Arsenic in tube well water and health consequences

Project Summary

The discovery of arsenic in groundwater in Bangladesh has aroused widespread concern. Many of the tube wells for drinking water in the country are contaminated with arsenic. Experience from other countries indicates that the consequences will be extensive and include excess morbidity and mortality from cancer and cardio-vascular diseases. However, little is known about the weight of this new burden of disease and about the rate at which arsenic-induced morbidity and mortality is likely to develop in Bangladesh. Skin lesions are visible manifestations of chronic arsenicosis, but we have insufficient knowledge on the dose-effect in different age groups and gender. It is not known whether the toxicity is already resulting in excess mortality in exposed communities. Little is known about reproductive health consequences, and about the possible aggravating role of the widespread malnutrition in Bangladesh on arsenic-induced health effects. This knowledge is needed for proper prioritisation and planning of interventions.

The overall objective of this project is to establish a strong epidemiological platform of research on levels of arsenic exposure through drinking water and current health consequences. It aims to provide answers to questions such as: Who develops arsenic-induced skin lesions and what are the risks at different exposure levels? Does malnutrition increase the risk of developing skin lesions? Has arsenic exposure resulted in excess number of miscarriages, stillbirths and neonatal deaths? Has arsenic exposure already resulted in excess deaths from cancer and cardio-vascular diseases? Is a shift to alternative, arsenic-free water sources increasing the risk of diarrhoeal diseases?

ICDDR,B maintains a health and demographic surveillance system in 142 villages of the Matlab thana. The surveillance system contains demographic information, reproductive outcomes, health information, nutritional and health data, as well as a linked geographic information system. This area is heavily affected by arsenic contamination of drinking water. We screened the population of 220,000 for skin lesions, assessed the arsenic content of the 13286 tube wells in the Matlab surveillance area, and established a database for epidemiological studies of the levels of arsenic exposure and manifestations of arsenicosis in the population. Analyses will be performed on the risk of arsenic-related skin lesions, possible effects on reproductive outcome, and effects on cardio-vascular and cancer mortality. A village-based arsenic mitigation activity is co-ordinated with the survey, and priority is given to the areas with the highest exposure. Reversibility of skin lesions will be assessed. The consequences of a shift to other, arsenic-free, water sources will also be evaluated, including monitoring of diarrhoeal diseases through the surveillance system in Matlab. The mitigation activity is collaborated with BRAC, a major national NGO with the longest experience of arsenic mitigation programmes in Bangladesh. Collaboration in arsenic biochemistry is with the Institute of Environmental Medicine Division of Metals and Health, Karolinska Institutet (Professor Marie Vahter) including technology transfer to the laboratory at ICDDR,B regarding analysis of arsenic metabolites in urine. The fieldwork started in early 2002, and is estimated to be completed in the second half of 2003. Results will be available within 2003 and will be communicated through scientific reports, popular reports and seminars/workshops. The project has so far received financial support from Sida and WHO but additional funding is needed.