WQRA HealthStream - Issue 54

Issue 54 Public Health Newsletter of Water Quality Research Australia June 2009

In this Issue:

Recreational Access To Catchments 1

Brisbane Fluoride Overdose Incident 5

Stormwater Harvesting For Orange 6

Circulation Report 7

News Items 7

From The Literature 8

Web Bonus Articles

Cyanobacteria

Developing Nations

Disinfection Byproducts

Fluoride

Fungi

Household Interventions

Regulation

Risk Assessment

Uranium

Water Disinfection

Mailing List Details 20

Editor Martha Sinclair

Assistant Editor Pam Hayes WQRA Internet Address:

www.wqra.com.au A searchable Archive of Health Stream articles, literature summaries and news items is available via the WQRA Web page.

Recreational Access To Catchments The catchment is the first component in the drinking water supply system, and land use in surface water catchments is the primary influence on source water quality. For this reason, limitation or exclusion of human activities in water catchments has traditionally been the first potential barrier which can be applied to protect the quality of drinking water eventually delivered to the consumer. Protection of surface water catchments by complete exclusion of public access typically results in high quality source water which requires only disinfection before being supplied to consumers. Such protected catchments also provide valuable habitats for native plants and animals, preserving natural ecosystems and protecting biodiversity. Major cities and towns within Australia currently have differing degrees of public access to their water catchments. Some catchments are fully protected with all public access to the land and the water body prohibited, while for others access to most of the land in the catchment is allowed but there is an exclusion zone 2 to 3 kilometres in width around the reservoir. In some instances there is no catchment protection, with multiple land uses including housing and farming existing in the catchment as well as recreational access to the land and the water body. In recent years continuing urban expansion combined with increasing affluence and leisure time has seen mounting pressure to permit public recreational access to currently protected catchments. This pressure is particularly strong where these high quality natural environments are located close to the major population centres which they serve.

HEALTH STREAM JUNE 2009 PAGE 1

http://www.waterquality.crc.org.au/

WATER QUALITY RESEARCH AUSTRALIA

The Water Services Association of Australia has just released a new Occasional Paper on the effects of recreational access on water catchments (1). This comprehensive report is intended to inform the debate between those who favour increased development and recreational access and those who support preservation of ecological and water quality assets through catchment protection. The report reviews the published literature on different aspects of this topic including the impacts of public access on fire risk, soil and vegetation quality, the potential introduction of animal and plant pest species, the spread of animal and plant diseases, effects on aquatic ecosystems and water quality, and risks to human health. Fire Bushfires are a major risk to water catchments as they may have severe impacts on water quality and quantity in both the short and longer term. Depending on the rainfall patterns following a fire, water quality may be adversely impacted by sediment inflow as ash and exposed soil are washed into the water body. Levels of iron and manganese are often increased, and increased nutrient inflows may lead to cyanobacterial blooms. Regeneration of vegetation after bushfires can have a variable effect on water yield from catchments. Where high intensity fires kill most above-ground vegetation, water yields may increase for the first few years as the new growth uses less water than mature trees. However after 2 to 8 years, depending on the species of tree predominating in the burnt area, water use by vegetation increases rapidly and water yields decline. Full recovery to pre-fire levels of water yield may take from 20 to 200 years. Native plant and animal species in the Australian bush have evolved a number of mechanisms to survive bushfires, however the success of these adaptations is strongly influenced by the frequency, seasonal timing and intensity of fires. Fire patterns different from natural patterns are likely to have adverse effects on survival and biodiversity of many species, and weeds may more readily invade fire-affected areas. Climate modelling suggests that fire danger levels in southern Australia will continue to increase in coming decades. An analysis of the causes of over 25,000 unplanned fires in Australia during 2002/2003 showed that the

proportion caused by camping and cooking fires (9%) was similar to that caused by lightning strikes (10%), while arson and other deliberately lit fires were by far the largest source (35.6%). Data from the New South Wales Parks and Wildlife Service covering 30-years of bushfires indicated a higher risk from camping activities (24%) and a significantly increased risk of ignition on weekends which corresponds to the presence of high visitor numbers. Increasing public access to catchment areas is likely to lead to an increased frequency of bushfires in these areas through both accidental and deliberate ignition events. Soil Human access to natural areas for walking, bicycling, horse-riding and driving vehicles results in soil impacts through compaction and erosion along tracks and roads. Soil compaction results in a range of physical and biological changes to soil including reduced water infiltration. All types of access lead to loss of vegetation and erosion, and even in fully protected catchments the limited number of access roads and fire tracks are known to be the major source of sediment entering streams and reservoirs. Use of roads and tracks also causes loss of leaf litter and reduction of the soil humus layer. The erosion caused by human activities can be severe, depending on the type of activity, intensity of use, soil type, topography, and rainfall patterns. Steep, wet areas are particularly vulnerable to erosion. A number of studies have noted the tendency of affected areas to increase in size and number as official campsites and trails expand and encroach into the forest, and unauthorised campsites, walking trails and 4-wheel drive tracks proliferate. If access to the waters edge is permitted, this can directly affect riparian vegetation which is important in maintaining water quality, and result in bank erosion at access points. Flora Vegetation can be affected by direct physical damage from human activities and also by increases in soil compaction which reduce root penetration, seedling establishment and water infiltration. Loss of surface litter and the humic layer also affect nutrient availability and water retention, which in turn affect the survival of different plant species. The severity and duration of effects is highly variable and is dependent on the plant species present and the nature



and intensity of human activities. The factors affecting plant responses to disturbance can be described in terms of resistance (relative ability of individual plants to withstand disturbance before being damaged), resilience (relative capacity of individual plants to recover after disturbance) and tolerance (relative ability of a plant species to withstand a cycle of disturbance and recovery). These factors are determined by the morphology, anatomy and life cycle of the particular species. Over time, plant species which are more sensitive to disturbance will decline or disappear from affected areas and may be replaced by more tolerant species or by weeds. Campsites typically show a large percentage of vegetation loss, and additional impacts on surrounding areas from activities such as gathering of firewood. Horse riding has also been shown to have a significant impact on vegetation cover even at relatively low intensities, and in some studies has also been associated with the presence of fungal plant pathogens and weeds along riding trails. Fauna The effects of human activities on wildlife in former wilderness areas may occur through four mechanisms; exploitation (hunting, fishing, trapping of animals), disturbance (human presence causing interference with normal feeding, drinking or breeding activities, or causing animals to avoid the area), habitat modification (fire impacts, removal of logs and rocks, fragmentation of habitat areas by roads and tracks) and pollution (strangling and entrapment in packaging materials). For some animal species, road kills may have a significant effect on local populations. Pests Increased access to catchment areas will also increase the potential for accidental or deliberate introduction of pest species of animals or plants. Australia has a number of feral animal species that have in the past been deliberately released into the environment or have escaped from domestication. These animals (including rabbits, goats, cattle, buffalo, pigs, donkeys, camels, foxes, dogs, cats and cane toads) have caused significant adverse impacts on native animal species and habitats in many areas of the country. Although evidence is difficult to document, it is believed that deliberate release of feral pigs by hunters has occurred in a number of

locations around Australia, including Sydney’s drinking water catchments. Feral pigs are able to survive in a wide range of environments, but constitute a particular concern in terms of erosion around watercourses due to their habit of wallowing in mud and disturbing the ground when searching for food. Feral pigs also compete for food and habitat with native animals, and may also spread weed species and transmit a range of diseases. Introduced fish species have also caused considerable damage to native fish species in Australia, through competition for food, predation and alteration of habitats. In most cases, exotic fish species have been deliberately introduced for recreational or commercial fishing, however some species are believed to have become established following illegal release of imported aquarium fish. Establishment of several species of non-native aquatic snails has also been attributed to release of aquarium stock. At least one of these species has become a nuisance pest in some Australian water supplies due to growth in pipes and tanks. Plant species may be accidentally introduced to wilderness areas through carriage of seeds and plant fragments on vehicles and boats. Fertile seeds may also be present in horse manure and become dispersed along riding trails. It is estimated that about 15% of plant species in Australia are non-native and about half of the introduced species can invade native vegetation. Many species of aquatic weeds can grow from small plant fragments which are easily carried by boats and fishing gear, and these species are very difficult to control once established in water bodies. Growth of such weeds can have severe ecological impacts and adverse effects on water quality leading to subsequent difficulties in drinking water treatment. Recreational access to drinking water reservoirs for fishing and boating poses a significant risk of aquatic weed introduction. Animal Diseases The potential impact of public access to catchment areas on disease rates in native animals, or on risks of disease transmission from catchment animals to humans is not well understood. Deliberate dumping of pets or stock has the potential to introduce diseases which were formerly absent in the area. Poor hygienic practices (such as failure to



bury human faeces when toilet facilities are not available) could result in introduction of human pathogens to animal populations. Conversely, contact with catchment animals and their faeces may expose humans to pathogens not otherwise encountered. Plant Diseases The most significant plant disease in Australia is Phytophthora cinnamomi, a water mould commonly known as “dieback disease”, which is believed to have been introduced to this country in 1921. This pathogen affects a wide range of plant species, but mainly attacks woody trees and shrubs. The disease is easily spread through spores in infected soil or plant material. Spread of P. cinnamomi can occur through construction work, logging, changes in drainage and via off-road vehicles and equipment. It can be carried on muddy footwear and tyres, and by animals such as horses and feral pigs. Strict access controls are considered critical to controlling spread of this pathogen. Aquatic Ecosystem And Water Quality Human activities in catchments can impact on streams and reservoirs through changes in a number of water quality parameters including suspended sediment, nutrients, metals and natural organic matter. Nutrients such as nitrogen and phosphorus are often attached to fine-grained sediments, and increased erosion can result in increased nutrient levels and eutrophication of water bodies. Phosphate from detergents used at campsite may also find its way into nearby water courses. Eutrophication can lead to a drop in oxygen levels and release of iron and manganese from sediment. These metals can subsequently cause “dirty water” problems in drinking water supplies. Eutrophication also increases the risk of cyanobacterial blooms. Use of power boats brings consequent pollution problems from fuel and oil spills, leading to adverse effects on aquatic ecosystems. Power boats can also directly damage water plants, disturb sediment and contribute to bank erosion problems. Research from New Zealand has shown boats to be a major vector for spread of aquatic weeds from one water body to another. Powerboats also impact on water bird activity and populations. The likely impacts of fishing on freshwater aquatic ecosystems and water quality are not well understood. Overfishing of

marine waters has been well documented but there are few studies on freshwater systems. Even where catch and release policies are implemented to conserve fish stocks, there is evidence that a significant percentage of released fish do not survive. Use of live bait by anglers is a possible route of introduction of exotic species into pristine water bodies. Many of the impacts caused by human activity may contribute to transition of shallow lakes from a clear-water vegetated state to a turbid-water unvegetated state. Such a change is highly undesirable from ecological, aesthetic, amenity and drinking water perspectives. Human Health The major concern associated with public access to drinking water catchments is the potential for contamination of source waters with pathogenic microorganisms. Although animals may carry bacteria or protozoa which are infectious to humans, it is recognised that human faecal material constitutes a greater risk of disease due to the additional presence of large range of pathogenic viruses. Primary contact recreation (swimming and other activities associated with full body immersion) can result in water contamination due to accidental or deliberate defecation, and residual faecal traces on the body surface. Improper disposal of human faeces in recreational areas is a well documented problem, and can also contribute to water contamination. There are many literature reports of disease outbreaks among swimmers due to such contamination incidents, however it is difficult to demonstrate direct linkage between recreational use of drinking water reservoirs and illness in populations who eventually consume the water. While extensive dilution of microbial contaminants might be expected from consideration of reservoir volumes, the phenomenon of short-circuiting may mean that contaminated water will sometimes reach off-take points relatively quickly and with little mixing. It is acknowledged that routine disease surveillance mechanisms are relatively insensitive, and some outbreaks of enteric disease (whether from drinking water or other sources) may pass unnoticed by health authorities. Quantitative Microbial Risk Assessment has been used to estimate disease risks for source water with recreational access, with some studies indicating that primary contact recreation may result in unacceptable



risks to drinking water consumers even when the water receives full conventional drinking water treatment before distribution. As noted above, human activities in catchment areas may increase the likelihood of cyanobacterial blooms. Such blooms can generate adverse tastes and odours in drinking water and require increased treatment times and costs. Some blooms also produce toxins, and if these cannot be adequately removed by available water treatment methods, it may be necessary to stop using the water source until the bloom has dispersed. Blooms may also make the water unsuitable for recreational use due to the presence of toxins and irritant effects. Increased levels of organic matter in source waters may also lead to generation of higher levels of disinfection byproducts when water is treated. The report concludes that there are many incompatibilities between permitting recreational access to catchments and the protection of existing natural ecosystem and source water harvesting environments. The literature covers many diverse aspects of this issue, but most studies are qualitative and locally focussed rather than quantitative and broad. For this reason it is not possible to make exact predictions about the impact of recreational activities. Nevertheless, there are a number of studies which demonstrate the vulnerability and uniqueness of ecosystems in major water supply catchments in Australia. Many of the identified impacts are cumulative, and recovery times (if the impact is reversible) may be prolonged. Where public access is permitted, effective management is needed and strict limits may be required to protect the quality of the recreational experience being sought, as well as ecological and water resource values. Given the increased risk levels associated with reduction in catchment protection, increases in water treatment capability would be needed to maintain finished water quality and provide adequate protection of public health. Krogh M, Davison A, Miller R, O’Connor N, Ferguson, C, McClaughlin V and Deere D. (2008). Effects of Recreational Activities on Source Water Protection Areas - Literature Review. Occasional Paper 22. Water Services Association of Australia, Melbourne, Australia. Available from: www.wsaa.asn.au

Brisbane Fluoride Overdose Incident Residents of Brisbane have been alarmed by a fluoride overdosing incident at one of the two water treatment plants serving the city of one million people. The incident is reported to have occurred on April 30th after the North Pine treatment plant had been shut down for three days of scheduled maintenance work. Due to a malfunction in control systems, the fluoride dosing equipment failed to turn off immediately, resulting in production of a ‘surge’ of highly fluoridated water for a period of about three hours when the plant was turned on again. It was initially reported that the water, containing up to 30 mg of fluoride per litre instead of the usual dose of 1 mg per litre, had been supplied to about 4000 homes in the northern suburbs of Brisbane, however further investigation showed that most of the affected water had been used within the treatment plant for backwashing filters, and little had passed into the distribution system. It is now believed a small amount of the highly fluoridated water was supplied to a YMCA campsite where about 200 school children may have been exposed, four houses located at the treatment plant, and possibly to around 400 homes in one Brisbane suburb. The maximum dose estimated to have reached taps was 19.4 mg per litre, with the duration of elevated fluoride levels being about one hour. The incident, which occurred only a few months after water fluoridation was introduced to Brisbane, has seriously embarrassed the water supplier SEQWater and the Queensland Government. Historically, Queensland has had the lowest coverage of water fluoridation of any Australian state, with the city of Townsville being the only large population centre previously receiving fluoridated water. However, in late 2007 the state government announced a 5-year program to introduce fluoridation to most water supplies in the state, with the aim of improving dental health. The prevalence of tooth decay in Queensland children aged 5-12 years is double that of children living in the Australian Capital Territory, which has 100% access to fluoridated water. The fluoridation program has been met with vigorous opposition from anti-fluoridation lobby groups.



The embarrassment caused by the overdosing was compounded by a series of errors in information given to the public. Apart from the incorrect information regarding the size of the affected area, the timing of the incident was also miscalculated. The initial public announcement said that the water supply to homes may have been affected on the morning of May 2nd, this was then revised to May 1st, and eventually to April 30th. There has also been criticism over the delay in detection of the incident. Although post-fluoridation water samples are collected daily at the water treatment plant, the results of fluoride tests on the April 29th samples were apparently not received until May 12th. Opponents of plans to introduce potable recycling to supplement the Brisbane water supply have also seized in the fluoride overdoing incident to argue the potential for failure of water treatment systems and safety controls. The Chief Health Officer for Queensland has advised the public that the possibility of adverse health effects from consuming the affected water is ‘extremely minimal’. Excess fluoride can be toxic, with gastrointestinal symptoms such as nausea, vomiting or diarrhoea possibly triggered by acute doses in the range of 0.2-0.3 mg/kg body weight. Thus, a 70 kg adult would probably need to have consumed approximately 700 ml or more of the affected water (assuming a concentration of 20 mg fluoride per litre) to have experienced such symptoms, while children could experience symptoms at proportionately lower ingested volumes. More serious and potentially fatal toxic effects occur at doses of 32-64 mg/kg body weight in adults and 16 mg/kg body weight in children – far in excess of any plausible exposure from this incident. According to media reports, no adverse health effects have been recorded among the school children who were at the YMCA camp, although some householders have reported gastrointestinal symptoms around the time of the incident. The Queensland Government has commissioned an expert investigation into the incident with an interim report already delivered in May and a final report, which will be made public, expected in late June.

Stormwater Harvesting For Orange A major project to harvest stormwater for potable reuse is nearing completion in the city of Orange in New South Wales (NSW), Australia. The city of 38,000 people is located on the Central Tablelands, about 260 kilometres west of Sydney, and 270 kilometres north of Canberra. Like many Australian towns, Orange has been exploring options for reducing water use and supplementing current water supply sources in response to continuing drought conditions. Demand management strategies have reduced water use in Orange by 38% since 2002 while the population has remained relatively constant, however new water sources are still required for long term water security. The $5 million stormwater harvesting project was designed and built in only 18 months with shared funding from the Orange City Council and the NSW state government. Stormwater from Orange drains into Blackman’s Swamp Creek, and the first stage of the project involved the building of two gross pollutant traps and a weir across the creek to remove debris and create a pool from which water could be pumped during high flow periods. Operating conditions for the stormwater harvesting system have been set to maintain adequate base flow levels to the creek. The harvested water is transferred to a 200 megalitre dam where settling of sediment occurs. From this dam water is then pumped to either of two 17 megalitre batching ponds where coagulant is added to remove suspended solids. After tests to confirm the water has reached the desired quality, it will then be transferred to the nearby Suma Park Dam (18,000 megalitres maximum storage capacity) which is the main drinking water source for the city. Water drawn from this dam is treated by ozonation, biological activated carbon filtration and disinfection at an existing treatment plant prior to distribution to consumers. The stormwater harvesting system is currently in a 3 month commissioning period and the first batch of treated stormwater water was released into the Suma Park Dam on 21 April 2009. The first stage of the system is expected to yield about 1,300 megalitres of water per year, equivalent to about 25% of the current water use for the city. Future expansion of the




system will increase the harvesting capacity to 2,200 megalitres per year. Orange is also implementing other water security measures including development of a dual reticulation water supply system for new housing developments. This will provide untreated water from Suma Park Dam for toilet flushing and garden watering, while treated water will be provided for all other household uses. This will limit the growth of potable water demand and associated water treatment costs. It is also expected to extend the life of the current water treatment plant by about 20 years.

News Items WHO Documents Open For Comment The World Health Organisation currently has a number of documents open for public comment until 15th July 2009: Draft Fact Sheet for Bromide Draft Chemical Background Documents for:

Potassium in Drinking-water Beryllium in Drinking-water Nitrobenzene in Drinking-water Temephos in Drinking-water

These documents and information on how to submit comments can be found on the website of the WHO Water Sanitation and Health Programme, Chemical hazards in drinking-water page at: www.who.int/water_sanitation_health/dwq/chemicals/en/ In addition WHO has made available a revised version of the Guidelines for Drinking-water Quality, 3rd Edition. This version incorporates changes made in the first and second addenda to the September 2004 publication. Available at: www.who.int/water_sanitation_health/dwq/gdwq3rev/en/index.html

Circulation Report – Issue 54 June 2009

Circulation for the print version of this issue is 2517 copies, with readers in 66 countries. A further 1807 readers are registered for email notification of new issues.

Australia

Algeria

Argentina

Austria

Bangladesh

Belgium

Brazil

Cameroon

Canada

Chile

Chinese Taipei

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Germany

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Greece

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Ireland

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Japan

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Luxembourg

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Morocco

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Russia

Saint Lucia

Singapore

Slovenia

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Sweden

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Thailand

Togo

UAE

UK

USA

Yugoslavia

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Zimbabwe

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Update on ADWG Revision Work on the current round of revisions to the Australian Drinking Water Guidelines is nearing completion, with a number of draft items already at the technical editing stage. The revisions have been undertaken by five expert Reference Groups (microbiology, disinfection byproducts, physical /chemical quality, organic pollutants and monitoring) under the guidance of the NHMRC Water Quality Advisory Committee. The required revisions were identified through consultation between the NHMRC and key stakeholder organisations during late 2006 and early 2007. The revisions include: new versions of Chapter 9 Overview of monitoring

and Chapter 10 Monitoring for specific characteristics in drinking water,

a number of new Fact Sheets including those for a large range of pesticides, several types of microorganisms (Bacteroides, Blastocystis, Clostridium perfringens, Coliphages, Cyclospora, heterotrophic plate counts, Helicobacter pylori, intestinal enterococci and pathogenic E. coli), Cylindospermopsin, Lanthanum and NDMA,

updates to a number of existing Fact Sheets, Information Sheets and sections of text.

At this stage it is anticipated that the draft revisions will be released for a six week public comment period in September 2009. The comments received will then be assessed by the Water Quality Advisory Committee and final revisions will be made where necessary. The revised ADWG document is expected to be published in the first half of 2010. Climate Change “Biggest Health Threat” Climate change has been named as the “biggest global health threat of the 21st century” in an article published in the prestigious medical journal The Lancet on 16 May this year. Water and sanitation was one of several key areas mentioned in the article. Water scarcity, sometimes alternating with extreme rainfall events, is likely to lead to increasing problems with provision of safe water supply and sanitation in many areas of the world. Increasing risks of floods and changes in patterns of water-related diseases like malaria are also expected.

From the Literature

Web-bonus articles Summaries of these additional articles are available in the web page version of Health Stream and are included in the searchable archive at: www.wqra.com.au/WQRA_newsletters Aluminum and silica in drinking water and the risk of Alzheimer's disease or cognitive decline: Findings from 15-year follow-up of the PAQUID cohort. Rondeau V, Jacqmin-Gadda H, Commenge D, et al. (2009) American Journal of Epidemiology, 169(4); 489-496.

Cancer mortality in Chinese populations surrounding an alloy plant with chromium smelting operations. Kerger BD, Butler WJ, Paustenbach DJ et al. (2009) Journal of Toxicology and Environmental Health. Part A, 72(5); 329-344.

Disinfection by-products and their potential impact on the quality of water produced by desalination systems: A literature review. Agus E, Voutchkov N and Sedlak DL. (2009) Desalination, 237(1-3); 214-237.

Public opinions on community water fluoridation. Quinonez CR and Locker D. (2009) Canadian Journal of Public Health, 100(2); 96-100.

Safe drinking water and clean air: An experimental study evaluating the concept of combining household water treatment and indoor air improvement using the Water Disinfection Stove (WADIS). Christen A, Navarro CM and Mäusezahl D. Int. J. Hyg.. Environ. Health (2009), doi:10.1016/j.ijheh.2009.01.001

Nitrate in drinking water and risk of death from pancreatic cancer in Taiwan. Yang CY, Tsai SS and Chiu HF. (2009) Journal of Toxicology and Environmental Health. Part A, 72(6); 397-401.

Drinking water in northwestern Alaska: Using or not using centralized water systems in two rural communities. Marino E, White D, Schweitzer P, et al. (2009) Arctic, 62; 75-82.

Point-of-use drinking water devices for assessing microbial contamination in finished water and distribution systems. Miles SL, Gerba CP, Pepper IL and Reynolds KA. (2009) Environmental Science and Technology, 43(5); 1425-1429.

An outbreak of Salmonella Typhimurium 9 at a school camp linked to contamination of rainwater tanks. Franklin LJ, Fielding JE, Gregory J, et al. (2009) Epidemiology and Infection, 137(3); 434-440.

Development and Validation of a Self-Administered Questionnaire to Measure Water Exposures in Children Gorelick MH, Wagner D and McLellan SL. (2008) Ambulatory Pediatrics, 8(6); 388-391.

Promotion and provision of drinking water in schools for overweight prevention: randomized, controlled cluster trial. Muckelbauer R, Libuda L, Clausen K et al. (2009) Pediatrics, 123(4); e661-667.

Large-scale freshwater microbiological study: rationale, results and risks. Till D, McBride G, Ball A, et al. (2008) Journal of Water and Health, 6(4); 443-460.

Comparing wastewater chemicals, indicator bacteria concentrations, and bacterial pathogen genes as fecal pollution indicators. Haack SK, Duris JW, Fogarty LR, et al. (2009) Journal of Environmental Quality, 38(1); 248-258.



Cyanobacteria Freshwater cyanobacterial blooms and primary liver cancer epidemiological studies in Serbia. Svircev, Z., Krstic, S., Miladinov-Mikov, M., Baltic, V. and Vidovic, M. (2009) Journal of Environmental Science and Health. Part C, Environmental Carcinogenesis & Ecotoxicology Reviews, 27; 36-55. Cyanobacterial toxins include neurotoxic alkaloids, hepatotoxic peptides (microcystins) and the hepatotoxic alkaloid (cylindrospermopsin). There is concern over the potential health effects of low-level chronic exposure to these toxins. Microcystin has acute toxic effects on the liver but may also promote the growth of pre-existing cancers in various organs. In Serbia, current drinking water treatment practices do not regularly monitor or actively remove these toxins from drinking water because this is a relatively new field of study and involves extremely expensive measures. Even with water treatment, low-level chronic exposure to cyanobacterial hepatotoxins is possible. After ingestion of cyanobacterial hepatotoxins, the primary target organ is the liver. These toxins may lead to tumour promotion for existing cancers or even carcinogenesis in persons who consume drinking water derived from contaminated surface water. Primary liver cancer (PLC) is the fifth most common cancer in the world and the fourth most common cause of cancer mortality. There are marked differences in incidence and mortality rates for PLC in different parts of Serbia. This study was undertaken to analyse PLC incidence and occurrence relative to prolonged blooming of drinking water reservoirs correlated with type of drinking water supply systems used in different regions of Serbia. Serbia is made up of 30 regions. These regions were divided into three parts for PLC studies to be conducted: Vojvodina with water supply from groundwater only (7 regions); Kosovo with a few high mountain reservoirs for water supply, no blooms occurred (5 regions); and Central Serbia (18 regions), which was divided into regions with extremely high PLC incidence and regions with lower PLC incidence. This study covered the years 1980-2003.

Data on PLC incidence and mortality rates were obtained. Cyanobacterial blooming events were obtained from the 25-year monitoring program in Serbia. PLC mortality was examined from 1980-1990 and PLC incidence and mortality were examined from 2000-2002. Microcystin concentration was measure in one water supply reservoir in Central Serbia (Celije) during and after cyanobacterial blooms in July 2004 and from Krusevac town-supplied tap water from the reservoir two days later. Concentrations of microcystin-LR in water samples were measured. In Central Serbia more than 20 reservoirs serve as drinking water supplies and 9 of these were found to have a history of severe and prolonged cyanobacterial blooming. The concentration of microcystin-LR in the Celije reservoir water in July 2004 was 650 micro g/L while in the drinking (tap) water of Krusevac city the concentration was 2.5 micro g/L. From 1980-1990, the standardised PLC mortality rate in Central Serbia was high in 9 regions with a rate of 11.6 per 100,000 inhabitants, while in the other 9 regions it was slightly lower with a rate of 8.3. In this same period the PCL mortality rate in Vojvodina was 7.6 per 100,000 inhabitants and only 2.7 in Kosovo. In 2000, there was a significant increase of PLC incidence in Central Serbia with an incidence rate of 16 per 100,000 inhabitants. This trend also continued in 2002 with an incidence rate of 18.8 while in Vojvodina in the same period incidence rates were only 6.6 and 6.2 for 2000 and 2002, respectively. Increasing of PLC incidence in Central Serbia in 2000-2002 was found to be extremely significant in three regions and was rated 34.7 per 100,000 inhabitants while in the rest of the Central Serbia regions the mean value was 13.6. PLC incidence in Vojvodina during the same period was 5.2. As the three most affected PLC regions in Central Serbia have water supply systems based on reservoirs which are regularly blooming during the summer months and some of them are also connected with boundary blooming reservoirs, it is possible that PLC incidence could be connected with the drinking water quality.



The results from this study clearly point to a relationship between drinking water reservoirs that were found blooming during the investigation period in Serbia and increased PLC incidence rates in these regions compared with the controls regions of Kosovo and Vojvodina and unaffected regions in Central Serbia. The priority for future research in Serbia needs to be based on cyanotoxin concentration monitoring in all drinking water reservoirs and the elimination of microcystins during drinking water treatment. Comment Excessive alcohol consumption and chronic hepatitis B or C infection are the major known risk factors for primary liver cancer, however the authors state that prevalence of these risk factors is lower in Serbia than in other European countries. No reason is advanced for the sudden change in incidence of PLC in 2000 - if this were attributable to cyanotoxins in drinking then it would suggest a large increase in population exposure levels occurred perhaps 10 or more years earlier. Developing Nations Estimating the impact on health of poor reliability of drinking water interventions in developing countries. Hunter, P.R., Zmirou-Navier, D. and Hartemann, P. (2009) Science of the Total Environment, 407(8); 2621-2624. Recent evidence suggests that drinking water interventions in developing countries may not reliably produce safe drinking water and therefore may not provide the expected improvements to health. A recent survey of the state of improved water supplies in 15 villages in an area of South Africa found that three villages did not have sufficient water availability. In two of these villages the borehole had dried up shortly after construction. Of the 12 remaining villages, five did not have water at the time of inspection. The reason for lack of water in two of the villages was that the pump had failed, in two more there was no money to buy diesel and in the fifth the pump operator was ill. This paper aims to estimate the magnitude of the effect of unreliability in treated drinking water provision on

the incidence of diarrhoeal disease, by assuming that populations have to revert to the consumption of untreated surface water for one or more days when safe supplies fail. Data from the literature was used and a Quantitative Microbiological Risk Assessment (QMRA) was undertaken of two Ugandan water system (Gaba 1 and Gaba 2) for three pathogens (Enterotoxigenic E. coli (ETEC), Cryptosporidium and Rotavirus). Both of these water systems take their water from Lake Victoria and apply rapid sand filtration and chlorination. Gaba 2 also has a coagulation-flocculation stage prior to filtration. This study used an average of the raw water quality between Gaba 1 and Gaba 2. Beta-Poisson distribution was used to estimate the daily infection risk for both treated and raw water for the three pathogens. Annual risk of infection was calculated for the three pathogens for consuming only treated water and having to consume raw water for various numbers of days because of supply failure. A further analysis was conducted to estimate the cumulative risk of infection among aged from 6 months to 36 months for each 6 month period assuming that one infection always leads to disease unless the person already has immunity from a previous infection. On days when the consumer had to drink raw water because of supply failure the probability of rotavirus infection was 0.858 compared to 0.006 for treated water, for Cryptosporidium the infection probability was 0.4 compared to 0.003 and for ETEC it was 0.12 compared to 0.000002. The cumulative annual risk of infection for both Cryptosporidium and Rotavirus was found to be over 50% per year due to poor treatment effectiveness, even if people only drink treated water. The annual risk for ETEC by contrast was predicted to be very low in people drinking only treated water. For those that have to revert to raw water consumption however, even for one day, the annual risk from ETEC increases two orders of magnitude. The risk increase for Cryptosporidium and Rotavirus was not as great, reflecting the fact the most people would be infected in a year even when drinking only treated water. There is still however a marked increase in risk with just a single day failure.



When safe water supplies fail on more than one day the yearly risk of illness increases to nearly 100% for both Cryptosporidium and Rotavirus. Risk from ETEC continues to increase, reaching 99% infection at 34 days of failure over one year. In the analysis of the probability of infection with age it was found that consumption of treated drinking water leads to only a very small risk of ETEC infection but that 38% of children will acquire a Cryptosporidium infection and 64% a rotavirus infection from drinking water between the ages of 6 and 12 months. The daily risk for ETEC from having to revert to drinking raw drinking water because of supply failure was found to be substantially greater, especially in children under 12 months and children will also experience infection with Cryptosporidium and Rotavirus earlier than they would have otherwise. This study found that even a few days of interrupted drinking water supply may be enough to destroy the health benefit from the provision of clean drinking water and therefore any intervention that is unreliable will not achieve the expected health gains. The results of the modelling for ETEC were strong compared to both Cryptosporidium and Rotavirus however both Cryptosporidium and Rotavirus are largely spread directly from person to person and drinking water only accounts for a minor proportion of infections. ETEC on the other hand does not spread directly from person to person and drinking water is a major pathway of transmission. This analysis shows that treated water delays the age of first infection. This is important because children under 12 months of age are most likely to die from diarrhoeal disease, and therefore postponing the age of first infection even by a few months can substantially reduce childhood mortality. Agencies responsible for implementing improved drinking water interventions will not reach public health targets if those systems are subject to poor reliability. Those funding water quality interventions in developing countries need to put greater effort into auditing the effectiveness of their investments including the nature and causes of failure and whether health benefits are being achieved.

Disinfection Byproducts Chlorination disinfection by-products, public health risk tradeoffs and me. Hrudey SE. (2009) Water Research 43(8); 2057-2092. This article provides an informative review of the issue of chlorination byproducts and health risks from the personal viewpoint of the author (an engineer with a long history of involvement in environmental health risk assessment and risk management). It traces the historical development of concerns over environmental degradation and pollution in the 1960s and early 1970s, and the widespread misinterpretation of statements by the World Health Organisation and the International Agency for Research on Cancer about the “environmental” causes of cancer which led to an almost exclusive focus on man-made chemicals. This set the context for public and scientific reaction to the 1974 discovery of disinfection byproducts (DBPs) in drinking water, and publication of positive carcinogenicity test results for chloroform only two years later. Subsequent decades led to the introduction of regulatory limits on trihalomethane (THM) and later haloacetic acids (HAA) levels in drinking water supplies, and the discovery of many other classes of DBPs. While regulatory concern has focused on chlorine-containing byproducts, it has become evident in recent years that some of the non-chlorinated byproducts (which are also produced as a result of chlorination or chloramination reactions) are possibly of greater toxicological concern. The properties of the linearised multistage model for cancer risk assessment is described, along with the underlying assumptions and limitations of this methodology, and the effect on derived risk estimates. The problems of attempting to modify established regulations in the light of advances in scientific knowledge are also discussed, using the example of chloroform. While DBP regulations were founded on the apparent carcinogenicity of this compound, it has now been established that the mechanism by which chloroform induces cancer does not operate at the low concentrations found in water supplies. The author then briefly summarises the



epidemiological evidence for association of DBP exposure with bladder cancer and adverse reproductive effects and the uncertainty surrounding interpretation of these studies. The problem of judging the strength of evidence in the face of disparity between the known toxicological properties of characterised DBPs (which predict very low, unmeasurable risks from levels present in drinking water supplies) and the outcomes of epidemiological studies (some of which suggest measurable increases in risk) is discussed. The management dilemma is worsened by mounting evidence that changes in drinking water treatment practices to reduce levels of regulated DBPs (THMs and HAAs) may lead to increased levels of more toxicologically potent but currently unregulated DBPs. The uncertainties surrounding risk levels and effectiveness of risk management options for DBPs need to be balanced against the well proven risks from microbial pathogens if water disinfection is inadequate. The author concludes that the uncertainties surrounding possible health risks from chlorination DBPs appear not to be appreciated by many of those involved in drinking water regulation, production or research. There is a need for more informed and sceptical debate of these issues if more productive approaches to DBP regulation and better targeted research strategies are to be developed. Comment This paper is partly based on a Knowledge Translation Review “Chlorination Disinfection By-Products (DBPs) in Drinking Water and Public Health in Canada”” conducted for the Canadian National Collaborating Centre on Environmental Health. The review, which contains some additional information, can be obtained from: www.ncceh.ca/en/contracted_reviews/chlorination_disinfection_by-products Fluoride Fluoride and health hazards: community perception in a fluorotic area of central Rajasthan (India): an arid environment. Hussain J, Hussain I and Sharma KC. (2009) Environ. Monit. Assess. DOI 10.1007/s10661-009-0771-6

India has 14.1% of the total fluoride deposits on the earth’s crust and has one of the highest rates of fluorosis. In India about 62 million people are at risk of developing fluorosis from drinking high fluoride water. In Rajasthan, where the main source of drinking water is groundwater from open wells, tube wells, hand pumps, etc, the availability of safe and potable water is low and18 of the 32 districts are fluorotic with 11 million people at risk. This study was undertaken in the rural area of Central Rajasthan which has high fluoride in the groundwater, to investigate the quality of drinking water (underground water) and to study the cases of fluorosis in the villages having more than 5.0 mg/l fluoride. Research has shown that fluoride concentrations between 0 an 0.5 mg/l favour the development of dental caries whereas concentrations between 1.5 and 5 mg/l can result in dental fluorosis. Ingestion of 5-40 mg/day of fluoride via drinking water can produce skeletal deformities, and knock knees have been reported in adolescents receiving greater than 10 mg/day in water, accumulated from birth. Fluoride concentrations between 0.5 and 1.5 mg/l have beneficial effects in reducing the development of caries. Groundwater samples from 1,030 villages of nine tehsils (administrative divisions) of Bhilwara district in Central Rajasthan were collected during the years 2003-2006 from manually operated hand pumps in residential localities. The fluoride concentration in the water samples was determined. A survey was also conducted for prevalence of dental and skeletal fluorosis in male and females grouped into six age categories. The survey was undertaken in 41 villages having a fluoride concentration above 5.0 mg/l. The survey was conducted from house-to-house and a questionnaire was administered which gathered information on age, sex and dietary habits of individuals. Individuals were examined for evidence of dental fluorosis and were graded according to severity. Adults over 21 years residing in the area since birth were examined for evidence of skeletal fluorosis. These adults were asked about symptoms of skeletal fluorosis and visible signs and deformities were examined. Bending or movements of different parts of the body were also observed for their



easiness. Skeletal fluorosis was graded according to the characteristics displayed. The fluoride concentration in the Bhilwara samples was found to range from 0.2-13.0 mg/l. In the nine tehsils, 274 villages (26.6%) had fluoride concentrations below 1.0 mg/l (1.0 is the maximum desirable limit as per the Bureau of Indian Standards (BIS)). There were 235 villages (22.8%) of the nine tehsils which had fluoride concentrations between 1.0 and 1.5 mg/l (1.5 mg/l is the maximum permissible limit of the BIS for fluoride in drinking water) and 342 villages (31.5%) had fluoride concentrations between 1.5 and 3.0 mg/l (above the permissible limit). In 137 villages (13.3%) the range of fluoride was 3.0 to 5.0 mg/l and in 60 villages (5.8%) the fluoride concentration was above 5.0 mg/l. Overall, groundwater at 521 (49.6%) of sampling sites was found to be unfit for drinking purposes as per the desirable and maximum permissible limit for fluoride in drinking water determined by the World Health Organization (1996) or by the Bureau of Indian Standards (1991). There were 4,252 individuals examined for dental and skeletal fluorosis in the 41 villages. There were only 982 individuals (23.10%) without dental fluorosis. Villages with high fluoride concentration in groundwater also had high percentages of dental fluorosis cases. Severe dental fluorosis was seen in 374 individuals (8.8%). Dental fluorosis rates were similar in both sexes up to age 30, but higher in males in the older age groups. The authors suggest this may be due to males tending to remain in their village of birth (thus having lifelong exposure to the same water source) while women traditionally move to their husband’s village after marriage (possibly changing their fluoride exposure level). The Dean’s Community Fluorosis Index was calculated for the study area with the scores representing the degree of fluorosis: 0 for normal, 0.5 for trace, 1.0 for very mild, 2.0 for mild, 3.0 for moderate and 4.0 for severe. The Community Fluorosis Index for the total study area was 1.62 with a maximum of 3.0. Skeletal fluorosis was examined in 1,998 individuals over 21 years of age. There were 1,049 individuals (52.5%) without skeletal fluorosis. There were 566

individuals (28.33%) with Grade I skeletal fluorosis, characterised by bone and joint pain. There were 12 individuals (0.6%) with Grade III skeletal fluorosis characterised by bone and joint pain, stiffness and rigidity of dorso lumber spine and restricted movements and deformities of spine and limbs. Prevalence and severity of skeletal fluorosis increased with increasing fluoride concentration. Rates of skeletal fluorosis were higher in males than females. The incidence of skeletal fluorosis also increased with age. The prevalence and severity of fluorosis was higher in subjects belonging to the economically poor communities, also in subjects using tobacco, bettle nuts and alcoholic drinks. Male labourers also showed a higher prevalence of fluorosis. Subjects who used citrus fruits and had a good nutritional status showed a lower prevalence. The authors note there are several significant sources of fluoride exposure in these communities in addition to drinking water including tea, tobacco and pan massala (a traditional mixture of nuts, seeds, herbs and spices eaten after meals). The level of fluoride in this area is higher than recommended by the current standards and therefore the probability of fluorosis is increased in this area. Consequently there is an urgent need to warn people against the risk of dental or even skeletal fluorosis and to advise people to adopt some techniques to defluoridate groundwater before using it for drinking purposes. Fungi The study of fungi in drinking water. Hageskal, G., Lima, N. and Skaar, I. (2009) Mycological Research, 113(2); 165-172. Fungi are possibly an underestimated problem in drinking water distribution systems. Some fungi are primarily adapted to aquatic environments and therefore are naturally found in water. Fungi present in soil, organic material and air and anything in contact with air may also enter drinking water from various locations, however this is considered an ‘unnatural’ habitat for them. The relevance of



waterborne fungi for water quality and human health is still poorly understood, although there is no indication that they cause acute health risks if ingested. This paper presents a review of the literature on this topic. Many of the early studies on fungi in drinking water were undertaken in response to water contamination problems (often taste and odour issues). More recently, studies with a specific focus on fungi in water supplies have been undertaken. In the various studies performed in the last decade, the prevalence of fungi has varied widely in different systems (between 7.5-89% positive samples), as have levels of fungi in positive samples. Fungi have been detected in raw and treated waters, distilled or ultra-pure water, and bottled drinking water. They appear to be about three times more common surface-sourced water compared with ground-sourced water. Sampling in buildings has shown fungi are more commonly recovered from cold water and shower water than from hot tap water. Filamentous fungi (moulds) are the most commonly found types in water, but yeasts also occur. A wide diversity of mould species has been isolated from drinking water including potentially pathogenic, allergic and toxigenic species including Aspergillus fumigatus. This species is a significant pathogen in severely immuno-compromised patients in hospitals, and hospital water systems have been proposed as a possible source of A. fumigatus and other fungal pathogens. Fungi may be aerosolised from taps and showers and therefore introduced to severely immunocompromised patients. Fungal infections in such patients are difficult and expensive to treat, and are often fatal. Penicillium species are also commonly found in water supplies. Several of the species in the Penicillium and Aspergillus genus are known to produce mycotoxins when growing in food and beverages, and in vitro studies have suggested that mycotoxins and other metabolites can be produced by fungi in water. The allergic potential of fungi in drinking water has not been studied however the possibility can not be ruled out and large studies are needed to investigate the issue. Fungi have been connected to taste and odour problems in drinking water, and some have been shown to produce

geosmin. Fungi can occur in biofilms on water and wastewater pipe surfaces. In this state they may be protected and therefore more resistant to water treatment. Fungi may also colonise filters in treatment plants and as a result affect the water treatment. There has been little research on the ecology of fungi in biofilms and further studies are required to investigate the character of fungi in biofilms. Methods for isolating fungi from water are not standardised and this makes comparisons between different studies difficult, and may explain much of the variation in the results reported. Culturing methods may limit the accuracy of results and are time-consuming, therefore better and more standardised methods for analysis need to be developed. Identification of fungi to the species level is difficult and may require a multi-phase approach. New molecular and spectral methods may help with the analysis of fungi in water. The current state of knowledge is insufficient to establish acceptable or normal levels of fungi in drinking water. Sweden appears to be only country which includes fungi in current water regulations. Opinions are currently strongly divided on the health significance of fungi in water. Some researchers believe tap water is the origin of Aspergillus infections in hospitals, and that vulnerable patients should avoid exposure. Precautionary measures suggested for high-risk patients in hospitals include: hospital water being tested for the presence of disease-related fungi, high-risk patients avoiding exposure to hospital water and using sterile water for drinking, also avoiding showers and using sterile sponges for bed-baths instead. It was also suggested that shower facilities be thoroughly cleaned to prevent fungal aerosols and that patients and health care workers should be educated regarding these issues. Others feel the current level of evidence is insufficient to justify such actions. However researchers on both sides of the argument agree that well designed epidemiological studies are needed to determine the real contribution of water supplies to the fungal disease burden.



Very few practical measures have been implemented in regard to fungi in water. This is basically due to the need for increased knowledge about the human health significance of the presence fungi in drinking water. In future, monitoring of water systems for the presence of fungi may be required, especially in hospital water systems. Water treatment is an option however most of the current water treatment methods are not adequate against fungi. Further studies are required to investigate the effects of water treatment options against fungi in water. Regulation may be required in the future at least with respect to ensuring adequate water quantity in healthcare institutions. Household Interventions Killing of enteric bacteria in drinking water by a copper device for use in the home: laboratory evidence. Sudha, V.B.P., Singh, K.O., Prasad, S.R. and Venkatasubramanian, P. Transactions of the Royal Society of Tropical Medicine and Hygiene, (2009), doi:10.1016/j.trstmh.2009.01.019 In developing countries public water distribution systems are often not maintained well, potentially allowing water quality to be compromised. Also treated water that is of good quality when collected is often re-contaminated within households due to unsafe storage and handling practices. Traditionally, Indian homes stored drinking water in copper and silver pots, however in recent years less expensive steel and plastic containers have become more common. Antimicrobial effects of copper and copper alloys on some pathogens have been reported, so this study investigated the effect of storing water inoculated to contain 500-1000 colony forming units (CFU)/ml of Escherichia coli, Salmonella Typhi and Vibrio cholerae overnight in copper pots or in glass bottles. The effects of using an inexpensive copper coil device were also examined. The effect of overnight storage of sterile distilled water inoculated with enteric bacteria in copper pots and control glass bottles was first investigated and water containing E. coli, S. Typhi and V. cholerae stored in copper pots did not yield any growth after 16 hours of storage at room temperature (27 plus or

minus 2 degrees C). The inoculated water stored in control bottles showed the presence of bacteria with more than 30-fold growth observed for E. coli and more than four-fold growth observed for S. Typhi and V. cholerae. Bacterial counts were enumerated by plating dilutions on nutrient or MacConkey agar. The effect of overnight storage of water inoculated with enteric bacteria in glass bottles with and without the copper device was then investigated. The copper coil device was made using 4 mm diameter copper cable purchased from a hardware shop in Bangalore, India. Preliminary experiments with copper cables and sheets of various sizes showed a ratio of 15.2 square cm of copper surface per litre of water was required for effective antimicrobial action. There was no growth of bacteria found after overnight incubation with the copper device, whereas the control bottles without the device showed more than a 30-fold increase in E. coli counts and more than a four-fold increase in S. Typhi and V. cholerae. The pH and levels of copper in the test containers were all well within the permissible limits set by the WHO of less than 8.5 and 2000 parts per billion, respectively. The copper device used here was inexpensive (one-tenth the cost of a copper pot) and can be used in a regular plastic pot. This device is also reusable, easy to maintain, durable, does not need energy or sunlight to run and appears to be safe. The use of such a device has the potential to reduce mortality and morbidity due to enteric pathogens, particularly V. cholerae, in rural areas and urban slums of developing countries. Field trials of this device need to be conducted in diarrhoea-prone areas where water and sanitation are a problem in order to test its benefits and adaptability. Tests are also needed on other categories of pathogens (viruses and protozoa). Comment This study examined only distilled water spiked with faecal bacteria, and the antimicrobial effects observed may differ in real drinking water samples due to the presence of dissolved solids, salts, organic matter and a diverse microbial population. The physico-chemical properties of water (eg pH, hardness) will also affect copper dissolution rates, perhaps producing copper levels in excess of drinking water guidelines in some water supplies.



Considerable further testing would be needed to determine if this device could provide reliable water quality improvements in natural waters. Regulation Ensuring safe drinking water in regional NSW: the role of regulation. Byleveld, P.M., Cretikos, M.A., Leask, S.D. and Durrheim, D.N. (2008) New South Wales public health bulletin, 19(11-12); 203-207. Microbial and chemical contamination of drinking water may pose a serious risk to public health if disinfection or treatment is inadequate. In regional and rural areas of the state of New South Wales (NSW), Australia, there are 107 local water utilities providing drinking water to a population of 1.7 million through 323 public water supply systems. The NSW Health department oversees these regional water utilities through the NSW Health Drinking Water Monitoring Program. This program provides guidance on drinking water monitoring as well as on the implementation of several elements of the Australian Drinking Water Guidelines 2004. The current NSW Health Drinking Water Monitoring Program has been operating comprehensively since 2001. Each public water supply system is tested for microbial and physical/inorganic chemical characteristics and results are stored in the internet-based NSW Drinking Water Database. The database records results for more than 20,000 samples per year from the 323 water supply systems. The Program recommends the minimum numbers of samples that should be taken on the basis of size and complexity of the water supply systems and in accordance with the Guidelines. Water samples are tested free of charge to the water suppliers. The Program also provides water utilities with protocols for responding to incidents of contamination or treatment system interruption and defines the roles of the NSW Department of Health Water Unit, local public health units and the local water utility in responding to such incidents. The Program is actively promoted to local water utilities by the Water Unit and local public health

units, and has been well accepted by local water utilities and government agencies. There is evidence that the current Program has helped to improve the management of regional and rural water supplies in terms of an increase in the number of water supply systems being tested, collection of adequate numbers of samples, and in terms of percentage compliance of samples with guideline values. In 2001, more than 3.5% of samples were non-compliant for microbial quality, in 2007 fewer than 2% of samples were non-compliant, (p less than 0.001). Adequacy of microbial sampling improved from approximately 70% of allocated samples collected in 2001 to more than 95% in 2007 (p less than 0.001). The improvement seen in non-compliance appears to have resulted from many factors including, improved reporting to the NSW Health Drinking Water Monitoring Program, monitoring and maintenance of regional drinking water systems, disinfection and treatment of drinking water supplies and sampling frequency. However, despite the improvements in regional microbial performance, some small water supply systems remained well below the targets for sampling frequency and water quality. Local public health units have access to the NSW Drinking Water Database and disease surveillance data. Public health units are notified of any non-compliant samples or failure of the water supplier to take adequate numbers of samples. If a risk to public health is identified, the public health unit will advise the water utility to issue an alert to boil water or other appropriate warnings to the community. During 2007, there were 12 such alerts issued in regional NSW. Two of these alerts were issued before the test results become available and were the result of contaminated raw water or treatment failure. The rest were issued following detection of E. coli in routine drinking water samples. In such circumstances the community may have already been exposed by the time a boil water alert was issued. If water utilities are to supply drinking water that is safe, as defined in the Guidelines, NSW Health strongly recommends that they implement the Guideline’s Framework for Management of Drinking Water Quality. This Framework sets out a preventive risk-management approach for reliable provision of safe drinking water.



The NSW Health Drinking Water Monitoring Program has contributed to a considerable improvement in the monitoring and quality of drinking water in regional NSW. This has been achieved through: a clear regulatory framework, a centralised system of ongoing sampling monitoring, technical support for local utilities and public health units and collaborative relationships between public health units and local water utilities. The NSW Drinking Water Database has aided in the identification of persistent and sporadic problems in water supplies, and provided useful data to inform decision making on improvements needed for specific supplies. The biggest future challenge is to ensure that all water utilities fully implement the Australian Drinking Water Guidelines Framework. Risk Assessment Long-term inactivation study of three enteroviruses in artificial surface and groundwaters, using PCR and cell culture. De Roda Husman, A.M., Lodder, W.J., Rutjes, S.A., Schijven, J.F. and Teunis, P.F.M. (2009) Applied and Environmental Microbiology, 75(4); 1050-1057. Viruses transmitted by contaminated drinking water may cause serious waterborne diseases such as meningitis and poliomyelitis, as well as gastroenteritis. Even at low levels that cannot be directly detected in drinking water, viruses can still cause waterborne disease. Quantitative viral risk assessment is a useful tool to assess the disease risk due to consumption of drinking water containing such low numbers of these pathogens, however this technique requires information not only about the number of virus particles present but also the ability of viruses to infect their host. Molecular methods used with water samples detect the viral genome, but do not indicate the infectivity of the virus in the environment. For some viruses, infectivity may be determined by cell culture, but for other viruses cell culture techniques are not available. Public health risks will be overestimated by QMRA if molecular methods used to enumerate viruses include both infectious and defective particles. This study investigated the inactivation of three different enteroviruses in artificial ground and surface waters

under different controlled conditions using both RT-PCR and cell culture methods to determine whether the ratio of infectious particles to defective particles changed over time. Inactivation experiments were conducted using three virus isolates, Coxsackievirus type B4 (CxB4) and poliovirus 1 (PV1) and poliovirus 2 (PV2). Three separate experiments were conducted with different viruses using salt-peptone medium, artificial groundwater and artificial surface water. Replicate flasks containing serial dilutions of viruses were stored in the dark at 4 degrees C or 20 degrees C, then assayed by RT-PCR and cell culture after different time intervals. On day 0 of the salt-peptone experiment, the number of infectious polioviruses determined by using cell culture was estimated to be 2,000 PFU/ml, compared with 20,000 RT-PCR detectable units/ml. Over time, little inactivation of poliovirus RNA was seen in the salt-peptone medium at 4 and 22 degrees C as determined by RT-PCR, however the number of infectious polioviruses detected by cell culture assay declined over time so that the ratio of RT-PCR viruses to cell culture viruses increased markedly. The decline in infectious virus occurred more rapidly at 22 degrees C than at 4 degrees C. In artificial groundwater, there was no significant decline in PV1, PV2 or CxB4 RNA over 400 days at 4 degrees C as determined by RT-PCR assay. PV1 RNA also showed no decline at 22 degrees C over 400 days, while PV2 and CxB4 RNA declined slightly at this temperature (less than 1 log, estimated from graphs). However all three viruses showed greater loss of infectivity as determined by cell culture at both storage temperatures. Again the decay was much more rapid at 22 degrees C than 4 degrees C. From initial concentrations of about 100,000 infectious viruses per litre, PV1 became undetectable in 160 days, PV2 in 150 days and CxB4 in 110 days. In artificial surface water, infectious PV2 declined more slowly than in artificial groundwater, while the decline of infectious PV1 and CxB4 were similar in both water types. The time taken to decline to undetectable levels from an initial inoculum of 100,000 infectious viruses per litre were 150 days for



PV1, 240 days for PV2 and 120 days for CxB4. There was no decline in viral genome numbers at 4 degrees C for all three viruses, and a small decline for PV2 and CxB4 but not PV1 at 22 degrees C. Under some conditions the rate of decay of infectious viruses appeared to be linear while in other conditions a biphasic decline was seen (initially rapid then slowing). The ratio of RT-PCR viruses to infectious viruses at time zero was estimated by extrapolating the calculated decay curves. For PV1 the ratio in artificial groundwater was 117.9 and for artificial surface water it was 39.7. For PV2 the ratios were 164.0 and 62.8 respectively, and for CxB4 99.5 and 80.6. The authors comment that coxsackie virus type B4 appears to be most stable (ie similar ratio on both water types). They also note that the decay of viral infectivity and loss for RT-PCR detectable virus in natural waters may be affected by the presence of other microorganisms and many other factors not replicated in these controlled experiments. Nevertheless the results found here are useful for quantitative assessment of the microbial risk associated with consumption of drinking water. Comment This paper illustrates a complex issue which is critical to risk assessment using QMRA – what fraction of pathogens detected by PCR or RT-PCR are capable of causing infection? The results presented here show that the infectious fraction is variable over time, and will differ for different pathogens according to water conditions and time elapsed since the pathogen entered the water. Uranium Nephrotoxicity of uranium in drinking water from private drilled wells. Seldén, A.I., Lundholm, C., Edlund, B., Högdahl, C., Ek, B.M., Bergström, B.E. and Ohlson, C.G. Environmental Research, (2009) 109(4): 486-494. Uranium is commonly found in bedrock in Sweden, and levels exceeding 15 micro g/l have been found in 23-40% of water samples from drilled private drinking water wells in several parts of the country. This paper reports an investigation of kidney function and uranium exposure from drinking water in

residents of the Arjang municipality, Varmland county in western Sweden. The study population consisted of individuals 18-74 years of age and included permanent residents in a rural part of Arjang municipality with drilled wells (exposed group), and others from the central Arjang community with a municipal water supply (control group). Exposed subjects and controls were mailed a questionnaire covering their drinking water consumption, health, use of prescribed pharmaceuticals, dietary supplements and tobacco, work exposures and leisure-time activities. Information was also requested on the characteristics of the well they used, including any water purification equipment. Those in the exposed group were requested to collect two water samples: one for radon analysis and one for analysis of selected metals (cadmium, lead, mercury and uranium). They were also asked to provide a morning urine specimen for biochemical analysis. Controls were asked to provide a morning urine sample but municipal water samples were only requested from a small number of controls. Urine samples were tested for uranium, lead and biochemical markers of kidney function. Urine and water tests were conducted without knowledge of the exposure/control status of the participant. There were 301 individuals representing 156 households in the exposed group and 152 individuals representing 96 households in the control group. Of the 153 well water samples available for analysis, about one-third (32.7%) contained at least 15 micro g/l of uranium, the recommended Swedish action level and WHO provisional guideline value. There were 8 samples which contained 100 micro g/l uranium or more, and the maximum detected level was 470 micro g/l. The median and mean uranium levels in the well water samples were 6.7 and 25.2 micro g/l, respectively, which was considerably higher than the levels in all of the control water samples (less than 0.2 micro g/l). One well water sample had a high lead level but no water samples had elevated levels of cadmium or mercury. There was a fairly weak but highly statistically significant correlation (r = 0.39; p less than 0.001) between uranium and radon levels in the well water samples



which increased (to r = 0.48) after excluding wells with water quality improvement equipment. The geometric mean uranium level in the exposed group’s urine samples was more than eight times that of the controls (38 ng/l vs. 4.3 ng/l). There was a strong curvilinear correlation (r2 = 0.66; p less than 0.001) found between uranium levels in the water samples and urine from corresponding subjects. There was no statistically significant difference between the two groups for 7 out of 9 markers of kidney function. For other two markers (calcium and the enzyme N-acetyl-beta-D-glucosaminidase) mean levels were significantly higher in the control group, but these differences disappeared when adjusted for background variables (age, gender and smoking). However when exposure was defined in terms of uranium levels in the subjects’ urine samples (without regard to exposed or control status), statistically significant correlations were found between the exposure and the markers beta2-microglobulin, kappa chains and protein HC, but no clear dose-response was found between the two highest exposure categories. When subjects with diabetes were excluded, a tendency towards a dose-response was seen for beta2-microglobulin, kappa chains and protein HC, suggesting a uranium-associated nephrotoxicity. Uranium in urine was found to be strongly related to uranium levels in drinking water from drilled wells. Overall there were no significant differences found in kidney morbidity or function between exposed subjects and controls. However after taking into account the entire range of uranium exposure and several background variables, including diabetes, a weak exposure-related effect was seen in urinary levels of several kidney function biomarkers. The clinical relevance of these findings is still uncertain. Comment: Naturally occurring uranium has chemical toxicity properties which affect kidney function at concentration below those where radioactivity would have an adverse effect. Guideline values are set on the basis of preventing chemical toxicity and thus provide an even higher degree of safety in terms of radiological exposure.

Water Disinfection Synergistic benefits between ultraviolet light and chlorine-based disinfectants for the inactivation of Escherichia coli. Rand JL, Shupe G and Gagnon GA. (2008) Water Quality Research Journal of Canada, 43(1); 63-68. Ultraviolet light (UV) can be used as a primary water disinfectant to target organisms that are chemically resistant and also because of the lack of disinfection by-product formation. Chlorine-based disinfectants may then be used as secondary disinfectants to provide residual protection in the distribution systems. Previous studies have shown synergistic effects between various chemical disinfectants in controlling bacteria, viruses and protozoa, but there have been few studies to date investigating synergy with UV in combination with chlorine-based drinking water disinfectants. This study investigated the presence of synergy between UV and chlorine-based disinfectants for the inactivation of Escherichia coli. Disinfection treatments were carried out at the laboratory scale comparing free chlorine, chlorine dioxide, monochloramine, UV light, UV and free chlorine, UV and chlorine dioxide and UV and monochloramine. The UV dose of 80 mJ/cm2 was used. This is similar to drinking water treatment and previous bench- and field-scale experiments. The desired log reduction from chemical disinfections was approximately 2.0 log to allow for a measurable reduction in E. coli concentration to be observed for chemical-only disinfection and also combined UV/chemical disinfection. Contact times (CT) for chlorine and monochloramine were established to be 34.2 seconds and 19.5 minutes respectively and for chlorine dioxide 30 seconds. In addition to these CTs, lower CTs for each disinfectant were also tested where contact times remained the same and the disinfectant dose was lowered. At high CT, samples that received primary UV treatment as well as secondary disinfection had no E. coli present following treatment. Each UV combination strategy received spiked water with an initial concentration of 1.73 x 108 CFU/mL of E. coli. The combination disinfection strategies achieved E.




coli removal of 8.24-log, which was essentially limited by the detection method. UV light alone was the second most effective disinfection strategy and achieved 4.31-log inactivation. When chemical disinfectants were used alone, chlorine dioxide was the most effective, achieving 2.77-log reduction, followed by chlorine (1.32-log) and monochloramine (1.13-log). At low CT, combination strategies also achieved the highest log removals compared with each disinfectant alone. The UV + NH2Cl strategy was found to have the highest reduction observed at 4.75-log, UV + Cl2 was next at 4.37-log and then UV + CIO2 at 4.11-log. Average reduction achieved by UV alone was 3.65-log removal. Chemical disinfectants produced less than 1-log removal at low CT. The data obtained was analysed using an equation presented in a previous study to calculate synergy. When the calculated value is positive, it is an indication that synergy is present (ie the effect of combined disinfection treatment is greater than the effects of the two separate treatments added together). Synergistic values were calculated to compare the efficacy of combination treatment with UV and chemical disinfectants alone. It was calculated that each UV combination with high disinfectant CT values demonstrated synergy according to the equation.

At lower CT values, synergy calculations were also positive for all combination disinfection strategies, however synergy values were not as high as compared to high CT results. These results suggest there are synergistic benefits occurring between UV light and chlorine-based disinfectants. Further research should consider parameters such as water quality and allow for analysis of decay kinetics, flow characteristics and other essential data. Drinking water utilities may see enhanced removal of bacteria and possibly other pathogens due to the synergistic benefits of UV combined with any chlorine-based disinfectant. Comment From the description of methodology in this paper it appears these experiments were carried out at pH 5.1, which is lower (more acidic) than the usual pH range for tap water (6.5 to 8.5). Free chlorine is more effective at low pH, however the optimum pH range for chloramination is between 8 and 8.4. The log reductions and degree of synergy between UV and chlorine-based disinfectants seen under actual drinking water treatment conditions may be different from those observed here.

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