Natural processes can limit spread of arsenic in water, study says
(PhysOrg.com) -- Many people in Bangladesh and other parts of Asia have been poisoned by drinking groundwater laced with arsenicnot introduced by humans, but leached naturally from sediments, and now being tapped by shallow drinking wells. In recent years, to avoid the problem, deeper wells have been sunk 500 feet or more to purer watersbut fears have remained that when deep water is pumped out, contaminated water might filter down to replace it. Now, a study has shown that deep sediments can grab the arsenic and take it out of circulationa finding that may help to keep wells safe elsewhere, including in the United States. The study, led by researchers at Columbia Universitys Department of Earth and Environmental Engineering and the Lamont-Doherty Earth Observatory, appears in the current online edition of the journal Nature Geoscience.