rate is the number of events expected to occur for this defined quantum of hazard.4 Hazard and risk Popularly. aqua-aerobics). 1. Human behaviour. probabilities and rates obey different laws.g. CHAPTER 1. use of non-slip surfaces. while risk is the chance that harm will actually occur. while less severe. Other injuries.4. 2003). drowning. Preventive and remedial actions take diverse forms and include general education. heat. near-drowning or injury). In simpler terms. agility and stamina limitations. however. near-drowning and spinal injury are severe health outcomes of great concern to public health. exercise class members (e. non-swimmers. INTRODUCTION 5 . preventing rough play or running poolside. the two values will be approximately equal. and air quality. including scuba divers. Drowning. canoeists and water polo participants. and specialist sporting users. illness or loss of life. Certain groups of users may be more predisposed to hazards than others. cause distress and decrease the benefits to well-being arising from recreation. a hazard is a set of circumstances that could lead to harm – harm being injury. the availability of health services such as first aid. For example: • Children may spend long periods in recreational waters and are more likely than adults to intentionally or accidentally swallow water. the availability of communication with health and rescue services. cold and sunlight (see also WHO. is a prime factor that increases the likelihood of injuries.1 Types of hazard encountered The most frequent hazards associated with the use of swimming pools and similar recreational water environments are: • • • • physical hazards (leading to. and the cleaning of pools and associated facilities. water quality. including clients of theme parks.• • • • • • • health club members. for example.1. leisure bathers. posting of warnings where appropriate. if the probabilities are small and the events are independent. preventing the use of glass near the pool. The risk of such an event is defined as the probability that it will occur as a result of exposure to a defined quantum of hazard. especially alcohol consumption. such as cuts and those arising from slip. Specific examples of the hazards and the associated adverse health outcomes are given in Table 1. the presence of lifeguards. • Immunocompromised individuals may be at higher risk from microbial or chemical hazards. • The elderly and handicapped may have strength. 1.
Figure 1. fungi and protozoa. Heat exposure in hot tubs or natural spas (using thermal water) or cold exposure in plunge pools (2). For example. 1. The impact may be driven by the participant (diving.4. 2003). the health risks associated with contamination by excreta and associated gastroenteric outcomes have been the topic of both scientific and general public interest. eye and ear infections arising from pollution of water by excreta from source waters and from bathers as well as non-enteric organisms arising from bathers or those naturally present in the aquatic environment. treading on broken glass and jagged metal – especially in outdoor pool surroundings). 2003). poor pool design and maintenance (2). Adverse health outcomes associated with microbial hazards also include skin.Table 1. which may be present in water and pool surroundings as a result of faecal contamination. Ingestion of. accidents arising from the use of water slides.2 Assessment of hazard and risk Assessments of hazard and risk inform the development of policies for controlling and managing risks to health and well-being in water recreation. Adverse health outcomes associated with hazards encountered in swimming pools and similar recreational water environments Type of adverse health outcome Drowning Impact injuries Examples of associated hazards (with chapter references in parentheses) Swimmers under the influence of alcohol. eye irritation and some additional eye infections probably occur as a result of reduction in the eye's natural defences through limited contact with water and do not relate to water quality or pollution per se. ingestion of algal toxins and inhalation of chemically contaminated air (4). Cumulative exposure to sun for outdoor pool users (refer to Volume 1 of the Guidelines – WHO. carried by participants or animals using the water or naturally present (3). no supervision. Impact against hard surfaces (2). Acute exposure to heat and ultraviolet (UV) radiation in sunlight (refer to Volume 1 of the Guidelines – WHO. Contact with. inhalation of or contact with pathogenic bacteria. Hazards to human health exist even in unpolluted environments. A severe health outcome such as permanent paralysis or 6 GUIDELINES FOR SAFE RECREATIONAL WATER ENVIRONMENTS . poor swimming ability. as well as the interpretation of data. collision. Physiological Infection Poisoning. Both draw upon experience and the application of common sense. In particular. inhalation of or ingestion of chemically contaminated water. toxicoses and other conditions that may arise from long-term chemical exposures Much attention has focused in recent years upon microbial hazards.2 provides a schematic approach to comparing health hazards encountered during recreational water use. viruses.1.
and thus require lower management priority. may affect only a small number of pool users annually but will warrant a high management priority. selflimiting (e. upper respiratory tract infection.2.g.) No incapacity (e. clinical surveillance of the incidence of illness and outbreaks. minor cuts. etc. of outcomes per bather-year) Low Very low priority Low priority Moderate priority Very high priority Extremely high priority High Life-threatening or permanent incapacity (e.) Low Figure 1. Systems for surveillance of public health operate in some countries. Figure 1.g. spinal injury. drowning. Minor skin irritations. as a result of diving into shallow water. Although 'incident records' held by local pools and authoritative bodies may be comprehensive. They serve the broad purpose of alerting either regulator or supplier to changes in incidence of CHAPTER 1. encountered at the other end of the scale. plantar warts.2 can be applied throughout the Guidelines.g. Legionnaires' disease or primary amoebic meningoencephalitis) Long-term incapacity (e. For each hazard discussed.Relative risk (e. most mild diarrhoea. sunburn. Schematic approach to comparing health hazards encountered during recreational water use death. scrapes. published statistics are seldom sufficiently detailed for risk assessment. may affect a higher number of users per year.g. INTRODUCTION 7 . epidemiological studies and surveys. Data on risk related to the use of swimming pools and similar recreational water environments take four main forms: • • • • national and regional statistics of illness and deaths. the severity of the hazard can be related to the relative risk in the figure and can serve as a tool to initiate further research or investigation into the reduction of risk as well as to highlight or emphasize priority protective or remedial management measures. leptospirosis) Relative severity Short-term incapacity. chronic sequelae as a result of microbial infection) Moderate incapacity or requires medical intervention (e. etc.g.g. near-drowning. and accident and injury records held by facility owners/managers and local authorities. but do not result in any significant incapacity.
flooding due to storm events) and misadventure in recreation. lifeguards).3 Degree of water contact For hazards where contact with water and ingestion of water are important. For example. natural disasters (e. as well as from ingesting pathogen-contaminated water. will considerably modify the risk. is the most reliable information. accompanied by clinical diagnosis. For example. 2005). There are considerable difficulties in determining causes in the cases of low-level exposures to chemical and physical agents that have a cumulative or threshold effect and of infectious diseases caused by those pathogens that have more than one route of infection or have a long period of incubation. Epidemiology may also be used as a research tool to investigate hypotheses concerning the causes of illness.disease and to the need for initiating immediate investigation of the causes and remedial action. lysozyme secretion in tears. the digestive tract and phagocytosis). enjoyment arises from the use of skill to avoid and overcome perceived hazards. sex. • Assessment of harm itself and the degree of harm suffered depends upon judgement at the time.g. The former comprises a wide range of biological and environmental factors (age. gastroenteric infections at swimming pool facilities may result from person-to-person contact or faulty food hygiene in catering. Galbraith & Palmer (1990) give details of the use of epidemiology in surveillance.. see Gerba et al.4.g. The degree of competence of participants and the use of properly designed equipment. national statistics on deaths by drowning will usually include suicides. Survey information is only as good as the care that has gone into the design and conduct of the survey. 1996). their memory of the events and any personal bias of the subject and interviewer. as well as body defences (impregnability of the skin. 1. Medical certification of injury and of physiological illness and infection. Such investigation will involve epidemiology (the study of the occurrence and causes of disease in populations). • Where data are in the form of published regional or national statistics giving attack rates. accompanied by appropriate supervision and training. • The causes of harm must be ascertained as far as possible at the time. occupational accidents (e. Information obtained by survey or questionnaire will contain a variable degree of uncertainty caused by the subjects' understanding of the questions. an understanding of the different degrees of contact associated with different pool types and uses is helpful. the exact basis on which the data are collected and classified must be ascertained. socioeconomic and geographic). nutrition. mucus and sweat. the degree of water contact directly influences the 8 GUIDELINES FOR SAFE RECREATIONAL WATER ENVIRONMENTS . There are other reasons why it is difficult to estimate risk directly. Previous challenge by pathogens often results in transient or long-lasting immunity. For example. such as the following: • In most active water sports. Immunocompromised individuals will be at greater risk of acquiring infectious diseases (see Pond. • It cannot be assumed that risk is directly proportional to exposure or that risks from multiple exposures or a combination of different factors will combine additively. • Risks of acquiring infectious disease will be influenced by innate and acquired immunity (for examples.
amount of exposure to pathogens and toxic agents found in contaminated water and aerosols and therefore the likelihood of illness. The degrees of water contact encountered in the many different types of swimming pools and similar recreational water environments may be classified as follows: • No contact – for example, use of outdoor pools just for sunbathing and not swimming. • Meaningful direct contact – involves a negligible risk of swallowing water, such as the use of a wading pool by adults. • Extensive direct contact – with full body immersion and a significant risk of swallowing water, e.g. swimming, diving.
1.5 Measures to reduce risks
Reduction of most, if not all, of the health risks associated with the hazards described in Table 1.1 can be obtained by avoiding the circumstances giving rise to the hazard or by mitigating their effect. For example, glass left on the poolside may cause cuts to walkers with bare feet, which may be overcome by regular cleaning of the pool, excluding glass from the pool area, provision of litter bins and educational awareness campaigns. Accidents caused by misuse of water slides may be overcome by increased supervision by lifeguards and education of users regarding proper behaviour. Each type of recreational activity should be subject to a hazard assessment to determine what type of control measures will be most effective. Assessment should include modifying factors, such as local features, seasonal effects (for outdoor pools) and competence of the participants. Controls for reducing risks in swimming pools and similar environments are discussed in Chapters 5 and 6. Different uses and types of pools involve different degrees of water contact and exposure to the various hazards. Measures for risk reduction will therefore be tailor-made to each pool type and to particular circumstances. Management of swimming pools and similar recreational waters can be classified into four major categories (as described in Chapter 6): • design and construction of facilities (including licensing and authorization, as appropriate); • operation and management (including pool safety plan and lifeguard training); • public education and information; and • regulatory requirements (including licensing of equipment, chemicals, etc., available for use in swimming pools and similar environments).
1.6 Nature of the guidelines
A guideline can be a level of management, a concentration of a constituent that does not represent a significant risk to the health of members of significant user groups, a condition under which exposures associated with a significant risk are unlikely to occur, or a combination of the last two. In deriving guidelines including guideline values, account is taken of both the severity and frequency of associated health outcomes. Recreational water use areas conforming to the guidelines may, however, present a health risk to especially susceptible individuals or to certain user groups. When a guideline is exceeded, this should be a signal to investigate the cause of the failure and identify the likelihood of future failure, to liaise with the authority responsible for public health to determine whether immediate action should be taken
to reduce exposure to the hazard, and to determine whether measures should be put in place to prevent or reduce exposure under similar conditions in the future. For most parameters, there is no clear cut-off value at which health effects are excluded, and the derivation of guidelines and their conversion to standards therefore include an element of valuation addressing the frequency and nature of associated health effects. This valuation process is one in which societal values play an important role. The conversion of guidelines into national policy, legislation and standards should therefore take account of environmental, social, cultural and economic factors. Many of the hazards associated with swimming pools and similar recreational water environments may give rise to health effects after short-term exposures: accidents and exposures to microbial infective doses may occur in very short periods of time. Shortterm deviations above guideline values or conditions are therefore of importance to health, and measures should be in place to ensure and demonstrate that recreational water environments are continuously safe during periods of actual or potential use. This volume of the Guidelines for Safe Recreational Water Environments does not address: • occupational exposures of individuals working in recreational water environments; • waters afforded special significance for religious purposes and which are therefore subject to special cultural factors; • therapeutic uses of water (hydrotherapy, balneotherapy or thalassotherapy); • facilities, such as bathing houses, that are drained and refilled between users; • risks associated with ancillary facilities that are not part of swimming pools and similar recreational water environments — thus, while poolside surfaces are addressed, toilet facilities in adjacent areas are not considered beyond assertion of the need for them in order to minimize soiling of the recreational environment; • 'biopools', which are artificially created small 'lakes' (which can be either indoors or outdoors) that are sealed against groundwater and natural surface water influence and are becoming increasingly popular. In these pools the water is not disinfected but is circulated through 'regeneration' areas (reeds or soil filters); • electrocution; • hazards associated with UV radiation (from sunlight); • aesthetic factors; • beneficial effects, health claims, the efficacy of therapeutic use or the scale of health benefits arising from relaxation and exercise associated with recreational water use; or • rescue, resuscitation or evacuation procedures from swimming pools and other recreational water facilities.
1.7 References
Galbraith S, Palmer S (1990) General epidemiology. In: Smith GR, Easmon CSF, eds. Topley and Wilson's principles of bacteriology, virology and immunity. Vol. 3. Bacterial diseases. London, Edward Arnold, pp. 11–29. Gerba CP, Rose JB, Haas CN (1996) Sensitive populations: who is at the greatest risk? International Journal of Food Microbiology, 30(1–2): 113–123.
Pond K (2005) Water recreation and disease: An expert review of the plausibility of associated infections, their acute effects, sequelae and mortality. IWA on behalf of the World Health Organization, London, UK. WHO (2003) Guidelines for safe recreational water environments. Vol. 1. Coastal and fresh waters. Geneva, World Health Organization, 219 pp. WHO (2005) Guide to ship sanitation. Geneva, World Health Organization, in preparation.
2. 2003). shown in Table 2.and middle-income countries (Peden & McGee. Analysis of figures from the whole 12 . • • • • This chapter addresses these adverse health outcomes. Browne et al.e. their causation and contributory factors. 382 million people drowned worldwide. A wider definition of drowning includes outcomes ranging from no morbidity to morbidity to death (World Congress on Drowning.1. in 2002. In the USA. along with evidence concerning preventive measures.g. occurred in swimming pools or hot tubs. not confined to swimming pools) for the USA. 2000.. 2003. with domestic pools predominating (123 cases). and this is the definition employed in these Guidelines. 2002). 2004). 2005). with 97% of drownings occurring in low. Smith. Blum & Shield. 2003. Drowning is a major cause of death. Not all drownings are related to recreational water use. 156 (18%) took place in pools or hot tubs (Browne et al. although the majority of available data relate to developed countries. support the observation from numerous studies that children less than 5 years of age and young adults between the ages of 15 and 24 years have the highest drowning rates (e. brain and head injuries). A total of 883 nonbathtub drownings that took place in-state were included in the study. Almost 60% of drownings in children aged 0–4 years. It is the third leading cause of death in children aged 1–5 and the leading cause of mortality due to injury. major impact injuries (spinal. however. slip. trip and fall injuries. WHO. Of these. and disembowelment. 2003).1 Drowning Drowning has been defined as death arising from impairment of respiratory function as a result of immersion in liquid. Prominent among them are: drowning and non-fatal or near-drowning. an investigation into drownings in New York State residents (with a population of almost 18 million) between 1988 and 1994 found that there were on average 173 drownings a year (1210 over the seven-year period). with the mortality rates in male children being almost twice as high as those in female children (Peden & McGee. Overall drowning statistics (i.. and the percentage that is attributable to swimming pools and similar environments is likely to vary from country to country. and it has been estimated that.CHAPTER 2 Drowning and injury prevention A number of injuries may result from the use of swimming pools and similar recreational water environments.
CHAPTER 2. 2004).19 2. 1987) found that for every 10 children who die by drowning. with most of these drownings occurring in hotel or apartment pools. During a period of over 20 years (since 1980).86 1. The recovery rate from near-drowning may be lower among young children than among teenagers and adults. lakes..Table 2.) than in swimming pools.05 1. that at least 14 British children drowned while abroad. Studies show that the prognosis depends more on the effectiveness of the initial rescue and resuscitation than on the quality of subsequent hospital care (Cummings & Quan. the USA Consumer Product Safety Commission (CPSC) has received reports of more than 700 deaths in hot tubs. DROWNING AND INJURY PREVENTION 13 . Browne et al. 1990). In the Netherlands. Liller et al. however.13 1.15 1.1. it has been reported that on average there are about 300 drowning fatalities a year and an additional 450 cases who survive the drowning incident.93 1. Analysis of data from the USA for 2001–2002 led to the estimation that about 4174 people on average each year are treated in hospital emergency departments for non-fatal drowning injuries in recreational water settings.83 1. 390 are admitted to hospital for further treatment (Bierens. 1993). Some survivors suffer subsequent anoxic encephalopathy (Pearn et al. although pools still account for a substantial proportion of drowning. Death by drowning is not the sole outcome of distress in the water. although some never recover.58 Deaths 533 223 225 388 327 291 1996 Rates 2. 1985. Pearn & Nixon. In the State of Arizona. (2003) reported that there are on average 173 drownings among New York State residents every year. etc.. Approximately one third of these were drownings of children under five years of age (CPSC. children are more likely to drown in natural water bodies (sea. In the United Kingdom.. USA.80 1.76 1..43 1. 2002). 2004). with 19% of drowning deaths in children aged 0–14 years being attributable to pools in 1988–1989. 1976. undated).08 1. Drowning statistics for the USA (per 100 000)a Ages (years) 0–4 5–9 10–14 15–19 20–24 25–29 a 1997 Deaths 516 234 215 349 316 298 Rates 2. These authors note.29 2. 1999). One study (Wintemute et al. 1977) leading to long-term neurological deficits (Quan et al. 1989). with 18% of fatal drownings occurring in swimming pools (CDC.16 1.19 1.54 Adapted from National Center for Health Statistics. 140 are treated in emergency rooms and 36 are admitted to hospitals for further treatment (see also Spyker. of these. 1996).53 Deaths 596 222 242 442 348 292 1995 Rates 3. over 65% of these cases occurred in swimming pools and over 52% were in children under the age of 5 (CDC. and it is estimated that there are 177 non-fatal hospitalizations. Near-drowning is also a serious problem.. 85% of emergency calls relating to drownings and near-drownings in children aged four or less were associated with swimming pools (CDC. 1998 of the USA for 2001 reveals similar results.69 1. and 11% in 1998–1999 (Sibert et al.
Quan et al. 1989). causing the victim's head to be held under water. 1988. 17 (22%) occurred in the domestic pool of a relative and 8 (10%) occurred in a neighbour's domestic pool (M. Hair entrapment occurs when the water flow into the inlet takes the bather's hair into and around the outlet cover. Asher et al. 1988. with excellent swimming skills. Levin et al. In this study.. there are conflicting opinions as to the role of swimming skills in preventing drowning and near-drowning (Patetta & Biddinger. Howland et al. 43 of 77 (56%) of the drownings in children aged 0–4 occurred in the child's family pool. In the USA. 1985). Peden & McGee. Although hyperventilation makes it possible for a person to extend his or her time under water.. 1995. 1993. almost exclusively males. although alcohol consumption by the parent or guardian may also play a role in the lapse of supervision (Petridou. 2005)... Petridou. • access directly from the house. 1974. Nichter & Everett. Alcohol consumption is one of the most frequently reported contributory factors associated with adolescent and adult drownings in many countries (Howland & Hingson. lapses in parental supervision are the most frequently cited contributory factor (Quan et al. Hyperventilation before breath-hold swimming and diving has been associated with a number of drownings among individuals. 2003). pers. 1989. Although the proportion of alcohol-related drownings is often not presented according to body of water (and swimming pools and hot tubs are the site of relatively few adult and adolescent drownings). 1996).). Mackie. and the hair is pulled into the drain as a result of the suction created. Most accidents involve people with shoulder-length or longer hair. a similar study found that more than half of the children studied drowned in unfenced or unsecured pools and hot tubs. 1985). Browne et al.2. 2005). no separate fence (completely enclosing the pool area) or fence in disrepair. 1989. 2005). The following were found to be the most common: • open or unlocked gate or ineffective latch. Browne. • no fence.). 1978. Plueckhahn. 1979. 1976. While a high proportion of persons drowning are non-swimmers or poor swimmers (Spyker. This is generally attributed to higher exposure to the aquatic environment and a higher consumption of alcohol (leading to decreased ability to cope and impaired judgement) and their inclination towards higher risk-taking activity (Dietz & Baker. Brenner. Among children. Browne. comm. during a six and a half 14 GUIDELINES FOR SAFE RECREATIONAL WATER ENVIRONMENTS . Browne et al. Where children gained access to fenced pools. Spyker. (2003) examined the means of access of young children involved in domestic swimming pool drownings. comm. pers. most did so through faulty or inadequate gates or through gates that were propped open (Blum & Shield. 2003.. it may result in a loss of consciousness by lowering the carbon dioxide level in the blood and decreasing the partial oxygen pressure in the arterial blood on surfacing (Craig. 2000).1.g. pool filters)..1 Contributory factors Males are more likely to drown than females (Browne et al.. In Australia. Access has also infrequently been as a result of climbing onto objects next to the pool fence (e. in one study a blood alcohol screen was positive for approximately 50% of drowning victims over 14 years of age (M. Inlets and outlets where the suction is extremely strong can trap body parts or hair. 2003. and • ladder to above-ground pool left in accessible 'down' position.
especially in combination with alcohol consumption.. 1995). Lapses in supervision may make this an insufficient preventive measure alone (Quan et al. 1988. Young children. are particularly likely to play with open drains. undated). between 1990 and 1996. Mackie. 1993). The need for adult supervision is not decreased when young children acquire increased skills. Children should be taught to stay away from water and pools when unsupervised. the CPSC received reports of 49 incidents of hair entrapment/entanglement in hot tubs. inserting hands or feet into the pipe and then becoming trapped with the resulting suction. may cause drowsiness. typically between the ages of 8 and 16 years. • those related to the staff.1. Swimming pool designers need to consider this when locating windows and designing lighting systems. 1991). pool users and lifeguards may not be able to identify people in distress. barriers such as fences or walls will prevent some drownings by preventing a child from entering a swimming pool area unsupervised or may delay their entry long enough for the carer to realize they are missing. 2. such as water depth. 2005). This suction problem may also occur in the main pool drains of swimming pools. 1989). Surprisingly. For domestic pools. A number of drowning deaths have also occurred after the body or a limb has been held against a drain by the suction of the circulation pump.year period. Natural and artificial reflected light from the water surface may also affect vision in a similar way to poor water clarity. 2005). such as lack of proper training for emergency response. and • those related to the pool facility. 13 of which resulted in drowning (CPSC. a person entering the pool may not be able to see someone under the water or may not be able to judge the pool bottom configuration. consequently. 2002.g.. and the value of swimming lessons and water safety instruction as drowning preventive measures has not been demonstrated (Patetta & Biddinger. Mackie. drowning (Press. Any open drain or flat grating that the body can cover completely. such as a pre-existing health condition (e. there is no clear evidence that drowning rates are greater in poor swimmers (Brenner. In addition. water clarity. which may lead to unconsciousness and. Water clarity is particularly critical to water safety. but to a much lesser extent than with hot tubs.2 Preventive and management actions It has been estimated that over 80% of all drownings can be prevented. High temperatures (above 40 °C) in spas or hot tubs. DROWNING AND INJURY PREVENTION 15 . In the USA. If it is not possible to see the bottom of the pool at its deepest point. and the possibility that training decreases parental vigilance has not been assessed (Asher et al. Further contributory factors in drowning and near-drowning include: • those related to the bather. undated). pool configuration and pool size. and prevention is the key management intervention (World Congress on Drowning. There is a significant debate regarding the age at which swimming skills may be safely acquired. presents this hazard. care must also be taken to prevent unauthorized entry (especially by young children). 2005). CPSC reported 18 cases of body entrapment over a 20-year period.5). CHAPTER 2. Ten of these resulted in disembowelment (see Section 2. seizure disorder – Ryan & Dowling. combined with a plumbing layout that allows a build-up of suction if the drain is blocked. but for outdoor pools. and five other cases were fatal (CPSC.
The principal contributory factors and preventive actions (some of which have received scientific evaluation) concerned with drowning and near-drowning are summarized in Table 2. Above-ground pools should have steps or ladders leading to the pool that can be secured and locked to prevent access when the pool is not in use. 1988. the child could slip under the cover and be trapped by it. conducted in Australia. Liller et al. In fact. (2003). Care should also be taken to ensure that poolside equipment is not positioned such that it may be used to climb the fence and access the pool. Kyriacou et al.5 m/s and there should be a minimum of two outlets to each suction line. and according to the Think First Foundation (2004). 2005) has been reported to be important in determining the outcome of potential drownings. which separates the pool from the remaining yard and house. it is recommended that the velocity of water flowing from the pool through outlets should not exceed 0. 1989. Pool fences around domestic pools should have a self-closing and self-latching gate and should isolate the pool.Installation of isolation fencing around outdoor pools. Present. Fence slats should be no more than 10 cm apart to prevent a child squeezing through. In Australia. Milliner et al. with an annual rate of incidence of around 30 new spinal cord injuries per million persons at risk. pool covers may themselves contribute to drowning – if they are not strong enough to hold the child's weight. they should be sized and located such that they cannot be blocked by the body of a single bather. Blum & Shield (2000) found that in the childhood drowning that they studied. 1994. it is recommended that locked safety covers be used when the hot tub is not in use. The results of the review are supported by Stevenson et al. In addition. Orlowski. Grilles in outlets should have gaps of less than 8 mm. unsecured or damaged. no child had gained unaided access to a pool fitted with a fully functional gate and fence that met the Australian standard. This study.2 m high and have no hand. A systematic review of studies (Thompson & Rivara. To prevent entrapment. covers may delay the discovery of a drowning victim. pools and hot tubs should not be used if any of the covers are missing.2. 1987). 1993. 1977. Also.. In addition. USA.. has been shown in some studies to decrease the number of drownings and near-drownings by more than 50% (Pearn & Nixon. 2000) examining the effectiveness of pool fencing indicated that pool fencing significantly reduced the risk of drowning. found that during a 12-year period 50 children under the age of five drowned in domestic swimming pools and 68% of the drownings occurred in pools that did not have isolation fencing. Stover & Fine (1987) estimated the total prevalence of spinal cord injury in the USA to be around 906 per million. 10% of all spinal cord injuries are related to 16 GUIDELINES FOR SAFE RECREATIONAL WATER ENVIRONMENTS . 1980. thus ensuring that the safety barrier itself is not a hazard. The availability of cardiopulmonary resuscitation (CPR) (including infant and child CPR) skills (Patetta & Biddinger.. or the child could drown in small puddles of water formed on their surface. 2. Pool alarms and pool covers have not been shown to be reliable preventive measures for very young children. Barrier fencing should be at least 1. For domestic or outdoor hot tubs. Pepe & Bierens. with isolation fencing (enclosing the pool only) being superior to perimeter fencing (enclosing the pool and the property).or footholds that could enable a young child to climb it.2 Spinal injury Data concerning the number of spinal injuries sustained as a result of pool use are not widely available.
In Australia.. Tator & Edmonds (1986) report that between 1948 and 1983. the majority (62%) with diving. Canada. Australian. 212 of 2587 spinal cord injuries were sports related. In Ontario. The financial cost of these injuries to society is high..9% of all recreational-related spinal cord injury – 60 major spinal injuries each year. less commonly. which typically cause quadriplegia (paralysis affecting all four limbs) or. Blanksby et al. 1997). 1984).8% and 14% of traumatic spinal cord injuries in a comparison of French. 1983. Blanksby et al. 1980).Table 2. because persons affected are frequently healthy young people. spinal injuries are almost exclusively located in the cervical vertebrae (Minaire et al. diving accounted for 58. 1997).2.. and at least two suction outlets per pump • Accessible emergency shut-off for pump • Grilles/pipes on drain gates preclude hair entrapment • Wearing bathing caps • Maintaining water temperature in hot tubs below 40 °C • Access to emergency services diving into water. DROWNING AND INJURY PREVENTION 17 . CHAPTER 2.. for example. 1983). (1997) tabulated data from a series of studies concerning diving accidents as the cause of acute spinal injury in various regions of the world. In diving incidents of all types. Drowning and near-drowning: Principal contributory factors and preventive and management actions Contributory factors • Falling unexpectedly into water • Easy unauthorized access to pools • Not being able to swim • Alcohol consumption • Excessive 'horseplay' or overexuberant behaviour • Swimming outside the depth of the user • Breath-hold swimming and diving • High drain outlet suction and poor drain and drain cover design • High water temperatures Preventive and management actions • Isolation fences with self-closing and self-latching gates around outdoor pools • Locked steps/ladders for above-ground pools • Locked doors for indoor pools • Locked safety covers for domestic and outdoor hot tubs • Continuous parental/caregiver supervision of children • Provision of properly trained and equipped lifeguards • Teaching children to stay away from water when unsupervised • Education/public awareness that drowning can happen quickly and quietly • Restriction of alcohol provision or supervision where alcohol is likely to be consumed • Suction outlets cannot be sealed by single person. English and American studies (Minaire et al. typically males under 25 years of age (DeVivo & Sekar. 1997). Statistics such as those cited above therefore underestimate the importance of these injuries. In one study (Steinbruck & Paeslack. for 2. paraplegia (paralysis of both legs). diving incidents account for approximately 20% of all cases of quadriplegia (Hill.3% in a South African study and for 21% in a Polish study (Blanksby et al. 139 of which were associated with water sports. Diving-related injuries were found to be responsible for between 3.
In Ontario. awareness raising and education regarding safe behaviours are required early in life. Familiarity with the pool may not necessarily be protective.2. Diving or jumping from trees.. the establishment of preventive programmes by Sportsmart Canada and widespread education decreased the incidence of water-related injuries substantially between 1989 and 1992 (Tator et al.5 m or less) and few in very shallow water (i. may provide an inadequate time for deceleration response (Yanai et al. with an average age of 24 years. for example. Because of the young age of many injured persons. 86% of the 341 persons with spinal injuries resulting from swimming pool incidents were men. where the hazard may be more obvious (Gabrielsen. 1997) because of the movements of the spine during the rescue technique. The act of rescue from drowning may also exacerbate spinal cord trauma after the initial impact (Mennen. 1993).. A proportion of spinal injuries will lead to death by drowning. balconies and other structures is particularly dangerous. less than 0. Evidence suggests that diving technique and education are important in injury prevention (Perrine et al. 1996). 1988. Most diving injuries occur in relatively shallow water (1. in one study from South Africa (Mennen. but which may provide a forum for increased public safety (Damjan & Turk.3. 1995).2. 1999). in the study by DeVivo & Sekar (1997).2 m of water (DeVivo & Sekar. 1981). Blanksby et al. it does not appear to be common (see. in part because some people have been found to take little notice of posted signs and regulations (Hill. Young males appear to be more likely to experience spinal injury.6 m). 1997). 1997). for example. 1994. 1991). In a sample of 341 persons with spinal injuries resulting from swimming pool incidents. and there were no warning signs in 87% of cases (DeVivo & Sekar. A lack of signage may also be a contributory factor. Alcohol consumption may contribute significantly to the frequency of injury. 1997). it was noted that the typical injurious dive is into a water body known to the individual. 2. Education and awareness raising appear to offer the most potential for diving injury prevention.. as are special dives such as the swan or swallow dive. 1996. Blanksby et al..2 Preventive and management actions The principal contributory factors and preventive actions for spinal cord injuries are summarized in Table 2.2. Branche et al. but the role played by water depth has been debated.. through diminished mental faculties and poor judgement (Howland et al. EEA/WHO.e. even in clear water. 18 GUIDELINES FOR SAFE RECREATIONAL WATER ENVIRONMENTS . depth indicators were not present in 75% of cases. 1984) in isolation.. 1981.. and preventive programmes can be effective. Blanksby et al.. While data on this are scarce. almost all the injuries (87%) occurred in private/domestic pools. Minimum depths for safe diving are greater than is frequently perceived. Inexperienced or unskilled divers require greater depths for safe diving. The velocities reached from ordinary dives are such that the sight of the bottom. Many countries have schoolage swimming instruction that may inadequately stress safe diving. over half of the injuries occurred when the individuals dived into less than 1.1 Contributory factors Data from the USA suggest that diving into the upslope of a pool bottom or shallow water is the most common cause of spinal injuries in pools. In the same study. 1980). 1997). because the arms are not outstretched above the head but are to the side of the body (Steinbruck & Paeslack.
2. leg and foot/toe injuries have occurred from a variety of activities in pools and their immediate surroundings. trip and fall accidents may be the result of swimming aids. dislocations. as well as disfigurement.Table 2. etc. such as jumping onto others in the pool from poolside or from dive boards on the pool deck. such as rings. supervision of pool users. uneven pavements.3. broken bottles and cans. may also result in injury. other impact injuries. There are reports of injuries sustained as a result of stepping on glass. including scalp and facial abrasions and breaks. The contributory factors and preventive and management actions are similar to those for spinal injuries and for limb and minor impact injuries and are summarized in Table 2. Banning of glass containers and use of alternative materials for drinks in the pool and hot tub area will minimize these types of injuries. CHAPTER 2. Spinal injury: Principal contributory factors and preventive and management actions Contributory factors • Diving into a shallow pool or the shallow end of a pool • Diving into a pool of unknown depth • Improper diving • Jumping or diving into water from trees/balconies/other structures • Poor underwater visibility • Alcohol consumption • Lack of supervision • Lack of signage Preventive and management actions • Lifeguard supervision • General public (user) awareness of depth hazards and safe behaviours • Early education in diving hazards and safe behaviours/diving instruction • Restriction of alcohol provision or supervision where alcohol is likely to be consumed • Poolside wall markings • Access to emergency services 2.4 Fractures. jumping into shallow water. improved pool design and construction. DROWNING AND INJURY PREVENTION 19 . Slippery decks.4. providing appropriate warnings. floats. Reckless water entries.3 and Table 2.4 provides examples of some of the factors that contribute to impact injuries and associated preventive and management actions. running on decks and water slide-related incidents (see Section 2. hand. uncovered drains and exposed pool spouts may cause injuries to pool users. Expert opinion suggests that these incidents are common and generally go unreported. have been associated with swimming pools and similar environments and may result in permanent neurological disability. Slip.7). left around the pool area.. ensuring good underwater visibility and pool safety education are among the actions that can reduce these incidents. Table 2. Maintenance of surfaces. cuts and lesions Arm.3 Brain and head injuries Impact on the skull and injuries to the head.
Gomez-Juarez et al.4. 2003)..6 Hazards associated with temperature extremes Water ranging in temperature from 26 to 30 °C is comfortable for most swimmers throughout prolonged periods of moderate physical exertion. through multiple outlets and a maximum velocity – see Section 2. It is recommended that drain covers be designed to avoid the possibility of disembowelment by. the resulting suction force can cause disembowelment. Porter et al.g.1. The comfortable upper limit of water temperature for recreational immersion varies from individual to individual and seems to depend on psychological rather than physiological considerations. minor impact injuries. The drain covers in pools and hot tubs can become brittle and crack. since these occur almost immediately at a small pressure differential. ladders) • Poor underwater visibility • Slippery decks • Glass or rubbish around the pool area • Swimming aids left poolside Preventive and management actions • Lifeguard supervision • General user awareness of hazards and safe behaviours • Appropriate surface type selection • Appropriate cleaning and litter control • Use of alternative materials to glass • Limits on bather numbers 2. for example.Table 2. there have been reports of incidents in which the suction from the pool or spa drain has pulled intestines out of the body (Hultman & Morgan.2) is as effective against disembowelment injuries as it is against drowning. The drain. having no openings on the top. or they may become loose or go missing. cuts and lesions: Principal contributory factors and preventive and management actions Contributory factors • Diving or jumping into shallow water • Overcrowded pool • Underwater objects (e. with the water entering the drain through a series of openings on the side. 1997. 1994. undated). 18 incidents of evisceration/disembowelment were reported to the CPSC during a 20-year period (CPSC.1. In the USA. Preventive measures are similar to those against entrapment leading to drowning (see Table 2. Limb. This is a particular hazard for young children in shallow pools. 20 GUIDELINES FOR SAFE RECREATIONAL WATER ENVIRONMENTS .1).5 Disembowelment In addition to hair and body entrapment resulting in drowning (Section 2. which was located on the second of the steps giving access to the water.2). 2. had not been recovered after cleaning. a six-year-old girl suffered a rectal prolapse after being sucked onto a swimming pool drain from which the cover had been removed (Davison & Puntis. In the UK. It is uncertain if reduced vacuum (e.g.. If a person sits on a broken cover or uncovered drain. 2001). for example.
1991. users with medical problems and young children. Failure to leave the area immediately after arriving from the slide may also present physical hazards. which may lead to unconsciousness (especially when associated with alcohol consumption). and prolonged immersion in hot tubs or other pools with high or low temperatures should be avoided or approached with caution. undated). slow down or stand up on the slide. after some time when the core body temperature has fallen. too close to each other or headfirst.7 Injuries associated with 'feature pools' Pools may contain features that present their own particular requirements to ensure safe use.5). loss of control of breathing and. 2003). muscle cramps and loss of consciousness. It is recommended that water temperatures in hot tubs be kept below 40 °C. Table 2. warnings from lifeguards and pool staff. Plunge pools present similar problems.1). where water temperatures may be above 40 °C.5. In addition. The CPSC has received reports of several deaths from extremely hot water (approximately 43 °C) in hot tubs (CPSC. CDC reported CHAPTER 2. undated). hypothermia. see Section 2. Hazards associated with temperature extremes: Principal contributory factors and preventive and management actions Contributory factors • Cold plunge when not conditioned • Prolonged immersion in hot water Preventive and management actions • Supervision • Signage. but at the other temperature extreme. These small. High temperatures can cause drowsiness. people with medical conditions • Limitation of alcohol intake prior to use of hot tubs 2. high temperatures can lead to heat stroke and death (CPSC. Water slides add excitement but may present physical hazards. or where riders stop. deep pools generally contain water at a temperature of 8–10 °C and are used in conjunction with saunas or steam baths. including time limits for exposure • A maximum temperature of 40 °C for hot tubs • Gradual immersion • Medical recommendations for pregnant women. Educational displays and warning signs. DROWNING AND INJURY PREVENTION 21 . resulting in drowning (Press. Further information on this subject is given in Volume 1 of the Guidelines for Safe Recreational Water Environments (WHO. exposure to temperature extremes should be avoided by pregnant women. regulations on time limits for exposure and limiting use by people with medical conditions are some examples of preventive actions for hazards associated with temperature extremes (see Table 2. Adverse health outcomes that may result from the intense and sudden changes in temperature associated with the use of these pools include immediate impaired coordination.Body overheating can occur in natural spas and hot tubs. particularly where riders go down in pairs. In general. slowed heart beat. In the USA.
1. Rivara FP. complications and prognosis. falls from which could injure the climber or other user. Injuries included fractures. Cummings P.injuries relating to the use of a water slide (CDC. In a six-week period. PhD thesis Netherlands. may also be necessary. Pathophysiology. all parts of the wave machine should be enclosed by a guard. 1988 and 1989.. Extra vigilance is needed by lifeguards and bathers alike. Sattin RW. Sports Medicine. 53(21): 447–452. As grilles must be large enough to allow water flow. Damjan H.html. in press. Design issues. 65 people were injured while using the slide and sought medical care. Paraplegia. Elliott BC. Sniezek JE. http://www. Prevention. Blanksby BA. CDC (1990) Current trends child drownings and near drownings associated with swimming pools – Maricopa County. 33(5): 246–249. Washington. Morbidity and Mortality Weekly Report. 1988–1994. Accident Analysis and Prevention. 88: 584–586. Springer. The slide consisted of two fibreglass tubes. concussions. Bierens JJLM (1996) 2944 submersion victims: an analysis of external causes. user awareness and education are important considerations in feature pools. rescue and treatment. 6: 288–290. Branche CM. 39(26): 441–442. hot tubs. Wave machines may provide a higher level of excitement and also often increased bather load. bruises and abrasions and sprains and strains. In: Bierens JJLM et al. Lewis-Michl EL. 387. 1984). Turk KK (1995) Prevention of spinal injuries from diving in Slovenia. Arizona. Archives of Diseases in Childhood. Netherlands. Dunne R (1995) Water safety training as a potential means of reducing risk of young children's drowning. 23(4): 228–246. Medicine and Science in Sports. 33(27): 379– 382. Injury Prevention. DC. eds.2 m wide and over 100 m in length. 118(5): 448–458. when the waves are in action. CPSC (undated) Spas. In: Drownings in the Netherlands. This included nine spinal fractures. 2. United States Consumer Product Safety Commission (CPSC Document #5112. Browne Ml. Journal of the American Medical Association. 22 GUIDELINES FOR SAFE RECREATIONAL WATER ENVIRONMENTS . 1(4): 228–233. Handbook on drowning. accessed 15 November 2004). Vance L. 281: 2198–2202. CDC (1984) Injuries at a water slide – Washington. Biltvich JD (1997) Aetiology and occurrence of diving injuries. concomitant risk factors. University of Utrecht. Injury Prevention. swimming ability and the risk of drowning. In-water features may also present a physical hazard.8 References Asher KN. Felix D. Craig AB Jr (1976) Summary of 58 cases of loss of consciousness during underwater swimming and diving. 2001–2002. adequate supervision to prevent users holding onto the grilles. A review of diving safety. 8(3): 171–175. Public Health Reports. Davison A. Puntis JWL (2003) Awareness of swimming pool suction injury among tour operators. and whirlpools. CDC (2004) Nonfatal and fatal drownings in recreational water settings – United States.cpsc. Shield J (2000) Toddler drowning in domestic swimming pools. 23(1): 13–17. Mirkin IR (1991) Water recreation-related spinal injuries: Risk factors in natural bodies of water. Brenner R (2005) Swimming lessons. as they may be slippery or encourage climbing. Quan L (1999) Trends in unintentional drowning. Morbidity and Mortality Weekly Report. The possibility exists for entrapment of limbs in wave machine chambers. The role of alcohol and medical care. Wearne FK. Morbidity and Mortality Weekly Report. Stark AD (2003) Unintentional drownings among New York State residents.gov/cpscpub/pubs/5112. Blum C. therefore. epidemiology and clinical studies.
Biron A (1983) Life expectancy following spinal cord injury: a ten-years survey in the Rhone-Alpes Region. Mennen U (1981) A survey of spinal injuries from diving. 103(4): 406–411. 40: 321–336. Hingson R. Howland J. Centers for Disease Control and Prevention. Minaire P. 1997. 1969–1980. (1988) Diving safety: a position paper. Epidemiology and prevention. Handbook on drowning. American Journal of Public Health. Girard R. EEA/WHO (1999) Water resources and human health in Europe. Kyriacou DN. 59(22): 788–790. 35(8): 509–515. In: Proceedings of the New South Wales Symposium on Water Safety. Bell N. Nixon J. ed. Gomez-Juarez F. 1(17): 616–618. Dietz PE. Prevention. rescue and treatment.DeVivo MJ. Capilla P. Kent AB. 51: 398–399. American Journal of Public Health. Everett PB (1989) Childhood near-drowning: is cardiopulmonary resuscitation always indicated? Critical Care Medicine. 1(12): 652–653. Public Health Reports. Department of Sport and Recreation. in press. Garcia-Blazquez E. Garcia-Olmo D. Public Health Reports. Berard E. Turner G (1993) Drowning and near-drowning. Brink LW. eds. Patetta MJ. Springer. IN. Medical Journal of Australia. Usero S. Deidier C. Guard R (1980) Will fenced pools save lives? A 10-year study from Mulgrave Shire. In: Bierens JJLM et al. Milliner N. 83: 1065–1066. Nixon J (1977) Prevention of childhood drowning accidents. 94: 137–142. 64(4): 303–312. National Center for Health Statistics (1998) National mortality data. 17(10): 993–995. Liller KD. Gomez-Juarez M. Accident Analysis and Prevention. Pediatrics. Orlowski JP (1989) It's time for pediatricians to "rally round the pool fence". Kraus JF (1994) Effect of immediate resuscitation on children with submersion injury. Medical Journal of Australia. Hyattsville. Hingson R (1988) Alcohol as a risk factor for drowning: a review of the literature (1950– 1985). Baker SP (1974) Drowning. DROWNING AND INJURY PREVENTION 23 . Hultman CS. 2(25–26): 942–946. Pediatrics. Morgan R (1994) Transanal intestinal evisceration following suction from an uncovered swimming pool drain: case report. Mackie I (2005) Availability and quality of data to assess the global burden of drowning. Pearn J. Demolin P. Bourret J. 20: 19–25. CHAPTER 2. MacDermott RJ (1993) Risk factors for drowning and near-drowning among children in Hillsborough County. Eyssette M. Toro LO. New South Wales. Gabrielsen JL. Pearn J. South African Medical Journal. France. Peek C. 37(5): 843–847. 28–33. Anderica F (2001) Complete evisceration of the small intestine through a perianal wound as a result of suction at a wading pool. Indianapolis. Howland J. Pediatric Clinics in North America. Sekar P (1997) Prevention of spinal cord injuries that occur in swimming pools. Wilkey I (1976) Freshwater drowning and near-drowning accidents involving children: A five-year total population study. Pearn J. Medical Journal of Australia. Nichter MA. 21(1): 11–15.. Arcinue EL. Mackie I (1978) Alcohol and aquatic disasters. Morris FC. Queensland. Mangione TW. MD. Medical Journal of Australia. 2: 510–511. Spinal Cord. United States Diving. Arcari C. Florida. Biddinger PW (1988) Characteristics of drowning deaths in North Carolina. Bak S (1996) Why are most drowning victims men? Sex difference in aquatic skills and behaviours. A study of patients in Pretoria and Cape Town. Journal of Trauma. 108(3): 346–353. European Environment Agency and World Health Organization Regional Office for Europe. 86(1): 93–96. Paraplegia. Journal of Trauma. Levin DL. Cascales P. pp. Hill V (1984) History of diving accidents. Netherlands. Sydney.
Edmonds VE (1986) Sports and recreation are a rising cause of spinal cord injury. WHO (2004) The World Health Report 2004: Changing history. American Journal of Public Health. Stover SL. July 1.. Vickery K (2003) Childhood drowning: barriers surrounding private swimming pools. Handbook on drowning. Prevention. Dowling G (1993) Drowning deaths in people with epilepsy. Think First Foundation (2004) Think First Foundation website (http://www. Press E (1991) The health hazards of saunas and spas and how to minimize them. Rivara FP (2000) Pool fencing for preventing drowning in children. Ryan CA. 83(6): 1035–1040. Wintemute GJ. Thompson DC. Prevention. eds. Quan L. Pediatric Clinics of North America. in press. Directorate for Epidemiology. Ontario. WHO (2003) Guidelines for safe recreational water environments. Edmonds VE. Smith GS (2005) The global burden of drowning. In: Bierens JJLM et al. 111(2): e115–e119. Fine PR (1987) The epidemiology and economics of spinal cord injury. Cornall P. Injury Control and Safety Promotion. United States Consumer Product Safety Commission. Lyons RA. accessed 2 March 2004. rescue and treatment. Physician and Sportsmedicine. Wright M (1987) Drowning in childhood and adolescence: a population-based study. In: Bierens JJLM et al. eds. Lapeczak X (1993) Ontario Catastrophic Sports Recreational Injuries Survey. Kraus JF. Springer. Weiner RI (1994) When alcohol and water don't mix: diving under the influence. Toronto. eds. Porter ES. Netherlands. 2(5): 226–228. Pediatrics. 46(6): 297–298. Spyker DA (1985) Submersion injury.thinkfirst. Paeslack V (1980) Analysis of 139 spinal cord injuries due to accidents in water sport. Pepe P. American Journal of Public Health. World Health Organization. Maryland Medical Journal. in press. Gore EJ. World Health Organization. Steinbruck K. 2: CD001047.html). 25(3): 225–228. Wentz K. Tator CH. Allen J. Geneva. Rimajova M. Washington. 24 GUIDELINES FOR SAFE RECREATIONAL WATER ENVIRONMENTS . Vol.Peden M. Perrine MW. Farrell KP (1997) Preventing wading pool suction-drain injuries. Sumner V. 77: 830–832. Handbook on drowning. Bierens J (2005) Resuscitation: an overview. 324: 1070–1071. Paraplegia. 1992. Geneva. Kohlstadt IC. Kemp AM on behalf of the Safe Water Information Monitor Collaboration (2002) Preventing deaths by drowning in children in the United Kingdom: have we made progress in 10 years? Population based incidence study. Teret SP. Tator CH. Prevention.. Canadian Medical Association Journal. prevention and management. 55(5): 517–524. 1: Coastal and fresh waters. rescue and treatment. British Medical Journal. Netherlands. 148(3): 270. 1991 – July 30. In: Bierens JJLM et al. Sibert JR. Novack AH (1989) Ten year study of pediatric drownings and near drownings in King County. Netherlands. Craven MA. Petridou E (2005) Risk factors for drowning and near-drowning injuries. Pediatrics. 18(2): 86–93.org/news/facts. DC. 14: 157–167. 10(4): 195–199. Springer. Edgecombe D. Think First Canada. Paraplegia. Stevenson MR. Medical Journal of Australia. McGee K (2003) The epidemiology of drowning worldwide. Plueckhahn VD (1979) Drowning: community aspects. Washington: lessons in injury prevention. Epidemiology. in press. Handbook on drowning. Mundt JC. Present P (1987) Child drowning study: A report on the epidemiology of drowning in residential pools to children under age 5. 81(8): 1034–1037. rescue and treatment. Smith BA. Springer.. 32(1): 113–125. Cochrane Database of Systematic Reviews. Journal of Studies on Alcohol.
DROWNING AND INJURY PREVENTION 25 . In: Proceedings of the World Congress on Drowning. Gerot JT (1996) Three dimensional videography of swimming with panning periscopes.World Congress on Drowning (2002) Recommendations. Hay JG. Yanai T. CHAPTER 2. Amsterdam. 26–28 June 2002. Journal of Biomechanics. 33(5): 246–249.
which may lead to skin infections in other patrons who come in contact with the contaminated water or surfaces. in pool or hot tub components or facilities (including heating. may be the result of direct animal contamination (e. may accumulate in biofilms and present an infection hazard. monitoring for potential microbial hazards is done using indicator microorganisms (rather than specific microbial pathogens).1. 'Opportunistic pathogens' (notably bacteria) can also be shed from users and transmitted via surfaces and contaminated water. The traditional role of indicator parameters was to show the presence or absence of faecal pollution in water supplies. The faecal contamination may be due to faeces released by bathers or a contaminated source water or. from birds and rodents). In each case. certain freeliving aquatic bacteria and amoebae can grow in pool. ventilation and airconditioning [HVAC] systems) or on other wet surfaces within the facility to a point at which some of them may cause a variety of respiratory. Faecal matter is introduced into the water when a person has an accidental faecal release – AFR (through the release of formed stool or diarrhoea into the water) or residual faecal material on swimmers' bodies is washed into the pool (CDC. mucus. from vomit. In addition. as illustrated in Figure 3. dermal or central nervous system infections or diseases. In many cases. The sections reflect the origin of the microbial contaminant. in outdoor pools. although general management strategies for managing air and water quality are described in detail in Chapter 5. most notably non-faecally-derived bacteria (see Section 3. In most cases.CHAPTER 3 Microbial hazards variety of microorganisms can be found in swimming pools and similar recreational water environments. Non-faecal human shedding (e. 2001a). This chapter describes illness and infection associated with microbial contamination of swimming pools. which may be introduced in a number of ways. Some bacteria. Outdoor pools may also be subject to microorganisms derived directly from pets and wildlife.4). The use of these microorganisms in monitoring water quality is covered in Chapter 5. the risk of illness or infection has been linked to faecal contamination of the water. The criteria associated with microbial indicators of pollution are outlined in Box 3. natural spas and hot tubs. which are easy to enumerate and would be expected to be present in greater numbers than pathogens.g. a short subsection on risk assessment and risk management is given. saliva or skin) in the swimming pool or similar recreational water environments is a potential source of pathogenic organisms. natural spa or hot tub waters.1 and further discussed in WHO (2004). Infected users can directly contaminate pool or hot tub waters and the surfaces of objects or materials at a facility with pathogens (notably viruses or fungi). 26 A .g. Many of the outbreaks related to swimming pools would have been prevented or reduced if the pool had been well managed.
Microorganisms that are used to assess the microbial quality of swimming pool and similar environments include heterotrophic plate count – HPC (a general measure of non-specific microbial levels). • The indicator should not multiply in the environment. identify and enumerate. does not guarantee safety. Bacteria Shigella spp. however. Potential microbial hazards in pools and similar environments BOX 3. and there is no perfect indicator organism. • Indicator tests should be inexpensive. can be used to examine growth. P. thermotolerant coliforms and E. Mycobacterium spp.) should be examined.g. thereby permitting numerous samples to be taken (if appropriate). and Staphylococcus aureus can be used to determine non-faecal shedding. aureus and Legionella spp. The absence of these organisms. Pseudomonas aeruginosa. CHAPTER 3. HPC. • The indicator should be easy to isolate. E.1 CRITERIA FOR INDICATOR ORGANISMS AND THEIR APPLICATION TO POOLS AND SIMILAR ENVIRONMENTS • The indicator should be absent in unpolluted environments and present when the source of pathogenic microorganisms of concern is present (e. Figure 3. coli). • The indicator should respond to natural environmental conditions and water treatment processes in a manner similar to the pathogens of concern.1. Staphylococcus aureus and Legionella spp. • The indicator should be present in greater numbers than the pathogenic microorganisms. aeruginosa. faecal material). faecal indicators (such as thermotolerant coliforms. coli 0157 Viruses Molluscipoxvirus Papillomavirus Adenoviruses Protozoa Giardia Cryptosporidium Protozoa Fungi Trichophyton spp. MICROBIAL HAZARDS 27 . Plasmodium spp. Pseudomonas aeruginosa and Legionella spp. E. HPC. Staphylococcus aureus Leptospira spp.g. Pseudomonas spp. As health risks in pools and similar environments may be faecal or non-faecal in origin. coli are indicators in the strict sense of the definition. as some pathogens are more resistant to treatment than the indicators. S.Microorganism hazard Faecally-derived Viruses Adenoviruses Hepatitis A Noroviruses Enteroviruses Non-faecally-derived Bacteria Legionella spp. Epidermophyton floccosum Naegleria fowleri Acanthamoeba spp. both faecal indicators and non-faecally-derived microorganisms (e. Faecal indicators are used to monitor for the possible presence of faecal contamination.
Viruses of six types (rotavirus. The outbreak was brought under control by raising the pool's free residual chlorine level above 0.1. The authors speculated that faecal contamination of the unchlorinated swimming pool water could have been the source of the contamination. Some adenoviruses may also be shed from eyes and the throat and are responsible for swimming pool conjunctivitis.2 Outbreaks of viral illness associated with pools 1. 1998). 28 GUIDELINES FOR SAFE RECREATIONAL WATER ENVIRONMENTS ..3. 1997). Foy et al. resulting in no free chlorine in pool water samples. the etiological agents were detected in the water in only two cases (D'Angelo et al. the evidence linking the outbreak to the pool is generally circumstantial. and noroviruses cause the most cases of viral diarrhoea in adults.1 Faecally-derived viruses 3. An investigation of the pool-related facilities suggested that the school swimming pool was the source of the infection. 1979. adenovirus. In the outbreaks summarized in Table 3.1. A total of 72 cases were identified. they are also associated with respiratory and ocular symptoms and non-faecally-derived transmission. However. The main symptoms were fever. Papapetropoulou & Vantarakis. Types 40 and 41 cause gastroenteritis in young children.3 mg/l. Even when outbreaks are detected. Viruses cannot multiply in water.1. (1974) reported an outbreak of conjunctivitis associated with adenovirus type 7 in seven members of a community swimming team. Adenovirus-related outbreaks There are over 50 types of adenoviruses (Hunter. enterovirus and hepatitis A virus) are all shed following infection. it should be kept in mind that non-outbreak disease is likely to occur and that virus-associated pool or hot tub outbreaks are very uncommon. The virus was also detected in samples of pool water. (1979). Caldwell et al. respectively. and therefore their presence must be a consequence of pollution. astrovirus. norovirus. Clinical data show that rotaviruses are by far the most prevalent cause of viral gastroenteritis in children. An investigation showed that inadequate levels of chlorine had been added to the pool water. Adequate chlorination and closing the pool for the summer stopped the outbreak of illness. The virus could not be isolated from the pool water. and while some may cause enteric infections and are therefore shed in faeces. Adenovirus type 4 was isolated from 20 of 26 swab specimens.1. The attack rates in the two teams were 65% and 67%. few waterborne pool outbreaks have been associated with these agents. 3. Although outbreaks are highlighted.1 Hazard identification The viruses that have been linked to swimming pool outbreaks are shown in Table 3. The main symptoms were associated with the eyes. pharyngitis and conjunctivitis. Adenovirus type 4 was the causative agent of a swimming pool-related outbreak of pharyngo-conjunctivitis reported by D'Angelo et al. as both the pool chlorinator and pool filter had failed. (1968) reported an outbreak of pharyngo-conjunctival fever caused by adenovirus type 3. but there is no documented association with waterborne transmission. The infection occurred in two children's swimming teams after exposure to unchlorinated swimming pool water.
1987 Papapetropoulou & Vantarakis. fever. The authors suspected that the level of free chlorine in the pool water was less than 0. 2001 Solt et al.1. at least 105 cases were identified. Summary of waterborne disease outbreaks associated with pools due to faecallyexcreted viruses Etiological agent Adenovirus 3 Adenovirus 7 Adenovirus 4 Adenovirus 3 Adenovirus 7a Adenoviruses Adenovirus 3 Hepatitis A Source of agent Possible faecal contamination Unknown Unknown Unknown Unknown Unknown Unknown Accidental faecal release suspected Cross-connection to sewer line Norovirus Unknown Probably via public toilets No details available No details available Possible faecal contamination Echovirus 30 Vomit Disinfection/ treatment None Improper chlorination Inadequate chlorine level Pool filter system defect. headache and anorexia. 1987).. 2004 Operating properly Kee et al. Seventy-seven individuals were identified with the symptoms of pharyngitis (inflammation of the pharynx).. Conjunctivitis affected only 34 of the individuals. Based on surveys... They also pointed out that while the virus was probably transmitted through water. 1968 Caldwell et al. 1980 Turner et al.Table 3. 2004 Yoder et al... MICROBIAL HAZARDS 29 .4 mg/l. The outbreak coincided with a temporary defect in the pool filter system and probably improper maintenance of chlorine levels... 1980).. 1998 Harley et al.. 1994 A second outbreak in the same locality and year was linked to adenovirus type 3 and swimming activity (Martone et al. 2004 Yoder et al. 2004 CDC.. Use of a swimming pool was linked to the illness. 1979 Martone et al. an outbreak of adenovirus type 7a infection was associated with a swimming pool (Turner et al.. 1974 D'Angelo et al. failed chlorinator Malfunctioning chlorinator Inadequate chlorination Inadequate chlorination and pool maintenance None Operating properly Reference Foy et al. personto-person transmission could not be ruled out. A telephone survey indicated that persons who swam at the community swimming pool were more likely to be ill than those who did not.. 1992 Chlorinator disconnected Manual chlorination three times a week No details available No details available Chlorination failure Kappus et al.. Swimmers who reported swallowing water were more CHAPTER 3.. 1994 Mahoney et al. The illness was characterized by sore throat. In 1987. 1982 Maunula et al.
Further investigation showed that the pool chlorinator had reportedly malfunctioned during the period when the outbreak occurred. An outbreak of pharyngo-conjunctivitis caused by adenoviruses occurred among swimmers participating in a competition. Twenty of 822 campers developed hepatitis A infections. 2. All of the cases were males between the ages of 5 and 17 years. inspection of the pool revealed that it was poorly maintained and inadequately chlorinated (Harley et al. Case–control studies indicated that swimmers were more likely than non-swimmers to become ill. The pool chlorinator had not been reconnected before the outbreak.. which occurred at the beginning of the swimming season.2 mg/l) was considered to have contributed to the outbreak (Papapetropoulou & Vantarakis. The outbreak ceased when proper chlorination was reinstated. which was not chlorinated. Over 80 people were found to be suffering from symptoms. Kappus et al. Although adenoviruses were not isolated from the pool water. Maunula et al. which may have been associated with a public swimming pool. It was concluded that the crowded conditions and generally poor hygienic conditions contributed to the outbreak. (1982) reported an outbreak of norovirus gastroenteritis associated with a swimming pool that affected 103 individuals. Investigation of potential common sources eliminated food. The illness typically lasted 24 h and was characterized by vomiting and cramping. The pool. An outbreak of hepatitis A in several states in the USA during 1989. Finland. (2004) reported an outbreak of gastroenteritis associated with norovirus contracted from a wading pool in Helsinki. All of the patients had reported swimming at a summer camp swimming pool. Adenoviruses were identified in swimming pool samples using nested polymerase chain reaction. Hepatitis A-related outbreaks Solt et al. The pool was generally overcrowded during the month of August. Case–control studies indicated that swimmers or those who used a specific hot tub were more likely than controls to become ill. an outbreak of illness related to adenovirus type 3 was detected. The source of the virus was not found. It was found that there was a strong association between the presence of symptoms and swimming at a school camp. Further investigation discovered 25 additional cases.likely to be ill than those who did not. It was hypothesized that a cross-connection between a sewage line and the pool water intake line may have been responsible for the outbreak or that one of the swimmers may have contaminated the water. 3. Serological studies suggested that norovirus was the cause of the gastroenteritis among the swimmers. was half full of water for a period and was used by younger children. Norovirus and astrovirus were isolated from water samples taken from the pool. and poor chlorination (residual chlorine levels <0. In 2000. the attack rate was significantly higher in swimmers who had swallowed water than in those who had not. The disinfectant levels in the pools met local standards. The pool was heavily used 30 GUIDELINES FOR SAFE RECREATIONAL WATER ENVIRONMENTS . Norovirus-related outbreaks Few outbreaks of norovirus-related disease (previously known as Norwalk virus or Norwalk-like viruses) associated with swimming pools have been reported. drink and person-to-person transmission. Similarly. 1998). was reported by Mahoney et al. (1994) reported an outbreak in Hungary in which 31 children were hospitalized following hepatitis A infection. 2001). (1992).
and poor pool water quality monitoring and maintenance contributed to the outbreak. adenoviruses 40 and 41 and noroviruses) require molecular detection methods.g. Thirty-three bathers had symptoms of vomiting. CDC (2004) reported an outbreak of gastroenteritis in children. 1995 and reviewed by Wyn-Jones & Sellwood. Enteric viruses occur in high numbers in the faeces of infected individuals.1. but most (e. especially if the faecal release is undetected or detected but not responded to adequately. 4. diarrhoea and headache shortly after swimming in an outdoor swimming pool. SCA. MICROBIAL HAZARDS 31 . one of which was associated with a hotel pool and hot tub. If the virus has remained in contact with water containing free disinfectant for some time. Fifty-three people reported illness. then detection of infectious virus may not be possible. (1994). but they were inadequate to contain the risk of infection from vomit in the pool water. There was no routine monitoring of free chlorine. Given the high densities at which some viruses can be shed by infected individuals. Enterovirus-related outbreaks Enteroviruses include polioviruses. enteroviruses) may be detected in cell culture. whose only common exposure was attendance at a swimming club the previous weekend. It is believed that the pool had been heavily contaminated with human faecal material. 3.g. Some agents (e. 2001). Concentration techniques for viruses in water are available (e.. Hepatitis A virus has been found at densities of 1010 per gram (Coulepis et al. and noroviruses have been estimated at 1011 per gram. This is clearly not a routine procedure. The only documented case of enterovirus infection following pool exposure was associated with echovirus. Individuals who had swallowed water were more likely to become ill than those who had not. The outbreak is believed to have been caused by a bather who swam while ill and vomited into the pool. which may be adapted to pool water samples. Proper disinfectant levels had been maintained at the pool. An undetected accidental faecal release was suspected. Echovirus 30 was isolated from the case who had vomited and from six other cases.3 Risk assessment Determination of polluted pool water as the unequivocal cause of a viral disease outbreak requires the detection of the virus in a water sample. 1980). which were found to be grossly contaminated (although a number of nappies were also found at the bottom of the pool during the cleaning operation). but gave no other details. although echoviruses may reach only 106 per gram. and norovirus was isolated from a number of cases. Yoder et al. as reported by Kee et al. it is not surprising that accidental faecal releases into swimming pools and hot tubs can lead to high attack rates in pools where outbreaks occur. situated very close to the pool. but is something that is done in response to a suspected disease outbreak.during the summer months (with as many as 500 bathers a day) and was manually chlorinated three times a week. (2004) reported two outbreaks of norovirus infection that were associated with swimming pools in the USA between 2000 and 2002. The pool was emptied and cleaned and subsequently fitted with continuous filtration and chlorination. echoviruses and coxsackieviruses types A and B.g. CHAPTER 3. with the contamination apparently being carried from the public toilets.
The only approach to maintaining public health protection under conditions of an accidental faecal release or vomit is to prevent the use of the pool until the contaminants are inactivated (see Chapter 5).. and vaccine poliovirus is also found where there is a high percentage of individuals immunized (although no investigations have been reported where this has been found in pool water). Virus is shed before the onset of symptoms. Episodes of gross contamination of a swimming pool due to an accidental faecal release or vomit from an infected person cannot be effectively controlled by normal disinfectant levels... ranging from 18% to 52% (Martone et al. Symptoms occur within 48 h of exposure and include diarrhoea. including the application of disinfectants. and detection relies on molecular methods (reverse transcriptase polymerase chain reaction – RT-PCR). anorexia. The disease has an incubation period of 15–50 days. but is detectable by RT-PCR for up to five days. 1996).4 Risk management The control of viruses in swimming pool water and similar environments is usually accomplished by proper treatment. Turner et al.1% in swimmers less than 18 years of age (Mahoney et al. The attack rate for swimming pool outbreaks linked to adenovirus serotypes is moderately high. None of the enteroviruses commonly cause gastroenteritis in the absence of other disease. nausea and fever. though more usually associated with infections of the eyelids and/or throat (pharyngo-conjunctival fever). 3. stops soon after onset of symptoms. with water and sewage being a frequent source of infection. vomiting and often jaundice being the common symptoms. most infections are asymptomatic. although they are associated with a wide variety of symptoms.2% to 6. as detected by electron microscopy. which may be detected by molecular biological techniques. 1969). Echoviruses are found less often. for example. 1987). Adenoviruses Most adenoviruses can be grown in commonly available cell cultures. Types 40 and 41 are those usually associated with gastroenteritis. reported an attack rate of 71% for those swimmers who had swallowed water. (1982). 1980. and.. with the exception of types 40 and 41.. Noroviruses Environmental detection of these agents is restricted to RT-PCR since there is no cell culture system available. Hepatitis A virus Culture of hepatitis A virus is generally impractical. principally by the polymerase chain reaction – PCR (Kidd et al.1. vomiting. Enteroviruses Coxsackieviruses are frequently found in polluted waters. Other types. 4. Kappus et al. 1992). Virus shedding. Attack rates are generally very high. 2. The attack rate in one outbreak of illness associated with a swimming pool ranged from 1. may also be shed in the faeces for extended periods (Fox et al. nausea.1. The education of parents/caregivers of small children and other water users about good hygienic behaviour at swimming pools is another approach that may prove to be useful for improving health safety at 32 GUIDELINES FOR SAFE RECREATIONAL WATER ENVIRONMENTS . 3. The virus is transmitted by the faecal–oral route.
In 1993.1 Hazard identification Shigella species and Escherichia coli O157 are two related bacteria that have been linked to outbreaks of illness associated with swimming in pools or similar environments. The pool had neither recirculation nor disinfection. It is thought that the transmission of shigellosis over several days may have been a result of residual contaminated water present after draining and people with diarrhoea visiting the pool on subsequent days. Sixty-nine people were considered to be infected with shigellosis. USA (CDC. except that chlorination or other forms of disinfection are not being used. 3. coli O157 phage type 59 was isolated from the six cases. Shigella-related outbreaks An outbreak of shigellosis associated with a fill-and-drain wading pool (filled on a daily basis with potable water) was reported from Iowa. 2001b). coli. six children with haemorrhagic colitis. of which 26 cases were laboratory confirmed as S.. was frequented by very young and nontoilet-trained children. sonnei. These outbreaks are summarized in Table 3. E.2 Outbreaks of bacterial illness associated with pools 1. coli O157 infection was epidemiologically and clinically linked to a collapsible children's paddling pool (Brewster et al. 1994).. The lack of water movement means that these water bodies behave very much as if they were swimming pools. The pool. MICROBIAL HAZARDS 33 . although only the pool specific outbreaks are covered in detail. were epidemiologically linked to a disinfected public paddling pool (Hildebrand et al. E. Similar non-pool outbreaks have been described for E.2. and one asymptomatic case were identified.2 Faecally-derived bacteria 3. 3. Free chlorine levels in the pool were less than 1 mg/l at the time of sampling. coli O157-related outbreaks In 1992. 1996). three of whom developed haemolytic uraemic syndrome.2.swimming pools and the reduction of accidental faecal releases. although there have also been two outbreaks reported where the source was a children's paddling pool. coli O157 phage type 2 was isolated from faecal specimens of five cases. including one case of haemolytic uraemic syndrome. E. It was believed that the pool had been initially contaminated by a child known to have diarrhoea. It is recommended that people with gastroenteritis should not use public or semi-public pools and hot tubs while ill or for at least a week after their illness. 2. E. which had a maximum depth of 35 cm. Shigella has been responsible for outbreaks related to artificial ponds and other small bodies of water where water movement has been very limited. coli O157) was detected in the pool during the investigation. coli O157. as they illustrate the potential risk that might be experienced in swimming pools under similar conditions.2. One pool sample was found to contain thermotolerant coliforms and E. CHAPTER 3. Six cases of diarrhoea. coli (but not E. an outbreak of E. The pool had not been drained or disinfected over the three-day period surrounding the outbreak. in order to avoid transmitting the illness to other pool or hot tub users.
1991 CDC.Table 3. They ferment glucose and lactose. Shigella species are shed at similar but somewhat lower levels by individuals who have contracted shigellosis (Table 3. coli O157 does not produce glucuronidase. coli O157 infection. 1996 E. E. 1994 Brewster et al. coli.3). coli O157 is known to be shed at densities as high as 108 per gram. coli O157 3. 1994 Hildebrand et al. coli O157 causes non-bloody diarrhoea. coli O157 are small. which can progress to bloody diarrhoea and haemolytic uraemic syndrome. coli O157 shed these bacteria at similar or slightly higher densities than the non-enterohaemorrhagic Shigella. The incubation period for shigellosis is 1–3 days. Literature reports indicate that E. 1996 Cransberg et al. Individuals infected with E. occurs most frequently in infants. DuPont. Haemolytic uraemic syndrome..... but longer periods are not uncommon. Bacterial exposure factors Agent Shigella Density shed during infection 10 per gram 6 Duration of shedding 30 days Infective dose <5 × 10 /ID50 2 Reference Makintubee et al. E. Gram-negative. Source of agent AFR Not known AFR Likely AFR AFR AFR AFR Not known Not known AFR – Accidental faecal release Disinfection/ treatment None None None None None Not known Inadequate treatment None None Reference Sorvillo et al.. young children and elderly people.3 Risk assessment Shigella species are small. characterized by haemolytic anaemia and acute renal failure. 1988 Makintubee et al. 1988 Pai et al.. The infection usually lasts for 4–7 days and is self-limiting.2.3. 2001b Keene et al. facultatively anaerobic rods.2.. E. fever and nausea. Symptoms associated with shigellosis include diarrhoea. 1987. non-motile. About 5–10% of individuals develop haemolytic uraemic syndrome following an E.5 °C. In most instances. The usual incubation period is 3–4 days. the illness typically resolves itself in about a week. 1987 Blostein. with the production of acid but not gas. Summary of outbreaks of disease associated with pools due to faecally-excreted bacteria Etiological agent Shigella spp.. 1996 CDC. They ferment glucose but not lactose. facultatively anaerobic rods. nor does it grow well at 44. motile. non-spore-forming. Unlike most E. Gram-negative. Other symptoms include vomiting and fever in more severe cases. 1984 Escherichia coli O157 108 per gram 7–13 days Not knowna ID50 – dose of microorganisms required to infect 50% of individuals exposed a Probably similar to Shigella 34 GUIDELINES FOR SAFE RECREATIONAL WATER ENVIRONMENTS . Table 3.
1984). coli O157 is unknown but is likely to be similar to that for Shigella species. Adequate chlorine levels were maintained in the pool. The stool survey revealed a 61% prevalence of Giardia infection. In 1994. There have been a number of outbreaks of disease attributed to these pathogens.3. 3. as summarized in Table 3.The infective dose for Shigella species is usually between 10 and 100 organisms (Table 3. 3.2. Lower doses.4.1 Hazard identification Giardia and particularly Cryptosporidium spp. Giardiasis cases were identified from disease surveillance reports over a one-year period (Gray et al. (1994) suggested that the infective dose is very low. the elderly or immunocompromised individuals. The identification of this case of giardiasis led to a stool survey of 70 of the class participants. Eight of 23 children (35%) exposed only at a better maintained pool to which the classes had been moved four weeks prior to the survey were positive. CHAPTER 3. However.3). In 1984. 3. 1994).4 Risk management One of the primary risk management interventions is to reduce accidental faecal release occurrence in the first place – for example. such as evacuation of the pool (see Chapter 5). Seventy-four cases and 108 matched controls were identified. The infective dose for E.3. MICROBIAL HAZARDS 35 .. The investigators did not find any evidence of transmission to non-swim-class pool users. if an accidental faecal release has occurred in a swimming pool or hot tub. Contamination of the pool was thought to be due to an undetected accidental faecal release. Giardia-related outbreaks Giardiasis has been associated with swimming pools and water slides. and other steps will have to be taken to provide time for disinfectant effect. by educating pool users. E. These two organisms are similar in a number of respects. coli O157 and Shigella species are readily controlled by chlorine and other disinfectants under ideal conditions. they have a low infective dose and they are shed in high densities by infected individuals. Other recreational exposures and ingestion of potentially contaminated water were found to be not significantly related to giardiasis. USA (Harter et al. it is likely that these organisms will not be instantly eliminated. They have a cyst or oocyst form that is highly resistant to both environmental stress and disinfectants. Keene et al. based on experience in an outbreak. may cause illness in infants.3 Faecally-derived protozoa 3.2 Outbreaks of protozoan illness associated with pools 1. however. a case– control study was conducted in the United Kingdom to determine the risk factors for giardiasis. None of the non-swimming playmates was positive. Analysis of the data indicated that swimming appeared to be an independent risk factor for giardiasis. a case of giardiasis was reported in a child who had participated in an infant and toddler swim class in Washington State. are faecally-derived protozoa that have been linked to outbreaks of illness in swimming pools and similar environments..
2000 CDC. 2000 CDSC..Table 3. Summary of disease outbreaks associated with pools due to faecally-derived protozoa Etiological agent Giardia Source of agent AFR AFR AFR AFR Sewage intrusion AFR Sewage intrusion Not known AFR AFR Likely AFR AFR Not known Not known Likely AFR Suspected AFR Likely AFR Not known Not known Not known Not known AFR Not known Disinfection/ treatment Inadequate treatment Inadequate treatment Adequate treatment Adequate treatment Plumbing defects Not known Not known Not known Adequate treatment Adequate treatment Adequate treatment Faulty ozone generator Plumbing and treatment defects Adequate treatment Treatment problems Adequate treatment Inadequate treatment Adequate treatment Adequate treatment Not known Ozonation problems Not known Not known Reference Harter et al. The source of Giardia contamination was a child who had a faecal accident in the pool. 2000 CDSC. Pool records showed that no chlorine measurements had been taken on the day of the accidental faecal release and that no free chlorine level was detectable on the following day. 1994 Hunt et al. 2003 Cryptosporidium AFR – accidental faecal release Adequate treatment – in terms of indicator bacteria monitoring results In the autumn of 1985. Infection most likely occurred following ingestion of swimming pool water contaminated with Giardia cysts.. 1994 CDC. 2000 CDSC. 8 others were positive for Giardia. In 1988. 2000 CDSC. A stool survey of the child's group showed that of 20 people tested. 1999 CDSC. an outbreak of giardiasis occurred among several swimming groups at an indoor pool in north-east New Jersey. Cases ranged 36 GUIDELINES FOR SAFE RECREATIONAL WATER ENVIRONMENTS . 1988). These cases had no direct contact with children or other risk factors for acquiring Giardia. 2001c Galmes et al. who was a member of the group that swam the same day as the women's swimming group. 1995 Sundkist et al... Among 107 hotel guests and visitors surveyed. 1997 CDSC.. 1988 Greensmith et al. 1991 Bell et al.. eight of whom had Giardia-positive stool specimens. USA (Porter et al.4. 1994 CDSC.. 1990 Joce et al... A 39% attack rate was observed for the group of women who had exposure on one day. and two were children. Nine clinical cases were identified. 1999 CDSC. an outbreak of giardiasis was associated with a hotel's new water slide pool (Greensmith et al. 1988). 1993 McAnulty et al. 1998 CDSC. 2000 CDSC. seven were adults (>18 years).. 1988 CDC.. 29 probable and 30 laboratory-confirmed cases of Giardia infection were found. All were female. 1984 Porter et al. 1997 CDSC.
which had allowed ingress of sewage from the main sewer into the circulating pool water. The sources of Cryptosporidium contaminating the pools were believed to be either sewage or the swimmers themselves. 1994). including diarrhoea. An investigation implicated one of two pools at a local sports centre. An outbreak of cryptosporidiosis occurred in British Columbia. had occurred in the pool before and during the outbreak. Several accidental faecal releases. loss of appetite. USA. Cryptosporidium-related outbreaks A number of outbreaks of cryptosporidiosis have been linked to swimming pools. In August 1993. a potential source of faecal material. foul-smelling stools. public health officials in Oregon.. A number of outbreaks are reviewed below. whereas none of the controls indicated this activity. MICROBIAL HAZARDS 37 . 9 of 18 case patients reported swimming at the local wave pool. drinking municipal drinking-water or drinking untreated surface waters. By October of that year. In 1992. 1993). Water in the slide pool was treated by sand filtration and bromine disinfection. Wisconsin. to the water slide pool. The epidemiological investigation confirmed an association between head immersion and illness. Analysis using laboratory-confirmed cases showed that the illnesses were associated with swimming in the children's pool within two weeks before onset of illness.. A possible contributing factor was the proximity of a toddlers' pool. Oocysts were identified in the pool water. In 1988. Symptoms in the 59 cases included diarrhoea. Swimmers were exposed to pool water in which there had been a single accidental faecal release. A case–control study and illness survey indicated that the transmission occurred in a public children's pool at the local recreation centre. Seventeen case patients were finally identified as swimming in the same pool. that her daughter was ill with a laboratory-confirmed Cryptosporidium infection and that members of her daughter's swim team had severe diarrhoea CHAPTER 3. vomiting and weight loss.. Inspection of the pool pipework revealed significant plumbing defects. USA (CDC.from 3 to 58 years of age. which implied that disinfection was probably not maintained at an appropriate level. 2. 1990). Canada. The common factor linking infected individuals was use of the swimming pool. USA. Difficulty had been experienced in controlling the level of free chlorine residual. the first outbreak of cryptosporidiosis associated with a swimming pool in the United Kingdom was recognized following an increase in the number of cases of cryptosporidiosis that had been identified by the Doncaster Royal Infirmary microbiology laboratory (Joce et al. The investigators concluded that the outbreak of cryptosporidiosis was probably caused by exposure to faecally contaminated pool water. a parent informed the Department of Public Health of Madison. including 37 who were the first individuals ill in their households. using the water slide pool and swallowing pool water. They identified 55 patients with cryptosporidiosis. 1991). In August 1988. an outbreak of 60 cases of cryptosporidiosis was reported in Los Angeles County. The concentration of oocysts detected in the pool water samples that were tested was 50 oocysts per litre. fatigue. The attack rate was about 73%. noted a large increase in the number of stool specimens submitted for parasitic examination that were positive for Cryptosporidium (McAnulty et al. Significant associations were found between illness and staying at the hotel. cramps. 67 cases had been reported. Attack rates ranged from 8% to 78% for various groups of children's pool users. A case–control study involving the first 18 case patients showed no association between illness and day-care attendance. However. in 1990 (Bell et al.
The outbreak was detected in Scotland. 1994). Seven of the nine reported swimming at a large outdoor pool.. and that outbreaks could involve multiple pools. Outbreaks were associated with pools disinfected with chlorine and with ozone and with both well and poorly managed pools (PHLS. Almost 400 cases were identified. The resulting gastroenteritis is characterized by diarrhoea with accompanying abdominal cramps. although faecal contamination was known or suspected in a further five outbreaks. vomiting and abdominal cramps. cryptosporidiosis is generally chronic and more severe than in immunocompetent people and causes diarrhoea that can last long enough to be life threatening (Petersen. Forty-seven per cent of the 17 cases had had watery diarrhoea for more than five days. 2001c).3 Risk assessment Giardia cysts are 4–12 µm in diameter.(CDC. pers. In patients with severely weakened immune systems. A large outbreak of cryptosporidiosis has been associated with a hotel in Majorca. In both cases. Spain. with oocysts being detected in samples of the pool water (Galmes et al. A second cluster of nine cases was identified later in the month.). This outbreak resulted in guidelines on cryptosporidiosis prevention being produced for the Spanish hoteliers association (Confederation Española de Hoteles y Apartamentos Turisticos) and the UK Federation of Tour Operators (R. used by British tourists. comm. 2001).. The illness lasts about 10–14 days. 38 GUIDELINES FOR SAFE RECREATIONAL WATER ENVIRONMENTS . Cartwright. USA (CDC. Cryptosporidium species were the most common cause of gastrointestinal outbreaks of illness associated with treated swimming pool water. Public health authorities cleaned the pool. The illness lasts for about 7–10 days. following the detection of cryptosporidiosis in tourists returning from Majorca. 2003). 2004). Recognized accidental faecal releases at the pool occurred in four of the outbreaks. Cryptosporidium oocysts are 4–6 µm in diameter and are much more resistant to chlorine than Giardia cysts. accidental faecal releases (on more than one occasion) were observed. In Australia. In the USA.3. an analysis of recreationally-associated waterborne outbreaks of illness between 2001 and 2002 was conducted (Yoder et al. shock dosed with chlorine and prohibited people with diarrhoea from swimming in the pool. Fifty-five per cent of 31 pool users interviewed reported having had watery diarrhoea for two or more days. In the UK. The association was reported to be stronger for cases from urban areas. 32% of cases reported swimming during their illness or shortly afterwards. there is an incubation period of 4–9 days before symptoms appear. The authors noted that Cryptosporidium oocysts were more commonly detected from pools where at least two notified cases had swum. with symptoms typically including diarrhoea. such as those with HIV infection and cancer and transplant patients taking certain immune system-suppressing drugs. 18 outbreaks of cryptosporidiosis were associated with pools between 1989 and 1999. Two protracted outbreaks of cryptosporidiosis associated with swimming pools were reported from Ohio and Nebraska. Viable cysts that are ingested by humans have an incubation period of about 7–12 days. 3. a statewide outbreak of cryptosporidiosis in New South Wales was associated with swimming at public pools (Puech et al. 2000). 1992).. In the Nebraska outbreak. and the outbreak was thought to be associated with the hotel swimming pool. If viable oocysts are ingested.
Ozone is a more effective disinfectant (compared with chlorine) for the inactivation of Giardia cysts and Cryptosporidium oocysts. they were not performed in simulated recreational water where additional organic material is present). MICROBIAL HAZARDS 39 .e.e.. A near complete inactivation (99.. 1954.e. and for some strains fewer than 100 oocysts can lead to infection. Protozoan exposure factors Agent Cryptosporidium Density shed during infectiona 10 –10 per gram 6 7 Duration of shedding 1–2 weeks Infective dose 132/ID50 Reference Casemore. 1995).9%) of the oocysts are killed after 1 min (at pH 7 and a temperature of 25 °C). requires chlorine concentrations of 30 mg/l for 240 min (at pH 7 and a temperature of 25 °C) for a 99% reduction to be achieved (i. although this does depend upon the strain (Okhuysen et al. It should be noted. 1983 Giardia 3 × 106 per gram 6 months 25/ID25 ID50 (ID25) – dose of microorganisms required to infect 50% (25%) of individuals exposed a Figures represent the peak and are not representative of the whole of the infection period 3. Table 3. Cryptosporidium oocysts discharged by ill individuals are usually observed at densities of 106–107 per gram..9%) of Cryptosporidium occurs at UV exposures of 10 mJ/cm2 CHAPTER 3. Giardia cysts are sensitive to 0. however.6 mg of ozone per litre. studies have generally used oxidant demandfree water (i. sufficient concentration and time for inactivation must be ensured during treatment before residual ozone removal and return to the pool.5. 2002). DuPont et al. As ozone is not a residual disinfectant (i. The infection is self-limiting in most individuals. it is not applied so as to persist in pool water in use).5). (1999) found that the presence of faecal material increased the Ct value (disinfectant concentration in mg/l multiplied by time in minutes) needed to disinfect swimming pools. Inactivation of oocysts with chlorine is greater when ozone.3. Giardia cysts discharged in the faeces of infected individuals are usually at densities of 3 × 106 per gram.4 Risk management Giardia cysts and Cryptosporidium oocysts are very resistant to many disinfectants. Almost all (99. that the figures above represent removal under laboratory (i. an impractical level). Carpenter et al. lasting 1–3 weeks.. Feachem et al. for example (the more chlorine resistant of the two protozoa). 1990). Additionally. 1999). 1990. Ninety per cent of the cysts are inactivated after 1 min (at pH 7 and a temperature of 5 °C). chlorine dioxide or UV irradiation is also used (Gregory. The shedding of cysts can persist for up to six months (Table 3. Cryptosporidium oocysts are sensitive to 5 mg of ozone per litre. Cryptosporidium. UV is also effective at inactivating Giardia cysts and Cryptosporidium oocysts. including chlorine (Lykins et al. 1995 Rendtorff.e. The duration of shedding of these oocysts after infection is 1–2 weeks..The Cryptosporidium infective dose that affects 50% of the challenged population of humans is about 132 oocysts (DuPont et al. The infective dose of Giardia that will cause gastroenteritis in 25% of an exposed population is 25 cysts. ideal) conditions.
2004). Biofilms may form on the lining of pipes (for example) in contact with water and may serve to protect the bacteria from disinfectants. A number of these bacteria may be shed by bathers or may be present in biofilms (assemblages of surface-associated microbial cells enclosed in an extracellular matrix – Donlan. Removal and inactivation of cysts and oocysts occur only in the fraction of water passing through treatment.4. They may be present in high numbers in natural spas using thermal spring water. 3. Risk assessment Legionella are Gram-negative. which may be free-living or living within amoebae and other protozoa or within biofilms. turbidity should be low. The efficacy of UV is impacted by particulate matter and the growth of biofilms. 2004). In addition. Like ozone. the best intervention is to prevent accidental faecal releases from occurring in the first place. once it has occurred. and UV lamps need to be cleaned periodically to remove biofilms or other substances that interfere with UV light emission. Most outbreaks of giardiasis and cryptosporidiosis among pool swimmers have been linked to pools contaminated by sewage. 2004). in the absence of detected faecal releases. and they can also grow in poorly main40 GUIDELINES FOR SAFE RECREATIONAL WATER ENVIRONMENTS . the only possible response to this condition. At present. accidental faecal releases or suspected accidental faecal releases.. found only a single instance when Cryptosporidium oocysts were detected (Fournier et al.6. However. Giardia cysts are somewhat larger and are removed by filters with a porosity of 7 µm or less. therefore. both Cryptosporidium and Giardia were always detected in the filter backwash water (Bonadonna et al.4 Non-faecally-derived bacteria Infections and diseases associated with non-enteric pathogenic bacteria found in swimming pools and similar recreational water environments are summarized in Table 3. Cryptosporidium oocysts are removed by filtration where the porosity of the filter is less than 4 µm. UV leaves no disinfectant residual and thus should be combined with chlorine or another disinfectant that remains in the water after treatment (WHO. disinfection) is impossible (see Chapter 5).. as inactivation in the water volume (i. Thus. Inactivation of Giardia cysts (99%) occurs at lower UV intensities of 5 mJ/cm2 (WHO. An Italian investigation of 10 chlorinated swimming pools found Cryptosporidium and Giardia in 3% of pool water samples despite otherwise good water quality (according to microbial monitoring results) and free chlorine levels of approximately 1 mg/l.e. the rate of reduction in concentration in the pool volume is slow. 1.(WHO. although statistics on removal efficiency during filtration should be interpreted with caution. 2002). are heterotrophic bacteria found in a wide range of water environments and can proliferate at temperatures above 25 °C. motile. 2002). through education of pool users about appropriate hygienic behaviour. A study conducted in six pools in France. Since a pool is a mixed and not a plug flow system. 2004).1 Legionella spp. is to prevent use of the pool and physically remove the oocysts by draining or by applying a long period of filtration. non-spore-forming. 3. Immunocompromised individuals should be aware that they are at increased risk of illness from exposure to pathogenic protozoa. the most practical approach to eliminating cysts and oocysts is through the use of filtration. Pool maintenance and appropriate disinfection levels are easily overwhelmed by accidental faecal releases or sewage intrusion. Legionella spp. aerobic bacilli.
1999). cigarette smoking and excess consumption of alcohol. asymptomatic production of antibodies or development of a mild flu-like illness. influenza-like illness. can cause legionellosis. a range of pneumonic and non-pneumonic disease (WHO. nontransmissible. ventilation and air conditioning tained hot tubs. Generally. Although the attack rate is often less than 1%. mortality among hospitalized cases ranges widely up to 50%. pneumophila. there is no reaction to such exposure. Non-faecally-derived bacteria found in swimming pools and similar environments and their associated infections Organism Legionella spp. include frequency of hot tub use and length of time spent in or around hot tubs. Swimming pool granuloma Hypersensitivity pneumonitis Staphylococcus aureus Leptospira spp. MICROBIAL HAZARDS 41 .6. Skin. it must be considered that people are frequently exposed (at least to low numbers). chronic lung disease. non-fatal. wound and ear infections Bather shedding in pool water Haemorrhagic jaundice Aseptic meningitis Pool water contaminated with urine from infected animals HVAC – heating. including associated pipes and air-conditioning units. The attack rate can be as high as 95% in the total exposed population. namely granular activated carbon. Specific risk factors. Legionella spp. age (50 or older). The risk of infection following exposure to Legionella is difficult to assess and remains a matter of some debate (Atlas. maintaining a continuous disinfectant residual in hot tubs (where disinfectants are not used. However. which may not be attributed to Legionella infection. Legionnaires' disease is characterized as a form of pneumonia. exposure to Legionella is preventable through the implementation of basic management measures.Table 3. there must be a high dilution rate with fresh water) and the maintenance and physical cleaning of all natural spa. can also multiply on filter materials. including filtration. Ninety per cent of cases of legionellosis are caused by L. hot tubs and HVAC systems Poorly maintained showers or heated water systems Bather shedding in pool and hot tub waters and on wet surfaces around pools and hot tubs Bather shedding on wet surfaces around pools and hot tubs Aerosols from hot tubs and HVAC systems Pseudomonas aeruginosa Folliculitis (hot tubs) Swimmer's ear (pools) Mycobacterium spp. associated equipment and HVAC systems. hot tub and pool equipment. in relation to pools and hot tubs. CHAPTER 3. Patients with no underlying illness or condition recover in 2–5 days without treatment. General risk factors for the illness include gender (males are roughly three times more likely than females to contract Legionnaires' disease). Pontiac fever is a non-pneumonic. 2005). Due to its prevalence in both natural and artificial environments. Infection/disease Legionellosis (Pontiac fever and Legionnaires' disease) Source Aerosols from natural spas. Legionella spp.
1985. household hot and cold water maintained between 25 °C and 50 °C. Outbreaks as a result of using swimming pools have not been reported (Marston et al. especially.Risk of legionellosis from pools and similar environments is associated with proliferation of Legionella in spas or hot tubs. ensuring an adequate disinfection residual in pools and hot tubs. 42 GUIDELINES FOR SAFE RECREATIONAL WATER ENVIRONMENTS . may be a source of high numbers of Legionella spp. 2000). Piped drinking-water distribution systems. • programming 'rest periods' during hot tub operation.. 1993). Mashiba et al. the principal responsibility will not lie with the water supplier. (2001) concluded that showers may present a greater risk of legionellosis than pool water. Mashiba et al. and they have been implicated in cases of legionnaires' disease (Bornstein et al. In hot tub facilities it is impractical to maintain a water temperature outside this range.. 1993). Althaus. 1986.. including cooling towers and evaporative condensers operating at these facilities. Martinelli et al. in order to discourage excessive use and also to allow disinfectant levels to 'recover'. although Leoni et al. 1989. associated equipment and HVAC systems. Natural spa waters (especially thermal water) and associated equipment create an ideal habitat (warm. or aspiration following ingestion. at least daily and when triggered by a pressure drop). evaporative condensers of air-conditioning devices. nutrient-containing aerobic water) for the selection and proliferation of Legionella. 2001). although.. Therefore. Risk management Control of Legionella follows similar general principles to water safety plans applied to drinking-water supplies (WHO. although Legionella spp.. 2004).. during natural spa or hot tub use may lead to disease...g.. proper maintenance and cleaning of equipment. Authorities responsible for regulation of recreational facilities should ensure the implementation of safety plans. 1989. Bornstein et al. The inference to be drawn from reported outbreaks and documented single cases is that inhalation of bacteria. Most of the reported legionellosis associated with recreational water use has been associated with hot tubs and natural spas (Groothuis et al. and adequate ventilation. it is necessary to implement a range of other management strategies. and such plans should address not only pools and hot tubs but also other water systems. Hot tubs used for display in retail/wholesale outlets are also potential sources of infection (McEvoy et al. which may include: • ensuring a constant circulation of water in the hot tub. Leoni et al. 1989. (Bornstein et al. As safety plans are limited to the recreational facility and the dose response is not easily described. have been isolated from pool water and filter samples (Jeppesen et al. 2000. to minimize the available surface area within the pool and hot tub system and associated pipework to reduce the area for possible bacterial colonization. • frequent inspection and cleaning of all filters. Important control measures include appropriate design. Increased risk of Legionella in drinking-water has been associated with systems operating within the temperature range 25–50 °C. in this instance. water fountains and mist-generating machines are also potential sources of exposure to Legionella.. Hot tubs integrated into larger swimming pool complexes appear to be less of a source of Legionella infection where shared water treatment facilities exist due to dilution of hot tub water into larger volumes of water for treatment. adequate control measures should be defined in terms of practices that have been shown to be effective. cooling towers. 2001). Thermal spring waters. 2.. 1994). including backwash filters (e.
• inspection and maintenance of cleaning operations (daily to weekly). cosmetics and organic debris that can act as a source of nutrients for bacterial growth and neutralize oxidizing biocides. where used. free chlorine. • maintaining and physically cleaning heating. 1985).5–4 µm. (e.g. In order to control the growth of Legionella in hot tubs and natural spas.g. It can metabolize a variety of organic compounds and is resistant to a wide range of antibiotics and disinfectants.g. P.2 Pseudomonas aeruginosa 1. Gram-negative. daily). drains.. and • where microbial testing for Legionella is undertaken. benches and floors provided by pools and similar environments is ideal for the growth of Pseudomonas. 3. physical cleaning of surfaces is critical. and high residual disinfectant concentrations may be required – e. Risk assessment Pseudomonas aeruginosa is an aerobic. • completely draining hot tubs and thoroughly cleaning all surfaces and all pipework (e. 1988). Bather density and duration spent in hot tubs should also be controlled. These materials protect CHAPTER 3.g. Bathers should be encouraged to shower before entering the water. • replacing at least half the water in each hot tub (e. The warm.5–1 µm × 1. This will remove pollutants such as perspiration. and it can grow well up to temperatures of 41 °C (Price & Ahearn.g. • inspection of the sand filter (e. Features such as water sprays. straight or slightly curved rod with dimensions 0. Although shedding from infected humans is the predominant source of P. non-spore-forming. aeruginosa in pools and hot tubs (Jacobson. must be at least 1 mg/l at all times. by use of a solution of at least 5 mg of hypochlorite per litre).g.4. ventilation and air-conditioning systems serving the room in which hot tubs are located (e. ensuring that Legionella levels are <1/100 ml. the surrounding environment can be a source of contamination. including: • checking and adjusting residual disinfectant levels and pH (several times a day).• cleaning pool surroundings. daily). inspection of the physical conditions of the hot tub (e. motile. It has been proposed that the high water temperatures and turbulence in aerated hot tubs promote perspiration and desquamation (removal of skin cells). Pseudomonas tends to accumulate in biofilms in filters that are poorly maintained and in areas where pool hydraulics are poor (under moveable floors. It is also likely that bathers pick up the organisms on their feet and hands and transfer them to the water. quarterly). etc. Public and semipublic spa facilities should have programmed rest periods during the day.g. moist environment on decks. weekly). in pool facilities should be periodically cleaned and flushed with a level of disinfectant adequate to eliminate Legionella spp. for example). aeruginosa is ubiquitous in water. and • ensuring staff are appropriately qualified and competent to operate the recreational facility. High-risk individuals (such as those with chronic lung disease) should be cautioned about the risks of exposure to Legionella in or around pools and hot tubs. vegetation and soil. MICROBIAL HAZARDS 43 . Operators of hot tub facilities should undertake a programme of verification of control measures. weekly to monthly).
The sex of bathers does not appear to be a significant risk factor. 1985).. aeruginosa-contaminated water next to the skin. presumably because one-piece suits trap more P.. 1991) and therefore could be caused by the inhalation of P. aeruginosa is otitis externa or swimmer's ear. predominantly P.. The rash appears 48 h (range 8 h to 5 days) after exposure and usually resolves spontaneously within 5 days. wounds and cornea caused by P. 1995). In swimming pools. 1986). Risk factors reported to increase the occurrence of otitis externa related to water exposure include amount of time spent in the water prior to the infection. Ratnam et al. in turn. aeruginosa endotoxins.. aeruginosa may damage skin and contribute to the bacteria's colonization (Highsmith et al. An indoor swimming pool with a system of water sprays has been implicated as the source of two sequential outbreaks of granulomatous pneumonitis among lifeguards (Rose et al. Some of these secondary symptoms resemble humidifier fever (Weissman & Schuyler. which may appear under surfaces covered with swimwear or may be more intense in these areas (Ratnam et al. aeruginosa (Ratnam et al. the primary health effect associated with P. 1980. 1985. Other symptoms. 1984. aeruginosa was isolated from all nine hot tubs examined (seven of which were commercial facilities and two domestic – Price & Ahearn. 1986). There are some indications that extracellular enzymes produced by P. 44 GUIDELINES FOR SAFE RECREATIONAL WATER ENVIRONMENTS . In the majority of hot tubs.organisms from exposure to disinfectants and contribute to the organic load. burning eyes and fever. Locally recommended disinfection levels (of between 3 and 5 mg/l chlorine or bromine) were not maintained in any of the commercial hot tubs examined. Infection of hair follicles in the skin with P. bather age and using the facility later in the day can be significant risk factors for folliculitis (Hudson et al. 1988). UK. aeruginosa densities of 104–106 per ml within 24–48 h following stoppage of disinfection. In Northern Ireland. the two domestic hot tubs developed P. respiratory tract. van Asperen et al. redness and pain in the external auditory canal. Inadequate chlorination led to the colonization of the spray circuits and pumps with Gram-negative bacteria. Otitis externa is characterized by inflammation. such as headache. Repeated exposure to water is thought to remove the protective wax coating of the external ear canal. Moore et al. P. 1998). Price & Ahearn. concentrations ranged from 102 to 105 per ml. they also act as a source of nutrients for the growth of P. aeruginosa. although folliculitis has also been reported (Ratnam et al. aeruginosa in 72% of hot tubs and 38% of swimming pools examined. In one study. It has been suggested that the infective dose for healthy individuals is greater than 1000 organisms per ml (Price & Ahearn. 2000). have been reported. 1986. Otitis externa and infections of the urinary tract. predisposing it to infection. but Hudson et al. the primary health effect associated with the presence of P. Dadswell. It has been suggested that warm water supersaturates the epidermis. 1997). (2002) found P. Ratnam et al. 1988. 1986). aeruginosa (Kush & Hoadley. reduces the residual disinfectant level. (1985) suggest that women wearing one-piece bathing suits may be more susceptible to infection. which. 1986. aeruginosa is folliculitis. Investigations have indicated that duration or frequency of exposure. 1988)... less than 19 years of age and a history of previous ear infections (Seyfried & Cook. muscular aches. aeruginosa produces a pustular rash. aeruginosa have also been linked to hot tub use. bather loads.. dilates dermal pores and facilitates their invasion by P.. In hot tubs. CDC. In the same study.. swelling.
aeruginosa was isolated from 5% of bromine-disinfected pools compared with only 0. Risk assessment Mycobacterium spp. and the water contained high concentrations of P. Atypical mycobacteria (i.. where possible. In the USA. He reported that during an outbreak investigation. pers.e. In eight of these outbreaks P. 1988). there were no further occurrences of disease among personnel. Shaw (1984) showed that chlorination was superior to bromine in controlling P. In all facilities. The floor of the pool was coated in abrasive grit. P. Another outbreak occurred in Germany due to high concentrations of P. Since the symptoms are primarily mild and self-limiting. P.). they are often referred to as acid-fast bacteria. aeruginosa in swimming pools and similar recreational environments (see Chapter 5). 2001). An outbreak of pseudomonas hot-foot syndrome. Wiedenmann. such as M. aeruginosa. Even in hot tubs with heterotrophic plate counts of <1 cfu/ml.. most patients do not seek medical attention.3 Mycobacterium spp. 1984). aeruginosa. Price & Ahearn. swimming pool. Routine. Risk management Maintaining adequate residual disinfectant levels and routine cleaning are the key elements to controlling P.8% of chlorine-disinfected pools (Shaw.4. comm.0–10 µm in size and have cell walls with a high lipid content. has been reported as a result of exposure to a community wading pool. aeruginosa in pools and similar environments is difficult to determine. disinfectants can quickly dissipate (Highsmith et al. CHAPTER 3. 2. 3. (2004) reported 20 outbreaks of dermatitis between 2000 and 2001 associated with pools and hot tubs. frequent monitoring and adjustment of pH and disinfectant levels are essential. hence.The bacteria and associated endotoxins were aerosolized and respired by the lifeguards when the sprays were activated. This feature means that they retain dyes in staining procedures that employ an acid wash. MICROBIAL HAZARDS 45 .. aeruginosa was identified from water or filter samples. erythematous plantar nodules. 1999). When the water spray circuits were replaced and supplied with an ozonation and chlorination system.or bromine-based disinfectants. in the other 12 outbreaks Pseudomonas was suspected to be the cause. aeruginosa (Fiorillo et al. tuberculosis) are ubiquitous in the aqueous environment and proliferate in and around swimming pools and similar environments (Leoni et al.5. are rod-shaped bacteria that are 0. 1. control the number of bathers and their duration of hot tub exposure (Public Health Laboratory Service Spa Pools Working Group. the design and operation of some hot tubs make it difficult to achieve adequate disinfectant levels in these facilities. Yoder et al. Most hot tubs use either chlorine. thorough cleaning of surrounding surfaces will help to reduce infections with P. aeruginosa could be isolated from water despite having a total bromine level of 5 mg/l and a pH of 7. While maintaining residual disinfectant levels in pools is relatively easy. other than strictly pathogenic species.6 µm × 1.2–0. aeruginosa on the stairs to a water slide and resulted in some of the children being admitted to hospital (A. In addition. Under normal operating conditions. 1985. 1994). It was noted that contributing factors to these outbreaks included inadequate pool and hot tub maintenance and exceeding the bather load limit. The true incidence of illnesses associated with P. hot tub and natural spa operators should strongly encourage users to shower before entering the water and.
In natural spas where the use of disinfectants is undesirable or where it is difficult to maintain adequate disinfectant levels. Humans are the only known reservoir of S. supplemented by the maintenance of disinfection at appropriate levels. In addition.. They are usually catalase positive and occur singly and in pairs. 1997). there are three clinically important species – Staphylococcus aureus. aureus..4 Staphylococcus aureus 1. aureus is the only coagulase-positive species and is clinically the most important (Duerden et al. 1984). 1977). tetrads. Khoor et al... In most instances the frequency of hot tub use was high. 46 GUIDELINES FOR SAFE RECREATIONAL WATER ENVIRONMENTS . M. epidermidis and S. 1997. non-spore-forming and non-encapsulated Gram-positive cocci (0. The illness followed the inhalation of heavily contaminated aerosols generated by the hot tub. Mangione et al. 2004). (Cirillo et al. Respiratory illnesses associated with hot tub use in normally healthy individuals have been linked to other atypical mycobacteria (Embil et al. as was the duration of exposure (an extreme example being use for 1–2 h each day). The reported cases relate to domestic hot tubs. avium in hot tub water has been linked to hypersensitivity pneumonitis and possibly pneumonia (Embil et al. many of which were located outdoors. 2001. 1986). Lumb et al. Therefore. occasional shock dosing of chlorine (see Chapter 5) may be required to eradicate mycobacteria accumulated in biofilms within pool or hot tub components (Aubuchon et al.. and the bacteria can be found in surface films in pool water. and it is found on the anterior nasal mucosa and skin as well as in the faeces of a substantial portion of healthy individuals.5 µm in diameter) that ferment glucose and grow aerobically and anaerobically. Risk assessment The genus Staphylococcus comprises non-motile. 2001. Robinton & Mood (1966) found that S. Infections frequently occur on abraded elbows and knees and result in localized lesions. thorough cleaning of surfaces and materials around pools and hot tubs where the organism may persist is necessary. S. superheating the water to 70 °C on a daily basis during periods of non-use may help to control M. It is likely that detected cases are only a small fraction of the total number of cases. Risk management Mycobacteria are more resistant to disinfection than most bacteria due to the high lipid content of their cell wall (Engelbrecht et al. aureus was shed by bathers under all conditions of swimming. Coagulase-positive Staphylococcus strains of normal human flora have been found in chlorinated swimming pools (Rocheleau et al. S. marinum (Embil et al. short chains and irregular grape-like clusters. malaise and headaches. 1997). and maintenance of disinfection and cleaning were not ideal. The organism is probably picked up from the pool edge by bathers as they climb in and out of the pool (Collins et al.. 2.. 1990). 1986). often referred to as swimming pool granuloma. 1997)...4. 2003.. Cappelluti et al.In pool environments. saprophyticus. Amoebae may also play a role in the transmission of Mycobacterium spp.5–1.. fever.. Symptoms were flu-like and included cough. marinum is responsible for skin and soft tissue infections in normally healthy people. 1997. chills. 3. 2001.. M. Grimes et al... For example. Kahana et al. Immunocompromised individuals should be cautioned about the risks of exposure to atypical mycobacteria in and around pools and hot tubs. In humans.
Diseases caused by Leptospira interrogans sensu lato have been given a variety of names.. the genus Leptospira consists of two species. Risk management Adequate inactivation of potentially pathogenic S. De Araujo et al. 1999). and. levels should be less than 100/100 ml. a classification system based on DNA relatedness is used (Brenner et al. 1988.4.. interrogans sensu lato and the saprophytic L. in a study on chlorinated pools where the free chlorine level varied between 0. aureus. interrogans sensu lato). 1991) or equivalent disinfection efficiency. impetigo and other infections (Calvert & Storey. however. There is evidence that showering before pool entry can reduce the shedding of staphylococci from the skin into the pool (Robinton & Mood. Serological tests within each species revealed many antigenic variations. In Italy. the pathogenic L. 1991). Risk assessment Leptospires are motile spirochaete (helically coiled) bacteria.. Free-living strains (L. cows and pigs) and are excreted in the urine. ranging from a mild flu-like CHAPTER 3. where samples are taken. Stuttgart disease and Weil's syndrome. wound infections. the pathogenic strains (L. live in the kidneys of animal hosts. Rivera & Adera. nose and conjunctiva. (1964) and Crone & Tee (1974). 50% or more of the total staphylococci isolated from swimming pool water samples are S. 2. Although it is not recommended that water samples be routinely monitored for S. urinary tract infections. biflexa sensu lato) are ubiquitous in the environment (Faine et al. including swineherd's disease.8 and 1. 3. Infections of S. biflexa sensu lato. 2004). S.The presence of S. Pool contamination can also be reduced if the floors surrounding the pool and in the changing areas are kept at a high standard of cleanliness. According to Favero et al. 1999). but collectively all of these infections are termed leptospirosis. The clinical manifestations of leptospirosis vary considerably in form and intensity. aureus acquired from recreational waters may not become apparent until 48 h after contact. The serological and genetic taxonomies are two different systems with only little correlation (Brenner et al. otitis externa. on this basis. In addition. Humans and animals (humans are always incidental hosts) become infected either directly through contact with infected urine or indirectly via contact with contaminated water. aureus was not recovered from water samples (Bonadonna et al. aureus in swimming pools can be attained by maintaining free chlorine levels greater than 1 mg/l (Keirn & Putnam. 1999). 1968. however.5 Leptospira interrogans sensu lato 1. (1990) have suggested that recreational waters with a high density of bathers present a risk of staphylococcal infection that is comparable to the risk of gastrointestinal illness involved in bathing in water considered unsafe because of faecal pollution. MICROBIAL HAZARDS 47 .2 mg/l. Continuous circulation of surface water through the treatment process helps to control the build-up of S. 1966). The current species determination is based on this principle. aureus. Leptospires gain entry to the body through cuts and abrasions of the skin and through the mucosal surfaces of the mouth. Rivera & Adera. Pathogenic leptospires live in the proximal renal tubules of the kidneys of carrier animals (including rats. eye infections.. aureus. leptospires are classified as serovars. aureus in swimming pools is believed to have resulted in skin rashes. which can then contaminate surface waters. Traditionally.
about 320 nm × 250 nm × 200 nm. Normal disinfection of pools is sufficient to inactivate Leptospira spp. pool or hot tub decks. 1999). de Lima et al.illness to a severe and potentially fatal form of the disease. Non-faecally-derived viruses found in swimming pools and similar environments and their associated infections Organism Adenovirusesa Molluscipoxvirus Infection Pharyngo-conjunctivitis (swimming pool conjunctivitis) Molluscum contagiosum Source Other infected bathers Bather shedding on benches. an innocuous cutaneous disease limited to humans. The virus causes molluscum contagiosum. and they cannot tolerate drying or exposure to direct sunlight (Noguchi. Weyant et al. Table 3.1 Molluscipoxvirus 1. The majority of reported outbreaks of waterborne leptospirosis have involved fresh recreational waters. Severity is related to the infecting serovar as well as host characteristics. including disinfectants.1. It is spread by direct person-to-person contact or indirectly through physical contact with contaminated 48 GUIDELINES FOR SAFE RECREATIONAL WATER ENVIRONMENTS . characterized by liver and kidney failure and haemorrhages (Weil's syndrome). Informing users about the hazards of swimming in water that is accessible to domestic and wild animals may also help to prevent infections. 2.8. Specific serovars are often associated with certain hosts. swimming aids Bather shedding on pool and hot tub decks and floors in showers and changing rooms Papillomavirus Plantar wart a Covered in Section 3. Domestic or wild animals with access to the implicated waters were the probable sources of Leptospira. 1958. it appears that the risk of leptospirosis associated with swimming pools and hot tubs is low. 1918.2 3.. Risk management The risk of leptospirosis can be reduced by preventing direct animal access to swimming pools and maintaining adequate disinfectant concentrations.7.5. Outbreaks are not common. Compared with many other pathogens.5 Non-faecally-derived viruses Infections associated with non-faecally-derived viruses found in swimming pools and similar environments are summarized in Table 3. They are seldom found in water of below pH 6. 1954. Risk assessment Molluscipoxvirus is a double-stranded DNA virus in the Poxviridae family. but two outbreaks have been associated with non-chlorinated swimming pools (Cockburn et al.7. thus. 1990). leptospires have a comparatively low resistance to adverse chemical and physical conditions. such as age and underlying health and nutritional status.. Alston & Broom. Virions are brick-shaped. 3..
The incubation period of the virus remains unknown. At facilities such as public swimming pools. Since the infection is relatively innocuous. back of the legs and back. 2. the reported number of cases is likely to be much less than the total number. they should not be ruled out as a route of exposure. CHAPTER 3. The incubation period is 2–6 weeks or longer. the most important means of controlling the spread of the virus is to educate the public about the disease. It is less common among adults. Johnson. The use of pre-swim showering. The infection appears as small. Lesions are most often found on the arms. MICROBIAL HAZARDS 49 . 1990. Papillomaviruses are extremely resistant to desiccation and thus can remain infectious for many years. the importance of limiting contact between infected and non-infected people and medical treatment. An infection that occurs on the sole (or plantar surface) of the foot is referred to as a verruca plantaris or plantar wart. the most important means of controlling the spread of the infection is to educate the public about the disease.surfaces. 3. benches around the pool.5–2 years. swimming aids carried into the pool or shared towels (Castilla et al. Individual lesions persist for 2–4 months. The infection is extremely common among children and young adults between the ages of 12 and 16 who frequent public pools and hot tubs. The virions are spherical and approximately 55 nm in diameter. but it is estimated to be 1–20 weeks. Risk management The primary source of papillomavirus in swimming pool facilities is infected bathers. Swimming pool-related cases occur more frequently in children than in adults.6 Non-faecally-derived protozoa Table 3. The total number of annual cases is unknown. suggesting that they acquire immunity to the infection. 1995). firm papules or lesions. the importance of limiting contact between infected and non-infected people and medical treatment. wearing of sandals in showers and changing rooms and regular cleaning of surfaces in swimming pool facilities that are prone to contamination can reduce the spread of the virus. Thorough frequent cleaning of surfaces in facilities that are prone to contamination can reduce the spread of the disease. Risk management The only source of molluscipoxvirus in swimming pool and similar facilities is infected bathers (Oren & Wende. plantar warts are usually acquired via direct physical contact with shower and changing room floors contaminated with infected skin fragments (Conklin. 1995).5. which grow to about 3–5 mm in diameter. 2. Hence. Risk assessment Papillomavirus is a double-stranded DNA virus in the family Papovaviridae. Although cases associated with hot tubs have not been reported..2 Papillomavirus 1. and cases resolve spontaneously in 0. suggesting transmission through physical contact with the edge of the pool. Papillomavirus is not transmitted via pool or hot tub waters. round. Hence.8 summarizes the non-faecally-derived protozoa found in or associated with swimming pools and similar environments and their associated infections. 3. The virus causes benign cutaneous tumours in humans. 1991). Indirect transmission via water in swimming pools is not likely.
high fever. The source of the contamination was traced to a cavity behind a false wall used to shorten the pool length. cases have been associated with pools and natural spas. Subsequent analysis confirmed the thermal springs to be the source of the infection (Kilvington et al. fowleri causes primary amoebic meningoencephalitis (PAM). 1997). Szenasi et al. in 1978. Czech Republic. Risk assessment Naegleria fowleri is a free-living amoeba (i. nausea. seizures and hallucinations. hot tubs and natural spas including water and components Acanthamoeba keratitis Aerosols from HVAC systems Granulomatous amoebic encephalitis (GAE) Malaria Seasonally used pools may provide a breeding habitat for mosquitoes carrying Plasmodium HVAC – heating.6. 1999). with smooth. Victims are usually healthy children and young adults who have had contact with water about 7–10 days before the onset of symptoms (Visvesvara. Plasmodium spp. One confirmed case of PAM occurred in Bath Spa. ventilation and air conditioning 3. fowleri is thermophilic. 8–12 µm in diameter. The life cycle includes an environmentally resistant encysted form. usually from diving. The victim was a young girl who swam in a public swimming pool fed with water from the historic thermal springs that rise naturally in the city (Cain et al. Respiratory symptoms occur in some patients and may be the result of hypersensitivity or allergic reactions or may represent a subclinical infection (Martinez & Visvesvara. Infection Primary amoebic meningoencephalitis (PAM) Source Pools. in the UK. stiff neck. death occurs usually 3–10 days after onset of symptoms. In Usti. 1981). Symptoms of the infection include severe headache. preferring warm water and reproducing successfully at temperatures up to 46 °C. jumping or underwater swimming. 1968). The pool took water from a local river. it does not require the infection of a host organism to complete its life cycle) present in fresh water and soil. N. The amoebae in the water then make their way into the brain and central nervous system. natural spas and artificial lakes (Martinez & Visvesvara..8. N.Table 3. For those infected. single-layered walls containing one or two mucus-plugged pores through which the trophozoites (infectious stages) emerge. 1997. Non-faecally-derived protozoa found in swimming pools and similar environments and their associated infections Organism Naegleria fowleri Acanthamoeba spp. 1991). 16 cases of PAM were associated with a public swimming pool (Cerva & Novak. Infection occurs when water containing the organisms is forcefully inhaled or splashed onto the olfactory epithelium. Cysts are spherical.1 Naegleria fowleri 1. Although PAM is an extremely rare disease.. fowleri has also been isolated from air-conditioning units (Martinez. vomiting.e. which was the likely source of the organism. Infection is usually acquired by exposure to water in ponds. The infection is not contagious. 1993). N.. 50 GUIDELINES FOR SAFE RECREATIONAL WATER ENVIRONMENTS . 1998).
and bromine-based disinfectants. such as a ready supply of bacteria and a suitable temperature. headaches. Risk management Risk of infection can be reduced by minimizing the occurrence of the causative agent through appropriate choice of source water. Symptoms include fever. Acanthamoeba keratitis affects previously healthy people and is a severe and potentially blinding infection of the cornea (Ma et al.. human contact with the organism rarely leads to infection. meningitis and visual abnormalities. polyphaga). culbertsoni. The precise source of such infections is unknown because of the almost ubiquitous presence of Acanthamoeba in the environment. 1994). Although only one eye is usually affected. Cysts measure 15–28 µm. 1990. with only 60 cases reported worldwide. Thus. they form a dormant encysted stage. GAE is extremely rare. GAE is a chronic disease of the immunosuppressed. All pathogenic species will grow at 36–37 °C. coagulation– filtration and disinfection. Risk management Although Acanthamoeba cysts are resistant to chlorine. they can be removed by filtration. Kilvington & White. 1991). castellanii. A. Although Acanthamoeba is common in most environments. 1. proper cleaning. the cysts hatch (excyst) and the trophozoites emerge to feed and replicate. cases of bilateral infection have been reported. Poor contact lens hygiene practices (notably ignoring recommended cleaning and disinfection procedures and rinsing or storing of lenses in tap water or non-sterile saline solutions) are recognized risk factors. Kilvington & White... depending on the species. Human pathogenic species of Acanthamoeba cause two clinically distinct diseases: granulomatous amoebic encephalitis (GAE) and inflammation of the cornea (keratitis) (Ma et al. 1990). although invasion of the brain may result from the blood following a primary infection elsewhere in the body.6. although the wearing of contact lenses while swimming or participating in other water sports may also be a risk factor. it is unlikely that properly operated CHAPTER 3.2 Acanthamoeba spp. The disease is characterized by intense pain and ring-shaped infiltrates in the corneal stroma. Contact lens wearers are most at risk from the infection and account for approximately 90% of reported cases (Kilvington & White. Risk assessment Several species of free-living Acanthamoeba are human pathogens (A. A. Samples et al. When favourable conditions occur. They can be found in all aquatic environments. acanthamoeba keratitis can lead to permanent blindness. 1991. 3. possibly the skin or lungs (Martinez. In noncontact lens related keratitis. GAE is either subacute or chronic but is invariably fatal. The route of infection in GAE is unclear. maintenance. disinfection and desiccation. 1994). The cysts will retain viability from –20 °C to 56 °C. 1994). 1990. infection arises from trauma to the eye and contamination with environmental matter such as soil and water (Sharma et al. Acanthamoeba cysts are highly resistant to extremes of temperature. with an optimum of about 30 °C. seizures. Under adverse conditions. MICROBIAL HAZARDS 51 . Martinez. In the untreated state. including disinfected swimming pools. 2. (1984) report a case of keratitis that may have been acquired from domestic hot tub use. 1985.2.
a study comparing students attending a regular swimming class with those who did not found a significantly greater level of infection in the swimmers (odds ratio of 8. were 52 GUIDELINES FOR SAFE RECREATIONAL WATER ENVIRONMENTS .6. but with anopheline mosquito larvae. The problem relates to the seasonal use of the pools. post-swim contact lens wash using appropriate lens fluid and use of daily disposable lenses. contaminated with infected skin fragments. Before people leave their summer houses. Risk assessment Swimming pools are associated not with Plasmodium spp. A number of precautionary measures are available to contact lens wearers. Immunosuppressed individuals who use swimming pools. and Epidermophyton floccosum 1.7 Non-faecally-derived fungi Infections associated with fungi found in swimming pools and similar environments are summarized in Table 3. Infection of the skin of the foot (usually between the toes) is described as tinea pedis or. Epidermophyton floccosum Infection Athlete's foot (tinea pedis) Source Bather shedding on floors in changing rooms. Fungi found in swimming pools and similar environments and their associated infections Organism Trichophyton spp. however. 1. showers and pool or hot tub decks 3. and Trichophyton spp. Risk management During the rains. In Japan. Mbogo et al. wearing goggles. etc.1 Trichophyton spp. with intense itching. 2. 1981). Symptoms include maceration. rainwater accumulated during the rainy season provides a suitable habitat for mosquito breeding. The swimming pools may also be treated with appropriate larvicides when not in use for long periods. however. Tinea pedis may be transmitted by direct person-to-person contact. they should be drained every 5–7 days to avoid mosquito larvae developing into adults. as 'athlete's foot' (Aho & Hirn.9. when the pools fill with water. including removal before entering the water. in swimming pools. Risk assessment Epidermophyton floccosum and various species of fungi in the genus Trichophyton cause superficial fungal infections of the hair.3 Plasmodium spp. 3. it may be transmitted by physical contact with surfaces. more commonly. the insect vectors of Plasmodium. with the attendant risks of malaria as a result. changing rooms.5).7.9. (submitted) found that over 70% of swimming pools sampled in urban Malindi in Kenya were positive for mosquito larvae. 3. it is common to drain the pool. natural spas or hot tubs should be aware of the increased risk of GAE. Table 3.. cracking and scaling of the skin. such as floors in public showers. fingernails or skin.swimming pools and similar environments would contain sufficient numbers of cysts to cause infection in normally healthy individuals.
Althaus H (1986) Legionellas in swimming pools. Routine disinfection appears to control the spread of these fungi in swimming pools and similar environments (Public Health Laboratory Service Spa Pools Working Group. Livingstone Ltd. 1987). Risk management The sole source of these fungi in swimming pool and similar facilities is infected bathers. 206–208. Fleurette J (1989) Exposure to Legionellaceae at a hot spring spa: a prospective clinical and serological study. Epidemiology and Infection. The fungus colonizes the stratum corneum when environmental conditions. Graham DR (1986) Atypical mycobacterial infection of soft tissue associated with use of a hot tub. but relatively benign. Epidemiology and Infection. Environmental Microbiology. The use of pre-swim showers. Alston JM. Blostein J (1991) Shigellosis from swimming in a park in Michigan. Al-Doory Y. Mikrobiologie und Hygiene B. Marmet D. Sharp JCM (1994) An outbreak of Escherichia coli O157 associated with a children's paddling pool. 68-A(5): 766–768. Wiley PF. Brenner DJ. People with severe athlete's foot or similar dermal infections should not frequent public swimming pools. wearing of sandals in showers and changing rooms and frequent cleaning of surfaces in swimming pool facilities that are prone to contamination can reduce the spread of the fungi (AlDoory & Ramsey. 173: 242–249. 84: 334–337. natural spas or hot tubs. Charles C. Nowicki M. MICROBIAL HAZARDS 53 . thus. Bornstein N. Warhurst DC (1981) Primary amoebic meningoencephalitis.B. A. it has been calculated that it takes approximately 3–4 h for the fungus to initiate infection. Sulzer KR. Houghton GL. 112: 441–447. 102: 31–36.] Annali di Igiene Medicina Preventiva e di Comunità. 16(6): 709–720 (in Italian). The infection is common among lifeguards and competitive swimmers. 106: 317–322. Cain ARR. 3. Brownwell B. Broom JC (1958) Leptospirosis in man and animals. Romano-Spica V (2004) [A preliminary investigation on the occurrence of protozoa in swimming pools in Italy. Thomas. Robertson D. From in vitro experiments. 1997). Public Health Reports. Bell A.8 References Aho R. particularly humidity. Surgot M. Archives of Diseases in Childhood. 38: 242–245. Edinburgh. Arslan A. Brewster DH. 1(4): 283–293. Atlas RM (1999) Legionella: from environmental habitats to disease pathology. Briancesco R. Orsini M. 2. Meeds D. Journal of Bone and Joint Surgery. Kaufmann AF. Farley JD (1993) A swimming pool associated outbreak of cryptosporidiosis in British Columbia. Ramsey S (1987) Cutaneous mycotic diseases. Guasparini R. IL. the true number of cases is unknown. Aubuchon C. In: Moulds and health: Who is at risk? Springfield. CHAPTER 3. Bimson J. detection and control. Magini V. Brown MI. Bonadonna L. Archiv des Badewesens. pp. Nov and four new Leptospira genomospecies. Esteve J. Hirn H (1981) A survey of fungi and some indicator bacteria in chlorinated water of indoor public swimming pools. Hill JJ. International Journal of Systematic Bacteriology. Hence. the most important means of controlling the spread of the fungus is to educate the public about the disease. 61–68. 1994). Rogers FC. Mathias RG. Canadian Journal of Public Health. are optimal.isolated from the floor of a hot tub and the floor of one of the changing rooms (Kamihama et al. Weyant RS (1999) Further determination of DNA relatedness between serogroups and serovars in the family Leptospiraceae with a proposal for Leptospira alexanderi sp.. 56: 140–143. Steigerwalt AG. the importance of limiting contact between infected and non-infected bathers and medical treatment. 49: 833–858. Zentralblatt für Bakteriologie.
Peterson LJ. Communicable Disease Report Weekly. 2004. 160: 92. Morbidity and Mortality Weekly Report. Reinhard KR (1954) Human leptospirosis associated with a swimming pool diagnosed after eleven years. 1999–2000. Spencer SS. Grange JM. Sports Medicine. 65(9): 3759–3767. CDSC (1995) Surveillance of waterborne diseases. 96(7): 12. Morbidity and Mortality Weekly Report. Journal of Applied Bacteriology. 2001. Carpenter C. CDSC (1997) Surveillance of waterborne disease and water quality: January to June 1997. 191(2): 165. 39: 343–345. Morbidity and Mortality Weekly Report. 45: 437–439. CDC (1996) Lake-associated outbreak of Escherichia coli O157-H7 – Illinois. American Journal of Epidemiology. CDC (2001b) Shigellosis outbreak associated with an unchlorinated fill-and-drain wading pool – Iowa. Lindsey NJ. CDSC (1998) Surveillance of waterborne disease and water quality: January to June 1998. 99: 230–234. 1999. Fayer R. Bohl FN (1974) Epidemic with adenovirus type 7 acute conjunctivitis in swimmers. Fraire AE. Vavra JD. 43: 561–563. Donnelly DD. Cappelluti E. 5(4): 579–584. CDC (2004) An outbreak of norovirus gastroenteritis at a swimming club – Vermont. Morbidity and Mortality Weekly Report. 57(2): 193–211. Schaefer OP (2003) A case of 'hot tub lung' due to Mycobacterium avium complex in an immunocompetent host. CDSC (1999) Surveillance of waterborne disease and water quality: January to June 1999. 50(37): 797–800. Castilla MT. 9: 100–119.Caldwell GG. 10: 65–68. CDC (1994) Cryptosporidium infections associated with swimming pools – Dane County. 50(20): 406–410. Bermudez LE (1997) Interaction of Mycobacterium avium with environmental amoebae enhances virulence. Fuentes S (1995) Molluscum contagiosum in children and its relationship to attendance at swimming-pools: an epidemiological study. Dann JR. Collins CH. 50: 410–412. Morbidity and Mortality Weekly Report. Casemore DP (1990) Epidemiological aspects of human cryptosporidiosis. 7: 317–319. CDSC (2000) Surveillance of waterborne disease and water quality: July to December 1999. Communicable Disease Report Weekly. Morbidity and Mortality Weekly Report. Communicable Disease Report Weekly. and summary of 1998. Tompkins LS. Calvert J. Mycobacterium in water. Science. Yates MD (1984) A review. Novak K (1968) Amoebic meningoencephalitis: sixteen fatalities. Emerging Infectious Diseases. Infection and Immunity. 8: 305–306. 53: 793–795. CDC (2000) Pseudomonas dermatitis/folliculitis associated with pools and hot tubs – Colorado and Maine. Beach MJ (1999) Chlorine disinfection of recreational water for Cryptosporidium parvum. CDC (1990) Swimming-associated cryptosporidiosis – Los Angeles County. Archives of Internal Medicine. 9: 305–308. 104: 1–28. 49: 1087–1091. Epidemiology and Infection. Communicable Disease Report Weekly. 5: 129. Trout J. Cockburn TA. 54 GUIDELINES FOR SAFE RECREATIONAL WATER ENVIRONMENTS . Conklin RJ (1990) Common cutaneous disorders in athletes. Cerva L. 2000. Storey A (1988) Microorganisms in swimming pools – are you looking for the right one? Journal of the Institution of Environmental Health Officers. 163: 845–848. CDC (2001a) Prevalence of parasites in fecal material from chlorinated swimming pools – United States. Communicable Disease Report Weekly. Cirillo JD. American Journal of Hygiene. Morbidity and Mortality Weekly Report. Morbidity and Mortality Weekly Report. 60: 1–7. CDC (2001c) Protracted outbreaks of cryptosporidiosis associated with swimming pool use – Ohio and Nebraska. Dermatology. Wisconsin. Sanzo JM. Wulff H. Falkow S.
Massarik MT. Brandt CD. Hatlen JB (1968) Adenovirus type 3 epidemic associated with intermittent chlorination of a swimming pool. Faroo S. DuPont HL (1988) Shigella. Fiorillo L. Santo CE. EPA 600/2-77-052). Chest. 8(9): 881–890. Wolff ED (1996) Four cases of hemolytic uremic syndrome – source contaminated swimming water? Clinical Nephrology. 332(13): 855–859. Donlan R (2002) Biofilms: microbial life on surfaces. Public Health Reports. Randall GB (1964) Use of staphylococci as indicators of swimming pool pollution. DuPont HL. MediSci. Fox JP. Stiliano SV. Gaussin F. Banffer JR. Nauta J. Journal of Infectious Diseases. Foy HM. Spigland CE. Observations of adenovirus infections. Seroepidemiological study. Gray SF. Santillana-Hayat M. Engelbrecht RS. Yasuda PH. Sao Paulo. American Journal of Epidemiology. 105(3): 69–73. Sakata EE. Fournier S. Chappell CL. Guimaraes VF. Cooney MK. Revista de Microbiologia. Jakubowski W (1995) The infectivity of Cryptosporidium parvum in healthy volunteers. FEMS Immunology and Medical Microbiology. VI. Sarfati C. NY. Epidemiology and Infection. Soler P (2003) Cryptosporidiosis outbreak in British tourists who stayed at a hotel in Majorca. Mendonca-Hagler LCS. 345(5): 335–338. van den Kerkhof JH. Keenlyside RA. Jewsbury JM. virus excretion patterns. 33: 209–213. Edward Arnold. New York. Bradley DJ. Galmes A. United States Environmental Protection Agency (Report No. Perolat P (1999) Leptospira and leptospirosis. Smith-Palmer A. Lee SH. Lalchandani A (1977) New microbial indicators of disinfection efficiency. Anderson LJ. efficiency of surveillance patterns of infection and relation to illness. Eurosurveillance Weekly. Dadswell J (1997) Poor swimming pool management: how real is the health risk? Environmental Health. Peters TJ (1994) Risk factors for giardiasis: a case–control study in Avon and Somerset. Gunnell DJ. Crone PB. Liguory O. de Araujo MA. Hershfield E (1997) Pulmonary illness associated with exposure to Mycobacterium-avium complex in hot tub water. Wernors K. 46: 45–49. Kogan A. Hall CE. 272 pp. Embil J. 74–76. 140: 42–47. Hernandez-Pezzi G. Yakrus M. Ribeiro FA (1990) Outbreak of human leptospirosis by recreational activity in the municipality of Sao Jose dos Campos. Zucker M. de Lima SC. Reid TMS. Okhuysen PC. Melbourne. Tee GH (1974) Staphylococci in swimming pool water. MICROBIAL HAZARDS 55 . Emerging Infectious Diseases. New England Journal of Medicine. 2nd ed. Brazil. 32(6): 474–479. Corne S. Guma M. New England Journal of Medicine. Gust ID (1980) Detection of hepatitis A virus in the feces of patients with naturally acquired infections. Gomis E. Molina JM. Sterling CR. 2(3): 599–605. Infectious Disease Clinics of North America. Favero MS. Severnin BF. Rose JB. van de Kar NC. 113: 95–102. Duerden BI. Mara DD (1983) Sanitation and disease: Health aspects of excreta and wastewater management. 89: 25–50. Feachem RG. Lehmann NI. Wassermann FE. Dubrou S. 141(2): 151–156. John Wiley and Sons. 79: 61–70. Hierholzer JC. Hagler AN (1990) Staphylococcus aureus and faecal streptococci in fresh and marine waters of Rio de Janeiro. D'Angelo LJ. Derouin F (2002) Detection of microsporidia. Journal of Infectious Diseases.Coulepis AG. 21(2): 141–147. Archives of Environmental Health. 73(2): 213–220. 111(3): 534–536. antibody response. Drake CH. Revista do Instituto de Medicina Tropical de Sao Paulo. Washington. Forrest D. Spain. Warren P. cryptosporidia and giardia in swimming pools: a one-year prospective study. Sawyer D. London. Lin AN (2001) The pseudomonas hot-foot syndrome. pp. Elveback LR (1969) The Virus Watch Program: A continuing surveillance of viral infections in metropolitan New York families. Cransberg K. CHAPTER 3. Garelick H. Locarnini SA. 17: 795–802. Arbona G. Adler B. Turk DC (1990) Microbial and parasitic infection. Nicolau A. DC. Martone WJ (1979) Pharyngo-conjunctival fever caused by adenovirus type 4: Recovery of virus from pool water. Journal of Hygiene (London). Bolin C. Faine S. 7(33). Haas CN. Stijnen C.
7: 91–94. Price TJ. Communicable Disease Report Review. Watson J (1994) A community outbreak of echovirus infection associated with an outdoor swimming pool. 162: 3592–3594 (in Danish). Tazelaar HD. Kimura T. Johnson LW (1995) Communal showers and the risk of plantar warts. Communicable Disease Report Review. Journal of Applied Bacteriology. Libby J (1984) Giardiasis in an infant and toddler swim class. Infection Control. Harrower B. Noah ND. Colby TV (2001) Diffuse pulmonary disease caused by nontuberculous mycobacteria in immunocompetent people (hot tub lung). Baker C. 6(10): 407–412.] Ugeskrift for Laeger. Williams LP Jr. Leslie KO. 4(2): R20–R22. Chest. 107: 497–508. 6: 398–401. Lyon M. 16: 145–148. Putnam HD (1968) Resistance of staphylococci to halogens as related to a swimming pool environment. John Wiley & Sons. Munn VP (1985) Characteristics of Pseudomonas aeruginosa isolated from whirlpools and bathers. Hunt DA. Marks JS. Infection Control. 111: 242–245. Joce RE. Kiely D. Fast MV (1988) Giardiasis associated with the use of a water slide. Gregory R (2002) Bench-marking pool water treatment for coping with Cryptosporidium. Highsmith AK. Jeppesen VF (2000) [Legionella pneumophila in pool water. Stanwick RS. Chapman PA. Groothuis DG. Takase T. 56 GUIDELINES FOR SAFE RECREATIONAL WATER ENVIRONMENTS . New England Journal of Medicine. Harley D. 74: 155–156. American Journal of Epidemiology. 25(1): 9–12. Communicable Diseases Intelligence. Bruce J. Hudson PJ. Halliman RE. Pediatric Infectious Diseases Journal.Greensmith CT. Journal of Family Practice. 111: 249–253. Kee F. Jeppesen C. Casemore DP (1994) Cryptosporidiosis associated with a swimming pool complex. Chichester. Bagge L. Cole TJ. Ueji M. Kay JM. Kappus KD. Keene WE. Havelaar AH. Vogt RL. Yakrus MA. McAnulty JM. Grimes MM. Frost F. 40: 136–138. Helmers RA. 331(9): 579–584. Fleming DW (1994) A swimming-associated outbreak of hemorrhagic colitis caused by Escherichia coli O157:H7 and Shigella sonnei. American Journal of Clinical Pathology. Oxman GL. Keirn MA. Health Laboratory Science. 6: R33–R36. American Journal of Epidemiology. Coyle P. Hedberg K. American Journal of Public Health. 58(5): 479–481. Dick A (2001) A primary school outbreak of pharyngoconjunctival fever caused by adenovirus type 3. Hildebrand JM. Kangesu E (1996) An outbreak of Escherichia coli O157 infection linked to paddling pools. Hoesly FC. Le PN. Edmondson SG. Epidemiology and Infection. Jillson DA. Fowler III AA (2001) Obstructive granulomatous bronchiolitis due to Mycobacterium avium complex in an immunocompetent man. Watkins J. 115: 755–762. Dempster WB. Khabbaz RF. Grunenfelder G. 122: 915–917. Jacobson JA (1985) Pool-associated Pseudomonas aeruginosa dermatitis and other bathing-associated infections. Stewart D. 5(3): 180–193. Greenberg HB (1982) An outbreak of Norwalk gastroenteritis associated with swimming in a pool and secondary person to person transmission. Kappel SJ. 68: 411–415. Hunter PR (1997) Adenoviral infections. Gumsley P. Waserman S (1997) Mycobacterium avium complex infection in an immunocompetent young adult related to hot tub exposure. Veenendaal HR (1985) A note on legionellas in whirlpools. Khoor A. Smith HV. 1: 11–18. Kahana LM. Elliot BE. Kamihama T. Sebugwawo S. Public Health. Highsmith AK (1985) Duration of whirlpool-spa use as a risk factor for Pseudomonas dermatitis. Watts D (1991) An outbreak of cryptosporidiosis associated with a swimming pool. Pfaller MA. Hosokawa J-I. Harter L. Journal of Public Health Medicine. Respiration. Tagami K (1997) Tinea pedis outbreak in swimming pools in Japan. Journal of Environmental Health Research. McElroy G. 116: 834–839. Maguire HC. Bryant JK. Stalker R. Waterborne disease: Epidemiology and ecology. Norman P. Perkins-Jones K. Holman RC. Barrett TJ. Gary GW.
Verweij XX. diagnosis. CHAPTER 3. Mangione EJ. 13: S399–S402. 132: 737–743. American Journal of Public Health. Martone WJ. Bastian I (2004) Investigation of spa pools associated with lung disorders caused by Mycobacterium avium complex in immunocompetent adults. Visvesvara GS (1997) Free-living. von Bonsdorff C-H. Baily A. Garwicz D. 5: 12–20. 7: 1039–1042. Journal of Infectious Diseases. Kalso S. Warhurst DC (1991) Pathogenic Naegleria amoebae in the waters of Bath: a fatality and its consequences. Jonsson M. White DG (1994) Acanthamoeba: biology. Winkler WG (1980) An outbreak of adenovirus type 3 disease at a private recreation center swimming pool.Kidd AH. Legnani PP. Bucci Sabattini MA. Speziani F (2001) Detection of Legionella pneumophila at thermal spas. de Jong JC (1996) Rapid subgenus identification of human adenovirus isolates. Martinez AJ (1993) Free-living amebas: infection of the central nervous system. 111: 229–237. Fraser DW. FL. Hamamoto T. Doyle R. Martinelli F. Hierholzer JC. CRC Press. Hoadley AW (1980) A preliminary survey of the association of Ps. 7(1): 583–598. 89–96. D'Angelo LJ. Water Research. Visvesvara GS. Mashiba K. Epidemiology and Infection. aeruginosa with commercial whirlpool bath waters. Hot springs of Bath. 60(4): 271–278. ecology and human disease. Breiman RF (1994) Surveillance for Legionnaires' disease: Risk factors for morbidity and mortality. Theodore FH. Wilson SA. 70(8): 4906–4910. 77: 166–168. Goodrich JA.A. Torikai K (1993) [A case of Legionnaires' disease due to aspiration of hot spring water and isolation of Legionella pneumophila from hot spring water. Farley TA. Goodwin A. Lykins BW. Journal of Applied Microbiology. Mahoney FJ. 67: 163–166 (in Japanese). Pirani R (1999) Prevalence of mycobacteria in a swimming pool environment. prevention. Leoni E. Mann PG. Hoff JC (1990) Concerns with using chlorine-dioxide disinfection in the U. Kilvington S. Martinez AJ (1985) Free-living amebas: natural history. Pönkä A (2004) Wading pool water contaminated with both noroviruses and astroviruses as the source of a gastroenteritis outbreak. Legnani P. Mallonee J. pathology. Dagget PM. 12: 490–513. Marston BJ. Rau MP. Lumb R. 24: 259–264. Albrecht KD. Scroop A. 165: 613–618. Keenlyside RA. Martinez AJ. Reviews of Infectious Diseases. Boca Raton. Bath. Maunula L. Kajon AE. Sawyer TK (1990) Naegleria and Acanthamoeba infections: review. Kelso KY. Martinez AJ. Righi F (2001) Prevalence of Legionella spp. New Microbiology. pp. Scarcella C. Bath City Council. Journal of Clinical Microbiology. American Journal of Public Health. Emerging Infectious Diseases. American Journal of Epidemiology. Martinez AJ (1991) Infections of the central nervous system due to Acanthamoeba. 154(21): 2417–2422. Bond P. 87: 683–688. Horan JM.S. Leoni E. Wermenbol AG. 34: 622–627. In: Kellaway GA. Figoski M. Reviews of Infectious Diseases. Mount Sinai Journal of Medicine. ed. Huitt G. Makintubee S. 70: 279–281. Carasi S. Applied and Environmental Microbiology. Beebe J. Reviews in Medical Microbiology. Brain Pathology. Kush BJ. Lenaway D. Journal of Water Supply: Research and Technology – AQUA. Cunliffe D. Yakrus MA (2001) Nontuberculous mycobacterial disease following hot tub exposure.] Kansenshogaku Zasshi. and treatment of disease. Archives of Internal Medicine. in swimming pool environment. MICROBIAL HAZARDS 57 . amphizoic and opportunistic amebas. 35(15): 3749–3753. Lipman HB. 39: 376–386. Istre GR (1987) Shigellosis outbreak associated with swimming. Mucci MT. McFarland LM (1992) An outbreak of hepatitis A associated with swimming in a public pool. Kilvington S. Stapledon R. Ma P.
Beier JC (submitted) Ecology of malaria vectors and culicine abundance in urban Malindi. Public Health Laboratory Service Spa Pools Working Group (1994) Hygiene for spa pools. Journal of the American Medical Association. Martyny JW. Sims HB. Pai CH. Briere F (1986) Control of bacteria populations in public pools. Okhuysen PC. Communicable Disease and Public Health. Archives of Ophthalmology. Visvesvara GS. 78(6): 659–662. Samples JR. Porter JD. 26: 1650–1654. London. Robinton ED. Butler RW (1986) Whirlpool-associated folliculitis caused by Pseudomonas aeruginosa: Report of an outbreak and review. 15: 903–909. Kreiss K (1998) "Lifeguard lung": Endemic granulomatous pneumonitis in an indoor swimming pool. Gordon R. Ratnam S. PHLS (2000) Review of outbreaks of cryptosporidiosis in swimming pools. 180: 1275–1281. Wende SO (1991) An outbreak of molluscum contagiosum in a kibbutz. Giardia lamblia cysts given in capsules. Kahindi S. Staphylococci as microbial indicators in swimming pools. Clinical Infectious Diseases. 17: 609–614. 19: 117–128. Newman LS. Mood EW (1966) A quantitative and qualitative appraisal of microbial pollution of water by swimmers: a preliminary report. Journal of Hygiene (London). Chappell CL. Parkin WE (1988) Giardia transmission in a swimming pool. Heron L. Githeko AK. Lesjak M. McCammon JB. 5(1): 23–26. MacDonald A. Journal of Infection. Luibel FJ. Papapetropoulou M. McAnulty JM. Sterling CR. Petersen C (1992) Cryptosporidiosis in patients with the human immunodeficiency virus. Journal of Clinical Microbiology. American Journal of Public Health. Puech MC. Lafrance P. 101: 738–742. McAnulty JM. Marlow. Gonzalez AH (1994) A community-wide outbreak of cryptosporidiosis associated with swimming at a wave pool. 23(3): 655–659. Font RL. March SB. 126: 389–396. Rivera JB. 3(1):43–45. Binder PS. Foundation for Water Research. Sciences et Techniques de l'eau. Journal of Environmental Health. Hamilton G. Fleming DW. 102: 707–710. Batchelor N. Kenya. Milton DK. Kibe L. 36: 101–103. American Journal of Hygiene. 58 GUIDELINES FOR SAFE RECREATIONAL WATER ENVIRONMENTS . Millar BC. Crabb JH.Mbogo CM. Infection. Rose CS. Keating J. 64(4): 489–499. 59: 209–220. Githure JI. Elborn JS (2002) Incidence of Pseudomonas aeruginosa in recreational and hydrotherapy pools. Ahearn DG (1988) Incidence and persistence of Pseudomonas aeruginosa in whirlpools. Moore JE. Noguchi H (1918) The survival of Leptospira (Spirochaeta) icterohaemorrhagie in nature: observations concerning micro-chemical reactions and intermediate hosts. King TE Jr. Beebe JL. Peter CR (1984) Acanthamoeba keratitis possibly acquired from a hot tub. 88(12): 1795–1800. Shaw N. Sills A. Annals of Internal Medicine. Journal of Clinical Microbiology. Faiers M. Rocheleau S. Public Health Laboratory Service (DWI0812). Watson JM (2001) A statewide outbreak of cryptosporidiosis in New South Wales associated with swimming at public pools. Crowe M. Hogan K. Vantarakis AC (1998) Detection of adenovirus outbreak at a municipal swimming pool by nested PCR amplification. McEvoy M. Adera T (1991) Assessing water quality. 272: 1597–1600. Ragazzoni HP. Juranek DD. 19: 159–161. American Journal of Public Health. Journal of Vector Ecology. 53(6): 29–32. Rendtorff RC (1954) The experimental transmission of human intestinal protozoan parasites. Oren B. Journal of Infectious Diseases. Epidemiology and Infection. Waskin HA. Lee J. Journal of Experimental Medicine. DuPont HL (1999) Virulence of three distinct Cryptosporidium parvum isolates for healthy adults. Hoffman RE. Buchanon JD. Harrison T (2000) A cluster of cases of legionnaires' disease associated with exposure to a spa pool on display. Bryon LE (1984) Sporadic cases of hemorrhagic colitis associated with Escherichia coli O157:H7. Heaney N. Desjardins R. Blackmore Press (ISBN 0 901144 371). Price D. II. Communicable Disease and Public Health.
Yagita K. 1383–1384. Oetomo SB. Beauchamp H. eds.SCA (1995) Methods for the examination of waters and associated materials. Canadian Journal of Public Health. ASM Press. Lee SH. 80: 712–715. Visvesvara GS (1999) Pathogenic and opportunistic free-living amebae. George C (1990) Acanthamoeba keratitis in non-contact lens wearers. In: Murray PR.] Budapesti Kozegeszsegugy. van Leeuwen NJ. Morbidity and Mortality Weekly Report Surveillance Summaries. Casemore D. Canadian Journal of Public Health. Journal of Applied Microbiology. 38(3): 613–617. DC. Manual of clinical microbiology. Geneva. Vol. Soltanpoor N. Havelaar AH. Washington. Solt K. In: Samet JM. Sorvillo FJ. Southern Medical Journal. Sundkist T. MD. ASM Press. Johns Hopkins University Press. Csohan A. 75: 61–68. Communicable Disease Report Review. Endo T.. Levy DA. Craun GF. Yolken RH. Pfaller MA. England B (1988) Shigellosis associated with recreational water contact in Los Angeles County. in preparation. Spengler JD. Gabb R. MICROBIAL HAZARDS 59 . pp. Weissman DN. World Health Organization. 53: 1–22. American Journal of Tropical Medicine and Hygiene. Sprenger MW (1995) Risk of otitis externa after swimming in recreational fresh water lakes containing Pseudomonas aeruginosa. Baum M. Srinivasan M. 26(1): 8–12 (in Hungarian). Nagy E (1998) Isolation. Turner M. Tenover FC. Beach MJ (2004) Surveillance of waterborne-disease outbreaks associated with recreational water – United States. Weyant RS. Baltimore. 108: 676–678. Sellwood J (2001) Enteric viruses in the aquatic environment. Hill V. Seyfried PL. Journal of Medical Microbiology. DC. Kromhout D. 1: Recommendations. Washington. Colle C. Archives of Ophthalmology. Waterman SH. Shaw JH (1984) A retrospective comparison of the effectiveness of bromination and chlorination in controlling Pseudomonas aeruginosa in spas (whirlpools) in Alberta. 7th ed. Dryden M. Chen N. eds. de Rover CM. Arnold S (1987) Community outbreak of adenovirus type 7a infections associated with a swimming pool. Indoor air pollution: a health perspective. Schellekens JF. Szenasi Z. Baron EJ. Baron EJ. identification and increasing importance of 'freeliving' amoebae causing human disease. Cook RJ (1984) Otitis externa infections related to Pseudomonas aeruginosa levels in five Ontario lakes. Standing Committee of Analysts. Wyn-Jones AP. Stuart J (1997) Outbreak of cryptosporidiosis associated with a swimming pool in Andover. London. Csanady M. Kaufmann AF (1999) Leptospira and leptonema. 311: 1407–1410. HMSO. Tenover FC. 7: R190–R192. eds. Istre GR. 91: 945–962. CHAPTER 3. Calderon RL. Blackburn BG. Yoder JS. In: Murray PR. Vogt JK. 3rd ed. 7th ed. Manual of clinical microbiology. Schuyler MR (1991) Biological agents and allergenic diseases. WHO (2004) Guidelines for drinking-water quality. Sharma S. Nagy T. 47(1): 5–16. Hollos I (1994) [An outbreak of hepatitis A due to a thermal spa. WHO (2005) Legionella and the prevention of legionellosis. 2001– 2002. Bragg SL. British Medical Journal. Geneva. Pfaller MA. van Asperen IA. World Health Organization. 75: 83–90. Schijven JF. Yolken RH.
this aspect is not covered in this volume. etc. soap residues.1. deliberate additions such as disinfectants and the pool users themselves (see Figure 4.CHAPTER 4 Chemical hazards hemicals found in pool water can be derived from a number of sources: the source water. hot tub and spa water Source water-derived: disinfection by-products. haloacetic acids. dirt. the chemicals typically found in pool water and their possible health effects. C Chemicals in pool. • inhalation of volatile or aerosolized solutes. Possible pool water contaminants in swimming pools and similar environments 4. lotions (sunscreen. pH correction chemicals. precursors Bather-derived: urine. sweat.) Management-derived: disinfectants. chlorate. cosmetics.1 Exposure There are three main routes of exposure to chemicals in swimming pools and similar environments: • direct ingestion of water. This chapter describes the routes of exposure to swimming pool chemicals. 60 GUIDELINES FOR SAFE RECREATIONAL WATER ENVIRONMENTS . and • dermal contact and absorption through the skin. While there is clearly a need to ensure proper consideration of health and safety issues for operators and pool users in relation to the use and storage of swimming pool chemicals. coagulants Disinfection by-products: e. trihalomethanes.g. nitrogen trichloride Figure 4.1).
1. The duration of exposure will vary significantly in different circumstances. but for adults. including the period of contact with the water. CHAPTER 4. hot tub or spa user and be absorbed into the body. within a hot tub (for example) or where there is significant splashing. therefore. A number of estimates have been made of possible intakes while participating in activities in swimming pools and similar environments. but the data are of high quality compared with most other estimates. with the most convincing being a pilot study by Evans et al. 1999). but will also include some inhalation of aerosols. This study found that the average water intake by children (37 ml) was higher than the intake by adults (16 ml).1. There will. The upper 95th percentile intake was for children and was approximately 90 ml. This used urine sample analysis. skill and type of activity. the intake by boys (45 ml) was higher than the intake by girls (30 ml). 1988). the intake by adult men (22 ml) was higher than that by women (12 ml). There appear to be no data with which to make a more detailed assessment.. However. with 24-h urine samples taken from swimmers who had used a pool disinfected with dichloroisocyanurate and analysed for cyanurate concentrations. Individuals using an indoor pool also breathe air in the wider area of the building housing the pool.4.g. All the participants swam.1. age. and the volume of air inhaled is a function of the intensity of effort and time. The situation with children is much less clear. Some may have a direct impact on the skin.1 Ingestion The amount of water ingested by swimmers and pool users will depend upon a range of factors. The normal assumption is that an adult will inhale approximately 10 m3 of air during an 8-h working day (WHO. but there is no information on the participant swimming duration. the temperature of the water and the concentration of the chemical. be significant individual variation depending upon the type of activity and level of effort. are based upon empirical data rather than assumptions. In this volume. a 'worst case' intake of 100 ml for a child is assumed in calculating ingestion exposure to chemicals in pool water. eyes and mucous membranes. and so there would be a lower rate of ingestion in a comparable time than for less skilled users. However. 4. this will also depend on the physical effort involved. extended exposure would be expected to be associated with greater skill (e. CHEMICAL HAZARDS 61 .2 Inhalation Swimmers and pool users inhale from the atmosphere just above the water's surface. (2001). Inhalation exposure will be largely associated with volatile substances that are lost from the water surface. the concentration of pool-derived chemical in the pool environment will be considerably diluted in open air pools. This was a small study. competitive swimmers).3 Dermal contact The skin will be extensively exposed to chemicals in pool water. In addition. Two pathways have been suggested for transport across the stratum corneum (outermost layer of skin): one for lipophilic chemicals and the other for hydrophilic chemicals (Raykar et al. and the estimates. including experience. The extent of uptake through the skin will depend on a range of factors. but chemicals present in pool water may also cross the skin of the pool. 4.
1). adequate ventilation in indoor pools and hot tubs will be an important consideration. that are excreted by bathers (in a number of ways) react with free disinfectant to produce several by-products.. Although more than 80% of the total nitrogen content in urine is present in the form of urea and the ammonia content (at approximately 5%) is low. some of which may be important with respect to pool.1). phosphates and. hot tub and spa safety. The urine release into swimming pools has been variously estimated to average between 25 and 30 ml per bather (Gunkel & Jessen.2 Source water-derived chemicals All source waters contain chemicals. for chloraminated systems. amino acids and creatinine.1. Under such circumstances. primarily in the form of urea. 1997a). Significant amounts of nitrogen compounds can also be discharged into pool water via urine (Table 4. Water from a municipal drinking-water supply may contain organic materials (such as humic acid. A number of nitrogen compounds can be eluted from the skin (Table 4. Nitrogen-containing compounds in sweat and urinea Sweat Nitrogencontaining compounds Urea Ammonia Amino acids Creatinine Other compounds Total nitrogen a Urine Mean content (mg/l) 10 240 560 280 640 500 12 220 Portion of total nitrogen (%) 84 5 2 5 4 100 Mean content (mg/l) 680 180 45 7 80 992 Portion of total nitrogen (%) 68 18 5 1 8 100 Adapted from Jandik. The distribution of total nitrogen in urine among relevant nitrogen compounds (Table 4. Seawater contains high bromide concentrations.5) from previous treatment/ disinfection processes. monochloramines. It therefore appears that there is degradation of urea following chemical reactions with chlorine. ammonia. Depending on the circumstances. lime and alkalis.5 ml per bather (Erdinger et al.3 Bather-derived chemicals Nitrogen compounds. Table 4. swimming pool water exhibits considerable concentrations of ammonia-derived compounds in the form of combined chlorine and nitrate. 1988) and be as high as 77. 1977 62 GUIDELINES FOR SAFE RECREATIONAL WATER ENVIRONMENTS . which is a precursor of disinfection by-products). In some circumstances. the composition of sweat varies widely. WHO is considering radon in relation to drinking-water quality guidelines and other guidance.4. 4. particularly ammonia. disinfection by-products (see Section 4.1) has been calculated from statistically determined means of values based on 24-h urine samples. radon may also be present in water that is derived from groundwater. The nitrogen content in sweat is around 1 g/l. although this area has not been well researched.
chlorine. in one of its various forms. CHEMICAL HAZARDS 63 .2 (and covered in more detail in Chapter 5). Chlorine.e. Only insignificant amounts of the volatile by-products were found to be lost to the atmosphere. accounting for 4–28% of the dosed amino nitrogen (Judd & Bullock. kill or inactivate microorganisms as the water undergoes treatment. the results showed that organic carbon. such as ozone and UV.4 Management-derived chemicals A number of management-derived chemicals are added to pool water in order to achieve the required water quality. 'free' to distinguish it from combined chlorine (which is not a disinfectant). soap residues. Disinfectants and disinfecting systems used in swimming pools and similar environments Disinfectants used most frequently in large. suntan oil. which generally includes filtration (often in conjunction with coagulation). A proportion of pool water is constantly undergoing treatment. pH correction and disinfection (see Chapter 5). and only nitrate was found to accumulate.4. heavily used pools Chlorine • Gas • Calcium/sodium hypochlorite • Electrolytic generation of sodium hypochlorite • Chlorinated isocyanurates (generally outdoor pools) Bromochlorodimethylhydantoin (BCDMH) Chlorine dioxidea Ozonea UVa a Disinfectants used in smaller pools and hot tubs Bromine • Liquid bromine • Sodium bromide + hypochlorite Lithium hypochlorite Disinfectants used for small-scale and domestic pools Bromide/hypochlorite UVa UV–ozonea Iodine Hydrogen peroxide/ silver/copper Biguanide Usually used in combination with residual disinfectants (i.or bromine-based) CHAPTER 4.In a study on the fate of chlorine and organic materials in swimming pools using analogues of body fluids and soiling in a model pool. Thus. 4. The active available disinfectant in the water is referred to as 'residual' or. in the case of chlorine. where these types of disinfection are used. They are added in order to inactivate pathogens and other nuisance microorganisms. is the most widely used disinfectant. 4. No information is available on concentrations of chemicals in actual swimming pool water from cosmetics.2. chloramines and trihalomethanes all reached a steady state after 200–500 h of operation. 2003). but there is no lasting disinfectant effect or 'residual' that reaches the pool and continues to act upon chemicals and microorganisms in the water. The most common are outlined in Table 4.or bromine-type disinfectant is also employed to provide continued disinfection. etc.1 Disinfectants A range of disinfectants are used in swimming pools and similar environments. Some disinfectants. a chlorine. In the case of Table 4.
While it should not be used to compensate for inadequacies of other management practices. the choice of disinfectant must be made after consideration of the efficacy of a disinfectant under the circumstances of use (more details are given in Chapter 5) and the ability to monitor disinfectant levels. The type and form of disinfectant need to be chosen with respect to the specific requirements of the pool.bromine. Due to the nature of hot tubs (warmer water.7 mg of cyanuric acid per day) for a 10-kg child.3. They dissociate in water to release free chlorine in equilibrium with cyanuric acid. periodic shock dosing can be an effective tool to maintain microbial quality of water and to minimize build-up of biofilms and chloramines (see Sections 4. The primary issues would then become acceptability to swimmers. Lower free chlorine concentrations may be health protective when combined with other good management practices (e. often accompanied by aeration and a greater user to water volume ratio).4). usually in the form of chlorine gas. while in other countries allowable levels may be considerably higher. 1. sodium. Concentrations significantly in excess of this may not be of health significance with regard to ingestion (as no adverse effect level was identified in the study used). In the case of small and domestic pools. but in public and semi-public pools these should not exceed 3 mg/l and in public/semi-public hot tubs these should not exceed 5 mg/l. These are all loosely referred to as 'chlorine'. the WHO health-based guideline value for chlorine in drinking-water is 5 mg/l (WHO. there is no need to distinguish between the two. In all cases. Chlorine-based disinfectants Chlorination is the most widely used pool water disinfection method. 2004). effective coagulation and filtration. even though there might be some problems regarding eye and mucous membrane irritation. To avoid consuming the TDI. Using high levels of chlorine (up to 20 mg/l) as a shock dose (see Chapter 5) as a preventive measure or to correct specific problems may be part of a strategy of proper pool management. A residual of cyanuric acid and a number of chlorine/cyanuric acid products will be present in the water. free chlorine levels of less than 1 mg/l are considered acceptable in some countries. important requirements are easy handling and ease of use as well as effectiveness. calcium or lithium hypochlorite but also with chlorinated isocyanurates. assuming 100 ml of pool water is 64 GUIDELINES FOR SAFE RECREATIONAL WATER ENVIRONMENTS . as the combined form is also a disinfectant. 2004). Chlorine in solution at the concentrations recommended is considered to be toxicologically acceptable even for drinking-water. This would translate into an intake of 20 mg of NaDCC per day (or 11. acceptable free chlorine levels tend to be higher than in swimming pools. so 'total' bromine is measured. The chlorinated isocyanurates are stabilized chlorine compounds. For example.5 and 5.) or when ozone or UV is also used. pre-swim showering. It is recommended that acceptable levels of free chlorine continue to be set at the local level. Practice varies widely around the world. The Joint FAO/WHO Expert Committee on Food Additives and Contaminants (JECFA) has considered the chlorinated isocyanurates with regard to drinking-water disinfection and proposed a tolerable daily intake (TDI) for anhydrous sodium dichloroisocyanurate (NaDCC) of 0–2 mg/kg of body weight (JECFA. etc.g. as do the levels of free chlorine that are currently considered to be acceptable in order to achieve adequate disinfection while minimizing user discomfort. which are widely used in the disinfection of outdoor or lightly loaded swimming pools.
used in conjunction with conventional chlorine. 1994) and as high as 140 mg/l (Latta. there are a number of reported measurements of high levels of cyanuric acid in pools and hot tubs in the USA. Other studies have reported that 25% of pools (122 of 486) had cyanuric acid concentrations greater than 100 mg/l (Rakestraw. 2. Levels of cyanuric acid should be kept between 50 and 100 mg/l in order not to interfere with the release of free chlorine. The use of bromine-based disinfectants is generally not practical for outdoor pools and spas because the bromine residual is depleted rapidly in sunlight (MDHSS.7 mg/l (based on a TDI of 0. They are.03 mg/kg of body weight) (WHO. Regular dilution with fresh water (see Chapter 5) is required in order to keep cyanuric acid at an acceptable concentration.5 mg/l and a maximum of 406 mg/l. The primary health issue in ozone use in swimming pool disinfection is the leakage of ozone into the atmosphere from ozone generators and contact tanks. and this is also the provisional guideline for chlorate. Chlorine dioxide Chlorine dioxide is not classed as a chlorine-based disinfectant. 3. they should be maintained below 3 mg/l (assuming a 10-kg child and an intake of 100 ml). CHEMICAL HAZARDS 65 . There are reports that a number of swimmers in brominated pools develop eye and skin irritation (Rycroft & Penny. therefore. There is potential for a build-up of chlorite/chlorate in recirculating pool water with time. and neither leaves residual disinfectant in the water.and bromine-based disinfectants. As with chlorine-based disinfectants. Kelsall & Sim (2001) in a study examining three different pool disinfection systems (chlorine. and it is recommended that levels should not exceed 100 mg/l. 4. chlorine/ozone and bromine/ozone) did not find that the bromine disinfection system was associated with a greater risk of skin rashes.9 mg/l with a median of 57.swallowed in a session would mean that the concentration of cyanuric acid/chlorinated isocyanurates should be kept below 117 mg/l. 1983). It is also appropriate to include a deozonation step in the treatment process. Unpublished data from the Olin Corporation suggest that levels up to 500 mg/l may be found. In order to remain within the TDI levels of chlorate and chlorite. Bromine-based disinfectants for pools are available in two forms. Chlorine dioxide breaks down to chlorite and chlorate. and it is. although no comprehensive surveys are available. therefore. to prevent carry-over in the treated water. as it acts in a different way and does not produce free chlorine. it is recommended that total bromine does not exceed 2. important that ozone concentrations in the atmosphere of the pool building are controlled. which will remain in solution. the WHO health-based drinking-water provisional guideline value for chlorite is 0. which need to be properly ventilated to the outside atmosphere. The air quality guideline value CHAPTER 4. Although there is limited evidence about bromine toxicity.5 mg/l. Bromine-based disinfectants Liquid bromine is not commonly used in pool disinfection. However.0–2. However. 1995). although the number of bathers studied was small. Sandel (1990) found an average concentration of 75. bromochlorodimethylhydantoin (BCDMH) and a two-part system that consists of sodium bromide and an oxidizer (usually hypochlorite). Ozone and ultraviolet Ozone and UV radiation purify the pool water as it passes through the plant room. Ozone is a severe respiratory irritant. local practice varies. undated). and acceptable total bromine may be as high as 10 mg/l. 2004).
but these will be 66 GUIDELINES FOR SAFE RECREATIONAL WATER ENVIRONMENTS .11. it is most important that proper consideration is given to replacement of water to prevent excessive build-up of the ions. However. Acidic disinfectants (e. there will be a range of by-products.0 (see Section 5.g. chlorine. this can be oxidized to form bromine. although they are important in terms of atmospheric contamination in enclosed pools and hot tubs.e. usually a solution of sodium carbonate (soda ash). polyaluminium chloride) may be used to enhance the removal of dissolved. of which di. 2000) is an appropriate concentration to protect bathers and staff working in the pool building. Most information available relates to the reactions of chlorine.4. Although there is potentially a large number of chlorine-derived disinfection by-products. Alkaline disinfectants (e. chlorine gas) normally require the addition of an alkali. This means that the bromide/hypochlorite system of disinfection would be expected to give much higher proportions of the brominated by-products. as will be seen from Tables 4. depending on the nature of the precursors and pool conditions.3). It is probable that a range of organic chloramines could be formed. The floc is then trapped during filtration.5 Disinfection by-products (DBP) Disinfectants can react with other chemicals in the water to give rise to by-products (Table 4. especially in small pools. 4. Other disinfectants Other disinfectant systems may be used. In all pools in which free halogen (i.3 Coagulants Coagulants (e.g.of 0. usually a solution of sodium hydrogen sulfate. 4.2 and 8. the substances produced in the greatest quantities are the trihalomethanes (THMs).2 pH correction The chemical required for pH value adjustment will generally depend on whether the disinfectant used is itself alkaline or acidic. A similar situation would apply to biguanide. There should be no adverse health effects associated with the use of these chemicals provided that they are dosed correctly and the pH range is maintained between 7. When inorganic bromide is present in the water.12 mg/m3 (WHO.and trichloroacetic acid are generally present in the greatest concentrations (WHO. 2000).4–4. 5. Data on their occurrence in swimming pool waters are relatively limited. carbon dioxide or hydrochloric acid.10. 4. no matter what form the halogen donor takes. colloidal or suspended material. Seawater pools might also be expected to show a proportion of iodinated by-products in view of the presence of iodide in the water. of which chloroform is generally present in the greatest concentration. Seawater pools disinfected with chlorine would also be expected to show a high proportion of brominated by-products since seawater contains significant levels of bromide.4. These work by bringing the material out of solution or suspension as solids and then clumping the solids together to produce a floc.3). which will also take part in the reaction to produce brominated by-products such as the brominated THMs. Hydrogen peroxide used with silver and copper ions will normally provide low levels of the silver and copper ions in the water. which is also used as a disinfectant in outdoor pools.g. and the haloacetic acids (HAAs). sodium hypochlorite) normally require only the addition of an acid for pH correction. bromine or iodine) is the primary disinfectant.
respectively (Table 4. 1977). Nitrogencontaining organic compounds. there appear to be few data on the concentrations found in swimming pools and similar environments. it is unlikely to be of conCHAPTER 4. However. Although those by-products found commonly in ozonated drinking-water would be expected. Isaak & Morris. Predominant chemical disinfectants used in pool water treatment and their associated disinfection by-productsa Disinfectant Chlorine/hypochlorite Disinfection by-products trihalomethanes haloacetic acids haloacetonitriles haloketones chloral hydrate (trichloroacetaldehyde) chloropicrin (trichloronitromethane) cyanogen chloride chlorate chloramines bromate aldehydes ketones ketoacids carboxylic acids bromoform brominated acetic acids chlorite chlorate trihalomethanes. may react with hypochlorite to form organic chloramines (Taras. dichloramine and nitrogen trichloride) and bromamines (collectively known as haloamines). chlorate can build up within sodium hypochlorite solution. The use of ozone in the presence of bromide can lead to the formation of bromate.1). While chlorination has been relatively well studied. 1980). such as amino acids. 1953. to form chloramines (monochloramine. mainly bromoform bromal hydrate bromate bromamines Ozone Chlorine dioxide Bromine/hypochlorite BCDMH a UV is a physical system and is generally not considered to produce by-products found at significantly lower concentrations than the THMs and HAAs. CHEMICAL HAZARDS 67 . but hydrolysis of urea will give rise to more ammonia in the water (Jandik.Table 4. During storage. and this can contribute to chlorate levels in disinfected water. it must be emphasized that data on ozonation by-products and other disinfectants are very limited. with ammonia in the water. which can build up over time without adequate dilution with fresh water (see Chapter 5). The mean content of urea and ammonia in urine is 10 240 mg/l and 560 mg/l. extremely rapidly.3. Both chlorine and bromine will react.
However. if ozone were used to disinfect seawater pools. Many of these data are relatively old and may reflect past management practices. Gundermann et al. Ozone can react with residual bromide to produce bromate.11 below. 1. Fantuzzi et al.1 Exposure to disinfection by-products While swimming pools have not been studied to the same extent as drinking-water. (2001) reported total THM concentrations of 17. >3 mg/l). temperature and pH. in which case the efficacy of the hypochlorite is likely to be compromised. while in seawater pools. including aldehydes and carboxylic acids.4 µg/l (Erdinger et al. Trihalomethanes Sandel (1990) examined data from 114 residential pools in the USA and reported average concentrations of chloroform of 67.3 µg/l for chloroform. 125. disinfectant dose. the temperature and the amount of splashing and surface 1 Mean values in Table 4.cern to health unless the concentrations are allowed to reach excessive levels (i. it is usually bromoform (Baudisch et al. This is of concern in drinking-water systems but will be of lower concern in swimming pools.. UV disinfection is not considered to produce by-products.5). haloacetonitriles and others) measured in different pools is provided in Table 4. and it seems to significantly reduce the levels of chloramines.4 and Tables 4.. A summary of the concentrations of various prominent organic by-products of chlorination (THMs. More data are required on the impact of UV on disinfection by-products when used in conjunction with residual disinfectants.. In hot spring pools. so they will also be found in the air above indoor pools (Table 4. The THM found in the greatest concentrations in freshwater pools is chloroform.4 are arithmetic means.5. 1997.e.8–70. the median concentration of chloroform was 3. although the data are limited to a small number of the major substances. bromate is a by-product of the electrolytic generation of hypochlorite if the brine used is high in bromide. Chu & Nieuwenhuijsen (2002) collected and analysed pool water samples for total organic carbon (TOC) and THMs. 4. residual disinfectant level. there are some data on the occurrence and concentrations of a number of disinfection by-products in pool water. THMs are volatile in nature and can be lost from the surface of the water.1 µg/l with a maximum value of 313 µg/l. there was a linear correlation between the number of people in the pool and the concentration of THMs. Where bromide is present. Ozone also reacts with organic matter to produce a range of oxygenated substances. which is quite stable and can build up over time (Grguric et al.9–4. it can also result in the formation of brominated products similar to liquid bromine. Concentrations will vary as a consequence of the concentration of precursor compounds. 1997b). In addition. They reported a geometric mean1 for all swimming pools of 5. 1994). 68 GUIDELINES FOR SAFE RECREATIONAL WATER ENVIRONMENTS . Transport from swimming pool water to the air will depend on a number of factors.8 µg/l in swimming pools in Italy.8 µg/l and the maximum was 6.8 mg/l for TOC. the concentration of bromate would be expected to be potentially much higher. including the concentration in the pool water.. In a study of eight swimming pools in London. The pool concentrations of disinfection by-products will also be influenced by the concentration of THMs and the potential precursor compounds in the source and make-up water. 1997). HAAs.2 µg/l for total THMs and 113.
(2004) found that in a study in which subjects swam with and without scuba tanks.disturbance. Dichloroacetic acid has also been detected in swimming pool water. 2.6 µg/l and 119. these are summarized in Tables 4.9–4. 3. The concentrations at different levels in the air above the pool will also depend on factors such as ventilation. (1990. Erdinger et al. 40 mg/l.6). 1992).1 µg/m3 ± 24. They found concentrations of up to 0. The difference between the results of these two studies may be due to differences in the amounts of chlorine used to disinfect swimming pools. since the concentration of THMs in the outdoor pool water was higher than the concentration in the indoor pool water. THMs were mainly taken up by the respiratory pathway and only about one third of the total burden was taken up through the skin.1 µg/m3 and concentrations of 26. Studies by Aggazzotti et al. the size of the building and the air circulation. 1995. (1995) in response to complaints of eye and respiratory tract irritation by pool attendants.84 mg/m3 and that levels were generally higher in pools with recreational activities such as slides and fountains. and the chlorate levels were related to the levels in hypochlorite stock solutions. but the concentration in alveolar air rapidly falls after exiting the pool area (Tables 4. chlorate concentrations varied from 1 mg/l to. 1998) showed that exposure to chlorinated swimming pool water and the air above swimming pools can lead to an increase in detectable THMs in both plasma and alveolar air.7 and 4. Strähle et al. but the mean concentration of chlorate in sodium hypochlorite-disinfected pools was about 17 mg/l. but the concentrations in air above the pool and in blood were higher in the indoor pool than in the outdoor pool. They showed that intake via inhalation was probably the major route of uptake of volatile components. (2000) found chlorate concentrations of up to 142 mg/l. Other disinfection by-products A number of other disinfection by-products have been examined in swimming pool water. Erdinger et al. Chlorate concentrations were much lower in pools disinfected with hypochlorite and ozone. CHEMICAL HAZARDS 69 . (1999) examined the concentrations of chlorite and chlorate in swimming pools and found that while chlorite was not detectable. In a German study of 15 indoor and 3 outdoor swimming pools (Clemens & Scholer. 1998). in one extreme case. This would imply that good ventilation at pool level would be a significant contributor to minimizing exposure to THMs. The concentrations of chlorate in chlorine-disinfected pools were close to the limit of detection of 1 mg/l.8). Strähle et al.9 µg/l in indoor and outdoor pools.0 µg/m3 ± 22. CHAPTER 4. chlorite and chlorate Exposure to chloramines in the atmosphere of indoor pools was studied in France by Hery et al. (2001) examined THM levels in five indoor pools in Italy and found mean concentrations of total THMs in poolside air of 58. dichloroacetic acid concentrations averaged 5. Chloramines. or addition or exchanges of water in the pools.11. respectively. The mean concentration of dichloroacetic acid in three indoor pools in the USA was 419 µg/l (Kim & Weisel. 1993. (2000) studied the THM concentrations in the blood of swimmers compared with the concentrations of THMs in pool water and ambient air (Table 4. Fantuzzi et al. sample collection time relative to chlorination of the water.3 µg/m3 in the reception area.
1 0.03–3..4 <0.3 0.1–1..6–111 43–980 0.3 2.6–82.8 1.22 10.5 <0.4 2.51 <0.59 1.5–10 0.1 2.<2–62.1 0.16 0.9 8.6 1.9 0.8 0.0 <0.0–11.1 0. DBCM = dibromochloromethane .4 1. 1995 Schössner & Koch..69–114 0.3 1–72 1–90 <0.7 33.9 0. 1995 Jovanovic et al.03–4.5 <0.6–17.5 4.7 Reference Biziuk et al.8 0.1–15.5–23.2–203.4 2.7 74.9–16.67–2 indoor pools Erdinger et al.08 <0.1 <0.7 0.83 <0.8–28 8–11 0...3 3.4 1. 1994 Cammann & Hübner. 4.1–1 outdoor <0.1 0.1–60 indoor <0.5 4.7 0.3–27.67–7 indoor outdoor indoor indoor hydrotherapy hydrotherapy outdoor indoor indoor outdoor indoor indoor indoor indoor outdoor hydrotherapy spa indoor pool indoor indoor 0.8 . 1987 Borsányi. 1981 Ewers et al.) 7. 1998. 1995 Aggazzotti et al.9 80.8 0.1–183 hot tub 1.1–8 0.1–0.9 <0.82–12 6.7 19–94 9–179 25–43 indoor indoor 0.1–48 indoor <0.5 1.2–0.03–8.03–6.1–140 <0.9 3.9 0. 30.8 1.1 indoor Aggazzotti et al.5 3. 2004 Kaas & Rudiengaard. Concentrations of trihalomethanes measured in swimming pool water Country Poland Chloroform Mean Range 35.3–30 <0.0 Puchert et al.3 4.4 .1–105 <0.28 0.04–8..4–29.1–88 <0. 1993 Disinfection by-product concentration (µg/l) BDCM DBCM Mean Range Mean Range 2.8–2.1 45–212 BDCM = bromodichloromethane.1–1.3–3.1–0.3–14.9 4–402 3–580 <0.9–99.78–2.1–3..27–25 0.8 Bromoform Pool Mean Range type 0. 1997b Erdinger et al.4 <0. 1987 USA 37..6–117.1–24.6 0.9 0. 1999 14.2 indoor Italy 2.1–530 Germany 22.3 GUIDELINES FOR SAFE RECREATIONAL WATER ENVIRONMENTS UK 121. 1986 Eichelsdörfer et al.9 11.1–4.91 0. 1981 Lahl et al.02–0.5–23 <1.03–0.8 2.12–15 0. 2002 Denmark 145–151 Hungary 11.8 14. 1989 Puchert. 1990 Armstrong & Golden. 1993 Aggazzotti et al.4. 1998 Copaken.4 <0.1–32.19–4.70 Table 4.0 <0..2–5.1–1 0.8 <0.6 <0.64 1.8 8.4 0.0 14.1 40.1–16..1–54.5 2.6 43 198 94.1–150 1.23 0. 1998 Chu & Nieuwenhuijsen.03–0.4–132 <0..1 93.51–69 0.1–3.69–5.3 <0. 1995 Stottmeister.4 (max.
5 mg/m3 chlorine species (expressed in units of nitrogen trichloride) in the atmosphere of indoor pools and hot tubs.5 mg/m3 would be suitable as a provisional value for chlorine species. the risks from exposure to chlorination by-products in reasonably well managed swimming pools would be considered to be small and must be set against the benefits of aerobic exercise and the risks of infectious disease in the absence of disinfection. nitrogen trichloride has an intense and unpleasant odour at concentrations in water as low as 0. ingestion of swimming pool water is considerably less than this. Bernard et al. available evidence indicates that for reasonably well managed pools. however. Uptake via skin absorption and inhalation (in the case of THMs) is proportionally greater than from drinking-water and is significant.2 Risks associated with disinfection by-products The guideline values in the WHO Guidelines for Drinking-water Quality can be used to screen for potential risks arising from disinfection by-products from swimming pools and similar environments. CHAPTER 4. (2004) reported two incidents. shorter exposure periods and non-ingestion exposure. In addition. Exposure. Since the drinking-water guidelines are intended to reflect tolerable risks over a lifetime. account for this. (1995) found that complaints from non-swimmers were initiated at a concentration of 0.. 2002. eye and throat irritation and difficulty in breathing. to an extent. needs to be minimized. and 32 guests reported coughs.. high chlorate concentrations have been reported. 1993). Drinking-water guidelines assume an intake of 2 litres per day.4. Under such circumstances. It is recommended that 0. Thickett et al..02 mg/l (Kirk & Othmer. One of the incidents related to a hotel pool. in some cases. Both incidents were attributed to chloramines on the basis of the clinical syndrome and setting. Studies of subjects using swimming pools and non-swimming attendants have shown a number of changes and symptoms that appear to be associated with exposure to the atmosphere in swimming pools. CHEMICAL HAZARDS 71 . but as considered above. 2002. which greatly exceeded the WHO provisional drinking-water guideline (0. Yoder et al. Hery et al. while making appropriate allowance for the much lower quantities of water ingested. but the low oral intake allows a margin that can. concentrations less than the drinking-water guideline values can be consistently achieved. The chloramines and bromamines.5. can give rise to significant eye and respiratory irritation in swimmers and pool attendants (Massin et al. particularly nitrogen trichloride and nitrogen tribromide. this provides an additional level of reassurance.. Although there are data to indicate that the concentrations of chlorination by-products in swimming pools and similar environments may exceed the WHO guideline values for drinking-water (WHO.1) indicate an extreme of about 100 ml (Evans et al.1.. result in possible toxic effects. with frequent dilution of pool water with fresh water. although the studies were unable to confirm the specific chemicals that were the cause of the symptoms experienced. 1998). for a child ingesting 100 ml of water. Various authors have suggested that these were associated with nitrogen trichloride exposure in particular (Carbonnelle et al. Symptoms are likely to be particularly pronounced in those suffering from asthma. recent measured data (Section 4. 2004). between 2001 and 2002. 2001). 2003). Levels of chlorate and chlorite in swimming pool water have not been extensively studied.. therefore. 1984). where a total of 52 people were adversely affected by a build-up of chloramines in indoor pool water. and care taken to ensure that chlorate levels do not build up in stored hypochlorite disinfectants.7 mg/l) and which would. which are both volatile (Holzwarth et al.
2 indoor 1) DBCM Mean 6.1 0.05–3.08 <0.9 0.7–136 USA <0.3 3.7 Stottmeister.5 17.03–3..16 0.5 <0.4 20 indoor 9. 1986 <0. DBCM = dibromochloromethane a Measured 20 cm above the water surface b Measured 150 cm above the water surface c Measured 200 cm above the water surface .05–2.1–14 indoor 3) 2) 597–1630 indoor1) Germany 65 36 5.0 0.03–0.4 9–14 0.72 Table 4.05 0.2 0.1–1 Armstrong & Golden. 1999 1.6 0.03–0.03–0.1–47 GUIDELINES FOR SAFE RECREATIONAL WATER ENVIRONMENTS BDCM = bromodichloromethane.2 indoor 2) Chloroform Range 5–100 2–58 16–24 11. Concentrations of trihalomethanes measured in the air above the pool water surface Disinfection by-product concentration (µg/m3) BDCM Mean Reference Aggazzotti et al. 1995 Aggazzotti et al.3 0.9 0.08–2.5.1 <0.36–2.23–13 0.1–14 hot tub3) <0.7 indoor2) <0. 1998 Lévesque et al..0 indoor1) <0..8 outdoor1) outdoor1) outdoor1) outdoor <0..1–10 <0.2 indoor1) Range Mean Range Pool type Bromoform Country Mean Range Italy 214 66–650 140 049–280 169 35–195 Canada 3.02–0.1–5 <0.2 39 5. 1993 Aggazzotti et al..8 0.08 0.1 <0.6 2.1–5 <0.21 0.1–14 0.1 0.6–206 30 1.1 0.2 5.03 0. 1994 Jovanovic et al.3 4–30 0.9 4.1 4.2 0.1–260 <0.33–9.6 0.1 outdoor3) <0.4 0.03 1.2 indoor1) 13.1–10 <0. 1995 19.85–16 0. 1998.
1 2. 0.7 ± 1.5 ± 3.4 29.6 (4.6.20 ± 0. n.9–179.5 20.4 ± 2. C: After a 1-h swim.8. 1998 Five competitive swimmers (three males and two females) were monitored A: Prior to arrival at the pool.9) 61..3 ± 3.4 ± 13. CHEMICAL HAZARDS 73 .2 20.06–0.48 (0.2 ± 1.1) Adapted from Strähle et al.3 C 169.Table 4. 1990 Table 4.8 19.9 E 19.14 0.q. Adapted from Aggazzotti et al.q.1 ± 2.8) 93.23–0.q.2 n.q. D and E occurred after departing the pool area.q.1–13.2 n.0 ± 4.9 n.3 ± 0.0 ± 8. 1.8 11.1–0.88) 19.1 n. 0. Comparison of trihalomethane concentrations in blood of swimmers after a 1-h swim.1 THM Chloroform BDCM DBCM a No.1–3.2 n. samples 127/127 25/127 17/127 Adapted from Aggazzotti et al.q.4 26.7 ± 5. Comparison of trihalomethane levels in ambient air and alveolar air in swimmers prior to arrival at the swimming pool.7–4. range) Indoor pool Blood of swimmers (µg/l) Pool water (µg/l) Air 20 cm above the water surface (µg/m³) Air 150 cm above the water surface (µg/m³) a Outdoor pool 0.6 (23.1 (3.q.q.7) 0. 0.1 n.q. 2.3 n. in pool water and in ambient air of indoor and outdoor poolsa THM concentration (mean. = not quantified CHAPTER 4. 10.8 76.2 (2.1 n.q.5 (<0.3 9.5–45.q.6 (13.21) 73.1 Range of THM concentrations (µg/l) 0. positive/no. D: 1 h after swimming had stopped. n..1 n.7 ± 1.5 ± 1. 5. n.3 <0..2 n. Concentrations of trihalomethanes in plasma of 127 swimmersa Mean THM concentration (µg/l) 1.7 ± 26. n.q.4 ± 0.1 6. 2000 Table 4.7 ± 15.q.1 1. B: After 1 h resting at poolside before swimming. n.5 ± 18.4–147. 0. n.q.1–0.4 ± 4.q.5 h after swimming had stopped.q. during swimming and after swimminga THM levels (µg/m3) at various monitoring timesb A Chloroform Ambient air Alveolar air BDCM Ambient air Alveolar air DBCM Ambient air Alveolar air Bromoform Ambient air Alveolar air a b B 91. and E: 1.5 0.6 D 20.11 (<0.9) 2.8 ± 0.2–146) 8. 0.2 ± 8.9 ± 1.7.06 0.0 <0.
2–1.01–11 indoor <0.2–562 0. 1998. 1995 hot tub 132 6.01–24 1.5–3.8 1.08 <0.64 <0.01–0.8–27 0.32 32 2.5–2.7 42 3.01–10 outdoor indoor seawater Baudisch et al.9 45 GUIDELINES FOR SAFE RECREATIONAL WATER ENVIRONMENTS 24 DCAN = dichloroacetonitrile. 1997 Stottmeister.5–174 0.06 MCAA = monochloroacetic acid. DBAA = dibromoacetic acid.15 26 2.7 1.01–16 2.2–4.1–45 hydrotherapy 23 1.2–887 outdoor Lahl et al.9 <0. 1996 <0... Concentrations of haloacetonitriles measured in swimming pool water Disinfection by-product concentration (µg/l) DBAN Range 6.02 49 2.5–112 0. DBAN = dibromoacetonitrile.8 15 1. 1984 8. MBAA = monobromoacetic acid.8 hydrotherapy <0.5–199 indoor Mean Range Mean Range Mean Pool Range type DCAA DBAA TCAA MCAA Country Mean Range Mean Germany 26 2.5–1.6–81 0.8 <0.5–1. 1994 DCAN Country Mean Germany 13 9.3 249 8.3–100 indoor Mannschott et al. 1999 Reference Puchert.9.13–148 0.62 <0..2–7.5 1.57 <0.01–2. DCAA = dichloroacetic acid.2 <0. Concentrations of haloacetic acids measured in swimming pool water Disinfection by-product concentration (µg/l) MBAA Range Reference Stottmeister & Naglitsch.22–57 <0.3 <0.5 0. TCAN = trichloroacetonitrile .7 30 25–136 indoor 2.3 <0.7–18.3 Mean Range Mean TCAN Pool Range type indoor outdoor <0.5 0.5–192 0. TCAA = trichloroacetic acid Table 4.10.01–7.74 Table 4.
1994 Stottmeister.5–104 indoor seawater indoor Baudisch et al.32–0. 1984 Puchert.78 0.75 0.01–10 CHAPTER 4.01–0. Concentrations of chloropicrin.8 <0.04–0. 1997 Baudisch et al..20 1.6 0.3 75 .03–1.11. Chloropicrin Country Mean Germany CHEMICAL HAZARDS 0.1–2.6 0.Table 4.32 0. 1999 indoor indoor outdoor indoor hydrotherapy outdoor 265 230 0. chloral hydrate and bromal hydrate measured in swimming pool water Disinfection by-product concentration (µg/l) Chloral hydrate Mean Reference Schöler & Schopp. 1995 Range Mean Pool Range type Bromal hydrate Range 0. 1997 Mannschott et al.. 1998..
Doyle I (2003) Lung hyperpermeability and asthma prevalence in schoolchildren: unexpected associations with the attendance in indoor chlorinated swimming pools. The use of remote monitoring is becoming more commonplace in after-hours response to plant and equipment malfunction or shutdown. 76 GUIDELINES FOR SAFE RECREATIONAL WATER ENVIRONMENTS . A710: 181–190. Michel O. Michel O. Puchert W (1997) [Determination of volatile halogenated hydrocarbons in chlorinated swimming pool water. This hazard can be reduced. if not eliminated.expressed as nitrogen trichloride. Fantuzzi G. Archives of Environmental Health. Research report. Francaux M. Righi E. 45A(3): 175–179. Science of the Total Environment. in the atmosphere of indoor swimming pools and similar environments. Czerwinski J. Armstrong DW. International Journal of Environmental Analytical Chemistry. Prösch J. Landeshygieneinstitut MecklenburgVorpommern (in German). 4.6 Risks associated with plant and equipment malfunction Chemical hazards can arise from malfunction of plant and associated equipment. Hermans C. The use of gas detection systems and automatic shutdown can also be an effective advance warning of plant malfunction. It is particularly important that the management of pools used for such purposes is optimized in order to reduce the potential for exposure (Section 5. Occupational and Environmental Medicine. Aggazzotti G. Baudisch C. more specific data are needed on the potential for exacerbation of asthma in affected individuals. 59: 243–247. National Institute of Environmental Health. Pansch G. Buchet J-P. Kozlowski E (1993) Identification and determination of organohalogen compounds in swimming pool water. Righi E. Occupational and Environmental Medicine. de Burbure C. There is also a potential issue regarding those that are very frequent pool users and who may be exposed for longer periods per session. Archives of Environmental Health. Righi E. However. Aggazzotti G. Borsányi M (1998) THMs in Hungarian swimming pool waters. Predieri G (1995) Environmental and biological monitoring of chloroform in indoor swimming pools. Cammann K. Morel G. Higuet S. Department of Water Hygiene (unpublished). Nieuwenhuijsen MJ (2002) Distribution and determinants of trihalomethane concentrations in indoor swimming pools. Predieri G (1993) Chloroform in alveolar air of individuals attending indoor swimming pools. since this is a significant proportion of the population in some countries. Biziuk M. Archives of Environmental Health. 60: 385–394. 4. Golden T (1986) Determination of distribution and concentration of trihalomethanes in aquatic recreational and therapeutic facilities by electron-capture GC. Bernard A (2002) Changes in serum pneumoproteins caused by short-term exposures to nitrogen trichloride in indoor chlorinated swimming pools. Chu H. 46: 109–115. Tartoni PL. Budapest. Carbonnelle S. Journal of Chromatography. Carbonnelle S. Aggazzotti G. de Burbure C. through proper installation and effective routine maintenance programmes. LC-GC. 217: 155–163.7 References Aggazzotti G. 50: 61–65. Hübner K (1995) Trihalomethane concentrations in swimmers' and bath attendants' blood and urine after swimming or working in indoor swimming pools. Fantuzzi G. Predieri G (1998) Blood and breath analyses as biological indicators of exposure to trihalomethanes in indoor swimming pools. 7(6): 464–478. Bernard A. 4: 652–655. Dumont X. Doyle I. Fantuzzi G. Predieri G (1990) Plasma chloroform concentration in swimmers using indoor swimming pools. Cassinadri T. Dumont X. Biomarkers.] Außenstelle Schwerin. such as competitive swimmers. 48: 250–254.9). Fantuzzi G. Tartoni PL.
Clemens M, Scholer HF (1992) Halogenated organic compounds in swimming pool waters. Zentralblatt für Hygiene und Umweltmedizin, 193(1): 91–98. Copaken J (1990) Trihalomethanes: Is swimming pool water hazardous? In: Jolley RL, Condie LW, Johnson JD, Katz S, Minear RA, Mattice JS, Jacobs VA, eds. Water chlorination. Vol. 6. Chelsea, MI, Lewis Publishers, pp. 101–106. Eichelsdörfer D, Jandik J, Weil L (1981) [Formation and occurrence of organic halogenated compounds in swimming pool water.] A.B. Archiv des Badewesens, 34: 167–172 (in German). Erdinger L, Kirsch F, Sonntag H-G (1997a) [Potassium as an indicator of anthropogenic contamination of swimming pool water.] Zentralblatt für Hygiene und Umweltmedizin, 200(4): 297–308 (in German). Erdinger L, Kirsch F, Hoppner A, Sonntag H-G (1997b) Haloforms in hot spring pools. Zentralblatt für Hygiene und Umweltmedizin. 200: 309–317 (in German). Erdinger L, Kirsch F, Sonntag H-G (1999) Chlorate as an inorganic disinfection by-product in swimming pools. Zentralblatt für Hygiene und Umweltmedizin, 202: 61–75. Erdinger L, Kuhn KP, Kirsch F, Feldhues R, Frobel T, Nohynek B, Gabrio T (2004) Pathways of trihalomethane uptake in swimming pools. International Journal of Hygiene and Environmental Health, 207: 1–5. Evans O, Cantú R, Bahymer TD, Kryak DD, Dufour AP (2001) A pilot study to determine the water volume ingested by recreational swimmers. Paper presented to 2001 Annual Meeting of the Society for Risk Analysis, Seattle, Washington, 2–5 December 2001. Ewers H, Hajimiragha H, Fischer U, Böttger A, Ante R (1987) [Organic halogenated compounds in swimming pool waters.] Forum Städte-Hygiene, 38: 77–79 (in German). Fantuzzi G, Righi E, Predieri G, Ceppelli G, Gobba F, Aggazzotti G (2001) Occupational exposure to trihalomethanes in indoor swimming pools. Science of the Total Environment, 17: 257–265. Grguric G, Trefry JH, Keaffaber JJ (1994) Ozonation products of bromine and chlorine in seawater aquaria. Water Research, 28: 1087–1094. Gundermann KO, Jentsch F, Matthiessen A (1997) [Final report on the research project "Trihalogenmethanes in indoor seawater and saline pools".] Kiel, Institut für Hygiene und Umweltmedizin der Universität Kiel (in German). Gunkel K, Jessen H-J (1988) [The problem of urea in bathing water.] Zeitschrift für die Gesamte Hygiene, 34: 248–250 (in German). Hery M, Hecht G, Gerber JM, Gendree JC, Hubert G, Rebuffaud J (1995) Exposure to chloramines in the atmosphere of indoor swimming pools. Annals of Occupational Hygiene, 39: 427–439. Holzwarth G, Balmer RG, Soni L (1984) The fate of chlorine and chloramines in cooling towers. Water Research, 18: 1421–1427. Isaak RA, Morris JC (1980) Rates of transfer of active chlorine between nitrogenous substrates. In: Jolley RL, ed. Water chlorination. Vol. 3. Ann Arbor, MI, Ann Arbor Science Publishers. Jandik J (1977) [Studies on decontamination of swimming pool water with consideration of ozonation of nitrogen containing pollutants.] Dissertation. Munich, Technical University Munich (in German). JECFA (2004) Evaluation of certain food additives and contaminants. Sixty-first report of the Joint FAO/ WHO Expert Committee on Food Additives (WHO Technical Report Series No. 922). Jovanovic S, Wallner T, Gabrio T (1995) [Final report on the research project "Presence of haloforms in pool water, air and in swimmers and lifeguards in outdoor and indoor pools".] Stuttgart, Landesgesundheitsamt Baden-Württemberg (in German). Judd SJ, Bullock G (2003) The fate of chlorine and organic materials in swimming pools. Chemosphere, 51(9): 869–879. Kaas P, Rudiengaard P (1987) [Toxicologic and epidemiologic aspects of organochlorine compounds in bathing water.] Paper presented to the 3rd Symposium on "Problems of swimming pool water hygiene", Reinhardsbrunn (in German).
Kelsall HL, Sim MR (2001) Skin irritation in users of brominated pools. International Journal of Environmental Health Research, 11: 29–40. Kim H, Weisel CP (1998) Dermal absorption of dichloro- and trichloroacetic acids from chlorinated water. Journal of Exposure Analysis and Environmental Epidemiology, 8(4): 555–575. Kirk RE, Othmer DF (1993) Encyclopedia of chemical technology, 4th ed. Vol. 5. New York, NY, John Wiley & Sons, p. 916. Lahl U, Bätjer K, Duszeln JV, Gabel B, Stachel B, Thiemann W (1981) Distribution and balance of volatile halogenated hydrocarbons in the water and air of covered swimming pools using chlorine for water disinfection. Water Research, 15: 803–814. Lahl U, Stachel B, Schröer W, Zeschmar B (1984) [Determination of organohalogenic acids in water samples.] Zeitschrift für Wasser- und Abwasser-Forschung, 17: 45–49 (in German). Latta D (1995) Interference in a melamine-based determination of cyanuric acid concentration. Journal of the Swimming Pool and Spa Industry, 1(2): 37–39. Lévesque B, Ayotte P, LeBlanc A, Dewailly E, Prud'Homme D, Lavoie R, Allaire S, Levallois P (1994) Evaluation of dermal and respiratory chloroform exposure in humans. Environmental Health Perspectives, 102: 1082–1087. Mannschott P, Erdinger L, Sonntag H-P (1995) [Determination of halogenated organic compounds in swimming pool water.] Zentralblatt für Hygiene und Umweltmedizin, 197: 516–533 (in German). Massin N, Bohadana AB, Wild P, Héry M, Toamain JP, Hubert G (1998) Respiratory symptoms and bronchial responsiveness in lifeguards exposed to nitrogen trichloride in indoor swimming pools. Occupational and Environmental Medicine, 55: 258–263. MDHSS (undated) Swimming pool and spa water chemistry. Missouri Department of Health and Senior Services, Section for Environmental Health (http://www.health.state.mo.us/RecreationalWater/ PoolSpaChem.pdf ). Puchert W (1994) [Determination of volatile halogenated hydrocarbons in different environmental compartments as basis for the estimation of a possible pollution in West Pommerania.] Dissertation. Bremen, University of Bremen (in German). Puchert W, Prösch J, Köppe F-G, Wagner H (1989) [Occurrence of volatile halogenated hydrocarbons in bathing water.] Acta Hydrochimica et Hydrobiologica, 17: 201–205 (in German). Rakestraw LF (1994) A comprehensive study on disinfection conditions in public swimming pools in Pinellas County, Florida. Study conducted by Pinellas County Public Health Unit and The Occidental Chemical Corporation. Presented on behalf of the Pool Study Team at the NSPI International Expo, New Orleans. Raykar PV, Fung MC, Anderson BD (1988) The role of protein and lipid domains in the uptake of solutes by human stratum corneum. Pharmacological Research, 5(3): 140–150. Rycroft RJ, Penny PT (1983) Dermatoses associated with brominated swimming pools. British Medical Journal, 287(6390): 462. Sandel BB (1990) Disinfection by-products in swimming pools and spas. Olin Corporation Research Center (Report CNHC-RR-90-154) (available from Arch Chemical, Charleston). Schöler HF, Schopp D (1984) [Volatile halogenated hydrocarbons in swimming pool waters.] Forum Städte-Hygiene, 35: 109–112 (in German). Schössner H, Koch A (1995) [Investigations of trihalogenmethane-concentrations in swimming pool water.] Forum Städte-Hygiene, 46: 354–357 (in German). Stottmeister E (1998) Disinfection by-products in German swimming pool waters. Paper presented to 2nd International Conference on Pool Water Quality and Treatment, 4 March 1998, School of Water Sciences, Cranfield University, Cranfield, UK. Stottmeister E (1999) [Occurrence of disinfection by-products in swimming pool waters.] Umweltmedizinischer Informationsdienst, 2: 21–29 (in German).
Stottmeister E, Naglitsch F (1996) [Human exposure to other disinfection by-products than trihalomethanes in swimming pools.] Annual report of the Federal Environmental Agency, Berlin, Germany (in German). Strähle J, Sacre C, Schwenk M, Jovanovic S, Gabrio T, Lustig B (2000) [Risk assessment of exposure of swimmers to disinfection by-products formed in swimming pool water treatment.] Final report on the research project of DVGW 10/95, Landesgesundheitsamt Baden-Württemberg, Stuttgart (in German). Taras MJ (1953) Effect of free residual chlorination on nitrogen compounds in water. Journal of the American Water Works Association, 45: 4761. Thickett KM, McCoach JS, Gerber JM, Sadhra S, Burge PS (2002) Occupational asthma caused by chloramines in indoor swimming-pool air. European Respiratory Journal, 19(5): 827–832. WHO (1999) Principles for the assessment of risks to human health from exposure to chemicals. Geneva, World Health Organization (Environmental Health Criteria 210). WHO (2000) Disinfectants and disinfectant by-products. Geneva, World Health Organization (Environmental Health Criteria 216). WHO (2004) Guidelines for drinking-water quality, 3rd ed. Vol.1. Recommendations. Geneva, World Health Organization. Yoder JS, Blackburn BG, Craun GF, Hill V, Levy DA, Chen N, Lee SH, Calderon RL, Beach MJ (2004) Surveillance of waterborne-disease outbreaks associated with recreational water – United States, 2001– 2002. Morbidity and Mortality Weekly Report, 53(SS08): 1–22.
Managing water and air quality
his chapter builds upon the background provided in Chapters 2, 3 and 4 and provides guidance relating to water and air quality management (risk management specific to certain microbial hazards is covered in greater detail in Chapter 3). The primary water and air quality health challenges to be dealt with are, in typical order of public health priority: • controlling clarity to minimize injury hazard; • controlling water quality to prevent the transmission of infectious disease; and • controlling potential hazards from disinfection by-products. All of these challenges can be met through a combination of the following factors: • treatment (to remove particulates, pollutants and microorganisms), including filtration and disinfection (to remove/inactivate infectious microorganisms); • pool hydraulics (to ensure effective distribution of disinfectant throughout the pool, good mixing and removal of contaminated water); • addition of fresh water at frequent intervals (to dilute substances that cannot be removed from the water by treatment); • cleaning (to remove biofilms from surfaces, sediments from the pool floor and particulates adsorbed to filter materials); and • ventilation of indoor pools (to remove volatile disinfection by-products and radon). Controlling clarity, the most important water quality criterion, involves adequate water treatment, including filtration. The control of pathogens is typically achieved by a combination of circulation of pool water through treatment (normally requiring some form of filtration plus disinfection) and the application of a chemical residual disinfectant to inactivate microorganisms introduced to the pool itself by, for instance, bathers. As not all infectious agents are killed by the most frequently used residual disinfectants, and as circulation through the physical treatment processes is slow, it is necessary to minimize accidental faecal releases and vomit (and to respond effectively to them when they occur) and to minimize the introduction of bather-shed organisms by pre-swim hygiene. Microbial colonization of surfaces can be a problem and is generally controlled through adequate levels of cleaning and disinfection. The control of disinfection by-products requires dilution, selection of source waters without DBP precursors (may include water pretreatment if necessary), pre-swim showering, treatment, disinfection modification or optimization and bather education. Figure 5.1 outlines the components and shows a general layout of a 'typical' pool treatment system. Most pools have a pumped system and water is kept in continuous
Plant room Coagulant dosing (5.2) Strainer Pump Filtration (5.4)
Water disinfection (5.3)
alternative disinfection dosing point
pH correction dosing (5.10.3)
Surface water off-take
Balance tank
Dilution (5.5) and make-up water
Swimming pool
Treated water
Bottom off-take
Figure 5.1. Water treatment processes in a 'typical pool' (relevant section numbers are identified in parentheses) circulation (see Section 5.6), with fresh water being added for dilution of materials that are not effectively removed by treatment and to account for losses (often referred to as make-up water).
5.1 Pre-swim hygiene
In some countries, it is common to shower before a swim. Showering will help to remove traces of sweat, urine, faecal matter, cosmetics, suntan oil and other potential water contaminants. Where pool users normally shower before swimming, pool water is cleaner, easier to disinfect with smaller amounts of chemicals and thus more pleasant to swim in. Money is saved on chemicals (offset to some extent by the extra cost of heating shower water, where necessary). The most appropriate setup for showers (e.g. private to encourage nude showering, a continuously run or automatic 'tunnel' arrangement) will vary according to country, but pool owners and managers should actively encourage showering. Showers must run to waste and should be managed to control Legionella growth (see Chapter 3). The role of footbaths and showers in dealing with papillomavirus and foot infections is under question. However, it is generally accepted that there must be some barrier between outdoor dirt and the pool in order to minimize the transfer of dirt into the pool. A foot spray is probably the best of the alternatives to footbaths. Where outdoor footwear is allowed poolside (e.g. some outdoor pools), separate poolside drainage systems can minimize the transfer of pollutants to the pool water.
or bromine-based).. the oxidant demand of the water being treated must be satisfied and sufficient chemical must remain to effect disinfection. therefore. All users should be encouraged to use the toilets before bathing to minimize urination in the pool and accidental faecal releases. capacity and skills for supervision and management). and the entire water body is disinfected by the application of a residual disinfectant (chlorine. Circulating pool water is disinfected during the treatment process.g. operator safety is an important factor to consider). comm. then clumping the solids together (flocculation). Gregory. 5. • ability to remain in water as residual after application. which otherwise may pass through the filter. which is more easily trapped during filtration. ideally.g. If babies and toddlers (that are not toilet trained) are allowed in the pool facilities.3. 2002). • type and size of pool (e. chlorination) or physical (e.3 Disinfection Disinfection is part of the treatment process whereby pathogenic microorganisms are inactivated by chemical (e. they should. • bathing load.2 Coagulation Coagulants (or flocculants) enhance the removal of dissolved. • compatibility with the source water (it is necessary to either match the disinfectant to the pH of the source water or adjust the source water pH). which partially inactivates agents added to the pool by bathers. producing a floc. Facilities that are difficult or impossible to disinfect pose a special set of problems and generally require very high rates of dilution to maintain water quality.e. they should have access only to small pools that can be completely drained if an accidental faecal release occurs. Coagulants are particularly important in helping to remove the oocysts and cysts of Cryptosporidium and Giardia (Pool Water Treatment Advisorz Group. wherever possible. colloidal or suspended material by bringing it out of solution or suspension as solids (coagulation).g. 82 . Coagulant efficiency is dependent upon pH. wear leak-proof swimwear (that will contain any urine or faecal release) and. • capacity for ongoing oxidation to assist in the control of all contaminants during pool use. For disinfection to occur with any biocidal chemical.Toilets should be provided and located where they can be conveniently used before entering and after leaving the pool. needs to be controlled. 5. 5. and • operation of the pool (i. disinfectant may be more readily degraded or lost through evaporation in outdoor pools). The disinfectant used as part of swimming pool water treatment should ideally meet the following criteria: • effective and rapid inactivation of pathogenic microorganisms. UV radiation) means such that they represent no significant risk of infection.1 Choosing a disinfectant Issues to be considered in the choice of a disinfectant and application system include: • safety (while occupational health and safety are not specifically covered in this volume. pers. which.
cyanuric acid and chlorinated isocyanurate exist in equilibrium. lithium) or chlorinated isocyanurates.5.• a wide margin between effective biocidal concentration and concentrations resulting in adverse effects on human health (adverse health effects of disinfectants and disinfection by-products are reviewed in Chapter 4). hypochlorous acid (HOCl) is formed.8 – see Section 5. 3 (tri-) ↔ C3H3N3O cyanuric acid + HOCl hypochlorous acid Free chlorine.5. They are an indirect source of chlorine. 2 (di-). a change occurs from undissociated hypochlorous acid to nearly complete dissociation.0. At pH levels of 6. a hypochlorite salt (sodium. They are widely used in outdoor or lightly loaded pools. Hypochlorous acid is a much stronger disinfectant than hypochlorite ion. calcium. Together. While chlorine gas can be safely and effectively used. and • potential to measure the disinfectant concentration online to permit automatic control of disinfectant dosing and continuous recording of the values measured. The chlorinated isocyanurate compounds are white crystalline compounds with a slight chlorine-type odour that provide free chlorine (as hypochlorous acid) when dissolved in water but which serve to provide a source of chlorine that is more resistant to the effects of UV light. while at a pH of 8. The usual test for chlorine detects both free and total chlorine. The relative amounts of each compound are determined by the pH and free chlorine CHAPTER 5. as follows: HOCl hypochlorous acid ↔ H+ hydrogen ion + OCl– hypochlorite ion The degree of dissociation depends on pH and (much less) on temperature. At a pH of 8. oxidizing disinfectant). to determine the effectiveness of disinfection.2 Characteristics of various disinfectants 1. the pH value should be kept relatively low and within defined limits (7. • availability of a quick and easy measurement of the disinfectant concentration in pool water (simple analytical test methods and equipment). When chlorine gas or hypochlorite is added to water. hypochlorous acid and OCl– are referred to as free chlorine. Hypochlorous acid dissociates in water into its constituents H+ and OCl– (hypochlorite ion). usually in the form of chlorine gas. only 12% of that chlorine exists as hypochlorous acid.10.5–8. 21% of the free chlorine exists in the hypochlorous acid form (acting as a strong. the pH value must also be known. 5. For this reason. fast. MANAGING WATER AND AIR QUALITY 83 .2–7.3). Dissociation is minimal at pH levels below 6. and the reaction is represented by the equation: ClxH3–xCy + H2O chloroisowater cyanurates x = 1 (mono-).3. and care must be taken to ensure that health concerns do not arise. it does have the potential to cause serious health impacts. Chlorine-based disinfectants Chlorination is the most widely used pool water disinfection method.
BCDMH is an organic compound that dissolves in water to release hypobromous acid (HOBr) and hypochlorous acid.concentration. When bromine disinfectants are used. following addition of the test chemical. can be used to monitor levels. Cyanuric acid in chlorinated water (whether introduced separately or present through the use of chlorinated isocyanurates) will reduce the amount of free chlorine. combined bromine acts as a disinfectant and produces less sharp and offensive odours than corresponding chloramines. Bromine combines with some water impurities to form combined bromine. however. At low levels of cyanuric acid. however. more chlorine atoms are released from the chloroisocyanurates to form hypochlorous acid. shock dosing with chlorine is often necessary to oxidize ammonia and nitrogen compounds that eventually build up in the water (MDHSS. as the cyanuric acid level increases. It means. For effective disinfection. bromine compounds are usually available in two forms. and • a two-part system that uses a bromide salt dissolved in water. that the cyanuric acid level must be monitored and controlled relative to chlorine residual. Bromine-based disinfectants Elemental bromine is a heavy. However. The latter reacts with bromide (Br–) (formed by a reduction of hypobromous acid) to form more hypobromous acid: 84 GUIDELINES FOR SAFE RECREATIONAL WATER ENVIRONMENTS . unsatisfactory microbial conditions can result. dark red-brown. A simple turbidity test. the pH value must also be monitored. when even very high levels of chlorine become totally locked with the cyanuric acid (stabilizer) and unavailable as disinfectant. both of which are solids: • a one-part system that is a compound (bromochlorodimethylhydantoin – BCDMH) of both bromine and chlorine. because the influence of pH on disinfection efficiency is the same as described for chlorine as a disinfectant. bromine cannot be used for shock dosing. For pool disinfection. This results in an enrichment of cyanuric acid in the pool that cannot be removed by the water treatment process. Because of this. The balance between free chlorine and the level of cyanuric acid is critical and can be difficult to maintain. 2. and it is recommended that cyanurate levels should not exceed 100 mg/l. volatile liquid with fumes that are toxic and irritating to eyes and respiratory tract. this does not occur below cyanuric acid levels of 200 mg/l. including bromamines. Hypobromous acid reacts with sunlight and cannot be protected from the effects of UV light by cyanuric acid or other chemicals. each attached to a nitrogen atom of dimethylhydantoin (DMH) as organic support for the halogens. If the balance is lost because cyanuric acid levels become too high. is proportional to the cyanuric acid concentration. High levels of cyanuric acid cause a situation known as 'chlorine lock'. undated). however. Dilution with fresh water is necessary to keep the cyanuric acid concentration at a satisfactory level. and it is not considered suitable for swimming pool disinfection. the disinfecting and oxidizing properties of the free chlorine become progressively reduced. activated by addition of a separate oxidizer. and thus it is more practical to use bromine disinfectants for indoor pools. where the degree of turbidity. As the disinfectant (HOCl) is used up. there is very little effect. Bromine does not oxidize ammonia and nitrogen compounds.
8 and 1.10. MANAGING WATER AND AIR QUALITY 85 .5 g/m3. is easy to dose and often does not need pH correction (as it is nearly neutral and has little effect on the pH values of most water). ozone). which is added to activate the bromide into hypobromous acid: Br– + oxidizer HOBr Disinfectant action returns hypobromous acid to bromide ions.g. activated CHAPTER 5. 3.or bromine-based disinfectants). All of the circulating water is treated with sufficient amounts of ozone (between 0. As ozone can be inhaled by pool users and staff. followed by deozonation and addition of a residual disinfectant (i. it is generated on site and is potentially hazardous. as it readily vaporizes.8 and 8. 1995.0 using this disinfection system (see also Section 5. cartridges or packets. leading to discomfort and adverse health effects (Locher.e. failure to maintain the correct relationship between the disinfectant residual and the organic component can result in unsatisfactory microbial conditions. chlorine. The two-part bromine system consists of a bromide salt (sodium bromide) and an oxidizer (hypochlorite. Like the chlorinated isocyanurates. is toxic and is heavier than air. so it may be used in floating and erosion-type feeders. be used both for treatment (oxidation) and to provide a residual disinfectant. and the need to regularly monitor dimethylhydantoin by a qualified laboratory is a disadvantage of the use of BCDMH. The sodium bromide is dosed to the water. It is unsuitable for use as a residual disinfectant. thereby reducing subsequent residual disinfectant requirements within the pool water. Under these conditions. BCDMH is relatively innocuous in storage. Lower disinfectant demand allows the pool operator to achieve the desired residual with a lower applied chlorine (or bromine) dose. therefore. 1998). depending on the water temperature) to satisfy the oxidant demand of the water and attain a residual of dissolved ozone for several minutes.Br-(DMH)-Cl + 2 H2O bromochlorowater dimethylhydantoin disinfection HOBr oxidation HOCl + Br– Br– ↔ HOBr hypobromous acid + HOCl + H-(DMH)-H hypochlorous dimethylacid hydantoin HOBr + Cl– It can. particularly to the plant room operators. ozone oxidizes many impurities (e. which can again be reactivated. Ozone Ozone can be viewed as the most powerful oxidizing and disinfecting agent that is available for pool water treatment (Rice. trihalomethane [THM] precursors) and microorganisms (disinfection). BCDMH has a long shelf life and dissolves very slowly. passing through the treatment processes. The level of dimethylhydantoin in the water must be limited and should not exceed 200 mg/l. On the other hand. It is mostly available as tablets. Ozonation is. The pH value should be between 7. excess ozone must be destroyed (forming oxygen and carbon dioxide) by deozonation (using granular activated carbon. therefore. Saunus. There is no poolside test kit available. 1996).3). upstream of the oxidizer.
5. Algal growth is possible only if the nutrients phosphate. 4. Phosphate can be removed from the pool water by good coagulation and filtration during water treatment. chloramines) by photo-oxidation. it is also necessary to use a chlorine. It inactivates microorganisms and breaks down some pollutants (e. water temperature. this can be avoided by ensuring that there is residual disinfectant in the incoming water stream from the pool. Chloramines are oxidized by ozone into chloride and nitrate (Eichelsdörfer & Jandik. this BCDMH/ozone combination allows less BCDMH to be added. the use of algicidal chemicals for the control of algae is not necessary (Gansloser et al. then proprietary algicides can 86 GUIDELINES FOR SAFE RECREATIONAL WATER ENVIRONMENTS . the practice is to add only small amounts of ozone to this system to oxidize only the bromide (resulting from the spent hypobromous acid) back to hypobromous acid. as an oxidizer. Algal growth is best controlled by ensuring effective coagulation/filtration and good hydraulic design. the UV radiation process purifies the circulating water. Microbial colonization of the deozonation media (especially granular activated carbon) can occur.02 mg/l) (Eichelsdörfer et al. In such properly managed swimming pools. as substances that build up on the lamps will reduce their pathogen inactivation efficiency over time. maintaining the correct filter bed depth and an appropriate filter velocity. water flow rate to be treated. considerably more expensive than that of chlorine alone. 1999). as described above. As with ozone. The UV lamps need to be cleaned periodically. 1998). Eichelsdörfer. type of lamps (low or medium pressure).or brominebased disinfectant to provide a residual disinfectant in the pool. and rate of disinfection. The following criteria are important in the selection of an appropriate UV system: • • • • • • type of microorganisms to be destroyed.heat-treated anthracite or thermal destruction). however. the water must be pretreated to remove turbidity-causing particulate matter that prevents the penetration of the UV radiation or absorbs the UV energy (Saunus. therefore. resulting in very low levels of THMs (<0. 1979. without leaving a residual disinfectant. Algicides Algicides are used to control algal growths.. The use of ozone in conjunction with chlorine (to ensure a residual disinfectant throughout the pool or similar environment) is. and an ozone leakage detector should be installed in the plant room.g. however. UV dose. 1984). they are. added after this. For UV to be most effective. As residual disinfectants would also be removed by the deozonation process. However. An ozone system in combination with BCDMH is also in use. decreasing the oxidant demand of the purified water. 1981. Ozone can also be used in combination with sodium bromide. especially in outdoor pools. Ultraviolet (UV) radiation Like ozone. UV disinfection can be achieved by UV irradiation at wavelengths between 200 and 300 nm. Therefore. nitrogen and potassium are present in the pool water. and precursors of disinfection by-products are also destroyed. 1987) and other chlorinated organics. If problems persist..
All should be used in strict accordance with the suppliers' instructions and should be intended for swimming pool use. • Hand-dosing (i.3. pre-swim showering – see Section 5. Regular verification of the system (including manual tests on pool water samples) and good management are important. so that the post-treatment disinfection can be more effective and the amount of disinfectant required is minimized. putting chemicals directly into the pool) is rarely justified. CHAPTER 5. It is inevitable. may be produced in the pool water (depending upon the disinfection system used) and escape into the air.3 Disinfection by-products (DBP) The production of disinfection by-products (see Chapter 4) can be controlled to a significant extent by minimizing the introduction of precursors though source water selection.g. disinfectant dosing may occur pre. 5. Manual systems of dosing must be backed up by good management of operation and monitoring.e. • Residual disinfectants are generally dosed at the end of the treatment process. Individual disinfectants have their own specific dosing requirements. MANAGING WATER AND AIR QUALITY 87 . but the following principles apply to all: • Automatic dosing is preferable: electronic sensors monitor pH and residual disinfectant levels continuously and adjust the dosing correspondingly to maintain correct levels. this hazard can also be managed to some extent through good ventilation (see also Section 5. it is important that the pool is empty of bathers until the chemical has dispersed.1. that some volatile disinfection by-products. both hypochlorite and acid have been so dosed.10 describes the monitoring procedures. for example. then high local concentrations of the dosed chemical will occur.4 Disinfectant dosing The method of introducing disinfectants to the pool water influences their effectiveness. While levels of production should be minimized. such as chloroform and nitrogen trichloride (a chloramine). and. 5. If manual dosing is employed. as illustrated in Figure 5. On resumption of the circulation system. Section 5.3.or post-filtration.be used.9). however. the high concentration will progress to the pool. the resultant mix containing chlorine gas may be dangerous to pool users. If chemical dosing continues without water circulating. reduce the organic load (including precursors for the formation of disinfection by-products) and greatly reduce the microbial content.e. If. but any based on mercury (a cumulative toxic heavy metal) should not be added to swimming pools. filtration and ozonation or ultraviolet serve to clarify the water. maximizing their removal by well managed pool water treatment and replacement of water by the addition of fresh supplies (i. Quaternary ammonium and polyoximino compounds and copper salts can be used. good bather hygienic practices (e. dilution of chemicals that cannot be removed). • Dosing pumps should be designed to shut themselves off if the circulation system fails (although automatic dosing monitors should remain in operation) to ensure that chemical dispersion is interrupted.1). The treatment methods of coagulation.
it may take a long time to drop to safe levels before bathing can be resumed. because it can mask deficiencies in design or operation that may produce other problems. Shock dosing • Using a shock dose of chlorine as a preventive measure or to correct specific problems may be part of a strategy of proper pool management. Filtration is also effective against microbes.3). Shock dosing is used to control a variety of pathogens and nuisance microorganisms and to destroy organic contaminants and chloramine compounds.8). and conjunctival irritation and obnoxious odours in the pool area may be raised to high levels. routine shock dosing (which is practised in some countries) typically involves raising free chlorine levels to at least 10 mg/l for between 1 and 4 h. and the choice of filter will be based on several factors. As a preventive measure.e.1 Filter types There are a number of types of filter available. Particles can shield microorganisms from the action of disinfectants. • If not enough chlorine is added.• It is important that disinfectants and pH-adjusting chemicals are well mixed with the water at the point of dosing. 5. like circulation. notably free-living amoebae. the disinfectants may react with certain components of organic particles to form complexes that are less effective than the parent compounds. • Trying to compensate for inadequacies in treatment by shock dosing is bad practice. <5 mg/l – see Section 4. If too much chlorine is added.4. • Dosing systems. Chlorine levels should return to acceptable levels (i. or the disinfectants may oxidize the organic material. Disinfection will also be compromised by particulates.1) before bathers are permitted in the pool.4.4 Filtration The primary function of filtration is to remove turbidity to achieve appropriate water clarity. that harbour opportunistic bacteria such as Legionella and Mycobacterium species. thereby eliminating disinfection potential. Intervention shock dosing for a water quality problem (such as an accidental faecal release) may involve raising the free chlorine residual to 20 mg/l for an 8-h period while the pool is empty (see Section 5. Alternatively. including: • the quality of the source water. should operate 24 h a day. • the amount of filter area available and number of filters> Pools benefit greatly from the increased flexibility and safeguards of having more than one filter. Filtration is often the critical step for the removal of Cryptosporidium oocysts and Giardia cysts (see Section 3. 88 GUIDELINES FOR SAFE RECREATIONAL WATER ENVIRONMENTS . Destroying chloramines requires free chlorine levels at least 10 times the level of combined chlorine. Poor underwater visibility is a contributing factor to injuries (Chapter 2) and can seriously hamper recognition of swimmers in distress or a body lying on the bottom of the pool. Water clarity is a key factor in ensuring the safety of swimmers. 5. the combined chlorine (chloramines) problem may be exacerbated.
sand filters can remove over 99% of Cryptosporidium oocysts. Individual standards should be developed. Turbidity needs to be controlled both for safety and for effective disinfection. 2. the sand medium typically has a life of between five and seven years. Drinking-water treatment has shown that when operated with a coagulant. Medium-rate sand filters are comparatively large-diameter pressure vessels (in a horizontal or vertical format) and require large plant rooms. when a certain length of time without backwashing has passed or when a pressure differential is observed. a universal turbidity value is not considered to be appropriate. The filter medium is spun-bound polyester or treated paper. The benefit of precoat filtration is that it can provide a particle removal of 1–2 µm and. the lower the filtration efficiency. the less clarity. 5. as much depends on the characteristics of the individual pool. Cleaning is achieved by manual reverse flow backwashing. It is accomplished by reversing the flow. Table 5. 1. Studies in a pilot sand filtration plant under swimming pool filtration conditions have shown that without the addition of coagulant. when the allowable turbidity value has been exceeded. Using coagulants. • ease of operation. the higher the filtration rate. diatomite products and perlite.1 compares the alternative filter types. For indoor heated pools. Filter media include diatomaceous earth. removal of the Cryptosporidium oocyst surrogate (fluorescent polystyrene particles sized between 1 and 7 µm) was less than 50%.2 Turbidity measurement Turbidity is a measure of the amount of suspended matter in water. provide good removal of Cryptosporidium oocysts.4. For identifying bodies at the bottom of the pool. Their main advantage is the relatively small space requirement compared with other filter types. and the more turbid the water.• filtration rate: Typically. 3. such as surface reflection and pool material/construction. CHAPTER 5. as such. Sand filters Medium-rate sand filters can nominally filter down to about 7 µm in size with the addition of a suitable coagulant (such as polyaluminium chloride or aluminium hydroxychloride). • method of backwashing: The cleaning of a filter bed clogged with solids is referred to as backwashing. Ultrafine filters Ultrafine precoat filters (UFF) use a replaceable filter medium that is added after each backwash. pers. fluidizing the filter material and passing pool water back through the filters to waste. Cartridge filters Cartridge filters can nominally filter down to 7 µm and last up to two years. and they are often used with small pools and hot tubs. MANAGING WATER AND AIR QUALITY 89 .). and • degree of operator training required. with air scouring to remove body oils and fats to improve the backwash efficiency. polyaluminium chloride and polyaluminium silicate sulfate improved the removal up to 99% (Pool Water Treatment Advisory Group. comm. Backwashing should be done as recommended by the filter manufacturer. Cleaning is achieved by removing the cartridge and washing it. based on risk assessment at each pool.
25 m3/m2 pool water None A backwash tank may be required. filtration and disinfection will not remove all pollutants. determined by the nephelometric method (ISO. upper-limit guideline for turbidity is 0.5 Dilution Coagulation. Swimming pool design should enable the dilution of pool water with fresh water. evaporation and splash-out. 5. it should be possible to see a small child at the bottom of the pool from the lifeguard position while the water surface is in movement.Table 5. Treated water must 90 GUIDELINES FOR SAFE RECREATIONAL WATER ENVIRONMENTS .02 m3/m2 mains water None Hose-down and waste drain facility Particulate collection Nominal particle removal Pressure rise for backwash 70 kPa Comparative running costs High Comparative installation High costs UFF = ultrafine filter Depth 10 µm. Dilution rates need to account for the replacement of water used in filter backwashing. 1999). of byproducts of disinfection and of various other dissolved chemicals. Dilution limits the build-up of pollutants from bathers (e. 5. as a minimum. hose down 0.6 Circulation and hydraulics The purpose of paying close attention to circulation and hydraulics is to ensure that the whole pool is adequately served by filtered. Operators could determine these indicators as a turbidity equivalent through experience and then monitor routinely for turbidity. In terms of effective disinfection. 7 µm with coagulant 40 kPa Low High Degree of depth 7 µm 40 kPa Medium Low but it is recommended that.g.5 m3/m2/h Not applicable Manual. constituents of sweat and urine). Separation tank required to collect used filter media with periodic sludge removal Surface 1–2 µm Filter type Medium-rate sand Up to 10 m2 25–30 m3/m2/h 37–42 m3/m2/h Backwash 2. An alternative is to maintain water clarity so that lane markings or other features on the pool bottom at its greatest depth are clearly visible when viewed from the side of the pool.5 m3/m2 pool water Optional coagulants A backwash tank may be required Cartridge Up to 20 m2 1. As a general rule. disinfected water.1. Comparison of filter types Criteria Common filter sizes Design filter flow rate Cleaning flow rate Cleaning Average wash water Filter aid Cleaning implications UFF Up to 46 m2 3–5 m3/m2/h 5 m3/m2/h Backwash and media replacement 0. but not absolute. a useful. as in normal use.5 nephelometric turbidity unit (NTU). the addition of fresh water to disinfected pools should not be less than 30 litres per bather.
The bottom returns allow the removal of grit and improved circulation within the pool. the turnover should be calculated based upon the shallowest depth achievable. these include: • area of water – in terms of space for bathers to move around in and physical safety.25 h 1–2 h 2–2.7 Bathing load Bathing load is a measure of the number of people in the pool. BOX 5.5–1 h 5. and these should be employed at the design stage.1 gives some examples of turnover periods that have been employed in the UK. the following turnover periods for different types of pools have been recommended: Pool type Competition pools 50 m long Conventional pools up to 25 m long with 1-m shallow end Diving pools Hydrotherapy pools Leisure water bubble pools Leisure waters up to 0. 1999). MANAGING WATER AND AIR QUALITY 91 . Box 5.5 m deep Leisure waters over 1. some types of pool where circulation rate cannot realistically be derived from bathing load – diving pools and other waters more than 2 m deep.5–1 h 5–20 min 10–45 min 0. however. Turnover periods must.5–1. however. even water treatment may not give adequate pool water quality. Without good circulation and hydraulics. For a new pool. Circulation rate is related to turnover period.5 m deep Leisure waters 0. on bathing load. the more actual swimming there is and the more area a bather requires. where the bathing load relative to water volume may be very low.1 EXAMPLES OF TURNOVER PERIODS FOR DIFFERENT TYPES OF POOLS In the United Kingdom (BSI. CHAPTER 5.5 h 0. this is related to the likely pollution load based on the type of activity undertaken and the volume of water within the pool. Where pools have moveable floors.1 for an example of guidance). and polluted water must be removed – especially from areas most used and most polluted by bathers.5 m deep Teaching/learner/training pools Water slide splash pools Turnover period 3–4 h 2.5–3 h 4–8 h 0. There are.. • depth of water – the deeper the water. Formulae are available for calculating turnover rates.5–1. It is recommended that 75–80% be taken from the surface (where the pollution is greatest – Gansloser et al.5 h 0.5–1 m deep Leisure waters 1–1.get to all parts of the pool. which is the time taken for a volume of water equivalent to the entire pool water volume to pass through the filters and treatment plant and back to the pool. There are many factors that determine the maximum bathing load for a pool. also suit the particular type of pool (see Box 5. the bathing load should be estimated at the design stage. The appropriate circulation rate depends. The circulation rate is defined as the flow of water to and from the pool through all the pipework and the treatment system. for example. in most cases. with the remainder taken from the bottom of the pool. 2003).
is to empty and clean it before refilling and reopening. Even though most disinfectants deal relatively well with many bacterial and viral agents in accidental faecal releases and vomit. although it is likely that most go undetected. These figures may not be appropriate for all pool types or all countries. this is practically impossible in many larger pools. bacteria and pathogenic protozoa (Chapter 3). If draining down is not possible. 92 GUIDELINES FOR SAFE RECREATIONAL WATER ENVIRONMENTS .5 m a Maximum bathing load 1 bather per 2. sweeping and/or vacuuming (provided the equipment can be adequately disinfected after use). act immediately.0 m2 Adapted from BSI.2. • As much of the material as possible should be collected. The infectious stages (oocysts/cysts) are resistant to chlorine disinfectants in the concentrations that are practical to use. this may be done through netting. in other respects. Where the maximum bathing load has not been established. The safest action. however. If the faecal release is a solid stool. The scoop used to retrieve it should be disinfected so that any bacteria and viruses adhering to it are inactivated and will not be returned to the pool the next time the scoop is used. and • pool type and bathing activity. as the faeces or vomit is more likely to contain pathogens. The pool should therefore be cleared of bathers immediately. operating properly (i. the possibility exists that the diarrhoea or vomit is from someone infected with one of the protozoan parasites. If the stool is runny (diarrhoea) or if there is vomit. vomit may have a similar effect. 2003) can provide an approximation. The same applies to solid animal faeces. A pool operator faced with an accidental faecal release or vomit in the pool water must.5 m >1. that this is an imperfect solution that will only reduce but not eliminate risk): • The pool should be cleared of people immediately. no further action is necessary.0 m 1.• comfort. Cryptosporidium and Giardia. therefore.8 Accidental release of faeces or vomit into pools Accidental faecal releases may occur relatively frequently. it has been suggested in the UK that the figures in Table 5.7 m2 1 bather per 4. Table 5. removed and disposed of to waste.0–1. disinfectant levels are maintained). then a procedure based on the one given below should be followed (it should be noted.e. the situation is more likely to be hazardous. 2003 5. Pool operators need to be aware of the maximum bathing load and should ensure that it is not exceeded during the operation of the pool. An example of maximum bathing loadsa Water depth <1. for reasons of cost and extended periods of closure.2 (BSI. it should simply be retrieved quickly and discarded appropriately. As long as the pool is. Accidental faecal releases into swimming pools and similar environments can lead to outbreaks of infections associated with faecally-derived viruses.2 m2 1 bather per 2. However. if the incident has occurred in a small pool or hot tub.
• Lifeguards should be made responsible for looking out for and acting on accidental faecal release/vomit incidents. Reducing exposure to disinfection by-products in air should be pursued in order to minimize overall exposure to these chemicals. The quantity of water treatment by-products. humidity and velocity of the pool hall air should be appropriate to provide a comfortable environment. then the pool can be reopened. • The final residual disinfectant level and pH value should be checked. • The filter should be backwashed (and the water run to waste). with fresh air). and a significant proportion of such diarrhoea incidents may happen without lifeguards being aware of them.2–7. Pool operators are unlikely to know with certainty what has caused a diarrhoea incident. which involves both mixing and dilution (i. 5. • Using a coagulant (if appropriate). • Impact on the building fabric. and babies and toddlers that have not been toilet trained should ideally wear waterproof nappies or specially designed bathing wear. MANAGING WATER AND AIR QUALITY 93 . The most important contribution a pool operator can make to the problem is to guard against it.e. Although Legionella should primarily be controlled in the water systems. • Staff and user comfort. CHAPTER 5. • Parents should be encouraged to make sure their children use the toilet before they swim. this may mean closing the pool until the next day. The two areas of principal concern for health are Legionella and disinfection by-products.9 Air quality Air quality in indoor swimming pool facilities is important for a number of reasons. concentration of airborne particulate matter and fresh air need to be controlled. particularly chloramines. areas housing natural spas (thermal water) and hot tubs should also be well ventilated. as inhalation appears to be the dominant route of exposure during recreational water use (see Chapter 4). concentration of airborne particulate matter and quantity of water treatment by-products need to be controlled in order to avoid an 'aggressive environment' that may damage the building fabric. The temperature.• Disinfectant levels should be maintained at the top of the recommended range or chlorination to 20 mg/l at pH 7. and if satisfactory. including: • Staff and user health. There are a few practical actions pool operators can take to help prevent faecal release into pools: • No child (or adult) with a recent history of diarrhoea should swim. The willingness of operators and lifeguards to act is critical. • Young children should whenever possible be confined to pools small enough to drain in the event of an accidental release of faeces or vomit. As concentrations of disinfection by-products decrease rapidly with distance from the water. the water should be filtered for six turnover cycles.5 for 8 h (shock dosing) should be performed. this has implications for ventilation design. and building codes should stipulate appropriate ventilation rates (at least 10 litres of fresh air/s/m2 of water surface area). The air temperature.
2 mg/l). However. If the levels are high.10. residual disinfectant and pH) should be monitored most frequently and in all pool types.5. Failure to maintain target residual disinfectant should result in immediate investigation and follow-up testing.1 Turbidity Turbidity testing is simple. it is more appropriate in the long term to deal with the underlying problem.2.2 mg/l should not be necessary anywhere in the pool unless the pool is not well designed or well operated – if. Lower free chlorine concentrations (0. then it is likely that there is too much ammonia in the water. Higher concentra94 GUIDELINES FOR SAFE RECREATIONAL WATER ENVIRONMENTS . in practice. Whether any other parameters (physical. including how to act on any unexpected results. Management should review data and test systems regularly and ensure that pool operators have taken appropriate remedial action. circulation is too slow. Free chlorine levels well above 1.10. microbial monitoring is generally needed in public and semi-public pools. Exceedance of a turbidity standard suggests both a significant deterioration in water quality and a significant health hazard. If residuals cannot be rapidly re-established and maintained. 5. where this is the case. 5. experience has shown that adequate routine disinfection should be achieved with a free chlorine level of 1 mg/l throughout the pool. There should be pre-established (clear. Experience suggests that the combined chlorine level within pool water (chloramines) should be no more than half the free chlorine level (but combined chlorine should be as low as possible and ideally less than 0. Chlorine-based disinfectants For a conventional public or semi-public swimming pool with good hydraulics and filtration.5 mg/l or less) will be adequate where chlorine is used in conjunction with ozone or UV disinfection. that dilution is too low or that treatment is suboptimal. distribution is poor or bathing loads are too heavy. rather than increasing disinfection levels.4. and public health authorities should be consulted in determining whether the facility should remain open.2 Residual disinfectant level National or other standards for minimum and maximum levels of residual disinfectant vary widely. for example. determined by management capacity. 1.10 Monitoring Parameters that are easy and inexpensive to measure reliably and of immediate operational health relevance (such as turbidity. facility-specific turbidity standards are described in Section 5. intensity of use and local practice. approaches to establishing appropriate. indicating that bathing loads or pollution from bathers may be too high. Such exceedance merits immediate investigation and should lead to facility closure unless the turbidity can rapidly be brought within standards. operating within its design bathing load and turnover and providing frequent (or online) monitoring of chlorine and pH. chemical and microbial) need to be monitored is. The main factor is that the residual disinfectant level should always be consistent with satisfactory microbial quality. then full investigation of cause and prevention of repetition are merited. written) procedures set up by managers for acting on the results of monitoring. Operators must know what to do themselves or how to ensure that appropriate action is taken by someone else.
samples should also be taken from the pool itself. Sampling and analysis In public and many semi-public pools.0–2. for other semi-public pools and public and semi-public hot tubs. CHAPTER 5. during operating hours.N-diethyl-p-phenylenediamine (DPD) method. the pH value should be measured continuously and adjusted automatically.tions (up to 2–3 mg/l) may be required to ensure disinfection in hot tubs. for domestic pools.3 pH The pH of swimming pool water should be controlled to ensure efficient disinfection and coagulation. MANAGING WATER AND AIR QUALITY 95 . Samples should be taken at a depth of 5–30 cm. Bromine-based disinfectants Total bromine levels in swimming pools. It is suggested that the residual disinfectant concentration in domestic pools be checked before use.4).2 and 7. If BCDMH is the bromine source. because of higher bathing loads and higher temperatures.3. to avoid damage to the pool fabric and ensure user comfort. the level of dimethylhydantoin must also be monitored. then the level of cyanuric acid must also be monitored and controlled. 3. The tests employed should be capable of determining free chlorine and total bromine levels (depending upon the disinfectant used). it is advisable to measure prior to pool use. Actions to be taken on failure to maintain pH within the target range are similar to those for disinfectant residual. the disinfectant residual is generally lowest. It is suggested that for public pools.5 mg/l. In public and semi-public pools. it is suggested that monitoring be conducted several times a day. If the chlorine source is chlorinated isocyanurate compounds. This method can measure both free and total disinfectant and is available as both colorimetric and titration test kits.8 for chlorine disinfectants and between 7. it should not exceed 200 mg/l. microbial conditions may become unsatisfactory.2 and 8. It is good practice to include as a routine sampling point the area of the pool where. In addition to this. The frequency of measurement will depend upon the type of pool. using either liquid or tablet reagents. because of the hydraulics. residual disinfectant concentrations should be checked by sampling the pool before it opens and during the opening period (ideally during a period of high bathing load). The pH should be maintained between 7.0 for bromine-based and other non-chlorine processes. and increased freshwater dilution is required. Analysis is generally performed with simple test kits based on the N. All tests must be carried out immediately after the sample is taken. if it becomes too high (above 100 mg/l). 2. When bromine-based disinfectants are used in combination with ozone. 5. The frequency of testing while the swimming pool is in use depends upon the nature and use of the pool. Occasional samples should be taken from other parts of the pool and circulation system. there will be continuous monitoring of residual disinfectant levels as the disinfectant is dosed (see Section 5. should ideally be maintained at 2. the concentration of bromide ion should be monitored and maintained at 15–20 mg/l.10.
It is recommended that operational levels should be less than 200 cfu/ml. residual disinfectant levels and pH and then resample. When critical guidelines are exceeded. operational levels should be <10/100 ml. wait one turnover and resample. HPC The HPC (37 °C for 24 h) gives an indication of the overall bacterial population within the pool. pool operators should check turbidity. coli Thermotolerant coliforms and E. E. Operational levels should be less than 1/100 ml. 'Indicator' organisms As outlined in Chapter 3. backwash thoroughly. Such tests do not guarantee microbial safety but serve to provide information with which to judge the effectiveness of measures taken. Microorganisms used to assess the microbial quality of pools and similar environments include heterotrophic plate count (HPC). rather than specific microbial hazards (see Box 3. It is recommended that for continuously disinfected pools. thermotolerant coliforms. If high levels of P. 5. a pH value maintained at an appropriate level. although it is suggested that appropriate values should be determined on a case-by-case basis. resample. Where operational guidelines are exceeded. 1. the pool should be closed while investigation and remediation are conducted. coli should be measured in all public and semi-public pools. a deterioration in the quality of the pool water or known health problems. Pseudomonas aeruginosa Routine monitoring of Pseudomonas aeruginosa is recommended for public and semipublic hot tubs and natural spas. disinfectant residuals and pH. Legionella spp. Thermotolerant coliforms and E. and Staphylococcus aureus. pool operators should check turbidity. the pool should be closed and a 96 GUIDELINES FOR SAFE RECREATIONAL WATER ENVIRONMENTS . where natural spas operate with no residual disinfectant. In general terms for swimming pools and similar environments.5. Either thermotolerant coliforms or E.4 Oxidation–reduction potential (ORP) The oxidation–reduction potential (also known as ORP or redox) can also be used in the operational monitoring of disinfection efficacy. Nevertheless.1). levels in excess of 720 mV (measured using a silver/ silver chloride electrode) or 680 mV (using a calomel electrode) suggest that the water is in good microbial condition. hot tubs and natural spas. well operated filters and frequent monitoring of non-microbial parameters.10. It is suggested for public and semi-public swimming pools when there is evidence of operational problems (such as failure of disinfection or problems relating to filters or water pipes). coli. If high counts are found (>100/100 ml). monitoring for potential microbial hazards is generally done using 'indicator' microorganisms. samples of pool water from public and semipublic pools should be monitored at appropriate intervals for microbial parameters. operational levels should be <1/100 ml. aeruginosa remain. This should be monitored in public and semi-public disinfected swimming pools. Pseudomonas aeruginosa.10. coli are indicators of faecal contamination.5 Microbial quality There is limited risk of significant microbial contamination and illness in a well managed pool with an adequate residual disinfectant concentration.
Where samples are taken. Legionella spp. 2.g. especially from hot tubs. drained.3. along with a summary of operational guideline values. residual disinfectant concentration) are not maintained within target ranges Sample numbers should be determined on the basis of pool size and complexity and should include point(s) representative of general water quality and likely problem areas Operational guidelines are shown in parentheses e. Table 5. Shock chlorination may be appropriate if it is suspected that filters have become colonized. hot tubs should be shut down. and it is recommended that operational levels should be <1/100 ml. before it is put back into use. and as part of any investigation into possible adverse effects on bathers' health. if there are difficulties with the treatment system. MANAGING WATER AND AIR QUALITY 97 . levels should be less than 100/100 ml. coli Weekly (<1/100 ml) Monthly (<1/100 ml) Weekly (<1/100 ml) Weekly (<1/100 ml) Pseudomonas aeruginosa When situation demandsc (<1/100 ml) When situation demandsc (<1/100 ml) Weekly (<10/100 ml) Weekly (<1/100 ml) Legionella spp. public and heavily used Disinfected pools. cleaned and refilled. although monitoring may be undertaken as part of a wider investigation into the quality of the water when health problems associated with the pool are suspected. cleaned and refilled. samples should also be taken from public and semi-public facilities: • • • • before a pool is used for the first time. Hot tubs should be shut down. when health problems associated with the pool are suspected b c CHAPTER 5. Recommended routine sampling frequenciesa and operational guidelinesb for microbial testing during normal operation Pool type Disinfected pools.3. turbidity. pH. are outlined in Table 5. In addition to routine sampling. drained. Periodic testing for Legionella is useful.g. Staphylococcus aureus The routine monitoring of Staphylococcus aureus is not recommended. semi-public Natural spas Hot tubs a Heterotrophic plate count Weekly (<200/ml) Monthly (<200/ml) n/a n/a Thermotolerant coliform/E. Where this is exceeded. Sampling Guidelines on routine sampling frequencies. after it has been shut down for repairs or cleaning. Quarterly (<1/100 ml) Quarterly (<1/100 ml) Monthly (<1/100 ml) Monthly (<1/100 ml) Samples should be taken when the pool is heavily loaded Sampling frequency should be increased if operational parameters (e.thorough cleaning and disinfection programme initiated. in order to determine that filters are not being colonized.
5 mg/l hypochlorite solution). 5. Misleading information on pool water quality will result from incorrect sampling procedures. showers. Features such as water sprays should be periodically cleaned and flushed with disinfectant (e.11 Cleaning Good water and air quality cannot be maintained without an adequate cleaning programme. • total dissolved solids: Total dissolved solids (TDS) is the weight of soluble material in water. Public and semi-public hot tubs should be drained and the surfaces and pipework cleaned on a weekly basis. such as flumes. For microbial examination. dilution is likely to be the correct management action. not all are suitable. The higher the alkalinity. Many leisure pools will have additional features. it may be advisable to take samples from multiple sites. etching of surfaces and metal corrosion) and scaling water. 98 GUIDELINES FOR SAFE RECREATIONAL WATER ENVIRONMENTS .6 Other operational parameters Several parameters are important for operational purposes. and TDS levels should be monitored by comparison between pool and source water. and normal analytical 'resuscitation' procedures should be fully adhered to. Clearly. Depending on the size of the pool. weekly to monthly for those serving hot tubs).10. the testing laboratory must be advised before sampling if any other disinfectant is being used. Sodium thiosulfate (18–20 mg/l) is the agent used for chlorine. • calcium hardness: Calcium hardness is an operational measure that needs to be monitored to avoid damage to the pool fabric (e. These include: • alkalinity: Alkalinity is a measure of the alkaline salts dissolved in the water. the more resistant the water is to large changes in pH in response to changes in the dosage of disinfectant and pH correction chemicals. The real value of detecting an increase in TDS levels is as a warning of overloading or lack of dilution.g. Although a good-quality glass container will meet these requirements. representative samples should be taken.g.and bromine-based disinfectants. Bacteria in pool water samples and especially those from disinfected pools may be 'injured'. the risk of broken glass in the pool environment as a result of breakage has favoured the use of shatterproof plastic-coated glass containers. it can make pH adjustment difficult. 5. Disinfectants and other pool chemicals as well as bather pollution will increase TDS levels. All-plastic containers can be used provided they do not react with microorganisms or chemicals in the water. Heating. This should include the toilets. changing facilities and pool surroundings on at least a daily basis in public and semi-public pools. If TDS is high. Sample containers must be of a material that will not affect the quality of the sample either microbially or chemically. If the alkalinity is too high. the bottle must be sterile and contain an agent that neutralizes the disinfectant used in the pool water. ventilation and air-conditioning systems should be cleaned periodically (e. islands and backwaters with a complex system of water flow.g. away from any inlets.The most appropriate site for taking a single sample is where the water velocity is low.
] Gesundheits. 34: 167–172 (in German).mo. Rice RG (1995) Chemistries of ozone for municipal pool and spa water treatment.und Abwasser Forschung.health. ISO (1999) Water quality – Determination of turbidity. Weil (1981) [Formation and occurrence of organic halocarbons in swimming pool water. Hässelbarth U. water treatment plant and heating and ventilation systems – code of practice.12 References BSI (2003) Management of public swimming pools – water treatment systems. Geneva. International Organization for Standardization (ISO 7027:1999). Archiv des Badewesens. British Standards Institute. Eichelsdörfer D. Gansloser G. Journal of Environmental Health Research. Gregory R (2002) Bench-marking pool water treatment for coping with Cryptosporidium.B. III. Roeske W (1999) [Treatment of swimming pool and bathing water.und Umwelttechnik. Saunus C (1998) [Planning of swimming pools. Eichelsdörfer D. Note: Pool water treatment with ozone in long time contact. Jandik J (1979) [Ozone as oxidizer.] A. Jandik J.] A. 1(1): 25–44. Eichelsdörfer D (1987) [Investigations of anthropogenic load of swimming pool and bathing water. Jandik J (1984) [Investigation and development of swimming pool water treatment. 17: 148–153 (in German). Journal of the Swimming Pool and Spa Industry.state. Archiv des Badewesens.us/RecreationalWater/Pool SpaChem. 3: 18–19 (in German). Locher A (1996) [Non-chlorine treatment of pool water. MDHSS (undated) Swimming pool and spa water chemistry.] Düsseldorf. Beuth Verlag (in German). 1(1): 11–18.B. 37: 257–261 (in German). Section for Environmental Health (http://www. Missouri Department of Health and Senior Services.5.] Zeitschrift für Wasser.] A. Krammer Verlag (in German). Publicly Available Specification (PAS) 39: 2003.] Berlin.B. Eichelsdörfer D. MANAGING WATER AND AIR QUALITY 99 . 40: 259–263 (in German).pdf ). Archiv des Badewesens. CHAPTER 5.
2). negative health effects may also arise as described in previous chapters.1 summarizes examples of good practice in design. It is necessary to address these issues and implement effective management options in order to minimize the adverse health consequences through implementation of the Guidelines. However. Successful implementation of the Guidelines will require development of suitable capacities and expertise and the elaboration of a coherent policy and legislative framework.4). Many decisions taken at the design and construction stage will have repercussions on the ease with which safe operation can be ensured once the pool is in use. R This chapter is arranged according to these categories. less formal guidelines may be established by these authorities or by professional or trade associations. specification or construction of swimming pools and similar environments in relation to the major health issues discussed in previous chapters. Table 6.2 examines specific risks in various pool types in relation to design and construction issues. should be aware of the requirements to ensure safe and enjoyable use of facilities. Competent and experienced persons may be members of professional associations or may be subject to licensing schemes in order to practise (see Section 6. Local and national authorities may set specific requirements that must be met in the design and construction of swimming pools and similar recreational water facilities (see also Section 6. with the main stakeholders indicated for each category.1 Design and construction People responsible for commissioning pools and similar environments. There may be a process of approval for design and during construction – for example. 100 GUIDELINES FOR SAFE RECREATIONAL WATER ENVIRONMENTS . and regulatory requirements (including compliance). Alternatively. through building regulations. while Table 6. The typical areas of responsibility may be grouped into four major categories. along with designers and contractors. although there may be overlap between these and stakeholders with responsibilities falling within more than one category: • • • • design and construction. public education and information.4. 6. Different stakeholders play different roles in the management of the recreational water environment for safety.CHAPTER 6 Guideline implementation ecreational water activities can bring health benefits to users. operation and management. including exercise and relaxation.
include small. by dye tests). Provide easy-access toilets and showers. with drains sufficiently separated to prevent trapping. marked by contrasting colour. Temporary fixtures create no hazard when removed (e. Steps. especially in shallow (e. Design pre-swim showers so bathers have to shower before entrance to the pool area. Non-slip surround surfaces. Plain pool bottom assists recognition of bodies. Area bordering pool clear of tripping hazards (e. Changes in depth identified by use of colour-contrasted materials. drains. Clear indication of depth in locally comprehensible manner at frequent intervals. All areas of pool visible from lifeguarding posts. Pump shut-off permanently accessible to lifeguards or public (if no permanent lifeguard).Table 6. Strategic placement of footbaths. Steps/ladders for easy access in and out of pool. disinfection systems that use less chlorine – e. Avoid unauthorized access. Pool surround sloped to drain effectively. Ensure air flow across water surface (forced or natural ventilation) and adequate fresh air exchange.g.g. separate pools for children to facilitate draining in response to accidental faecal releases.g. Adequate artificial light. Side and end walls vertical for a minimum of 1 m.g. Provide easy access to toilets and showers.2 m high with self-closing. For public and semi-public pools (where possible). starting blocks). treads. Examples of good practice in design and construction: major health-related issues Objectivea Prevention of entrapment injuries (2) Typical actions/requirements of good practice Specify minimum two suction drains per pump system. Prevention of diving accidents (2) Enable adequate lifeguarding (2) Prevention of slip/trip/fall accidents (2) Minimize unintentional immersion and enable self-recovery (especially for non-swimmers) (2) Minimize and control faecal and non-faecal microbial contamination (3) Minimize exposure to volatile chemicals (4) Minimize formation of disinfection by-products by control of precursor input (5) a Relevant chapter references are identified in parentheses CHAPTER 6. GUIDELINE IMPLEMENTATION 101 . UV or ozone plus chlorine).g. Pool and surround free of sharp edges or projections. etc.g. On commissioning or after equipment change or modification to pipes. Design pool treatment system to reduce DBP formation (e.. confirm circulation pattern and absence of 'dead spots' (e. isolation fencing (enclosing the pool only) at least 1. etc. Provision of adequate treatment capacity. self-latching gate is recommended for pools where children could obtain unsupervised access. pipes and equipment). Edge of pool surround in contrasting colour (unless gentle slope from surface).5 m depth) waters. water pretreatment if necessary. Avoid abrupt changes in depth. Glare does not impede underwater visibility. Properly installed outlets and drain grates to prevent suction entrapment. <1.1.
to discourage excessive use and allow disinfectant levels to 'recover' Temperature too hot a Domestic pools (including temporary and portable pools) Hot tubs Pre-set maximum temperature <40 °C Relevant chapter references are identified in parentheses 102 . when the pool is closed or unsupervised) Algal growth (5) Principal requirement/action No sudden underwater depth changes or steps Refer to WHO Guide to Ship Sanitation (in preparation) Exclusion of unsupervised children through fencing. walls with childproof gates/doors Best controlled by good hydraulic design Provision of pre-swim showers and footbaths Contamination by mud and grass on users' feet (5) Contamination by animal faeces.Water quality best controlled by ment increases the risk of illness (3) ensuring appropriate treatment capacity. animal Exclusion of animals urine and wind-blown matter (3 and 5) Edge drainage draining away from the pool Ensuring adequate treatment capacity and good circulation and hydraulic design Semi-public pools Lack of adequate water quality manage.g.2. Facility designed to residual disinfectant level (3 and 4) enable 'rest periods' to be programmed. when the hot tub is unsupervised) on domestic and outdoor hot tubs Difficulty in maintaining an appropriate Provide identifiable seats to prevent overcrowding.e.Table 6. the inclusion of automatic monitoring and chemical dosing systems and good circulation and hydraulic design Unauthorized access to children (2) Provision of isolation fencing with (i. when the pool is unsupervised) child-proof gates Unauthorized access to children (2) Provision of lockable safety covers (i.e. Health risks and design and construction issues associated with various pool types Pool type or use (refer to Chapter 1) Special risk factorsa Natural spa waters Inability of users to see changes of (coloured or turbid) depth (2) Inability of lifeguards to see bodies under surface (2) Flow-through seawater Polluted water in harbour areas Injuries during ship movement in heavy swimming pools on cruise ships and ferries seas Open-air pools Unauthorized access to children (2) (e.
2. action to be taken on hearing the alarm. which consists of a description of the system. Table 6. including special supervision requirements for equipment. arrangements for communicating safety messages to customers. Detailed work instructions. fire alarms. including the safe use of pool covers. including lines of supervision. Conditions of hire to. including operation. 5. 9.. 2003 CHAPTER 6. first aiders. 11. maintenance arrangements. Details of the pool(s). 6. features and equipment and a plan of the whole facility. work rotation and maximum poolside working times. BOX 6. guidance may be available with regards to the most suitable materials to use for construction to minimize problems with corrosion. normal operating procedures. an emergency evacuation procedure and a generic emergency plan (for things not covered under the specified incidents). 3. this should include dimensions and depths. including pool cleaning procedures.4. or use by.4 examines specific risks in relation to good operation and management by pool type. Good operation is vital to minimize possible negative health impacts. In addition. its monitoring and maintenance.Equipment specified or purchased should meet prevailing standards (see Section 6. ensuring maximum bather numbers are not exceeded.2). arrangements for checking it. a description of the main hazards and user groups particularly at risk is required before safe operating procedures can be identified. 8. details of the operational and critical limits and actions to be taken if water quality is not satisfactory. The plan should include positions of pool alarms. 4. including how often. call-out procedures. Table 6. GUIDELINE IMPLEMENTATION 103 . outside organizations.2.1. all alarm systems and emergency equipment provided. First-aid supplies and training. 6. a set of procedures for specified incidents.2).2. Adapted from Sport England & Health and Safety Commission. Lifeguard's duties and responsibilities (see Section 6. 7. Dealing with the public.1 Pool safety plan The facility operator should have a pool safety plan. Water quality monitoring. 10. 12. Systems of work. customer care and poolside rules. lifeguard training and numbers of lifeguards for particular activities. Details of alarm systems and any emergency equipment. Examples of what should be included within the normal operating procedure are outlined in Box 6. including equipment required. emergency exit routes and any other relevant information.2 Operation and management Facility operators play a key role and are responsible for the good operation and management of the recreational water environment. Controlling access to a pool or pools intended to be out of use. Response to an accidental faecal release (or this may be covered under an incident plan). testing arrangements and maintenance. safe setting up and checking of equipment and setting up the pool for galas. Potential risk. first-aid training and disposal of sharp objects. etc.1 EXAMPLES OF NORMAL OPERATING PROCEDURES 1. how and where samples are to be taken. its location.3 summarizes examples of good practice in operation and management to deal with the hazards identified in previous chapters. location. 6.
• Total drain-down and cleaning of children's pools. Declared process for dealing with adverse trends and unacceptable values. High boards with non-slip surfaces and side rails. Accident response Written emergency evacuation procedure and generic emergency plan. Good practice in operation and management: major health-related issues Typical actions/requirements of good practice Provision of properly trained and equipped lifeguards.b Forbidding consumption or sale of alcohol at recreational facility. Filtration performance periodically monitored and action taken if outside operational requirements. Stated water quality and facilities monitoring programme implemented and recorded by trained staff. Maintenance of toilets. capability (2) Rescue and resuscitation equipment available to lifeguards.Table 6.3). For example: releases (3 and 5) • Evacuation of pool immediately after accidental faecal releases. increased supervision. socially acceptable state. and suitable exchange with fresh air. Communication links to local emergency and first-aid facilities readily available. Objectivea Prevention of drowning incidents (2) Maintenance of air quality (5) a Chapter b references are given in parentheses Signage is also an education issue and is covered in more detail in Section 6. Declared procedure for dealing with emergencies. Natural spas and hot tubs operated at temperatures below 40 °C. slip/trip/fall Minimize presence of moveable objects (i. six full turnovers of filtration cycle during which disinfectant concentrations to be elevated and maintained at maximum normal operating concentration. Maintenance of water quality and clean ancillary facilities (3 and 5) Encouraging users to shower before using the facilities (e. Previous identification of source of expertise/reference in case of problems.3.3.g. Where possible (larger pools).1 104 GUIDELINES FOR SAFE RECREATIONAL WATER ENVIRONMENTS . Prevention of Regular cleaning programme for all surfaces subject to algal or bacterial growth. Water turbidity monitored and action plan in place to deal with trends or deviations from acceptable range. • Pool maintained out of use for a specified period. Ensuring unauthorized access is prevented. Monitoring. Manage DBP formation by encouraging users to shower before using the facilities. Starting blocks and diving boards inaccessible to untrained persons. showers and changing rooms in clean. all staff trained accidental faecal and familiar. especially across the pool surface. Ensuring adequate ventilation. Prevention of Signageb against diving into shallower water. Prevention of enChecking that drain covers are in place and undamaged. Availability of critical parameter water-testing equipment. trapment injuries (2) Emergency shut-off is clearly marked. Control after Declared procedure for dealing with accidental faecal releases. active lifeguard supervision and diving injuries (2) intervention supported by management. Respect bathing load limits. Installation and maintenance of appropriate water safety signage. First-aid equipment readily available. designated areas for non-swimmers and children. through the use of posters and educational material – see also Section 6.e. all staff trained and familiar. objects that could be transported accidents (2) near to pool edge and constitute a trip hazard).
keeping a close watch over the pool and its users. In terms of water quality monitoring. and informing other lifeguards and facility staff when more help or equipment is needed. • preventing injuries by minimizing or eliminating hazardous situations.2. public health bodies. aqua-aerobics classes. Situations that are not covered by either the normal operating procedure or the incident plans are likely to be unanticipated emergency situations such as structural failure and should be dealt with according to an emergency evacuation procedure. 6. When operational limits are exceeded.5 outlines education requirements and responses to identified risks by pool type.2) or how to manage an accidental faecal release (if this is not covered under the normal operating procedure – see Section 5. • identifying emergencies quickly and responding effectively. through monitoring and appropriate management actions.2 Lifeguards The primary responsibilities of the lifeguard include the following (Sport England & Health and Safety Commission. exercising appropriate control and enforcing all facility rules and regulations. including warning bathers of the risks of their specific behaviours. local authorities. which may include closing the facility.8).10).3 Public education and information Facility operators.The normal operating procedures cover day-to-day management and aim to prevent problems such as poor air and water quality or overcrowding from arising. These secondary responsibilities include informing patrons about rules and regulations. • anticipating problems and preventing accidents. In addition to normal operating procedures. including effecting a rescue from the water. for a number of parameters there will be both operational and critical limits (see Section 5. more urgent action is required. A detailed example of the duties and requirements of a lifeguard and determination of lifeguard staffing levels are outlined in Appendix 1. pool-based clubs (such as swimming clubs. and • communicating with the pool users and colleagues. action should be taken to bring levels back in line with guidelines or standards. and undertaking maintenance or other tasks as assigned. GUIDELINE IMPLEMENTATION 105 . completing required records and reports on schedule and submitting them to the proper person or office. administering first aid or CPR. scuba clubs and so on) and sports bodies can play an important role in ensuring pool safety through public education and providing appropriate and targeted information to pool users. 2003): • supervising the pool area. The pool safety plan should be fully documented and the results of monitoring and any incidents recorded. intervening to prevent unsafe behaviours. Table 6. helping patrons locate a missing person. 6. CHAPTER 6. When a critical limit is exceeded. it is also necessary to have a series of incident plans that cover less routine matters. Secondary responsibilities should not interfere with the primary responsibilities of lifeguard personnel. such as an accident to a water slide user (see Box 6.
for example. impaired to alcohol judgement (2) 106 GUIDELINES FOR SAFE RECREATIONAL WATER ENVIRONMENTS . More intensive supervision.4. Contamination by mud and grass on Encouragement of the use of pre-swim showers and footbaths. Health risks and operation and management actions associated with various pool types Pool type or use (refer to Chapter 1) Special risk factorsa Natural spa and thermal waters High water temperatures (2) Microbial water quality if water is untreatable (problems may be encountered with filtration and/or disinfection) (3) Principal requirement/action Limit temperatures to below 40 °C. unsupervised) Exposure to UV radiation degrades residual disin fectant (5) Algal growth (5) Close monitoring of residual disinfectant or use of stabilizer (e. Cleaning. Avoid overcrowding Pre-warning of change in water conditions. inhibition of visibility (2) Maintenance of fencing. Special water quality management regime typically requires.g. Monitoring for faecal indicators required. etc. Removal of litter to discourage presence of animals. Flow-through seawater swimming pools on cruise ships and ferries Open-air pools Risk of contamination from sewage discharge in source water Injuries during ship movement in high seas Refer to WHO Guide to Ship Sanitation (in preparation) Flumes.Increased inappropriate behaviour. Public and semi-pub. Ensuring effective disinfection and good hydraulic design. Regular drain-down and a high rate of dilution to waste. animal urine and wind-blown matter (3 and 5) Banning of pets.g. Increased accident hazards. Contamination by animal faeces. Physical exclusion of access at unsupervised times. then proprietary algicides for swimming pool application may be used. Recommendations that facilities are not used while under the influence of alcohol. wave machines. physical cleaning of surfaces above and below water. Cleaning and users' feet (5) maintenance around the pool area. Drain-down obligatory after accidental faecal release. chlorinated isocyanurates) to lessen degradation. lic pools with access reduced ability to cope. Ensuring effective disinfection and filtration as well as good water circulation. Supervision required. walls with Unauthorized access to children (2) (e. when the pool is closed or child-proof gates/doors. If problems persist.Table 6.
a Relevant chapter references are identified in parentheses BOX 6. For example. loud whistle blast. Once you have given the signal. Legionella-specific management (see Section 3.4. If it is necessary to enter the water to make a rescue. you might use a compact jump from a head wall.child-proof gates. • Once the situation is under control. make sure the rescuing lifeguard's observation zone is covered. This report form should have a diagram of the pool or activity on the back so that the location of the incident can be marked for future study.g. Communication between the top and bottom positions is vital. if able. Hot tubs Unauthorized access to children (2) Securing of safety covers on domestic (e.Table 6. and users are allowed to participate in the activity again if there are enough guards to cover it. when the pool is unsuper.2 EXAMPLE INCIDENT PLAN FOR LIFEGUARDS MONITORING A WAVE POOL OR WATER SLIDE When you spot a user who needs help. wash and refill Deterioration in water quality (3) after an accidental faecal release. when the hot tub is unsuper. and portable pools) vised) Monitor water quality. • If you are not the lifeguard making the rescue. If it isn't necessary to enter the water. CHAPTER 6.1).and outdoor tubs. If you are on duty at the top of an attraction. At a wave pool.4. hit the emergency stop button to be sure the waves are turned off. Difficulties in maintaining disinfec. Implementation of 'rest periods' durtant residual (5) ing use to allow disinfectant levels to 'recover'. Drain pool (if small). do not dispatch any more riders.g. Lifeguards return to duty. use the entry most appropriate for the location you are lifeguarding. use the appropriate equipment to help the victim. members of the safety team can react to the situation. (continued) Pool type or use (refer to Chapter 1) Special risk factorsa Principal requirement/action Maintenance of isolation fencing with Domestic pools Unauthorized access to children (including temporary (2) (e. vised) Aerosolization (3) Limit temperature to below 40 °C. the lifeguard who made the rescue completes and files an incident report as soon as time permits. • Stop the waves or slide dispatch. GUIDELINE IMPLEMENTATION 107 . follow this procedure: • By immediately blowing one long. you notify your safety team that there is an incident. • Determine which method of rescue is needed.Increased disinfectant monitoring. • All equipment used in the rescue must be checked to ensure it remains in good condition and is returned to the appropriate location.
Signs can be used to inform people of hazards and safe behaviours and also reinforce previous educational messages. should be simple to understand and display a clear message.2). These should provide concise information and a single message (as distinct from notices and posters. in particular.Incident plan flowchart Lifeguard Recognizes Emergency and Acts Other Lifeguards Provide Backup and Coverage Contacts Victim and Moves to Safety Assesses Victim's Condition Victim is OK Complete Report Equipment Checked and Replaced Any Corrective Action Taken Return to Duty Victim Needs Care Other Lifeguard Assists First Aid Provided Emergency Medical Services Notified by Team Member Pool Cleared by Backup Lifeguard. Warning signs. and the International Organization for 108 GUIDELINES FOR SAFE RECREATIONAL WATER ENVIRONMENTS . 1995 6. if Necessary Staff Discussion Supervisor Notified Witnesses Interviewed Report Completed Equipment Checked and Replaced Any Corrective Action Taken Return to Duty Staff Discussion Adapted from American Red Cross. which are covered under Section 6.3. Many national organizations have adopted descriptive standards for warning and information signs.3.1 Signage Information can be conveyed by means of prominently and appropriately located signs.
However. 1984.g.g. Signs alone may have a limited impact on behaviour (Hill. no running. pictographs and labelling. such as pool depth markings.3. unsurprisingly. the health risk (e. 1988). danger). public health bodies (including health care providers).g. Goldhaber & de Turck. when not to use a pool or similar environment and how to identify possible hazards. no glass. reduced ability to cope. as. Extra attention may be required when designing signs applicable to tourist groups with different languages and cultures. Schools. signs are best deployed to reinforce previous awareness raising and education. impact of alcohol Education of children and parents/caregivers on the drowning hazard posed by pools and hot tubs Education for high-risk users (such as young. Signage can convey the need for awareness (e. Signage also includes pool labels and markings. the hazard (e.2 Education Education can encourage pool. impaired judgement (2) Unauthorized access to children (2) Aerosolization (3) Difficulties in maintaining residual disinfectant (5) Overheating (2) a Management action Education for high-risk users on infection risk Education of children and parents/caregivers on the drowning hazard posed by pools Education on the importance of pre-swim hygiene Information regarding peer supervision and safe behaviours. elderly.g.g. no alcohol). shallow water). facility operators CHAPTER 6. no diving. Therefore. pregnant women and immunocompromised) on infection risk and importance of avoiding excessive use Alcohol warnings Relevant chapter references are identified in parentheses Standardization (ISO) has adopted a standard for safety signs (not specifically swimming pool related) to try to avoid a proliferation of symbols that could cause confusion rather than send a clear message (ISO. some signs have been ineffective when such explanatory and precautionary information was in a language not understood by the pool users. 2003).5. paralysis may occur) or the prohibition (e. studies have shown that the public accept and recognize warning placards. Education to reduce health risks from special risk factors Pool type or use (refer to Chapter 1) Natural spa waters Open-air pools Special risk factorsa Microbial water quality if water is untreatable (3) Unauthorized access to children (2) (e.Table 6. GUIDELINE IMPLEMENTATION 109 . 6. when pool is unsupervised or closed) Water and air quality (5) Public and semi-public pools with access to alcohol Domestic pools (including temporary and portable pools) Hot tubs Increased inappropriate behaviour. hot tub and natural spa users to adopt safer behaviours that benefit both themselves and other users and should encompass issues such as preswim hygiene.
Follow advice provided for the safety of yourself and others. This will reduce the amount of germs. Regulation may control.3 EXAMPLE CODE FOR POOL USERS Spot the dangers. An attempt at education may also be made by handing safety leaflets to users at the pool entrance or to those in charge of organized group activities and displaying posters in reception and changing room areas (Sport England & Health and Safety Commission. steep slopes into deeper water. for instance. Look out for yourself and other swimmers. Be especially careful if you have a medical condition such as epilepsy. Keep an eye open for others. or shouting or screaming (which could distract attention from an emergency).4 Regulatory requirements National legislation may include different sets of regulations that will apply to swimming pools and similar recreational environments.3. especially those patients with diarrhoea and parents of children who are not toilet trained.and user groups can all provide information. water slides. diabetes or a heart problem.g. Box 6. Castor & Beach (2004). Always swim within your ability. particularly younger children and non-swimmers. Always do as the lifeguards say. BOX 6. running on the side of the pool. keep calm and do exactly as you are told. their operation and management (see 110 GUIDELINES FOR SAFE RECREATIONAL WATER ENVIRONMENTS . form part of a membership pack. and remember that a moment of foolish behaviour could cost a life. where membership to a facility is required. Avoid unruly behaviour that can be dangerous. In an emergency. wave machines. for example. on showering before swimming or that immunocompromised patients should take extra precautions or not swim in areas with a higher probability of being contaminated. scuba lessons. This would include messages on not swimming when you are suffering from diarrhoea.3 provides a code for pool users. suggest that health care providers can help to disseminate healthy swimming messages to their patients. swimming pools can be hazardous. 2003). Shower before you swim. Do not swim if you have a gastrointestinal (stomach) upset or skin or respiratory infection. ducking. asthma. Lifeguards can also act as information providers. etc.). Learn how to help. 2003 6. etc. Take care. and injuries can occur from hitting the hard surrounds or from misuse of the equipment. Bather safety may be improved if possible hazards are clearly identified at the facility (see Section 6. acrobatics in the water. This means that the water quality of the pool will be better. It is safer to swim with a companion. Water presents a risk of drowning. for example. Adapted from Sport England & Health and Safety Commission. so always make sure you know how deep the water is and check for other hazards. or patients who are particularly susceptible to certain diseases or conditions. call for help immediately. Every pool is different. sweat and chemicals (such as cosmetics) that you transfer to the water. Avoid holding your breath and swimming long distances under water.1). although this role should not interfere with their supervisory role. water aerobics. which could be displayed in public areas or. If you see somebody in difficulty.1) and users educated before they enter the pool environment. You are likely to pass on the germs that are making you ill. Never swim under the influence of alcohol. Educational information can also be added to agreements or contracts with groups that use pools for special purposes (e. such as diving boards. the design and construction of pools (see Section 6.
including amenities. The purpose of regulatory involvement is to ensure that pools and similar environments are operated as safely as possible in order that the largest CHAPTER 6. Once approved. the typical requirements. filters.1 Regulations and compliance The extent to which swimming pools and similar environments are regulated varies greatly. regulatory involvement should be welcomed and not seen as a burden on pool management.e. GUIDELINE IMPLEMENTATION 111 . as well as the general public. incident plans and an emergency plan. and their operation and maintenance may be less adequate than those at public pools per se. designed to ensure protection of pool employees (occupational health is not covered by these Guidelines. Local regulatory oversight can support the work of pool management and provide greater public health protection and public confidence.2).). in terms of a normal operating procedure. based on specific regulations and/or advisory codes of practice. Another aspect of pool management that may necessitate regulatory involvement is occupational health and safety legislation. chemical dosing system. and information regarding the individual circulation system components (pumps. In others. Inspections by the regulatory officials to verify compliance with the regulations are an important component of this oversight. Most regulations apply to public pools. as a means of comparing the health and safety records of different facilities. possibly. These may be quite detailed and specific in their requirements. In all cases. In terms of the operation and management of pools and similar environments. the construction of the facility may commence.2) and substances hazardous to health (e. prior to issuance of the final permit for operation. etc. sampling and testing regimes. for example.Section 6. covering water treatment processes. this may be useful in terms of public education material and. These plans generally include complete details and layout of the facility. if the regulator also provides comparable information from other venues. lifeguards. Within regulations it is likely that there will be a requirement for the use of certified material. design and construction engineers). 6. However. The preparation and use of such procedures ensure that the hazards specific to that facility have been evaluated and management actions determined. The design and construction plans are then reviewed and approved by a competent person. Regulations should provide for authority to close the facility if serious hazards and breaches to regulations or a significant risk to public health is identified. Local authorities may. In some countries. have already been outlined (Section 6. Periodic audits may be required to ensure continued compliance. public versus semi-public versus domestic). It may be a regulatory requirement that the results of hygiene and safety monitoring be made available to the public. with reopening prohibited until the problem has been rectified and measures are in place to prevent recurrence. These may be subject to periodic or informal supervision.4.g. and they may be applied differently according to the type of pool (i.g. chemicals). but limited evidence suggests that the greatest burden of disease and physical injury arises from domestic and semi-public pools. equipment and. a physical inspection of the final facility and a review of the pool safety plan or daily operations management are usually required. a level of regulatory oversight is provided. staff registered to certain bodies (e. a permit or licence to operate is required by the local municipal authority. require that the initial plans for the construction of a new pool be submitted by a licensed engineer. see Chapter 1).
process equipment (chlorine/bromine generators. Certification that the equipment or the entire pool is in compliance with the guidelines or regulatory requirements is helpful for all involved parties. three-way. UV disinfection systems and copper/silver ion generators). 112 GUIDELINES FOR SAFE RECREATIONAL WATER ENVIRONMENTS . As a result. heaters. sanitation and/or safety considerations includes the following: piping system. in that the purchaser has the assurance that the product installed is identical to the product evaluated for the certification. flow-through). Equipment that may be certified for performance. • Fourth party – Certification by governmental agencies. In some instances. These follow-up services often include audits of the production location. chemical disinfectants. Private entities also offer testing and certification services that monitor the continued compliance of the product. valves (multiport. As a result. pumps. regional and national regulatory agencies. regional or national governmental agencies will require that products be evaluated by the agency or a designated representative organization for compliance with regulations for installation. etc. all equipment components installed in the facility should meet minimum performance. Since a trade association represents and is often controlled by manufacturers. ongoing testing and complaint investigation. • Second party – Certification by a trade association or private party. second-party certifications are not considered to be completely independent. Third-party certifications provide for an independent evaluation of the product coupled with follow-up services that help ensure that products continue to comply with all requirements. these are outlined in Box 6. BOX 6. These follow-up services typically include audits of the production location. butterfly. Typically.4.). surface skimmers. continued compliance is often left up to the manufacturer. 6. In addition. There are four basic methods of certification in use. ozone generators. it is often difficult to determine whether a product selected for use is identical to the unit that was originally evaluated for certification. • Third party – Certification by an independent organization without direct ties to the manufacturing sector.g.possible population gets the maximum possible benefit. automated chemical monitor/controllers. no follow-up services to monitor continued compliance are provided.4 BASIC METHODS OF CERTIFICATION • First party – Self-certification of the product's compliance against a standard by the manufacturer. design. lifeguards) and personnel involved in the design and construction (for example) may be required to be registered with certain approved bodies. In many instances. not to close facilities or hinder their proper operation. no follow-up monitoring services are provided by the agency. use and operation. ongoing testing of representative products and complaint investigation. Typically. filters. and electrical equipment (safety). trade associations or private companies provide testing and certification services for products against industry standards or regulations. chemical feeding devices (mechanical. This provides for a more balanced assessment of the product and helps ensure that the product will be accepted by local. local. suction fittings and drain covers. Third-party certifiers also maintain close working relationships with the regulatory and user communities. Concerns are often raised with manufacturers' self-certification because of the potential bias of the manufacturer and the lack of ongoing monitoring to ensure that the product continues to comply.2 Registration and certification schemes Certain staff members (e. sanitation and safety requirements. The follow-up service aspect of third-party certification is an advantage.4.
Castor Ml. 28–33. it is necessary that these Guidelines inform and be adapted to suit national systems. diarrhea and the emergence of a new public health concern. Suffolk. GUIDELINE IMPLEMENTATION 113 . in preparation.4) • Health & safety • Construction • Use of Professional bodies Audit and review specified/certified materials • Building • Control of dangerous substances Training & self-regulation Operation & management(6. 3rd ed.2) Public education & information (6. Sport England & Health and Safety Commission (2003) Managing health and safety in swimming pools. UK. CHAPTER 6. de Turck MA (1988) Effectiveness of warning signs: 'familiarity effects'.5 Conclusions In order to ensure an effective overall system that will result in the safe and healthy use of swimming pools and similar recreational environments. Hill V (1984) History of diving accidents. Geneva. ISO Bulletin. 1: 281–301. Swimming.6. New South Wales. 23(9): 866–870.1 outlines how the Guidelines and the four categories of responsibility outlined within this chapter fit together. HSE Books (HSG Series No. Department of Sport and Recreation. October: 17–21. DC. Beach MJ (2004) Reducing illness transmission from disinfected recreational water venues. In: Proceedings of the New South Wales Symposium on Water Safety.3) Healthy pools and healthy users Figure 6. ISO (2003) Graphical symbols in safety signs: creating safety signs that everyone comprehends in the same way. Linkages between categories of responsibility 6. World Health Organization. Pediatric Infectious Disease Journal. Forensic Reports.1. 179). Goldhaber GM.1) Regulatory requirements (6. Sudbury. Figure 6. Design & construction (6. Washington. pp. Sydney.6 References American Red Cross (1995) Lifeguarding today. WHO (2005) Guide to ship sanitation.
• trained and have successfully completed a course of training in the techniques and practices of supervision. There are a multitude of courses offered for the training and certification of lifeguards. seating and other areas of potential hazard. Box A.2 gives an example of a lifeguard staffing approach. • a strong. there should be documentation on the roles and responsibilities of the groups' lifeguards: the hazards and the potential negative health outcomes associated with those hazards are no less when supervision and management are undertaken by volunteers. Box A. working day.3 provides examples of some important elements of lifeguard training.1 EXAMPLES OF REQUIREMENTS OF THE LIFEGUARD AND THEIR DEPLOYMENT The lifeguard will normally need to be: • physically fit. the term 'lifeguard' has been used throughout this appendix. • surveillance zones – observation and scanning requirements.APPENDIX 1 Lifeguards T his appendix relates to people who are trained and positioned at swimming pools to protect water users and who may be paid or voluntary. while Box A. Adapted from Sport England & Health and Safety Commission. Box A. be mentally alert and self-disciplined. able and confident swimmer. BOX A.1 outlines an example of requirements of a lifeguard. programmed breaks. size and usage. They may be referred to as lifesavers or lifeguards or given some other title. 2003 Should the pool be used by groups with their own lifeguards. rescue and first aid in accordance with a syllabus approved by a recognized training organization. 114 GUIDELINES FOR SAFE RECREATIONAL WATER ENVIRONMENTS .4 provides an example of an international pool lifeguard certificate. toilets. For simplicity. • supervision of changing facilities – showers. The deployment of lifeguards would normally take the following into consideration: • duty spells and structuring of duties – maximum uninterrupted supervision period. Furthermore. it is important that the criteria that apply to the professional pool lifeguard be equally applied to the groups' lifeguards. • lifeguard numbers – dependent on the pool type. have good vision and hearing.
Based on such rules.5 25. there should be adequate means of summoning assistance rapidly.0 × 12.1. have created general rules for how quickly they believe a lifeguard should be expected to observe a person in distress within their supervision area and how quickly the lifeguard should be able to reach that person. 2003).0 25. appropriate staffing levels can be derived. Lifeguard numbers per square metre of pool Approximate pool size (m) 20.0 × 10. Some lifeguard training organizations. The 'water area' column can be used as a guide for irregular-shaped pools.3 × 12.0 × 20. Where only one lifeguard is on duty.1 (Sport England & Health and Safety Commission.5 25.BOX A. training and evaluation.2 EXAMPLE OF A LIFEGUARD STAFFING APPROACH In the United Kingdom.3 EXAMPLES OF IMPORTANT ELEMENTS OF LIFEGUARD TRAINING Public interactions • Responding to inquiries • Handling suggestions and concerns • Addressing uncooperative patrons • Dealing with violence • Working with diverse cultures • Accommodating patrons with disabilities Responsibilities to facility operations Preventing aquatic injury Patron surveillance Facility surveillance Emergency preparation Rescue skills • General procedures • Entries • Approaching the victim • Victims at or near the surface • Submerged victims • Multiple victim rescue • Removal from the water • Providing emergency care APPENDIX 1. BOX A. lifeguard numbers may be determined as shown in Table A.0 Notes: 1.5 33. LIFEGUARDS 115 . Area (m2) 170 212 250 312 416 1000 Minimum number of lifeguards (normal) 1 1 1 2 2 4 Minimum number of lifeguards (busy) 2 2 2 2 3 6 The number of lifeguards required for safety can also be calculated based on sweep time and response time. 2. for example.5 50. Table A.0 × 8.0 × 8.
including: − Expired Air Resuscitation (adult. 3.5 m) − lift the dummy/person and tow minimum of 25 m to the edge of pool − lift the dummy/person out of the pool. the candidate must be able to: LEARNING OUTCOME 1: Perform water-based fitness skills in a pool environment. Airways.1 Perform basic patient management techniques. Assessment Criteria: 4. Reaction. Assessment Criteria: 3. 1995 BOX A. Assessment Criteria: 1. child. slide entry). LEARNING OUTCOME 3: Demonstrate the use of land-based rescue simulation skills.3 Retrieve three objects placed 5 m apart in water approximately 2 m deep. Breathing and Circulation (DRABC) − lateral position & patient rollover − calling for help 4. LEARNING OUTCOME 4: Perform emergency response techniques including resuscitation and first-aid techniques.4 INTERNATIONAL POOL LIFEGUARD CERTIFICATE OF THE INTERNATIONAL LIFE SAVING FEDERATION For successful recognition for the International Pool Lifeguard Certificate. or in the deepest end of a pool where the depth is less than 2 m.First aid for injuries First aid for sudden illnesses Spinal injury management • Anatomy and function of the spine • Recognizing spinal injury • Caring for spinal injury • Caring for a victim in deep water • Spinal injury on land After an emergency – responsibilities Adapted from American Red Cross.1 Swim 50 m in less than 50 s with the head above the water.2 Perform simulated rescue using a throwing aid to a conscious victim in the water over a minimum distance of 10 m. − 25 m freestyle with head above the water − surface dive to adult dummy/person (minimum depth of 1.1 Consecutively perform combined rescue technique in the following sequence in less than 2 min: − lifesaving entry (stride jump. 1.2 Swim 400 m in less than 8 min without using equipment. infant) 116 GUIDELINES FOR SAFE RECREATIONAL WATER ENVIRONMENTS . LEARNING OUTCOME 2: Demonstrate combined rescue without equipment. then. 1.1 Lift conscious patient and transport them over a minimum distance of 25 m using a recognized patient transport technique. Assessment Criteria: 2. including: − diagnosis/check for Dangers.2 Perform resuscitation techniques.
6. video review) Oral questioning Written examination (short answer. LEARNING OUTCOME 7: Identify and describe issues related to the facility/workplace.4 Practise emergency management plan. 2001 APPENDIX 1.− Cardiopulmonary Resuscitation – CPR (adult. multiple choice) Simulated rescue scenario Range of Variables: There are a number of variables that will affect the performance and assessment of the learning outcomes.g. 6. fractures.4 Identify and list medical services available for support in an emergency medical situation. including depth. 5. Candidates may be required to wear their recognized uniform. Assessment Criteria: 7. 7.1 Describe the application of appropriate emergency treatments in a rescue situation including CPR and spinal management.and two-person CPR operation − set up and apply oxygen equipment 4. • Dress • Candidates • Resources Adapted from International Life Saving Federation. 5.2 List the nearest available safety services. 6. Identification of equipment that is available for use. 5. LIFEGUARDS 117 . LEARNING OUTCOME 6: Choose and plan strategies to manage basic emergencies.3 Find and use potential resources for use in rescue. etc. shock. infant) − one.3 Identify and perform first-aid techniques for managing injury and emergency.2 Describe the use of medical equipment in emergency situations.1 Identify and select possible strategies for water rescues and emergencies. Assessment Strategy: These learning outcomes are best assessed using the following common assessment methods: Observation (personal.3 Design a basic emergency management plan.3 Identify regulations pertinent to managing emergency medical situations. Assessment Criteria: 5. use of hot tubs. arterial and venal bleeding.2 Identify and solve potential problems for putting plans into place. child. including: − patient management − identifying and managing injuries (e. These may include: Variable • Facilities Scope Swimming pool lengths/depths and measurements (metric/imperial). 7. spinal injury) LEARNING OUTCOME 5: Describe medical knowledge about a range of conditions associated with rescues.5 Review and modify basic emergency management plan.1 List the specifications of the pool. Candidates will have experience and will be seeking employment or currently employed as a lifeguard. access. Use of alternative aquatic locations where pools are not available. International Life Saving Federation member organizations will list and identify the use of theoretical and practical resources available to them. Assessment Criteria: 6. 6.
Sport England & Health and Safety Commission (2003) Managing health and safety in swimming pools. Approved by ILS Board of Directors. International Life Saving Federation (2001) International Pool Lifeguard Certificate. Suffolk. Washington. 3rd ed. HSE Books (HSG Series No. Sudbury. UK.References American Red Cross (1995) Lifeguarding today. September 2001. DC. 118 GUIDELINES FOR SAFE RECREATIONAL WATER ENVIRONMENTS . 179).
water quality. good design and construction. and good operation and management. ISBN 92 4 154680 8 . contamination of associated facilities and air quality. special interest groups. and activities available for their control through education of users. and facility users. The preparation of this volume has covered a period of over a decade and has involved the participation of numerous institutions and more than 60 experts from 20 countries worldwide. This volume will be useful to a variety of different stakeholders with interests in ensuring the safety of pools and similar environments. their monitoring and assessment. public health professionals. operators and designers (public. including hazards leading to drowning and injury. scientists and researchers. semi-public and domestic facilities). This is the first international point of reference to provide comprehensive guidance for managing swimming pools and similar facilities so that health benefits are maximized while negative public health impacts are minimized. The Guidelines include both specific guideline values and good practices. including national and local authorities. facility owners.Guidelines for Safe Recreational Water Environments Volume 2: Swimming Pools and Similar Environments provides an authoritative referenced review and assessment of the health hazards associated with recreational waters of this type. They address a wide range of types of hazard.
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