Hugh Brammer

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.

Mitigation of arsenic contamination in irrigated paddy soils in South and South-east Asia

It has recently become apparent that arsenic-contaminated groundwater used for irrigation in several countries of South and South-east Asia is adding arsenic to soils and rice, thus posing a serious threat to sustainable agricultural production and to the health and livelihoods of affected people in those countries. This paper describes the many environmental, agricultural and social factors that determine practical mitigation strategies and research needs, and describes possible mitigation measures that need to be tested. These measures include providing alternative irrigation sources, various agronomic measures, use of soil amendments, growing hyperaccumulator plants, removing contaminated soil and using alternative cooking methods.

After the Bangladesh Flood Action Plan: Looking to the future

The main objectives of the Bangladesh Flood Action Plan (FAP), to protect the country from river floods, were not achieved, for several political, economic and institutional reasons. Demographic and economic changes in the following 20 years have increased Bangladeshs exposure to damaging floods. The countrys newly elected government is committed to providing flood protection and surface-water irrigation as a means to achieve national foodgrain self-sufficiency. Therefore, the feasibility and affordability of comprehensive flood and water management systems need to be re-examined. The technical assessment must take into account the finding that severe floods in Bangladesh are caused mainly by heavy rainfall within Bangladesh as well as the increased flood and cyclone risks associated with global warming. An institutional assessment should examine practical means to overcome governance constraints and to increase local responsibility for managing flood protection and irrigation projects. If such projects cannot be provided, alternative measures must be sought to provide security for lives, livelihoods and economic production. These could include ‘flood-proofing’ urban and rural settlements, development of improved crop varieties, and more efficient use of irrigation and fertilizers. Measures to expand other sectors of the national economy would also be needed to generate the exports and incomes required to purchase increased food imports.