Arsenic in groundwater: a threat to sustainable agriculture in South and South-east Asia.

The problem of arsenic pollution of groundwater used for domestic water supplies is now well recognised in Bangladesh, India and some other countries of South and South-east Asia. However, it has recently become apparent that arsenic-polluted water used for irrigation is adding sufficient arsenic to soils and rice to pose serious threats to sustainable agricultural production in those countries and to the health and livelihoods of affected people. This paper reviews the nature of those threats, taking into account the natural sources of arsenic pollution, areas affected, factors influencing arsenic uptake by soils and plants, toxicity levels and the dietary risk to people consuming arsenic-contaminated rice.