Arsenic groundwater contamination in parts of middle Ganga plain, Bihar

Arsenic contamination of groundwater in low-lying Bhagarathi–Ganga deltaic plain is known for more than two decades. The problem was recognized in 1984 (ref. 1) in West Bengal, when 16 patients from a village of 24 Parganas district reported arsenicosis. Subsequent investigations revealed extensive arsenic contamination in groundwater in the Bengal Basin affecting the eastern part of West Bengal and a major part of Bangladesh. About 40 million inhabitants of this densely populated part of the world are residing in the risk-zone having groundwater arsenic level >0.5 mg/l (ref. 4). If the guideline value of 0.01 mg/l of World Health Organisation is to be considered, the affected population would be much more. In the Asian countries, contamination has been recorded from…