Agua Con Arsenico

Contamination of drinking-water by arsenic in Bangladesh: a public health emergency
Allan H. Smith,1 Elena O. Lingas,2 & Mahfuzar Rahman3
The contamination of groundwater by arsenic in Bangladesh is the largest poisoning of a population in history, with millions of people exposed. This paper describes the history of the discovery of arsenic in drinking-water in Bangladesh and recommendsintervention strategies. Tube-wells were installed to provide ‘‘pure water’’ to prevent morbidity and mortality from gastrointestinal disease. The water from the millions of tube-wells that were installed was not tested for arsenic contamination. Studies in other countries where the population has had long-term exposure to arsenic in groundwater indicate that 1 in 10 people who drink water containing 500mg of arsenic per litre may ultimately die from cancers caused by arsenic, including lung, bladder and skin cancers. The rapid allocation of funding and prompt expansion of current interventions to address this contamination should be facilitated. The fundamental intervention is the identification and provision of arsenic-free drinking water. Arsenic is rapidly excreted in urine, and for early ormild cases, no specific treatment is required. Community education and participation are essential to ensure that interventions are successful; these should be coupled with follow-up monitoring to confirm that exposure has ended. Taken together with the discovery of arsenic in groundwater in other countries, the experience in Bangladesh shows that groundwater sources throughout the world that areused for drinking-water should be tested for arsenic. Keywords: Bangladesh; arsenic poisoning, prevention and control; arsenic poisoning, therapy; water pollution, chemical, prevention and control; water treatment; environmental monitoring.

Voir page 1100 le resume en francais. En la pagina 1101 figura un resumen en espanol. ´ ´ ¸ ´ ˜

Introduction
Bangladesh is grappling with the largestmass poisoning of a population in history because groundwater used for drinking has been contaminated with naturally occurring inorganic arsenic. It is estimated that of the 125 million inhabitants of Bangladesh between 35 million and 77 million are at risk of drinking contaminated water (1, 2). The scale of this environmental disaster is greater than any seen before; it is beyond the accidents atBhopal, India, in 1984, and Chernobyl, Ukraine, in 1986. This paper suggests guidelines for responding when a population is exposed to arsenic, and it is based on information from several visits to Bangladesh made by Allan H. Smith as a consultant for the World Health Organization between 1997 and 1998 (3–5). In 1983, the first cases of arsenic-induced skin lesions were identified by K.C. Sahathen at the Department of Dermatology, School of Tropical
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Professor of Epidemiology, 140 Warren Hall, School of Public Health, University of California, Berkeley, Berkeley, CA 94720-7360, USA (email: ahsmith@uclink4.berkeley.edu). Correspondence should be addressed to this author. Doctoral Research Student, School of Public Health, University of California, Berkeley, USA. International Fellow,Public Health Sciences Division, International Centre for Diarrheal Disease Research in Bangladesh, Dhaka, Bangladesh; Division of Occupational and Environmental Medicine, Faculty of Health Sciences, Linkoping University, Sweden. ¨ Ref. No. 00-0751

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Medicine in Calcutta, India (6). The first patients seen were from West Bengal, but by 1987 several had already been identified who camefrom neighbouring Bangladesh. The characteristic skin lesions included pigmentation changes, mainly on the upper chest, arms and legs, and keratoses of the palms of the hands and soles of the feet (Fig. 1). After ruling out other causes, water sources used by the patients were analysed, and the diagnosis of arsenic-caused disease was confirmed. The primary drinking-water sources for the patients...