This is a joint proposal by Geological Survey of India and Geological Survey of Canada to IDRC.

The Geological Survey of Canada and the Geological Survey of India have initiated a study to investigate the geochemical processes leading to the release of arsenic from sediments into groundwater. This is to develop a risk management strategy in order to mitigate the detrimental effects of As on the health of people living in West Bengal State, India.

The presence of arsenic in groundwaters at concentrations exceeding the permissible level (0.05 mg/l) for human consumption was brought to the attention of the Government of West Bengal in 1978. It has been estimated that more than five million people are at risk from arsenic poisoning and conservative figures suggest that there are over 300,000 patients who are suffering various stages of arsenicosis (UNIDO 2001). In the eight districts of West Bengal State where arsenic is known to be a problem there are in excess of 160,000 tube wells. Rural communities depend heavily on tube wells and hand pumps that draw water from contaminated waters. Studies carried out by various agencies, including GSI (Geologic Survey of India) have established that arsenic is present in varying quantities in the groundwater and that the source of the arsenic is natural. Numerous studies have been conducted to identify the source of the problem and the geochemical processes that identify how the arsenic moves through the groundwater and enters the food chain. There are also well know and effective strategies for removing arsenic from the water supply and for "avoiding" the use of contaminated water for drinking purposes. However arsenic remains a problem indicating the complexity of the problem.

A multi-disciplinary approach needs to be taken to resolve the problem. Such an approach will rely on a sound information base, which includes scientific as well as social parameters. It is accepted that the source of the arsenic is natural being derived from arsenic rich sediments deposited during the Holocene era. However there are several explanations for the mechanism of release of As and its subsequent entry into the groundwater system. Mitigation of the problem will depend on an understanding of the processes responsible for the release as well as a variety of other scientific information that will establish the parameters relevant to the development of high levels of As.

Field work was conducted in December, 2004. Further information is available from Andy Rencz.