Arsenic in Groundwater in Selected Countries in South and Southeast Asia: A Review

Abstract

Abstract

In the past decade, there has been increasing awareness of the occurrence of high amounts of arsenic in groundwater and its effects on human health. The best known and most studied areas with naturally high levels of arsenic are Bangladesh and the Indian State of West Bengal. Other countries where this is known to be a problem include Vietnam, Cambodia, Nepal, and Myanmar. In Thailand, arsenic has never been found naturally in groundwater, although it has been shown to occur as a result of runoff from tin mining. Currently, it appears that arsenic contamination results from transportation and deposition of arsenic-rich erosion products from mountainous areas to other areas downstream. The current WHO guideline value for arsenic in drinking water is 10 ppb, which has been adopted by many countries, while many other countries still use the previously set standard of 50 ppb. Many technical solutions to the problem have been proposed, but currently there does not appear to be one perfect solution, although large regional water systems, such as in Bangkok, may be a good solution. If wells are drilled to provide safe water, they should be tested for arsenic before they are used. A more important issue is increasing both the amount of physical capital in a country and developing human resources in the affected countries in South and Southeast Asia.

Keywords: arsenic; groundwater; Bangladesh; Vietnam; contamination; tubewell