Arsenic and manganese contamination of drinking water resources in cambodia: coincidence of risk areas with low relief topography
Arsenic contamination of groundwater has been identified in Cambodia, where some 100,000 family- based wells are used for drinking water needs. We conducted a comprehensive groundwater survey in the Mekong River floodplain, comprising an area of 3700km2 (131 samples, 28 parameters). Arsenic ranged from 1-1340μg/L (average 163μg/L), with 48％ exceeding 10μg/L. Elevated manganese levels (57％>0. 4mg/L) are posing an additional health threat to the 1.2 million people living in this area. With 350 people/kin2 potentially exposed to chronic arsenic poisoning, the magnitude is similar to Bangladesh (200 per km2). Elevated arsenic levels are sharply restricted to the Bassac and Mekong River banks and the alluvium braided by these rivers (Kandal Province). Arsenic in this province averaged at 233μg/L (median 100μg/L), while concentrations to the west and east of the rivers were <10μg/L. Arsenic release from Holocene sediments between the rivers is caused by reductive dissolution of metal oxides. Regions exhibiting low and elevated arsenic levels are coincident with the present meter-scale topography featuring gently increasing elevation to the west and east of a shallow valley understood as a relict of pre-Holocene topography. Factors influencing the occurrence and magnitude of arsenic in groundwater will be discussed.
Phnom Penh Upper Mekong Delta arsenic groundwater health threat reductive dissolution
Michael Berg Johanna Buschmann Caroline Stengel Mickey L. Sampson
Swiss Federal Institute of Aquatic Science and Technology, Eawag, CH-8600 Dubendorf, Switzerland Resource Development International-Cambodia, RDIC, P. O. Box 494, Phnom Penh, Cambodia
国际会议
第九届痕量元素生物地球化学国际会议(9th International Conference on the Biogeochemistry of Trace Elements)
北京
英文
816-817
2007-07-15（万方平台首次上网日期，不代表论文的发表时间）