Water Quality, Microbial Contamination, and Health Hazards associated with

Recreational Use of Freshwaters and Beaches

Colin I. Mayfield

Professor of Biology, University of Waterloo and Assistant Director, United Nations University -

International Network for Water, Environment and Health

Recreational waters refer to those natural waters used not only for primary contact activities, such as swimming, windsurfing, and waterskiing, but also for secondary contact activities, such as boating and fishing.

Recreational use is defined as any activity involving the intentional immersion (e.g., swimming) or incidental immersion (e.g., waterskiing) of the body, including the head, in natural waters.

Natural water is defined as any marine, estuarine or fresh body of water, as well as any artificially constructed flow-through impoundment using untreated natural waters.

The total global health impact of human infectious diseases associated with pathogenic micro-organisms from land-based wastewater pollution of coastal areas has been estimated at about three million disability-adjusted life years (DALYs) per year, with an estimated economic loss of around 12 billion dollars per year (Shuval 2003).

Researchers in the United States have estimated that the health burden of swimming-related illnesses at two popular beaches in California, USA exceeds US $3.3 million per year.

The annual costs for each type of swimming-related illness at the two beaches were estimated to be: gastrointestinal illnesses, US $1,345,339; acute respiratory disease, US $951,378; ear complaints, US $767,221; eye complaints, US $304,335 (Dwight et al. 2005).

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Economic Costs

Issues

• Microbial contamination• Sources of contamination• Measurement of contamination • Patterns of contamination of freshwater• Beach contamination• Health Effects• Populations at higher risk• Future risks (emerging pathogens)• Developments in analytical technologies and

control measures• Summary

Microbial Contamination

The Great Lakes Water Quality Agreement states that:

“recreational waters should be substantially free from bacteria, fungus and viruses that may produce enteric disorders or ear eye, nose, throat and skin infections or other human diseases and disorders”

The primary tool used at present to evaluate water quality is the measurement of indicator organisms that estimate the level of faecal contamination of the water

The primary organisms used are faecal coliforms, Escherichia coli and enterococci.

They are considered indicative of faecal contamination and possible presence of intestinal-disease-causing organisms

Microbial Contamination

Standards vary, but Ontario closes beaches when E. coli levels reach 100 organisms per 100 mL

Other jurisdictions use 200 per 100 mL of faecal coliforms as the criterion.

Is there evidence that increased levels of these indicators leads to increases in infection?

95th percentile of IE/100 mL

10%

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2

1

0%

Risk of contracting Gastroenteritis and Respiratory illness (Acute Febrile Respiratory Illness) at different Intestinal Enterococci levels

0 50 100 150 200 250 300 350 400 450 500

AFRI

GI

European Union Directive 2002/0254

The ratio of Escherichia coli to Enterococci found in those studies to reflect equal risk was between 2 and 3

The European Union therefore developed the following standards for“bathing waters”:

Parameter Excellent Quality Good Quality

Intestinal enterococciIn cfu/100 mL 100 200

Escherichia coli incfu/100 mL 250 500

Monitoring frequency was made flexible to allow for waters with few contamination occurrences

Potential Pathogens in Fresh water

Campylobacter jejuni — one of the most common causes of bacterialgastroenteritis and chronic sequelae. The pathogen has been isolated fromrecreational waters on many occasions. However, few cases of illness have beenreported through this route. Campylobacter jejuni is more likely to be found inrecreational waters contaminated by animal and human waste.

E. coli O157 — although most outbreaks of E. coli O157 have beenassociated with food, a number of outbreaks have been reported fromrecreational use of waters, particularly in pools that were not adequatelychlorinated. Haemolytic uraemic syndrome with possible long-term sequelae isevident although no follow-up studies appear to have been conducted in peoplewho contracted the infection from recreational water use. The acute diseasetends to be moderately severe and of moderate duration.

Helicobacter pylori — water has been implicated as one mode oftransmission of H. pylori although the detection of the pathogen has proveddifficult. Therefore, it is possible that H. pylori infection is waterbome, but theseassumptions need to be substantiated. Current evidence for its association withrecreational waters is slight.

Legionella spp. — there are a number of reports of Legionnaires’ diseaseassociated with the use of, and proximity to, hot tubs in particular. The illness isconsidered to be severe with a high risk of death and severe acute symptoms.There are a number of documented cases of persons suffering sequelae as aconsequence of infection with Legionella spp.

Mycobacterium avium complex — there is clear evidence for theassociation of Mycobacterium avium complex with recreational waters. Thespecies of Mycobacterium that are associated with water are associated with avariety of diseases. Some, such as M. ulverans are pathogenic in previouslyhealthy individuals, others, such as M. avium, usually cause disease incompromised individuals. The majority of cases associated with recreationalwaters appear to be attributed to swimming pools and hot tubs resulting in skinand soft tissue infections in immunocompetent patients. However,hypersensitivity pneumonitis is also seen in immunocompetent persons withaerosol exposure to mycobacteria.

Salmonella spp.

Shigella spp. — epidemiological evidence exists for the association ofrecreational use of water and self-limiting infection with shigella bacteria. Thespecies responsible for the more severe illness, S. dysenteriae, is more commonin tropical regions but no cases associated with recreational waters were foundin the literature. However, it is biologically plausible that S. dysenteriae couldbe encountered in freshwaters used for recreation.

Vibrio vulnificus — this bacteria commonly occurs in marine andestuarine environments. Evidence exists for the association of recreational useof water and infection with V. vulnificus where the user has a pre-existing openwound. Surveillance of V. vulnificus infections is poor and the number of casesreported is likely to be underestimated.

Cryptosporidium — faecal accidents are implicated in most of the cases asthe cause of the outbreaks of cryptosporidiosis, which have primarily occurredin swimming pools, although some cases have been documented from waterslides, fountains and water parks. Cryptosporidium oocysts show resistance tochlorination. The risk of death and probability of developing long-term sequelaefrom this infection is low, however the acute illness can be prolonged andmoderately severe especially in immunocompromised persons.

Giardia — recreational use of water is a proven risk factor for giardiasis.The majority of symptomatic patients of Giardia will clear their infection afterone to several weeks although immunocompromised patients may not recoverfrom giardiasis. The risk of death and the probability of developing sequelaefrom this infection is low, however the acute illness can be prolonged andmoderately severe.

Microsporidia — although microsporidia are currently not commoncauses of recreational waterborne disease, their role as emerging pathogens isbeing increasingly recognised. Their small size makes them difficult to removeby conventional water filtration techniques and it is thought that, likeCryptosporidium they may show increased resistance to chlorine disinfection.Illness is generally reported in immunocompromised individuals although someinfections in immunocompetent individuals have been reported.

Naegeria fowleri has been shown to colonise warm freshwater habitats,such as swimming pools and natural hot springs and there is a high risk of deathin infected persons. The acute illness is severe with symptoms lasting more thanseven days and death always occurs. Although the infection is rare, new casesare reported every year.

Schistosoma spp. — in some cases serious pathology associated withinfection by Schistosoma spp. occurs and can lead to long-term health issues.Schistosoma is only a potential hazard in certain geographic areas (e.g., sub-Saharan Africa). Surveillance for schistosomiasis is currently poor, inferringthat many more cases associated with recreational waters occur but are notpublished. Evidence shows that exposure to schistosomes is difficult to avoidbut it has been shown that towel-drying after exposure to infested water canmarkedly reduce the risk of infection

Adenovirus — the diseases resulting from infection with adenovirusinclude conjunctivitis, pharyngitis, pneumonia, acute and chronic appendicitis,bronchiolitis, acute respiratory disease, and gastroenteritis. Adenovirusinfections are generally mild; however, there are a number of fatal cases ofinfection reported in the literature. Transmission of adenovirus in recreationalwaters, primarily inadequately chlorinated swimming pools, has beendocumented via faecally-contaminated water and through droplets, although nofatal cases attributable to recreational waters have been documented in theliterature.

Coxsackievirus — although there have been very few outbreaks ofcoxsackievirus linked to recreational water recorded, and epidemiologicalevidence remains scarce the virus has been frequently isolated from marine andfreshwaters. As with other viruses (hepatitis A virus (HAV), adenovirus andechovirus) transmission of the virus is possible and biologically plausible insusceptible persons. Coxsackievirus is responsible for a broad range of illnessfrom mild febrile illness to myocarditis and other more serious diseases.

Echovirus — as with the other enteroviruses discussed in this review,there are few published cases of infection by echovirus in recreational water,those that are recorded are primarily from swimming pool water. The mostlikely source of the virus is through faecal contamination, although secretionsfrom the eyes or throat are possible. There are likely to be many unreportedcases of infection with echovirus.

Hepatitis A virus — has been isolated from surface waters which may beused for recreational purposes and a number of cases of HAV have beendocumented associated with recreational water users. Fulminant hepatitis is rareand has not been reported in any cases linked with the use of recreationalwaters. No cases of sequelae of HAV contracted through the use of recreationalwaters were found in the literature and the probability of developing long-termsequelae is low. The acute disease is usually moderately severe and of moderateduration but risk of death is low.

Hepatitis E virus (HEV) — has been isolated from surface waters whichmay be used for recreational purposes. Fulminant hepatitis is rare. No cases ofsequelae of HEV contracted through the use of recreational waters were foundin the literature and the probability of developing long-term sequelae is low. Theacute disease is usually moderately severe and of moderate duration but risk ofdeath is low except where cases occur during pregnancy.

Sources of Contamination

Many sources contribute to microbiological contamination, including:

combined or sanitary sewer overflows (CSOs and SSOs), unsewered residential and commercial areas, and failing private, household and commercial septic systems.

Other sources may be:

agricultural runoff (such as manure fecal coliforms from animal/pet fecal waste washed from soil

by heavy rains, either from the beach or washed into residential storm sewers

wildlife waste, as from large populations of gulls or geese fouling the beach

direct human contact, such as swimmers with illnesses, cuts or sores; or high numbers of swimmers/bathers in the water, which are related to increased bacterial levels

direct discharges, for example from holding tanks of recreational vessels.

Other factors affecting contamination levels are:

low (shallow) water levels hot weather and higher temperatures high winds that can cause increased wave action that can

transport bacteria from contaminated, non-recreational areas to recreational-use areas

high winds that can stir up bacteria that are in the sediments

calmer waters that can slow dispersal and create excess concentrations of bacteria.

Other Sources

Beach sand and mats of algae floating along shorelines both harbour E. coli for long periods.

E. coli can even survive over winter in beach sand.

Bacteria sheltered in sand or algae can repopulate shoreline water with such high concentrations that beaches are closed even when there are no obvious new sources. Such sources would include sewer overflows or heavy rains that either flush contaminants out of storm sewers or wash bird droppings off nearby parking lots.

Whitman (USGS).

Other Sources

As Lake Michigan's water level has receded to near-record low levels in the last year, beaches have become wider and attracted more waterfowl, particularly gulls. Gull feces is loaded with E. coli. "You would need 1,000 geese to match the E. coli burden from a single gull," (Sandra McLellan, an assistant scientist at the Great Lakes WATER Institute in Milwaukee)

As beach areas increase, there are higher average concentrations of E. coli. At one site, North Point Marina, the beach increased in size by 255% between 1997 and 2000 while average E. coli concentrations rose 391%.

Mark Pfister, an aquatic biologist with the Lake County Health Department in Waukegan, Ill consistently found the highest concentrations of E. coli at Waukegan South Beach where there were no storm or sanitary sewers discharging close to it, but it did have the greatest number of gulls among beaches in the county.

Sandra McLellan, an assistant scientist at the Great Lakes WATER Institute in Milwaukee, agreed that researchers "must cut to the chase" and answer the question of whether there are pathogens present when E. coli concentrations rise above federal guidelines for recreational water.In the meantime, however, McLellan is pursuing one possible surrogate - testing for caffeine in water. The chemical would come only from sewage, and its presence would confirm human waste in the water.McLellan's study of water quality at Milwaukee beaches has found that E. coli contamination abruptly stops about 10 meters off shore."The whole lake is OK," she told those attending Thursday's conference. "We are seeing local contamination problems at beaches."Julie Kinzelman, a microbiologist with the City of Racine Health Department, said that the U.S. Environmental Protection Agency was searching for other indicators of recreational water quality.For now, health officials need "to err on the side of caution" and use the E. coli test, she said."We also need to be able to identify whether E. coli is coming from a human or non-human source," Kinzelman said.McLellan's laboratory at the University of Wisconsin-Milwaukee should help municipalities do just that. She is looking for antibiotic resistance in E. coli, a trait that would only be found in bacteria from humans. In addition, she is identifying the genetic makeup of E. coli from humans, gulls, cattle and dogs.Distinct genetic "fingerprints," or sequences of DNA, will help researchers recognize the source species.

The Risk Management Approach to Ensuring Safe Recreational Bathing WatersThe most effective way to ensure that our waters remain safe for use is to become aware of the types of hazards (microbiological, chemical and physical) that can impact a bathing area. Examples can range from industrial and sewage discharges, to overland runoff from heavy rainfall, to safety hazards such as underwater obstructions or currents.

Under the Risk Management approach to safe recreational water quality, a inspection of the bathing area is first used to identify all of the sources of risk to human health and safety. Then, appropriate procedures or management actions are introduced as barriers to reduce these risks.

This concept is similar to the Multiple Barrier Approach used in the management of safe drinking water supplies. Using this approach, compliance with the Guidelines becomes but one key piece of a larger picture of preventative risk management.

For example, if an inspection of the bathing area has determined that the water quality results are poor following rainstorms, one action might be to restrict bather access immediately following periods of heavy rainfall.

The majority of beach closings are due to indications of the presence of high levels of harmful microorganisms found in untreated or partially treated sewage. Most of this sewage enters the water from combined sewer overflows, sanitary sewer overflows, and malfunctioning sewage treatment plants. Untreated storm water runoff from cities and rural areas can be another significant source of beach water pollution. In some areas, boating wastes and malfunctioning septic systems can also be important local sources of beach water pollution.

Combined sewer systems are designed to carry both raw sewage and storm water runoff to sewage treatment plants. During heavy rainstorms, these systems can become hydraulically overloaded and discharge a mixture of raw sewage and polluted runoff from streets into local waterways. The discharges pollute water around the outfalls and at downstream beaches.

Heavy rainfall can also hydraulically overload separate sanitary sewer systems which carry raw sewage to sewage treatment plants.

This is especially a problem for systems with excess infiltration of rainfall through the ground into leaky sanitary sewers and with large inflows from sources such as roof drains connected directly to sewers.

When flows exceed the capacity of the system, sewers can overflow and discharge untreated sewage from manholes and bypasses at pump stations and sewage treatment plants.

The discharges flow into local waterways and pollute the water.

People who swim in water near storm drains can become ill. A recent Southern California epidemiological study, for example, revealed that individuals who swim in areas adjacent to flowing storm drains were 50 percent more likely to develop a variety of symptoms than those who swim further away from the same drain.

Swimmers who did not avoid the drains experienced an increased risk for a broad range of adverse health effects. These include fever, nausea, and gastroenteritis; flu-like symptoms -- such as nasal congestion, sore throat, fever, and/or coughing-- are also possible.

Storm drains can even be a source of problems during drier weather because broken pipes or connections to sanitary disposal systems may contribute pathogens to the storm drains

Models for Assessing Potential Water Contamination

Waterborne pathogens reaching recreational areas can originate from various sources located either within the proximity of the beach or at upstream locations within the drainage area or watershed. These sources can be grouped into three categories:

(1)nonpoint source-dominated systems, where pathogen contamination is governed by rainfall events;

(2) point source-dominated systems, where pathogen impact is due to either continuous or intermittent discharges; and

(3) episodic releases of untreated wastewater due to uncontrolled discharges and accidental spills.

Review of Potential Modeling Tools and Approaches to Support the BEACH Program (EPA)United States Environmental Protection Agency Office of Science and Technology, Standards and Applied

Science Division, 401 M Street, SW Washington, DC 20460

Model Categories

The overall objective of all beach advisory predictive tools is to reduce the risk of illness due to exposure to elevated levels of pathogens. The tools currently in use by responsible agencies vary in their complexity and approach to minimizing exposure.

Rainfall Analysis In the case of the City of Milwaukee, City of Stamford, and Delaware

Department of Natural Resources and Environmental Control (DNREC), the approach taken was regression analysis to relate rainfall to pathogen concentration. Models developed based on this approach are site-specific since they are derived from locally observed relationships between water quality and rainfall data.

Simulation of water quality conditions Models can be used under a variety of scenarios of untreated or partially

treated wastewater. Comparison of the resulting water quality conditions to the established action level, such as the water quality standard, can serve as the basis for the beach advisory or closure.

The use of water for recreational purposes poses a number of health risks which depend on factors such as the nature of the hazard, the characteristic of the water body and the immune status of the user.

Although evidence from outbreak reports and other epidemiological evidence have proven a link between adverse health effects and immersion in poor quality recreational water, the difficulties associated with attributing an infection to recreational water use are numerous and the majority of research in this field has focussed on infections associated with the use of recreational waters resulting in minor, self-limiting symptoms.

There are many unanswered questions regarding the severity and frequency of illness associated with recreational water use. It is plausible that more serious illnesses could result from the recreational use of water and this association has not yet been investigated to any great extent.

It is also increasingly apparent that a number of micro-organisms or their products are directly or indirectly associated with secondary health outcomes or sequelae and a number of these sequelae may result from waterborne infections.

• The acute diseases attributable to waterborne pathogens and their epidemiology have been well described, but the sequelae that can result from these diseases have not. Assessing potential sequelae of waterborne infections is a critical part of microbial risk assessment and the formulation of public policy.

• Even where illness is severe, it may still be difficult to attribute it to recreational water exposure due to the large number of other transmission routes of the pathogens in question. Nevertheless, evidence does exist to show that although much less frequent, more serious and potentially fatal disease is a risk to recreational users of water.

Consideration of whether an illness is severe or not is based on three factors:

• acute symptoms of the disease which are debilitating;• the ability and probability that the illness will lead to sequelae; and• the effect of the disease on certain susceptible subpopulations.

Each factor can be considered in its own right or in combination with one or both of the other factors. A simplified index of severity has been created and applied wherever possible to the illnesses considered, taking into account possible sequelae.

The outcome measures used to ascertain the relative severityare case-fatality rate, average duration of illness, median percentage of cases requiring hospitalisation, the frequency of development of sequelae and the severity of sequelae.

The index is limited by the availability of data and does not take into account the probability of infection following exposure. The index is designed to help public health professionals prioritize recreational water management decisions to reduce the potential for severe disease outcomes..

Diseases that are normally mild and self-limiting in the general population canhave severe manifestations in susceptible sub-populations with certainattributes.

A variety of host factors impact susceptibility to severe diseaseoutcomes. Human immune status can be affected by diseases (HIV, cancer),age, medications taken (e.g., chemotherapy treatment of cancer weakens theimmune system), pregnancy, nutritional status, genetics and other factors (Carr and Bartram 2004).

Host factors can influence both the severity of the acute symptoms and the propensity to develop sequelae (Reynolds 2003).

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The population of immuno-compromised individuals is growing (Soldatou and Davies 2003). This population is more susceptible to waterborne infections and tend to experience more severe outcomes (e.g., debilitating illness, death) following infection (Reynolds 2003).

• A number of studies have shown that enteric diseases are the most common and serious problems that affect persons with acquired immunodeficiency syndrome (AIDS). Between 50% and 90% of people with HIV/AIDS suffer from chronic diarrhoeal illness, and the effects can be fatal (Janoff and Smith 1988). People with reduced immune function due to cancer treatment have been shown to have a case-fatality rate for adenovirus infection of 53% (Hierholzer 1992).

Likewise, in the 1993 Cryptosporidium outbreak in Milwaukee, Wisconsin, USA, 85% of the deaths occurred in people with HIV/AIDS (Hoxie et al. 1997).

People with liver diseases are at particularly high risk of fatal septicaemia after ingestion of, or percutaneous exposure to, Vibrio vulnificus (Levine and Griffin 1993).

Table shows the case-fatality observed for enteric pathogens in nursinghome patients in the USA who are more susceptible to infection compared withthe general population.

There are many unanswered questions regarding the severity and frequency of illness associated with recreational water use.

The difficulties associated with attributing an infection to recreational water use are numerous and the majority of research in this field has focussed on infections associated with the use of recreational waters resulting in minor, self-limiting symptoms.

However, it is plausible that more serious illnesses could result from the recreational use of water and this association has not yet been investigated to any great extent.

It is also increasingly apparent that a number of micro-organisms or their products are directly or indirectly associated with secondary health outcomes or sequelae and a number of these sequelae may result from waterborne infections.

The acute diseases attributable to waterborne pathogens and their epidemiology have been well described, but the sequelae that can result from these diseases have not.

Assessing potential sequelae of waterborne infections is a critical part of microbial risk assessment and the formulation of public policy.

The guidelines deal with health hazards associated with recreational water use, as well as aesthetic and nuisance conditions. Health hazards associated with direct contact with water include infections transmitted by pathogenic microorganisms, as well as injuries and illness due to physical and chemical properties of the water.

The guidelines discuss the indicator organisms – enterococci, Escherichia coli, other fecal coliforms, and coliphages – as well as health risks related to exposure to waterborne pathogenic bacteria, viruses, protozoa, and toxic blue-green algae.

Sampling of recreational waters is also addressed.

Other sections deal with physical, chemical, and aesthetic characteristics, nuisance organisms, microbiological methods of sampling and analysis, and posting of beaches and other recreational waters.

Waters used for recreational purposes should be sufficiently free frommicrobiological, physical, and chemical hazards to ensure that there is negligible risk to the health and safety of the user. The determination of the risk of disease or harm from microbiological, physical, or chemical hazards is based on a number of factors, including the following:

Environmental health assessments

Epidemiological evidence

Indicator organism limits

Presence of pathogens.

The decision to post a warning to users of recreational areas or to close an area for public use should be made by the Medical Health Officer or other appropriate authority in accordance with the statutes existing in each province.

This decision will be based on an assessment of existing hazards usingavailable information on the factors listed above.

Environmental Health Assessments

An annual environmental health assessment should be carried out prior tothe bathing season on the watershed or the area from which water flows to a recreational area, as well as on the recreational area itself.

This survey should identify all potential sources of contamination and physical hazards that could affect the recreational area.

Attention should be paid to the following:

the risk of inadequately treated sewage, fecal matter, or chemical substances entering the water, from either a discharge or a spill

knowledge of all outfalls or drainage in the area that may contain sewage, including urban storm water and agricultural waste or runoff

an inspection of the area for physical hazards

an assessment of the seasonal variability of hazards, the density of bathers, the water temperature, the frequency of change or circulation of the water, changes in water depth, and the occurrence of algal blooms

the fluctuation of water quality with rainfall (wet and dry conditions)

a reporting mechanism to ensure that health authorities are informed of any malfunction or change to a municipal, private, or industrial waste treatment facility that might cause a deterioration of the water quality of

Epidemiological Evidence

The local health authorities responsible for making recommendations fora recreational area should, wherever possible, establish surveillance for bather illness or injuries.

This can be established by comprehensive epidemiological studies or by formal and informal reporting from physicians and hospital emergency departments. This surveillance will be increased if there have been reports of suspected illness or injuries. The water quality may be considered impaired and appropriate recommendations made as a result of this surveillance.

Procedures for the investigation of illness associated with recreationalwaters should adhere to the recommendations given in Procedures toInvestigate Waterborne Illness (International Association of Milk, Food and Environmental Sanitarians, Inc. 1979).

Presence of Pathogens

Tests for pathogenic organisms may be carried out when there have beenreports of illnesses of specific etiology, when there is suspected illness of undetermined cause, or when levels of an indicator organism demonstrate a continuous suspected hazard. The tests will help to determine the source of contamination (e.g., sewage pollution, agricultural or urban runoff, bather origin).

The local health authorities should take action when pathogenic organisms are identified in sufficient quantity or frequency to be considered a hazard.

Such pathogenic organisms may be Aeromonas spp., Pseudomonas aeruginosa, Staphylococcus aureus, Shigella spp., Salmonella spp., Campylobacter spp., Giardia spp., human viruses, and toxic phytoplankton.

An appropriate response should be based on the knowledge of the source of the organism and the probability of the hazard being temporary or continuous.

The best indicators of the presence of enteric pathogens in fecal pollution sources should have the following properties (National Academy of Sciences 1977; Cabelli et al. 1983; Elliot and Colwell 1985):

present in fecal-contaminated waters when enteric pathogens are present but in greater numbers

incapable of growth in the aquatic environment but capable of surviving longer than pathogens

equally or more resistant to disinfection than pathogens

easily and accurately enumerated

applicable to all types of natural recreational waters (e.g., fresh, estuarine, and marine)

absent from non-polluted waters and exclusively associated with animal and human fecal wastes

density of indicator should be directly correlated with the degree of fecal contamination

density of indicator should be quantitatively related to swimming associated illnesses.

Indicator Organism Limits

An indicator organism or organisms should be chosen by the local healthauthority in consultation with the laboratory microbiologists for each area.

It is recommended that one of the following indicator organisms be used for routine monitoring of recreational water quality – enterococci, Escherichia coli, or fecal coliforms.

Recreational waters may be contaminated by direct human contact and bywaterborne pollutants from external sources (e.g., sewage, storm water andagricultural runoff).

Many epidemiological studies have identified gastrointestinal and upper respiratory illnesses in bathers that were a result of such contamination.

The indicator organisms are surrogates for the presence of pathogenic organisms that may cause gastrointestinal illnesses.

Escherichia coli, enterococci, and, to a lesser degree, fecal coliforms arecurrently considered the best fecal indicators, because they most closely fit the above characteristics.

Escherichia coli and fecal coliforms

Maximum Limits

The geometric mean of at least 5 samples, taken during a period not toexceed 30 days, should not exceed 2000 E. coli/L.

Resampling should be performed when any sample exceeds 4000 E. coli/L.

The Working Group agreed that the tests to be used to fulfil these requirements are as follows:

1. When experience has shown that greater than 90 per cent of the fecalcoliforms are E. coli, either fecal coliform or E. coli may be determined.

2. When less than 90 per cent of the fecal coliforms are E. coli, only E. colimay be determined.

Summary

1. In fresh waters, E. coli is the best available indicator of fecal contaminationfrom warm-blooded animals.

2. Klebsiella is not a good indicator of fecal contamination, but it may bepresent at high levels in certain industrial wastes (e.g., pulp and papermills, food processing plants). It is not likely to cause infection or illnessin healthy individuals.

3. Where there is evidence that greater than 90 per cent of the fecal coliformsare E. coli, the E. coli and fecal coliform tests will be consideredequivalent.

4. The presence of E. coli is associated with bather-associated illness, butits absence cannot be equated with the lack of risk of illness.

Summary

5. Current microbiological-epidemiological studies are not sufficientlyvalidated to allow calculation of risk levels. However, there is someevidence for increased risk of illness from bathing compared with non-bathing(i.e., wading or remaining on the beach).

6. The 1983 guidelines were, in principle, based on the definitive fecalcoliform, E. coli. However, at that time, the more general fecal coliformtest was considered the method of choice. The Working Group reaffirmsthat E. coli is the indicator of choice and recognizes that either the E. colitest or the fecal coliform test may be used to enumerate this organism,depending on the circumstances.

The maximum acceptable concentration of 2000 E. coli (or fecal coliforms)/L can be calculated to correspond to a seasonal gastrointestinal illness of 1 to 2 per cent, based on the U.S. Environmental Protection Agency studies.

Marine Waters - Summary

1. In marine waters, the enterococci group is the best available indicator offecal contamination from warm-blooded animals.

2. Fecal coliforms do not survive well in marine waters and thus may not bereliable indicators of fecal contamination.

3. Enterococci survive longer than fecal coliforms in marine waters and thusare preferred when there is considerable time or distance between thesource of fecal pollution and the bathing area.

4. There is a positive correlation between gastrointestinal illness and levelsof enterococci in marine waters, but the absence of enterococci does notindicate a lack of risk.

5. Based on the U.S. Environmental Protection Agency epidemiologicalstudy, a seasonal geometric mean of 35 enterococci/100 mL correspondsto a seasonal gastrointestinal illness rate of 1 to 2 per cent. Because fecalcoliforms do not survive well in marine waters, the use of the fresh watermaximum limit may increase the risk of illness.

Coliphages – Summary

1. No limit on coliphages can be established at this time. Monitoring andepidemiological studies are required to determine the levels of coliphagesin water and the health effects associated with swimming in watercontaining coliphages.

Pseudomonas aeruginosa – Summary

1. Pseudomonas aeruginosa is typically isolated from fresh recreationalwaters in low numbers. The levels of P. aeruginosa in a bathing area areinfluenced by density of bathers, especially individuals that are infectedwith P. aeruginosa or are carriers.

2. Levels of P. aeruginosa are influenced by sewage or urban drainagesources.

3. Pseudomonas aeruginosa has been associated with the occurrence ofotitis externa in bathers.

4. One Ontario study has demonstrated that when levels of P. aeruginosaexceed 10/100 mL in at least 25 per cent of the seasonal samples, otitisexterna may be expected to occur.

Staphylococcus aureus – Summary

1. Staphylococcus aureus is known to be a major pathogen to man. It isresponsible for boils, ear infections, and other purulent infections.

2. There appears to be a relationship between bather numbers andstaphylococci levels in the water, but there does not appear to be asignificant relationship between bather illness and concentration ofS. aureus in the water.

3. For these reasons, no limit is being established for staphylococci at thistime. Monitoring and epidemiological studies for this pathogen arerecommended.

Salmonella – Summary

1. Salmonella organisms are pathogenic, and a health hazard exists if theseorganisms can be consistently isolated from a bathing area.

2. The methods for the isolation of Salmonella have not been standardized,and routine enumeration is not practical.

3. Salmonella can be considered as a support parameter to aid regulatoryagencies in determining the health risk involved in using waters forrecreation.

Other Pathogens

Shigella

Aeromonas

Campylobacter jejuni

Legionella

Viruses

Summary

1. Viruses are known to be pathogenic in low numbers. As few as oneinfective tissue culture unit can cause disease when ingested. Concentrationand enumeration steps are too detailed to make routine monitoringpractical.2. Very few data are available on current virus levels in recreational waters.3. There is no correlation between viral and bacterial counts in recreationalwaters

Pathogenic Protozoa

Summary

1. Routine monitoring of waters for protozoa is not recommended. However,provincial laboratories should be able to participate in the investigation ofdocumented waterborne outbreaks.

Toxic Phytoplankton

Summary

1. No limits are recommended for toxic phytoplankton, but swimming inwaters containing blue-green algal blooms should be avoided.2. Bather poisonings have occurred after immersion in lakes and pondscontaining dense blooms of blue-green algae.3. Sampling recreational waters for toxic phytoplankton should beconsidered only for epidemiological investigations.

WHO

Beach Pollution

Average E. coli levels from beach sand collected on wet and dry days during 2005 beach season

From: Identification and Quantification of Bacterial Pollution At Milwaukee County Beaches Great Lakes WATER Institute Technical Report. Sandra L. McLellan , Erika T. Jensen. Great Lakes WATER Institute.University

of Wisconsin-Milwaukee

Larry J. Wymer, Kristen P. Brenner, John W. Martinson, Walter R. StuttsStephen A. Schaub*, Alfred P. Dufour. U.S. Environmental Protection Agency Office of Research and Development, National Exposure Research Laboratory, Cincinnati, OH 45268

EMPACT Study – Highlighted -- Fresh water Beaches

Major findings on spatial variation are:

In every case, the zone from which the sample was collected was found to have the greatest predictable impact on microbial indicator densities of all factors investigated in this study, spatial or temporal. Bacterial densities become progressively lower as one moves from ankledeep to knee-deep to chest-deep water.

Two of the study beaches, Belle Isle and Miami Beach Park, exhibited some form of systematic spatial variation that was not adequately accounted for by zones alone. It may or may not be a coincidence that both of these beaches are associated with river systems.

Summary of Factors (correlates) of microbial indicators in recreational waters (from the EMPACT study)

Spatial Factors – lower levels in deeper waters (away from shore)

Temporal Factors – lower levels in the afternoon than the morning (often lower on sunny days than on overcast days)

Temporal factors – Faecal indicator levels varied significantly from day to day – only limited statistical relationship between sampling on one day and the next day’s samples

Environmental factors –

Substantial rainfall increased levels

Onshore winds increased levels

Bather density did not give consistent effects

Water Recreation and Disease - Plausibility of Associated Infections: Acute Effects, Sequelae and Mortality Kathy Pond Published on behalf of the World Health Organization by IWA Publishing, Alliance House, 12 Caxton Street, London SW1H 0QS, UK

Developments in analytical technologies and control measures

Current situation is that indicator organisms such as Escherichia coli only give an indirect estimate of presence of pathogens

Escherichia coli, faecal coliforms and enterococci survive for different times in recreational waters based on many environmental factors such as temperature, aeration, nutrient availability, etc.

Pathogens may survive for much longer periods and so absence of indicator organisms may provide a false negative result

Ideally, all pathogens that can cause disease should be detected in as short a time as possible to give accurate and timely evidence for beach closures or warnings to recreational water users

Pathogen numbers can vary over very short time periods (hours) in water

Developments in analytical technologies and control measures

Improvements in detection technologies for pathogens (or even for more rapid indicator organism detection) would lead to better and more accurate risk assessments.

Such technologies might include:

Rapid E. coli detection systems based on colour reactions or fluorogenic substrates coupled with microscopic detection of colonies on membrane filters

Quantitative Polymerase Chain Reaction (QPCR) to detect and amplify the DNA of organisms such as enterococci and Bacteroides species. This test typically takes 2 hours and can provide rapid, early assessment of contamination

Detection of compounds such as faecal sterols and caffeine that are thought to be only present in water as a consequence of faecal contamination – chemical detection methods are routine and very rapid.

Developments in analytical technologies and control measures

New technologies based on microchips containing DNA probes or specific antibodies to pathogens coupled with detection of changes in physical properties of the substrates when coupled to the pathogens. Such chips could, in theory, detect up to 100 pathogens on one chip and communicate results almost immediately. Work continues!

Improved descriptions and “libraries” of DNA specific to human pathogens in water so as to improve the discrimination of human pathogens from other animal sources

Improved modelling techniques (maybe on a site-specific basis) that predict contamination reliably and accurately based on weather, hydrological conditions, and contamination events (both non-point source and point source). These would need extensive calibration and verification.

Developments in analytical technologies and control measures

The “ideal” system would:

Detect all pathogens (bacteria, fungi, viruses and protozoa) that could be present in water in a very short time period (minutes to hours)

Communicate these results immediately to the responsible authority

Be reliable (no false negative results), reusable and very inexpensive

Developments in analytical technologies and control measures

No such technology exists today, but many laboratories and companies are working to develop such systems. Such efforts are usually under the umbrella of “nanotechnology”

But – to quote an old (apocryphal?) Chinese curse: May you get what you wish for !

What would be the impact (socially, legally, economically, etc) of having such accurate and immediate information?

Would every beach be closed permanently because of the detected presence of one pathogenic organism in the samples?

Would the public demand that many, large samples of water or sand be used to improve detection accuracy?

Monitoring of recreational waters for indicators of fecal contamination has been required for decades in the implementation of EPA Ambient Water Quality Criteria (AWQC) to protect swimmers against acute gastrointestinal illness (AGI). The AWQC criteria were established after epidemiology studies were conducted in the late 70s and early 80s which demonstrated a correlation of AGI illness rates to E coli and enterococci levels in the water. While these are good indicators water quality, they require a 24 hour analysis period after sampling to find out if the water quality is acceptable for swimming. Recent intensive EPA monitoring studies have demonstrated that typical water quality may change rapidly so the water quality often can not be ascertained on the day a person is swimming

Quantitative Polymerase Chain Reaction (QPCR) technology can circumvent the problems of having to wait for 24 hours or longer to determine if safe levels of indicator organisms occur on any given beach day. QPCR provides the capability to determine water quality within 2 hrs of the start of sample analysis. QPCR methodology is being studied by the EPA for its use in measuring enterococci in recreational waters as well as the correlation with levels of AGI from swimming exposure. Companion studies of this technology are being conducted to determine if Bacteroides fragilis may also qualify as a recreational water quality indicator. This fecal bacterium is present in high numbers in the human body and doesn't grow outside of it.

"We also need to be able to identify whether E. coli is coming from a human or non-human source," Kinzelman said.McLellan's laboratory at the University of Wisconsin-Milwaukee should help municipalities do just that. She is looking for antibiotic resistance in E. coli, a trait that would only be found in bacteria from humans. In addition, she is identifying the genetic makeup of E. coli from humans, gulls, cattle and dogs.Distinct genetic "fingerprints," or sequences of DNA, will help researchers recognize the source species

Environmental Health Perspectives Volume 114, Number 1, January 2006Rapidly Measured Indicators of Recreational Water Quality Are Predictive of Swimming-Associated Gastrointestinal Illness Timothy J. Wade,1 Rebecca L. Calderon,1 Elizabeth Sams,1 Michael Beach,2 Kristen P. Brenner,3 Ann H. Williams,1 and Alfred P. Dufour31National Health and Environmental Effects Research Laboratory, Human Studies Division, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina, USA; 2Parasitic Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, USA; 3National Exposure Research Laboratory, U.S. Environmental Protection Agency, Cincinnati, Ohio, USA Full Article in HTMLFull Article in PDFEHP-in-PressAbstract Standard methods to measure recreational water quality require at least 24 hr to obtain results, making it impossible to assess the quality of water within a single day. Methods to measure recreational water quality in ≤ 2 hr have been developed. Application of rapid methods could give considerably more accurate and timely assessments of recreational water quality. We conducted a prospective study of beachgoers at two Great Lakes beaches to examine the association between recreational water quality, obtained using rapid methods, and gastrointestinal (GI) illness after swimming. Beachgoers were asked about swimming and other beach activities and 10-12 days later were asked about the occurrence of GI symptoms. We tested water samples for Enterococcus and Bacteroides species using the quantitative polymerase chain reaction (PCR) method. We observed significant trends between increased GI illness and Enterococcus at the Lake Michigan beach and a positive trend for Enterococcus at the Lake Erie beach. The association remained significant for Enterococcus when the two beaches were combined. We observed a positive trend for Bacteroides at the Lake Erie beach, but no trend was observed at the Lake Michigan beach. Enterococcus samples collected at 0800 hr were predictive of GI illness that day. The association between Enterococcus and illness strengthened as time spent swimming in the water increased. This is the first study to show that water quality measured by rapid methods can predict swimming-associated health effects. Key words: bathing beaches, cohort studies, diarrhea, gastrointestinal diseases, Great Lakes Region, recreational water, swimming, water quality. Environ Health Perspect 114:24-28 (2006).