Well-switching can mitigate arsenic crisis

"Well-switching should be more systematically encouraged in Araihazar and many other parts of Bangladesh and West Bengal, India," concluded Alexander van Geen and his colleagues from Columbia University in New York, and Dhaka University and the national Institute for Social and Preventive Medicine in Bangladesh. These researchers published their study findings in the September Bulletin of the World Health Organisation.

Some 48% of the 4,997 contiguous tube wells in the Araihazar district with a population of 55,000 met the current Bangladesh standard for drinking water, which is a maximum of 50 micrograms of arsenic per litre. Calculating the distance from each unsafe well to the nearest safe one, they found that although only half the inhabitants had access to safe water from their own well, 88% lived within 100 metres of a safe one, and 95% within 200 metres. Six currently safe wells that were sampled every two weeks for a year gave no indication of significant seasonal fluctuations in arsenic concentrations.

Switching to a safe well has not been aggressively promoted. In Araihazar 43% of the inhabitants surveyed thought this would be the best immediate option. Thirty-one percent favoured deepening the unsafe well or treating the water in it. Twenty percent favoured going back to surface water without treatment, although the microbial diseases transmitted by contaminated surface water were the reason for drilling the tubewells.

Switching wells is not so simple. Most wells are privately owned. Women are traditionally not expected to leave their bari or cluster of related households unaccompanied.