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30 World Heahh • November-December 1992 WHO on ••• New WHO drinking-water guidelines Nearly 3000 million people are still exposed to water containing pathogenic organisms. Cholera, dysentery, guinea-worm infection, hepatitis, schistosomiasis, and typhoid are some of the better known killers in the catalogue of water-borne diseases. The two-year old cholera epidemic in Latin America has reminded the world that there is no dividing line between quality of water and the health status of populations. At the other end of the scale there are concerns over pesticides and industrial chemicals threatening to contaminate water sources. WHO is reviewing its existing Guidelines for drinking-water quality, with the collaboration of experts from 34 countries representing all continents, as well as a number of specialists from the United Nations agencies, the European Economic Community, and nongovemmental organizations. Volume one of the new three-volume guidelines being published by the Organization should be available by mid-1993. They will include re-evaluation of such inorganic chemicals as aluminium, arsenic and copper as well as the following compounds: decomposition products, especially from pesticides; polyaromatic hydrocarbons; and by- products of chlorination and ozonization. Particular attention is to be given to chlorate, due to lack of toxicity data. Health-based guideline values are recommended for 35 inorganic and 18 organic chemicals. In the case of pesticides, for instance, this represents a fourfold increase compared with the present edition ( 1984 ). Of particular concern are contaminants that have cumulative toxic properties, such as heavy metals, pesticides and carcinogenic substances. For example, chemical disinfectants in water treatment sometimes result in the formation of potentially hazardous chemical by- products. However, the risks to health from these compounds are extremely small compared with the risks associated with inadequate disinfection. As regards the naturally occurring radionuclides in drinking- water, they contribute very little to the total ambient exposure. A case in point: lead Lead is toxic to the central and peripheral nervous system. Prolonged exposure may cause serious neurological damage, especially among infants, children and pregnant women. High lead content in drinking-water is habitually associated with household plumbing (through piping, solders and other lead-treated materials). Much more stringent guidelines for lead- I 0 f..lg per litre instead of 50 f..lg - are being recommended. Lead should also be reduced in air and food. Major health risks The greatest health risks worldwide are directly linked to ingestion of water contaminated with sewage. According to Or Peter Toft of the Canadian Department of National Health and Welfare, and Chairman of the meeting convened by WHO last September to review the guidelines, "Safeguarding drinking-water supplies is a major health responsibility. Safe water makes a powerful contribution to good health. World Health • November-December 1992 Cholera victim in northern Bangladesh. Different countries will, no doubt, have different priorities in their application of the guideline values. Nevertheless, we hope that all governments will find a use for the new guidelines, either in setting drinking-water standards or updating and expanding existing ones." • No epidemic with new AIDS virus Initial fears of a potential epidemic of a new viral AIDS-like disease in humans have been calmed after scientific meetings in the USA last August and at WHO headquarters in Geneva, Switzerland, last September. To date, fewer than 100 cases of AIDS-like disease or severe immunosuppression without other explanation have been found over a In the next issue Injuries and deaths due to acci- dents and violence affect a great number of people in the world today. WHO wil l devote its 1993 World Health Day-7 April-to this important public health problem, and the next issue of World Health wi ll cover many aspects of preven- tive action that can be undertaken . • period of at least six years among people who are not infected with HIV. This has led scientists to conclude that there is no epidemic of a new cause of severe immunosuppression. The available evidence does not suggest that these cases are due to a new HIV- like virus or any other infectious agent that could be transmitted, including transmission through blood or blood products. An extensive search for new cases in more than 21 countries throughout the world showed that severe immunosuppression not due to HIV infection or other known causes of immunosuppression is rare, in both industrialized and developing countries. Some cases could ultimately be shown to be attributable to temporary suppression of white AIDS is still an almost mythical disease. Fighting wrong ideas is pari of the struggle. Did you enjoy this issue? 31 blood cells, infections such as tuberculosis, or genetic conditions. Although preliminary reports suggest the presence of several different microorganisms from a very small number of cases, these findings have not yet been duplicated, and their role, if any, is unclear. No definitive evidence for any new virus causing immunosuppression exists. According to WHO, it is important to further investigate this disease. However, the priority today is to continue to concentrate efforts and resources on the prevention and control of AIDS, in the light of WHO's estimate that HIV has already infected some 11-13 million people around the world. • Photo Credits Cover Poge 3 Poges 4 Poge 5 Poge 6 Poge 7 Poge 6 Poge 9 Poge 10 Poge 11 Poge 11 Poge 13 Poge 14 Poge IS Poge 17 Poge 16 Poge 19 Poge 10 Poge 11 Poge 11 Poge 13 Poge 14 Poge 15 Poge 16 Poge 17 Poge 16 Poge 19 Poge 30 Poge 31 Bod cover : WHO/ P. Aimosy : WHOjT. Fol<os . WHO/ UNHCR · WHO/Iofor · WHO/C. Powol · WHO/ L Gubb . WHO/ IlO/ l. Moillord : WHO/ IlO/ l. Moillord; WHO/ Il0/ 0. Bregnord : WHO/L Joylor : WHO/ G. Oiez : WHO/C. Biockwell . WHO/ M. Serltis . WHO/ UNICEF /C. Wolson . WHO/ L Toylor WHO/ H Roy/ Ago Khoo Foundolion . WHO/ Iofor : WHO/ Il0/ 0. Bregnord; WHO/ Iofor : WHO/ I. ModO.y : WHOjT. Kel~; WHO/ l. Gubb : WHO Photo <ornpenlion/Boo ~ © : WHO/ P. lorsen : WHO/ L Joylor . WHO/H Roy/ Ago Khon Fooodolion . WHO/ G. Will<"" . WHO/ Intdmericon Bonk/ 0. Monguoon; WHO/ UNICEF /5. Sprogue , : WHO Photo <ornpenlion/ A. Ander<son © : WHO/ UNHCR : WHO/ J.Schylle : WHO/ H.Spruiit · WHO/H. Roy/ Ago Khon Fooodotion Why not take out a subscriplion la World Health and enjoy reading about the world's major health issues six times a year. 1993 subscription prices are listed below. WHO also offers its popular "Health Horizons" subscription, a combined subscription (at a reduced rate) to World Health and the quarterly World Health Forum. Orr/er form Card number-------------- D World Health ( 1993 subscription) at Sw. fr. 28.- /US$ 22.00 Expiry date Date of order D Health Horizons ( 1993 subscription) Signature at Sw. fr. 80.-/US$ 64.00 D Payment enclosed D Please charge to my credit card D Visa D American Express D Eurocard/Mastercard/ Access Name Address World Heoltfl Orgonizonon, Distribution ond Soles, 1211 Genevo 27, Switzerland. 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