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ARSENIC IN THE GROUNDWATERS OF BANGLADESH Guest Scientist: Lex Van Geen The groundwater arsenic crisis in Bangladesh – how extreme spatial variability can be turned to an advantage. Over the past 20 years, millions of inexpensive “tube wells” have been installed manually to depths of 90 m (300 ft) throughout Bangladesh and other South Asian countries. Although these wells supply microbially uncontaminated water, the naturally-elevated arsenic content of the pumped groundwater poses a significant risk of increased cancer for tens of millions of villagers. How should a crisis of such enormous proportions be tackled? This is one of the key research themes for health, social, and earth scientists at Columbia University and their colleagues in Bangladesh that are currently supported by the US Superfund Basic Research Program (http://superfund.ciesin.columbia.edu). Lex van Geen, a Lamont geochemist in charge of coordinating mitigation activities under this program, will present an overview of the problem as well as possible solutions. Participants will have a chance to navigate through a field of 6000 groundwater arsenic measurements using ArcView to get a sense of the extreme spatial variability of the composition of groundwater. The local drilling technology will be described and a simple device under development that builds on this technology to sample groundwater before a well is installed will be demonstrated. The most-widely used field kit for arsenic will also be demonstrated and its limitations will be discussed. Dr. Van Geen provides more information about these concepts through the lionks below. The Bangladesh Arsenic Crisis |
