Australian Drinking Water Guidelines

INFORMATION AND ANALYSIS FOR WATER AND HEALTH PROFESSIONALS

Issue 2 Public Health Newsletter of the CRC for Water Quality and Treatment June 1996

Australian Drinking Water Guidelines The revised Australian Drinking Water Guidelines have received final endorsement by the National Health and Medical Research Council and the Agricultural and Resource Management Council of Australia and New Zealand. The revision process has taken more than 3 years to complete, and the resulting documentation is much more comprehensive than previous versions.

In this Issue: Australian Drinking Water Guidelines 1 New Research Projects 1 Cyanobacterial bloom occurrence in drinking water and health effects Cyanobacterial tumour promotion Environmental arsenic exposure and human absorption US Information Collection Rule 4 Conference Reports 4 Epidemiology spot 7 Cohort Studies From the Literature 8 Program 1 Personnel 9 Forthcoming meetings 11 From the Literature (continued) 12 Cryptosporidium Disinfection By Products Surveillance Cholera Cancer Risk assessment Water quality Fluoride Hepatitis List of articles 19

Chapters on System Management, System Performance and Small Water Supplies have been included, and information on individual substances is presented in the form of “Fact Sheets”. The Guidelines take the form of a 2-part loose leaf document, comprising a 40 page summary, and a much larger main document. This format will allow easy insertion of new sections as research knowledge increases and updates are issued. The Guidelines are largely similar to the 1993 World Health Organisation Drinking Water Guidelines, but have also been significantly influenced by the input of specialist panels representing Australian and New Zealand water authorities, state and federal departments of health and water resources, CSIRO, universities and private industry.

For the first time, the Guidelines outline a suggested approach to community consultation to ensure adequate public participation in the decision making processes of water authorities. Community involvement should be sought in deciding the levels of service to be provided, and the time frame during which the necessary changes in treatment or distribution systems are to be implemented. While public health considerations must remain paramount, the financial implications of change will impact on the operation of water authorities, and each community will need to decide its own priorities for the allocation of resources.

New Research Projects

In addition to the Water Filter Study (featured in our last issue) three more research projects have been approved under Program 1 of the CRC for Water Quality and Treatment.

HEALTH STREAM June 1996 PAGE 1

COOPERATIVE RESEARCH CENTRE FOR WATER QUALITY AND TREATMENT

Cyanobacterial bloom occurrence in drinking water sources and health effects.

Project Leader - Dr Louis Pilotto, NCEPH.

This study aims to identify the location and nature of historic bloom data for cyanobacterial occurrence in Australia's waterways, and then to identify, from available data, the sources and types of drinking water for defined geographical areas that have been associated with and without cyanobacterial bloom

Then using a geographic coding of place of residence, state health data collections (eg. cancer registry, mortality register) will be matched with bloom data to investigate possible associated health outcomes. Rates of appropriate biochemical tests (eg. liver function tests and bilirubin) and their rates of abnormality for the identified geographical areas will also be determined from the records of pathology laboratory services in these geographic areas.

The NSW Department of Land and Water Conservation at Parramatta; Australian Water Quality Centre at Adelaide, South Australia; Murray-Darling Basin Commission, ACT; Brisbane City Council; and the South-East Queensland Water Board have agreed to participate by providing available bloom occurrence and toxicity information. The Pregnancy Outcome Unit of the South Australian Health Commission, the NSW Perinatal Data Collection Unit of the NSW Health Department, and the Victorian Perinatal Data Collection Unit have already given in-principal agreement to provide access to their data. It is anticipated that states will provide similar access to cancer registry data. Unit record mortality data will be purchased from the Australian Bureau of Statistics.

The correlation of cyanobacterial bloom occurrence with health outcomes will explore possible associations between exposure and disease. Currently there is very little information available from epidemiological studies to assist with assessing dangers from algal exposure. This study will identify the nature and extent of current cyanobacterial

monitoring in drinking water supplies for the South-Eastern part of Australia, evaluate the usefulness of these systems, and lay the groundwork for future, more rigorous analytic studies.

This project has been funded by the Commonwealth Environment Protection Agency and the CRC WQT. The project is expected to commence shortly and will take about 12 months to complete.

Cyanobacterial Tumour Promotion.

Project Leader - Prof Ian Falconer, University of Adelaide.

This project will investigate the interactions between cyanobacterial toxins, common dietary and environmental carcinogens and tumour growth using animal models. Four specific sub-projects will be carried out:

(i) Interaction between aflatoxin B1, and Microcystis toxins in initiation and growth of cancers.

(ii) Interaction between nitroso-compounds as dietary carcinogens and Microcystis toxins in initiation and growth of cancers.

(iii) Investigation of the potential role of cylindrospermopsin toxin from the tropical cyanobacterium Cylindrospermopsis raciborskii, as a carcinogen.

(iv) Investigation of the underlying mechanisms of tumour promotion by microcystins.

Projects (i) and (ii) will employ mice, which will be exposed to microcystins in their drinking water for the duration of the test period. Oral exposure will be used to replicate the most likely human exposure route, and in particular to explore gastrointestinal tumour growth when directly exposed to microcystins.

The carcinogens to be applied to initiate cells into tumourigenic potential have been selected to mirror possible environmental exposure. Aflatoxin Bl is a well recognised fungal carcinogen in the diet, and has been epidemiologically linked to hepatocellular carcinoma in human populations. As a fungal



metabolite present in grain and nut products as a result of spoilage, intermittent human exposure is likely, even in a regulated situation like Australia.

A second significant source of dietary carcinogens are the nitroso-compounds present in preserved and smoked meat and other foods, and as a result of nitrate/nitrite metabolism outside and inside the body. Endogenous nitroso-compounds are sources of carcinogen exposure throughout life, and have been associated with incidence of gastrointestinal and bladder cancer in the population.

In Project (iii) preliminary experiments will be done to evaluate the biological effects of various oral dosages of cylindrospermopsin. Once the dose levels have been established, a chronic exposure trial will be carried out for up to 12 months in Swiss albino or C57 mice, focussing on tumour incidence. Tumour growth will be measured postmortem, using computer analysis of histological sections.

For Project (iv) the effects of microcystin on cell-cycle control in C3H infant mouse hepatocytes will be investigated using flow cytometry and measurements of DNA replication. Enzyme and structural changes will be correlated to microcystin exposure. In the second phase of the project the previous carcinogens will be used to initiate cells to tumourigenic potential, and the growth potentiation by microcystin will be explored.

The results of this project will provide a greater understanding of public health risks from cyanobacterial toxins, particularly with reference to chronic low level exposures and their possible effects on cancer risks. The project has already commenced and will run for about 3 ½ years.

Environmental arsenic exposure and human absorption - the EnvAs Study.

Project Leader- Dr Malcolm Sim, DEPM.

At least fifteen rural areas in central and north eastern Victoria have been found to have high levels of arsenic in soil and groundwater, in some cases several orders of magnitude in excess of current national and international guidelines, making these

areas unique in terms of arsenic exposure in developed countries. The main source of this arsenic is waste from old gold mining activities and arsenic-based pesticides.

Environmental data gathered during a Pilot trial in 1995 confirmed high concentrations of arsenic in water and soil. There is therefore great potential for human absorption of arsenic through inhalation and ingestion, particularly in children. The number of residents in these areas potentially exposed to increased concentrations of arsenic from environmental contamination, is in the order of 200,000 people. This provides a unique opportunity to study the degree of human absorption following exposure to arsenic in several different environmental media present in a large range of concentration levels.

In the study to be commenced in 1996, 240 residents will be recruited in communities which have four distinct patterns of arsenic contamination in the environment. These four distinct areas will include high soil arsenic concentrations, high water arsenic concentrations, both high water and soil arsenic concentrations and no known environmental arsenic contamination. Residents in these areas will be asked to complete a questionnaire and provide samples of urine, hair and nails for arsenic analysis to document the degree of arsenic absorption. An ecological study, using cancer registry data from these areas is also underway.

Following evaluation of the environmental data, a small intervention study will be carried out involving 20 subjects identified as having the highest concentration of arsenic in their drinking water. These people will be asked to drink bottled water for a short period, and the effect on urine arsenic levels will be examined.

The Pilot study was funded by a PHRDC Small Grant, and a grant has now been obtained from the Department of Human Services (formerly Health and Community Services), Victoria to fund the main study. This project has been recognised as falling within the scope of CRC WQT research Program 1 as it will yield valuable information on the contribution



of drinking water to the body burden of arsenic. The field work phase of the main study will start soon, and the project is scheduled to be completed by the end of 1997.

US Information Collection Rule The "Information Collection Rule" governing compulsory monitoring of microbial contaminants and disinfection byproducts was officially signed by the US EPA Administrator on May 2nd and published in the US Federal Register on May 14th. The ICR specifies the monitoring and data reporting required for public water supplies serving different population sizes. Some water utilities will also be required to carry out bench or pilot scale studies and cost estimates on one of two treatment methods (granular activated carbon or membrane processes) for disinfection byproduct removal. The program is scheduled to commence early in 1997, and the data collection process will be continued for 18 months. It is planned to carry out a preliminary data analysis and make the data available to the public after 8 months.

The ICR is one component of a regulatory process that has been developed in an attempt to provide the optimum balance between health risks from microbial contamination and health risks from disinfection byproducts. The ICR was proposed in early 1994 but its promulgation was delayed by uncertainty over the performance of the testing method for Giardia and Cryptosporidium. This method (immunofluorescent assay) gave disappointing results in laboratory and field tests, and there was some speculation that testing for protozoa would be omitted from the ICR. However, the EPA has decided to include the test with due recognition of its limitations. Criteria for laboratory approval have been made more stringent, and the population limit for this type of test has been raised so that fewer water authorities will be required to conduct the tests. The EPA will also carry out its own surveys of Cryptosporidium in large and small water supplies to supplement the compulsory ICR testing program.

This will be part of a 5 year, $50 million research program to be conducted by the EPA and other research organisations. The data derived from the ICR and these research programs will be used as the basis for future revisions to the US drinking water regulations.

Conference Reports The Royal Australian College of Physicians Conference, Canberra.

Three members of the CRC WQT were invited to present papers at the Annual Scientific Meeting of the Royal Australasian College of Physicians which was held in Canberra on 7-10th May. This conference brings together medical specialists from the Faculties of Public Health, Rehabilitation Medicine, Occupational Medicine, General Medicine and Geriatric Medicine.

Bob Douglas, Ian Falconer and Louis Pilotto each gave a presentation in the session entitled:

“Water - is it safe to drink?”

The abstracts from these talks are reproduced below by permission of the Royal Australasian College of Physicians. The fourth speaker in the same session was Dr Graham Rouch of the Department of Human Services, Victoria, who spoke on the topic “Viruses in water”.

Ian Falconer’s talk at the RACP meeting was the subject of an article in The Advertiser newspaper (Adelaide) on Saturday May 11th. The article by medical writer Barry Hailstone outlined the health issues associated with blue green algal toxins and Prof Falconer’s studies into their possible relationship to cancers of the stomach and bowel.

CRYPTOSPORIDIOSIS AND GIARDIASIS: NOT ONLY IN AIDS. R.M.Douglas, S.Buetow. National Centre for Epidemiology and Population Health, Australian National University, Canberra, ACT.

Cryptosporidium and Giardia are protozoan parasites and common causes of diarrhoeal illness in humans. Both can cause life threatening disease in



immunocompromised individuals, and both are commonly present in Australian surface waters. Both are transmissible in cyst form through contaminated water or food, or from human to human through the faeco-oral route.

Both parasitic cyst forms are difficult to destroy through conventional water disinfection, and both are present in the catchments of many Australian water authorities, giving concern that episodes like the famous Milwaukee epidemic of cryptosporidiosis in 1993 which infected 400,000 individuals in one city in the course of a few days, could occur here.

The incidence and source of gastrointestinal infections with these parasites in Australia is poorly documented, and a major uncertainty facing health and water authorities relates to the contribution which their presence in reticulated water, makes to background gastrointestinal disease rates in the community. A primary water source could be complicated by secondary spread through family or preschool contact by food or faeco-oral contact. The problem relates both to the relatively infrequent investigation of clinical cases of diarrhoea by stool microscopy, and to the fact that routine monitoring of water supplies for cyst forms is cumbersome, insensitive and costly.

An added concern is the growing population of water consumers who are immunosuppressed and therefore particularly at risk of overwhelming systemic infection with these organisms.

BLUE-GREEN ALGAE - ARE HUMANS AT RISK? Ian R. Falconer, Deputy Vice Chancellor, University of Adelaide, Adelaide SA 5005

That domestic animals are at risk has been clearly understood for over a century, as widespread livestock deaths on the shores of Lake Alexandrina in South Australia were described as due to the poisonous green paint-like scum on the lake by George Francis in Nature (London) 1878. The dead animals included pigs, sheep, cattle and horses, as the toxicity is no respecter of style of gastrointestinal tract.

Death of pets and farm animals from consuming cyanobacteria have been reported worldwide, and toxicity falls into three general classes. The major cause is hepatotoxicity from a family of cyclic peptides, the microcystins and closely related nodularin. In Australia the Darling River algal bloom of 1990, which killed thousands of sheep and cattle, had paralytic shellfish poisons as the main toxins. The Palm Island community poisoning in 1979 was by a toxin of widely damaging effects, cylindrospermopsin.

Reports of human injury have come from varied sources, from trainee soldiers doing Eskimo rolls in canoes in a blue-green scum, to ordinary drinkers of a chlorinated tap water supply. In the latter cases (almost always) the water authority had treated a blue-green algal scum with copper sulphate to improve the taste and smell - and consequently released the toxins into the water supply! Of greatest current interest is the experimentally demonstrated promotion of tumour growth by the peptide hepatotoxins, and supporting epidemiological evidence from China of correlation with hepatocellular carcinoma.

DISINFECTION BY-PRODUCTS IN DRINKING WATER AND CANCER. LS Pilotto. National Centre for Epidemiology and Population Health, The Australian National University, Canberra, 0200.

Chlorine, commonly used to disinfect drinking water in Australia and overseas, produces by-products known to be carcinogenic and mutagenic. A literature review was conducted to examine evidence for the association between drinking water chlorination and cancer in humans.

A number of epidemiological studies have found exposure to chlorinated drinking water to be associated with cancers at various sites, including colon, rectum, urinary bladder and kidney. However, most of these studies were ecological in nature, or relied on case-control designs based on death certificates. Interpretation of results arising out of these studies is limited. Individual levels of toxicant exposure and many potential confounders



and effect modifiers are unable to be accounted for in the analysis. At best, these studies generate hypotheses that require more definitive investigation. Misclassification of individuals based on inaccurate assessment of true level of exposure is probable.

Four incident case control studies, able to better estimate exposure, suggest a clear link between exposure to chlorinated drinking water and the development of urinary bladder cancer, and possibly rectal cancer. Based on these studies, an attributable risk for bladder cancer of between 10 and 15% and for rectal cancer of 20% would suggest that 200 - 300 cases of bladder cancer and 500 cases of rectal cancer annually may be associated with the consumption of chlorinated drinking water in Australia. However, no studies have been done in Australia, and our true level of risk is unknown. Considering the widespread use of chlorination in Australia, even a low risk would translate into yearly cases high enough to create public health concern that warrants further investigation.

WaterTech Conference, Sydney.

Several members of the CRC WQT were co-authors of a paper presented at the WaterTech Conference which took place in Sydney on 27 and 28 May. The paper, was presented by Christine Cowie of the NSW Health Department. The abstract of the paper is reproduced below by permission of the Australian Water & Wastewater Association Inc.

A NATIONAL DRINKING WATER QUALITY DATABASE C Cowie (NSW Health Dept.), L Pilotto (NCEPH), R Douglas (NCEPH), D Bursill (SA Water Corp and CRC WQT), A Wade (ACTEW), C Reynolds (ACTEW), G Rouch (Dept of Human Services VIC), W Ho (NSW Dept. of Land & Water Conservation), M Chapman (Melbourne Water), D Bree (Power and Water Authority NT) and R Jones (SA Water Corporation).

The aim of this paper is to establish the need for and to promote the development of a standardised

national drinking water database for health related research. There is currently no national coordinated database on drinking water quality that can be used for observational health studies, or linked with existing health data sources, such as comprehensive cancer registries and hospital statistics. Although all water supply authorities currently monitor and record drinking water quality in their supplies, these data, in their current form may pose major difficulties for health related research. Sampling and analytical methodologies vary across water authorities, accessibility of data is difficult, and data are stored in a variety of ways. It is timely to discuss the potential for standardising water quality monitoring and establishing a national drinking water quality database.

OZWater & OzWaste Trade Exhibition, Sydney.

The CRC WQT was one of several water related CRCs represented in a joint display at the OZWater & OZWaste Trade Exhibition held in conjunction with the WaterTech Conference. The display was coordinated by the CRC for Freshwater Ecology.

Chlorine in Perspective - a case for sound science , Melbourne .

This one day meeting on 11th June was sponsored by CSIRO Division of Chemicals and Polymers, and the Royal Australian Chemical Institute. Nine speakers presented topics ranging from the economic aspects of chlorine use in Australia, to the effects on the atmosphere, and new methods of waste disposal for chlorinated substances.

The meeting at CSIRO’s Clayton branch was attended by about 80 people representing the chemical industry, water authorities, scientists, State and Federal environmental agencies and environmental activist organisations.

Dr Tony Priestley, Deputy Director of the CRC WQT spoke on “Chlorine and our Water System”. Tony began with some interesting historical



references with empirical advice on how to keep water “good”, then went on to compare the characteristics of chlorination, chloramination and other methods of modern water treatment. Ms Andrea Hinwood spoke on the “Role of Scientists in the Montreal Protocol”. Andrea is a currently studying for her PhD at DEPM Monash (on the EnvAs Study - see page 3). At this meeting she spoke in connection with her recent work with the United Nations Environment Programme on reduction of Ozone Depleting Substances. Andrea chaired the Technical Options Committee on Aerosols, Sterilants, Miscellaneous Uses and CTC, and was a member of the Technology and Economics Options Committee.

Professor Ian Rae, Deputy Vice Chancellor of the Victoria University of Technology concluded the formal presentations with some thought provoking remarks on the need for more constructive engagement between the industry/science and the environmental/green camps. He noted that the speakers for the day had largely represented the “pro-chlorine” camp and that the opposing viewpoint had been aired only briefly in an impromptu presentation by Greenpeace representative Matt Ruchel. Professor Rae called for serious consideration by the scientific community of some recently described observations which may be related to chemical exposure (including but not necessarily limited to chlorinated compounds). In particular, the potential effects of chronic exposure on fertility and reproduction need to be thoroughly explored.

The meeting concluded after a general question time with the feeling that further meetings with invited “green” representatives as well as the “industry” group would be more productive in improving communications, identifying specific concerns and perhaps clarifying some misconceptions held by both parties.

Epidemiology Spot COHORT STUDIES Epidemiological studies can be divided into observational and experimental studies. In an observational study the researcher

collects information about a group of subjects comparing the effect of an event(s) on the group but does not intervene nor influence the event(s). By contrast in an experimental study the researcher deliberately influences events and investigates the effects of the intervention.

A cohort study is an observational study where the researcher observes a group of individuals over time. The word cohort refers to the group of people under study. At the beginning of the study the group is defined on the basis of presence or absence of exposure to a suspected risk factor for a disease. At this time all potential subjects must be free of the disease under investigation. Eligible participants are then followed over a period of time to assess the occurrence of the disease being studied. The cohort may be subdivided at the outset into groups with different characteristics.

A good example of a cohort study was the British Doctors Study. In this study a group of doctors (the cohort) were followed over many years. The incidence of lung cancer (the disease outcome) was compared in both smokers (the exposure risk) and non-smokers. The group who smoked had a higher incidence of lung cancer compared with the non-smokers. This has been an influential study in establishing the relationship between lung cancer and smoking.

A cohort study can be prospective or historical:

Prospective cohort study - a group of subjects is identified and followed prospectively perhaps for many years with detailed information collected regularly.

Historical Cohort studies: - a past cohort is identified and their experience up to the present is obtained. This is a less common type of study because detailed records are often not available. This lack of data makes it difficult to be sure about an individual’s level of exposure or even whether they did or did not develop the disease under study. However, if good data is available a retrospective cohort study can be extremely effective and relatively inexpensive. An example of a good data source would be the renal transplant registry which has collected information on every person in Australia



and New Zealand who ever had a kidney transplant and their outcome. Detailed records are kept and updated annually.

Advantages of a cohort study:

• In a prospective cohort you are able to measure the level of exposure of a substance of concern before the disease occurs improving the accuracy of the data.

• Rare exposures are able to be measured when large groups are followed for long periods.

• Multiple health outcomes are able to measured in a single group being followed over time. For example in a cohort with smokers and non-smokers you could compare the incidence of lung cancer, heart disease and strokes between the two groups.

Within a group you can calculate the incidence of disease. Depending on how representative the group under study is compared to the general community the result can sometimes be extrapolated to the incidence of the disease in the community.

Disadvantages of a cohort study:

• Due to their nature cohort studies must continue until a fair proportion of the study group develops the outcome. For this reason cohort studies can take a long time and can be expensive.

• A cohort study needs good follow upon participants ( at least 80%) and losses occur due to the participant moving to another area, losing interest in the study, becoming ill or dying. If a participant cannot be contacted the concern is they may be sick from the disease under study or may have died, and if such results is not recorded the study result will be biased.

• Changes of exposure or habits. In a long term study people might change dietary habits, smoking habits, their work environment and the like altering their exposure level to the risk being studied. In the water industry this is of importance when trying to investigate the risks of long term exposure to chlorine and its by-products.

• Surveillance bias is also a problem with cohort studies. This occurs when a group suspected of being at high risk of a particular disease is closely monitored, the disease may be observed more frequently in this group simply because you are looking for it rather than being a true increase in its incidence compared to the general population.

• Confounding bias can occur. Confounding is due to the mixing of effects between the identified exposure, the disease and a third component which is associated with the identified exposure but also independently affect the outcome disease. A typical example of this is alcohol and smoking. Heavy drinkers are at increased risk of a number of diseases (an example being cancer of the tongue). Smoking also increases the risk of many diseases (including cancer of the tongue). Heavy drinkers are more likely to smoke than the general population. The difficulty with confounding is sorting out which aspect of the disease is due to smoking, which is due to alcohol and which is due to a combination to the two exposures.

Cohort studies have unique advantages and disadvantages that must be taken into consideration when a study is being designed. If used properly a cohort study is an extremely valuable strategy to obtain a valid estimate of the association between an exposure and disease.

From the Literature

Medline delays Regular users of the Medline Database will probably have received notification of delays in entry of references into the database. This problem was caused by budget restrictions imposed by the US Government following difficulties in the passage of the US Budget. The National Library of Medicine was forced to suspend data entry contract work in February, and as a result a large number of references were not entered on schedule (approximately 1,700 new references are normally entered each day). (continued on p12)



Program 1 Personnel We would like to introduce some of the people working on the various projects in Program 1 - starting in this issue with the senior staff members for each CRC WQT “node”.

Prof. John McNeil

Prof. Robert Douglas

Prof Ian Falconer

John McNeil is Head of the Department of Epidemiology and Preventive Medicine (DEPM), Monash University, a position he has held since 1986. His postgraduate qualifications include an MSc in Medical Statistics and Epidemiology from the University of London and a PhD in Clinical Pharmacology from the University of Melbourne.

Professor McNeil currently serves on several state and federal committees in the areas of Public Health, Toxicology and Therapeutics. He has carried out numerous of consultancies for federal and state health departments and private industry including environmental impact assessments, cost benefit studies and epidemiological investigations. His research interests include drug epidemiology, public health toxicology, cardiovascular drug therapy, risk assessment and aspects of water quality and public health. Professor McNeil is the Coordinator of Program 1 "Health Risk Assessment" of the CRC for Water Quality and Treatment.

Robert (Bob) Douglas is the founding Director of the National Centre for Epidemiology and Population Health (NCEPH), at the Australian National University. He was formerly Dean of the Medical School of the University of Adelaide; former President of the Australian and New Zealand Society for Epidemiology and Research in Community Health; and the Foundation President of the Australian Epidemiological Association.

Professor Douglas is a former member of the Council of the National Health and Medical Research Council, and has been a member of several hospital boards and a regional Board of Health. More recently, Professor Douglas has been responsible for the initiation and development of the Australian Health and Water Research Consortium, and is currently convenor of its steering group. Professor Douglas is a Subprogram Manager of Program 1 of the CRC for Water Quality and Treatment.

Ian Falconer is Deputy Vice Chancellor (Academic), and a researcher in the Department of Clinical and Experimental Pharmacology of the University of Adelaide. Prior to this, he was Dean of the Faculty of the Sciences at the University of New England, Armidale, and Professor of Biochemistry in the Department of Biochemistry, Microbiology and Nutrition.

His main research field at present is the health effects of cyanobacterial (blue-green algal) toxins in drinking water, including the chemical nature of the toxins, the biological consequences of poisoning, effective water purification methods for toxin removal, long-term health impacts of toxin consumption, and most recently the cancer promoting properties of these toxins. As a Subprogram Manager of Program 1 of the CRC WQT, Prof Falconer will be continuing his research on cancer promotion by blue-green algal toxins in drinking water, and also participating in epidemiological studies of cyanobacteria in drinking water supplies.



Dr Peter Nadebaum

Mr Mike Chapman

Dr Christopher Fairley

Peter Nadebaum holds a PhD on Chemical Engineering and is Principal of Environmental Management for CMPS&F Southern Region He has acted as senior adviser on many water quality and water treatment projects for government departments and water authorities, including new process research and development. Dr Nadebaum is recognised as a leading expert in air pollution investigation and control work, and has been involved in the investigation and design of a large number of industrial air pollution control facilities, hazardous waste incineration systems and municipal wastewater odour control systems.

In the field of environmental management and assessment, Dr Nadebaum is a prominent consultant for governments and industries in Australia and New Zealand; including the development of national and state environmental policy guidelines, environmental audits, licensing and risk assessments. In the CRC WQT, Dr Nadebaum will continue work on the development and application of risk assessment methodology for the water industry

Mike Chapman is a Chemical Engineer with over twenty years experience in the water industry. He has been involved in many water quality and water treatment projects over this time, working initially for consultants and then Melbourne Water. More recently he held the position of Manager, Water Quality and Treatment Assets and later Water Treatment Division Manager of Research and Development. Treatment technology and water quality risks from catchment to taps are the main focus of attention.

Mike Chapman was chairperson of one of the six panels (physical quality) who jointly developed the recently released NHMRC/ARMCANZ (1996) Drinking Water Guidelines. Mike initiated the Water Filter Study now being undertaken within the CRC WQT, and subsequently co-authored the project proposal with Professor John McNeil and Dr Malcolm Sim of Monash University. Mike was also instrumental in the development of the CRC WQT's Program I and was Melbourne Water's representative on the CRC Board during 1995. Mike recently left Melbourne Water and his role in the Water Filter Study has been assumed by Shane Haydon.

Christopher (Kit) Fairley is an infectious disease physician trained in epidemiology. He undertook his PhD at Monash University studying the epidemiology of human papillomavirus infection. Following this he was awarded a NH&MRC Fellowship to support a post doctoral position at the Communicable Diseases Surveillance Centre in the UK where he worked primarily on the epidemiology of vaccine preventable diseases. On returning to Australia in late 1995, he took up his present position at DEPM where his prime responsibility is for the public health research aspects of the Cooperative Research Centre for Water Quality and Treatment. His current main research interests are waterborne diseases, clinical infectious diseases and vaccine preventable disease. Kit is Project Leader for the Water Filter Study.


Mr Grant Wilson

Dr Louis Pilotto

Grant Wilson holds a Bachelor of Engineering Degree from Monash University in civil engineering and has thirteen years experience in the water industry. He has held a variety of positions in this time including planning, operations, and construction roles in water and wastewater areas.

Grant’s current position is Manager - Water Quality Upgrade Division, which involves the management of the capital works program for the Water Group in Melbourne Water, and management of a program of capital works to improve water quality across Melbourne and the Mornington Peninsula. As coordinator of the Water Filter Study within Melbourne Water, Grant will oversee the project management and contract management of water filter supply and maintenance by Streamline Australia (the trading arm of Melbourne Water).

Louis Pilotto holds a science degree in Statistics, and an Honours degree in Medicine from Sydney University, and a PhD in Epidemiology from the ANU. He is NCEPH's principal epidemiologist in relation to water pollution and health, and has worked in the area of occupational and environmental epidemiology, particularly air and water pollution for seven years.

Dr Pilotto is currently Chief Investigator on a project studying the health effects of recreational exposure to blue-green algae in NSW, SA and Victoria, and has played an integral role in the development of the Australian Health and Water Research Consortium. In the CRC for Water Quality and Treatment, Louis is continuing research into the effects of human exposure to cyanobacterial toxins.

Forthcoming Meetings Management Committee Meeting The next meeting of the Management Committee of the CRC WQT will take place on Monday 22nd July at the University of South Australia.

NOTE: this date has been altered from 15th July.

Board of Management The next meeting of the Board of Management of the CRC WQT is scheduled for Monday 16th September at the offices of the SA Water Corporation in Adelaide.

Program 1 Advisory Group The second meeting of this group will take place at the Australian National University in Canberra on Monday 12 th August.

NOTE: this has been altered from 19th August.

Water Supply Health Workshop Planning is underway for a workshop to be held in September (tentatively scheduled for Wed/Thurs 4th and 5th) at a venue to be decided. The workshop will address ways to rank health risks and prioritise research targets.


From the Literature (continued from p8)

The problem has now been resolved but clearing the backlog of entries will take some time. This is why users may notice “old” papers (eg from late 1995) suddenly appearing in the Medline updates.

Brief Summaries

Cryptosporidium

The infectivity of Cryptosporidium parvum in healthy volunteers.

DuPont HL, Chappell CL, Sterling CR, Okhuysen PC, Rose JB and Jakubowski W. New-Eng-J-Med 332(13) p855-59.

A total of 29 volunteers were selected following an informed consent procedure, and screening tests for normal immune function, general health, and lack of specific antibody against C. parvum. 12 were men and 17 were women, their ages ranged from 20 to 45 years, 19 were white, 6 were black and 4 were Hispanic.

These volunteers ingested gelatin capsules containing doses of 30 to 1,000,000 oocysts of a C. parvum strain that was initially isolated from and subsequently propagated in calves. All stools passed by the subjects were collected daily for 2 weeks following exposure, and then 24 hour specimens were collected on 2 days per week for 2 months. The actual dose of viable oocysts in each batch of capsules was estimated from excystation rates, viability staining and infection of mice.

Infection in the human subjects was defined as excretion of oocysts in stools more than 36 hours following ingestion of the test dose (to allow for passive excretion of the test organisms). Diarrhoeal illness was defined as the passage of 3 liquid or soft stools in 8 hours, or more than 3 liquid or soft stools in 24 hours plus one or more signs or symptoms (fever, nausea, vomiting, abdominal pain or cramps, intestinal gas). Cryptosporidiosis was defined as oocyst positive stools plus diarrhoeal illness. Subjects who had cramps, nausea etc but did not have diarrhoeal illness were classified as having enteric

symptoms. The results are summarised below:

Oocyst dose 30

100 300 500 ≥1000

No. subjects 5 8 3 6 7

Infection 1 3 2 5 7

Enteric symptoms

0 3 0 3 5

Cryptosporidiosis

0 3 0 2 2

Infection occurred at all dose levels, but was more likely at higher doses. Overall, 18 (62%) of the 29 subjects became infected, and 11 (38%) showed no evidence of infection. Of the 18 people judged to be infected (oocysts in stools), 11 (61%) had enteric symptoms but not all of these were deemed to have cryptosporidiosis as they did not develop diarrhoea (as defined in the study criteria). The estimated ID50 (dose where 50% of those exposed become infected) was 132 oocysts, which was similar to previous estimates for another protozoan pathogen Giardia lamblia in humans.

Higher doses tended to be associated with more rapid onset of illness and longer duration of oocyst excretion but these trends were not statistically significant. The average incubation period was 9 days and illness typically lasted about 3 days with about 13 soft or liquid stools in that period. All subjects with diarrhoeal illness were treated for 5 days with paromomycin (an antibiotic which has been shown to have some therapeutic effect against Cryptosporidium - this may have shortened the infection period), and one subject was given intravenous fluids for mild dehydration.

Prior to the study all subjects were instructed on self-treatment with oral electrolyte solution. Subjects were also advised on the importance of personal hygiene and avoidance of contact with young infants, pregnant women and elderly or debilitated persons. No secondary infections were detected among 30 household contacts of participants.



Cryptosporidium parvum: intensity of infection and oocyst excretion patterns in healthy volunteers.

Chappell C.L., Okhuysen P.C., Sterling C.R. and DuPont H.L. J-Infect-Dis 173 p232-36.

This paper describes features of experimentally induced Cryptosporidium infections in a group of 18 volunteers who became infected after receiving doses of 30 to 1,000,000 oocyts (described in the paper above).

Oocysts in stool specimens were enumerated by examination of triplicate aliquots from each specimen by direct fluorescent assay using a commercially available kit. The duration of the prepatent period (from ingestion of oocysts until first detected excretion) ranged from 4 to 14 days, and tended to be shortest in those with cryptosporidiosis (mean 5 days), slightly longer in those with enteric symptoms but not diarrhoea (6.4 days) and longest in those without symptoms (10.7 days). However these differences did not reach statistical significance. The duration of infection (excretion of oocysts) was less than 18 days in 15 of the 18 subjects, but 3 people showed prolonged infection (oocysts detected as long as 18, 20 and 38 days after ingestion).

Patterns of excretion appeared to be intermittent in several subjects, with some stool specimens negative for oocysts being followed by positive specimens on the same or subsequent days. The percentage of stool specimens with oocysts collected on days where diarrhoea occurred ranged from 20% to 100%, with a median of 62.5%. The authors acknowledge that this observation may have been partly due to limitations in the detection technique, nevertheless it is believed that oocyst shedding does not occur at a constant rate.

Attempts to determine the relationship between the ingested dose and total numbers of oocysts produced during the course of infection gave unexpected results. Although 16 of the 18 subjects produced more oocysts than they initially ingested, an inverse trend was seen - those with higher ingested dose tended to produce fewer oocysts overall. The authors note that a lack of correlation between increasing

doses of Cryptosporidium parvum and rates of illness has been previously observed. Several hypotheses have been suggested to explain this including production of a substance that is toxic to host cells or to developmental stages of the parasite, saturation of susceptible host cells, or increased host immune response at higher challenge doses. All of these remain speculative at present.

The results of this study further clarify the difficulty in diagnosis of Cryptosporidium infection in humans. Examination of a single stool specimen may not reveal the organism as shedding of oocysts appears to be intermittent even during diarrhoeal illness.

Cryptosporidiosis: an unrecognised cause of diarrhea in elderly hospitalised patients.

Neill M.A., Rice S.K., Ahmad N.A. and Flanigan T.P. Clin-Infect-Diseases. (1996) 22 p168-70.

Literature reports of cryptosporidial infection in developed countries have suggested that infection rates are highest in young children and in adults with specific immune system deficiencies (eg people with AIDS /HIV infection and cancer patients on immunosuppressive drugs). Infections in the elderly have seldom been reported. In this study, microbiological test records of faecal specimens examined over a 5 year period (1987-1991 inclusive) in a 325 bed acute care community hospital in Rhode Island USA were reviewed to identify patients who had cryptosporidial infection (diagnosed by modified acid-fast staining of faecal smears). The pre-existing medical conditions and other clinical test results of 36 such patients were investigated to determine whether such factors were associated with infection (the number of records reviewed to identify the 36 cases was not stated).

It was found that 18 (50%) of the 36 patients had HIV infection, 5 (14%) were healthy adults with no apparent risk factors for Cryptosporidiosis, and 13 (36%) were elderly people with chronic illnesses. These chronic illnesses included 8 patients with various types of cancer, but also 5



patients with non-malignant conditions such as chronic obstructive pulmonary disease and hypertension. The 13 elderly patients had been initially diagnosed as having Clostridium difficile diarrhoea (confirmed by detection of faecal C. difficile toxin in 6 patients), but had failed to respond to appropriate antibiotic treatment. In 7 of the 13, hospitalisation had been required due to the severity of diarrhoea. The authors suggest that cryptosporidial infection may be an unrecognised cause of diarrhoea in the elderly, and that coinfection with other pathogens may also be common.

Cryptosporidiosis: An outbreak associated with drinking water despite state-of-the-art water treatment.

Goldstein S.T., Juranek D.D., Ravenholt O., Hightower, A.W., Martin, D.G., Mesnik J.L. Griffiths, S.D, Bryant, A.J., Reich, R.R. Herwaldt, B.L. Ann-Intern-Med (1996) 124 (5) p 459-68.

An outbreak of cryptosporidiosis occurred in the first 4 months of 1994 in Clark County, Nevada despite a state-of-the-art water treatment plant. Most of the cases were reported in HIV infected persons. An investigation was undertaken to identify the magnitude and cause of the outbreak and to determine whether many cases had occurred in people not infected with HIV.

A review of laboratory and surveillance records was carried out to identify all cases of Cryptosporidium infection diagnosed during the study period (1 January to 30 April 1994), as well as a review of and death certificates of laboratory confirmed cryptosporidiosis. Of the 78 confirmed cases diagnosed in the study period, 61 of these were adults infected with HIV, 4 were adults not infected with HIV, 2 were HIV infected children and 11 were immunocompetent children. Of the 61 HIV infected adults, 32 died by the 30 June 1994 and at least 20 of these had cryptosporidiosis on their death certificates.

A case-control study of 36 “case-patients” (HIV infected adults ≥ 18 yrs, living in Clark County who were diagnosed for the first time with cryptosporidiosis during the study period) were matched by physician or clinic and CD4+ cell count with 107 HIV infected controls from the county. Telephone interviews were conducted. Controls were asked about exposures during the 4 weeks prior to the study period and illness for 4 months before. All case-patients and 31 controls had diarrhoea during the study period. Persons who drank any unboiled tap water were 4 times more likely to have cryptosporidiosis than those who drank only bottled water. The association was even stronger for those with CD4+ cell counts less than 100 cells/mm³. No association between illness and travel or exposure to potentially contaminated persons, animals, food or recreation water was found.

A similar case-control study was undertaken on children with 10 case-patients who had confirmed cryptosporidiosis and 26 matched controls. Parents were interviewed. All case-patients and no controls had diarrhoea during the study period. No statistically significant difference was found with regard to exposures.

A Community Health Survey was distributed to the employees of two Clark County agencies to determine whether during the study period they had a diarrhoeal illness and to identify their sources of drinking water. Of the employees 45.9% reported diarrhoeal illness during the study period. None of the ill employees were evaluated by a physician or stool specimens taken. Half of those who drank tap water reported diarrhoeal illness and 28.9% who did not drink tap water also had such an illness.

Water quality data was obtained from Lake Mead and reviewed for a 50 month period; data on water



quality for treated water was reviewed for 28 months and the water treatment plant inspected. No elevated turbidity values or coliform counts were found. So-called presumptive oocysts were intermittently found in samples of source water, filter backwash, and treated water.

It can be concluded that the outbreak was not limited to HIV infected people. Also that contamination of municipal drinking water was the most likely vehicle of transmission. The case-control study strongly implicated tap water and showed that drinking bottled water was protective if drunk exclusively. Illness was also more common in employees who drank tap water. This study highlights the importance of surveillance of Cryptosporidium and the need for more sensitive methods for detecting oocysts in water. Also the need for guidelines for preventing water-borne cryptosporidiosis infection among HIV+ people.

Disinfection By Products

Ingestion, inhalation and dermal exposures to chloroform and trichloroethene from tap water.

Weisel C.P. and Jo W-K. Envir-Health-Perspect 104(1) p48-51.

A series of 25 experiments were carried out to determine the relative significance of different exposure routes in the absorption of volatile compounds. Eleven volunteers (6 male, 5 female) with ages ranging from 20 to 50 years, were exposed via a single route in each experiment and their exhaled breath was analysed for chloroform and trichloroethene (chloroform is formed as a result of chlorination of municipal water supplies, and trichloroethene is a common contaminant of groundwater in the United States). "Dermal only" exposure during 10 minutes of showering (8 experiments) or 30 minutes of bathing (4 experiments) was achieved by having subjects breath purified air through a mouthpiece. "Inhalation only" exposure was achieved by having subjects shower (9 experiments) for 10 minutes in waterproof clothing. Water temperature was maintained at 40°C ± 2°C

during showering and bathing. For ingestion, 4 experiments were performed where 0.5 litres of water was consumed.

Breath samples were taken at times ranging from 1 minute to 6 hours after exposure. Water and exhaled breath samples were analysed for chloroform and trichloroethene by Gas Chromatography/ Mass Spectroscopy or Gas Chromatography/ Electron Capture Detection. It was found that trichloroethene could be detected in breath for only a few minutes after ingestion of residential well water, and chloroform could not be detected after ingestion of municipal water. The authors postulate that this could be due to complete metabolism of the ingested dose during one pass through the liver, so that blood concentrations (and therefore exhaled breath) were not elevated. The detection of trichloroethene in the first few minutes after ingestion was suggested to be due to residual water in the mouth and throat.

In contrast, elevated breath levels of chloroform or trichloroethene were detected after inhalation, and dermal exposure from showering or bathing, and persisted for several hours. The authors estimated that the internal dose received for either inhalation or dermal exposure during showering was equivalent to drinking 2 litres of water (assuming 100% absorption across the gastrointestinal tract). The combined dose from both routes during normal showering would presumably be additive. The authors also commented that compounds absorbed via dermal or inhalation routes could potentially circulate through the bloodstream to all bodily organs whereas those absorbed from the gastrointestinal tract would first be subject to metabolism by the liver. This may be significant for assessing the potential long term toxic effects of the native compounds or their metabolites.

Preliminary screening for the potential of drinking water disinfection byproducts to alter male reproduction.

Klinefelter G.R., Suarez J.D., Roberts N.L. and DeAngelo A.B. (1995) Reprod-Toxicol 9 (6) p571-578.



The effects of exposure to bromodichloromethane (BDCM) and chloral hydrate (CH) on sperm motility and testicular histopathology in rats was examined. Groups of four week old male F344 rats were exposed to various doses of the 2 compounds in drinking water as part of a chronic cancer screening project. Subgroups of exposed and control group rats (6 or 7 animals per exposure level) were killed after 52 weeks of exposure and their internal organs were examined. Sperm were isolated from the epididymidis and various motility parameters were examined.

No effect of BDCM or CH on gross organ morphology or histological appearance was seen, and no tumours were detected. At the higher exposure levels, both compounds had significant effects on sperm motility parameters. The exposure levels used were 0.33 and 0.62 g/l for BCDM (reported levels in US drinking water 4-7 µg/l) and 0.78 and 2.7 g/l for CH (reported levels in US drinking water 2-3 µg/l). In view of these results the authors suggest that the potential reproductive effects of DBPs should be considered when priorities for risk assessment are being set.

Surveillance:

Surveillance for waterborne-disease outbreaks - United States, 1993-1994

Kramer M.H., Herwaldt B.L., Craun G.F., Calderon R.L. and Juranek D.D. CDC Surveillance Summary (1996) 45 (SS1) p1- 33.

This report summarises data for disease outbreaks associated with drinking water and recreational water in the United States during 1993 and 1994, and for previously unreported outbreaks in 1992.

Drinking water. For 1993/94 a total of 30 outbreaks were reported including the largest documented outbreak of cryptosporidiosis which affected an estimated 403,000 people in Milwaukee. Cryptosporidium was identified as the causative agent in 4 other outbreaks, and Giardia lamblia was identified in 5 outbreaks. Bacterial agents accounted for 7 outbreaks - 3 were due to Campylobacter jejuni,

1 to Salmonella typhimurium, 1 to Shigella sonnei, 1 to Shigella flexneri, and 1 to non-O1 type Vibrio chloerae. Various kinds of chemical poisoning were identified in 8 outbreaks - lead in 3 outbreaks, fluoride in 2, nitrate in 2, and copper in 1 outbreak. In 5 outbreaks no causative agent could be definitely identified, but in 2 such outbreaks the characteristics were deemed to be consistent with viral agents.

Recreational water. For 1993/94 a total of 26 outbreaks were reported, including 14 outbreaks of gastroenteritis. Four of the 14 were attributed to Giardia lamblia and 6 to Crytosporidium parvum. Two outbreaks were caused by Shigella sonnei, 1 by Shigella flexneri and 1 by E. coli O157:H7. There were 9 outbreaks of Pseudomonas-associated dermatitis in swimming pools, hot tubs and spas. Two outbreaks of dermatitis were associated with incorrect use of swimming pool chemicals. There was one case of fatal amoebic meningoencephalitis (Naegleria fowleri) associated with swimming in contaminated water.

Cholera

Epidemiology of Vibrio cholerae 0139 with special reference to intrafamilial transmission in Calcutta.

Sengupta, P.G. Sircar, B.K. Mandal, S.K. Mukhopadhyay, A.K. Nair, G.B. Gupta, D.N. Ghosh, S. Saha, N.C. Deb, B.C. Sikder, S.N. et al J-Infect. (1995) 31(1) p 45-7.

To determine the extent of Vibrio cholerae 0139 among healthy contacts, 27 families of hospitalised patients suffering from acute watery diarrhoea caused by V. cholerae 0139 and 14 neighbourhood families were bacteriologically screened for 4 consecutive days. V. cholerae was isolated from faeces of 14.6% of patients families as compared to none in neighbourhood families. V. cholerae was found in handwashings, stored drinking water, open well water, flies and pond water used by the patients families and none from the neighbourhood families.



Cancer

Significance of exposure assessment to analysis of cancer from inorganic arsenic in drinking water in Taiwan.

Brown, K.G. Chen, C.J. Risk-Anal. (1995) 15(4) p 475-84.

Data was re-examined from a large ecological study in Southwest Taiwan which looked at dose-response patterns for lung, liver and bladder cancers to inorganic arsenic in drinking water. When villages where limited data on the arsenic concentrations were deleted from the analysis there was no evidence of excess risk below arsenic concentrations of 0.1 mg/l. If villages with limited data were included, the risks were much higher at lower doses.

Elevated incidence of childhood leukemia in Woburn, Massachusetts: NIEHS Superfund Basic Research Program searches for causes.

Durant, J.L. Chen, J. Hemond, H.F. Thilly, W.G. Environ-Health-Perspect. (1995) 103 Suppl 6 p 93-8.

Childhood leukemia rates in Woburn, Massachusetts were 4 fold higher than the national average between 1966 and 1986. The possibility was explored of a temporal correlation between elevated leukemia and mobilisation of toxic metals from a waste disposal site in north Woburn. Residents may have been exposed to excess arsenic and chromium levels by consuming municipal groundwater. The pathways of metal transportation, the principal human cell mutagens and the extent of exposure and genetic change in residents is currently being researched.

Primary prevention of hepatocellular carcinoma.

Yu, S.Z. J-Gastroenterol-Hepatol. (1995) 10 (6) p 674-82.

A correlation was found between hepatocellular carcinoma (HCC) mortality rates in China and both infection with hepatitis B virus and the intake of

aflatoxin B1, which contaminated foods particularly corn, peanut oil, soya sauce and fermented soya beans. In addition other large epidemiological studies have confirmed that people who drink pond ditch water experience higher HCC mortality rates. Blue-green algal toxin microcystin was a contaminant of pond-ditch water. Therefore a combined strategy of prevention of hepatitis, control of crops and control of drinking water is advocated for the primary prevention of HCC in China.

Risk Assessment

Risk-based concentrations: prioritizing environmental problems using limited data.

Smith, R.L. Toxicology. (1996) 106(1-3) p 243-66.

This paper looks at the quantitative approach incorporating USEPA risk assessment methods to prioritize locations, contaminants and media according to potential health risk. Risk-based concentrations, for 596 contaminants in air, drinking water and edible fish and soil were produced. This information can be used to calculate numerical ratios between measured environmental levels and risk-based concentrations.

Use of computer models to assess exposure to agricultural chemicals via drinking water.

Gustafson, D.I. Sci-Total-Environ. (1995) 171 (1-3) p 35-42.

Computer models are one of the most cost-effective tools available to assess exposure to agricultural chemicals via drinking water. They can be used to perform quantitative extrapolation and thereby quantify regional exposure from field-scale monitoring information.

Water quality Do Water Filters Work?

Goreman, C. (1996) Time Magazine, June 17.



This article presented interesting statistics; American home-owners spent $450 million last year on water treatment systems compared to $350 million in 1994. At least 12% of U.S. households treat their water and this number is expected to rise. The article described the range of filters available, and made the point that most systems need regular filter replacement or people can end up with water in worse condition than unfiltered tap water. Types of filters include: Activated-Carbon Filtration - these improve taste by removing contaminants such as chlorine and sediment. Reverse Osmosis (RO) - these remove lead, arsenic and some pathogens like Giardia. Distillation - these remove most inorganic contaminants and kill any pathogens but do not remove volatile chemicals. Prices range from about US$25 for a activated carbon filter jug to over US$800 for RO units. According to experts quoted in this article, home treatment of water is probably not worth the effort or cost.

Lead toxicity and public health policy.

Millstone, E. and Russell, J. J-R-Soc-Health. (1995) 115(6) p 347-50.

The public policy implications from the findings by UK scientists that lead exerts neurotoxic effects at blood lead levels as low as 10 micrograms/dL are outlined, especially in relation to drinking water, soil and household dust contamination. The proportion of 6 year old children with elevated blood lead levels for several locations is also estimated.

Reconciling science and policy in setting federal drinking water standards--four states’ perspectives.

Hutcheson, M.S. Dupuy, C.J. Matyas, B. McGeorge, L. Vanderslice, R. Regul-Toxicol-Pharmacol. (1995) 22 (1) p 11-23.

The reconciliation of legal mandates provided by the statutes and the science underlying them in setting federal drinking water standards is presented from the perspectives of four US states.

Environmental health and Hispanic children.

Metzger, R. Delgado, J.L. Herrell, R. Environ-Health-Perspect. (1995) 103 (Suppl 6) p 25-32.

The environmental health status of Hispanics and their children is poor with ambient air pollution, workers exposed to chemicals, indoor air pollution and drinking water quality all being threats to human health. There are also inadequacies in the collection of data on Hispanics. Improving the quantifiability of environmental exposures and risk based on race or ethnicity should be a priority as well as a health based approach to environmental justice.

Fluoride

Effects of fluoridated drinking water on bone mass and fractures: the study of osteoporotic fractures.

Cauley, J.A. Murphy, P.A. Riley, T.J. Buhari, A.M. J-Bone-Miner-Res. (1995) 10(7) p 1076-86.

2076 non-black women aged ≥65 years were recruited into the Study of Osteoporotic Fractures at the Pittsburgh clinic to determine if optimal fluoridation of public water supplies influences bone mass and fractures. Exposure to residential fluoridated water had no effect on bone mass. The risks of nonspine fractures, osteoporotic fractures and hip fracture in women exposed to fluoride for 20 years tended to be lower than non-exposed women but these differences were not statistically significant. There was no association with wrist or spinal fractures.

Hepatitis

An outbreak of viral hepatitis E: role of community practices.

Singh, J. Aggarwal, N.R. Bhattacharjee, J. Prakash, C. Bora, D. Jain, D.C., Sharma, R.S. Datta, K.K. J-Commun-Dis. (1995) 27(2) p92-6.

An outbreak of viral hepatitis due to HEV was spread in a community through sewage contamination of the water supply. The number of cases of jaundice was restricted by the community boiling drinking water until the water quality improved.



List of articles

Cryptosporidium The infectivity of Cryptosporidium parvum in healthy volunteers. DuPont H.L., Chappell C.L., Sterling C.R., Okhuysen P.C., Rose J.B. and Jakubowski W. New-Eng-J-Med 332(13) p855-59. Cryptosporidium parvum: intensity of infection and oocyst excretion patterns in healthy volunteers. Chappell C.L., Okhuysen P.C., Sterling C.R. and DuPont H.L. J-Infect-Dis 173 p232-36. Cryptosporidiosis: an unrecognised cause of diarrhea in elderly hospitalised patients. Neill M.A., Rice S.K., Ahmad N.A. and Flanigan T.P. Clin-Infect-Diseases. (1996) 22 p168-70. Presence of Cryptosporidium oocysts in fresh vegetables. Monge R. and Chinchilla M. J-Food-Protection (1996) 59 (2) p202-203. Cryptosporidium: sources of infection and guidelines for prevention. Juranek, D.D. Clin-Infect-Dis. (1995) 21 Suppl 1 p S57-61. Disinfection By Products Ingestion, inhalation and dermal exposures to chloroform and trichloroethene from tap water. Weisel CP and Jo W-K. Envir-Health-Perspect 104(1) p48-51. Preliminary screening for the potential of drinking water disinfection byproducts to alter male reproduction. Klinefelter G.R., Suarez J.D., Roberts N.L. and DeAngelo A.B. (1995) Reprod-Toxicol 9 (6) p571-578. Surveillance: Surveillance for waterborne-disease outbreaks - United States, 1993-1994 Kramer M.H., Herwaldt B.L., Craun G.F., Calderon R.L. and Juranek D.D. CDC Surveillance Summary (1996) 45 (SS1) p1- 33. Cholera Epidemic cholera in Latin America: spread and routes of transmission. Guthmann, J.P. J-Trop-Med-Hyg. (1995) 98(6) p419-27. Epidemiology of Vibrio cholerae 0139 with special reference to intrafamilial transmission in Calcutta.

Sengupta, P.G. Sircar, B.K. Mandal, S.K. Mukhopadhyay, A.K. Nair, G.B. Gupta, D.N. Ghosh, S. Saha, N.C. Deb, B.C. Sikder, S.N. et al J-Infect. (1995) 31(1) p 45-7. Cancer Significance of exposure assessment to analysis of cancer from inorganic arsenic in drinking water in Taiwan. Brown, K.G. Chen, C.J. Risk-Anal. (1995) 15(4) p 475-84. Elevated incidence of childhood leukemia in Woburn, Massachusetts: NIEHS Superfund Basic Research Program searches for causes. Durant, J.L. Chen, J. Hemond, H.F. Thilly, W.G. Environ-Health-Perspect. (1995) 103 Suppl 6 p 93-8. Primary prevention of hepatocellular carcinoma. Yu, S.Z. J-Gastroenterol-Hepatol. (1995) 10 (6) p 674-82. Age-specific carcinogenesis: environmental exposure and susceptibility. Thomas, R.D. Environ-Health-Perspect. (1995) 103 Suppl 6 p 45-8 Risk Assessment Realistic risk assessment. Stohrer, G. Regul-Toxicol-Pharmacol. (1995) 22(2) p 118-21 Risk-based concentrations: prioritizing environmental problems using limited data. Smith, R.L. Toxicology. (1996) 106(1-3) p 243-66. Risk assessment of chemical mixtures from a public health perspective. Mumtaz, M.M. Toxicol-Lett. (1995) 82-83 p 527-32 Probabilistic risk assessment of nephrotoxic effect of uranium in drinking water. Morris, S.C. Meinhold, A.F. Health-Phys. (1995) 69 (6) p 897-908. Use of computer models to assess exposure to agricultural chemicals via drinking water. Gustafson, D.I. Sci-Total-Environ. (1995) 171 (1-3) p 35-42. Water Quality Lead toxicity and public health policy. Millstone, E. Russell, J. J-R-Soc-Health. (1995) 115(6) p 347-50.



Reconciling science and policy in setting federal drinking water standards--four states’ perspectives. Hutcheson, M.S. Dupuy, C.J. Matyas, B. McGeorge, L. Vanderslice, R. Regul-Toxicol-Pharmacol. (1995) 22 (1) p 11-23. Need to revise the national drinking water regulation for copper. Sidhu, K.S. Nash, D.F. McBride, D.E. Regul-Toxicol-Pharmacol. (1995) 22 (1) p 95-100. Inactivation of fecal bacteria in drinking water by solar heating. Joyce, T.M. McGuigan, K.G. Elmore-Meegan, M. Conroy, R.M. Appl-Environ-Microbiol. (1996) 62(2) p 399-402. Environmental health and Hispanic children. Metzger, R. Delgado, J.L. Herrell, R. Environ-Health-Perspect. (1995) 103 Suppl 6 p 25-32. understanding of issues relating to water that cause problems for Aboriginal and Torres Strait Islander communities. Fluoride Effects of fluoridated drinking water on bone mass and fractures: the study of osteoporotic fractures. Cauley, J.A. Murphy, P.A. Riley, T.J. Buhari, A.M. J-Bone-Miner-Res. (1995) 10(7) p 1076-86. Outline of control practice of endemic fluorosis in China. Wang, L.F. Huang, J.Z. Soc-Sci-Med. (1995) 41 (8) p 1191-5 Hepatitis An outbreak of viral hepatitis E: role of community practices. Singh, J. Aggarwal, N.R. Bhattacharjee, J. Prakash, C. Bora, D. Jain, D.C., Sharma, R.S. Datta, K.K. J-Commun-Dis. (1995) 27(2) p92-6. Miscellaneous Outbreak of toxoplasmosis associated with municipal drinking water--British Columbia. The British Columbia Toxoplasmosis Team. Bell, A. Gill, R. Issac-Renton, J. King, A. Martinez, L. Roscoe, D. Werker, D. Eng, S. Can-Commun-Dis-Rep. (1995) 21 (18) p161-3, discussion p163-4. Analysis of the cyanide metabolite 2-aminothiazoline-4-carboxylic acid in urine by high-performance liquid chromatography. Lundquist, P. Kagedal, B. Nilsson, L. Rosling, H. Anal-Biochem. (1995) 228 (1) p 27-34.

Diabetes mellitus and arsenic exposure: a second look at case-control data from a Swedish copper smelter. Rahman, M. Axelson, O. Occup-Environ-Med. (1995) 52 (11) p 773-4. Environmental impact, healthful food and education in toxicology--trends in Croatia. Kniewald, J. Kniewald, Z. Cent-Eur-J-Public-Health. (1995) 3 (3) p 163-8.


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