Magnitude of arsenic pollution in the Mekong and Red River Deltas - Cambodia and Vietnam

Large alluvial deltas of the Mekong River in southern Vietnam and Cambodia and the Red River in northern Vietnam have groundwaters that are exploited for drinking water by private tube-wells, which are of increasing demand since the mid-1990s. This paper presents an overview of groundwater arsenic pollution in the Mekong delta: arsenic concentrations ranged from 1-1610 mu g/L in Cambodia (average 217 mu g/L) and 1-845 mu g/L in southern Vietnam (average 39 mu g/L), respectively. It also evaluates the situation in Red River delta where groundwater arsenic concentrations vary from 1-3050 mu g/L (average 159 mu g/L). In addition to rural areas, the drinking water supply of the city of Hanoi has elevated arsenic concentrations. The sediments of 12-40 m deep cores from the Red River delta contain arsenic levels of 2-33 mu g/g (average 7 mu g/g, dry weight) and show a remarkable correlation with sediment-bound iron. In all three areas, the groundwater arsenic pollution seem to be of natural origin and caused by reductive dissolution of arsenic-bearing iron phases buried in aquifers. The population at risk of chronic arsenic poisoning is estimated to be 10 million in the Red River delta and 0.5-1 million in the Mekong delta. A subset of hair samples collected in Vietnam and Cambodia from residents drinking groundwater with arsenic levels > 50 mu g/L have a significantly higher arsenic content than control groups (< 50 mu g/L). Few cases of arsenic related health problems are recognized in the study areas compared to Bangladesh and West Bengal. This difference probably relates to arsenic contaminated tube-well water only being used substantially over the past 7 to 10 years in Vietnam and Cambodia. Because symptoms of chronic arsenic poisoning usually take more than 10 years to develop, the number of future arsenic related ailments in Cambodia and Vietnam is likely to increase. Early mitigation measures should be a high priority

Title: 

	Magnitude of arsenic pollution in the Mekong and Red River Deltas - Cambodia and Vietnam
Authors:	Pham Thi Kim Trang Pham Hung Viet Berg, Michael Stengel, Caroline
Keywords:	arsenic groundwater pollution Phnom Penh Hanoi health risk hair urine reductive dissolution iron manganese ammonium DOC Kandal province An Giang province Dong Thap province
Issue Date:	2007
Publisher:	ELSEVIER SCIENCE BV, PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS
Citation:	ISIKNOWLEDGE
Abstract:	Large alluvial deltas of the Mekong River in southern Vietnam and Cambodia and the Red River in northern Vietnam have groundwaters that are exploited for drinking water by private tube-wells, which are of increasing demand since the mid-1990s. This paper presents an overview of groundwater arsenic pollution in the Mekong delta: arsenic concentrations ranged from 1-1610 mu g/L in Cambodia (average 217 mu g/L) and 1-845 mu g/L in southern Vietnam (average 39 mu g/L), respectively. It also evaluates the situation in Red River delta where groundwater arsenic concentrations vary from 1-3050 mu g/L (average 159 mu g/L). In addition to rural areas, the drinking water supply of the city of Hanoi has elevated arsenic concentrations. The sediments of 12-40 m deep cores from the Red River delta contain arsenic levels of 2-33 mu g/g (average 7 mu g/g, dry weight) and show a remarkable correlation with sediment-bound iron. In all three areas, the groundwater arsenic pollution seem to be of natural origin and caused by reductive dissolution of arsenic-bearing iron phases buried in aquifers. The population at risk of chronic arsenic poisoning is estimated to be 10 million in the Red River delta and 0.5-1 million in the Mekong delta. A subset of hair samples collected in Vietnam and Cambodia from residents drinking groundwater with arsenic levels > 50 mu g/L have a significantly higher arsenic content than control groups (< 50 mu g/L). Few cases of arsenic related health problems are recognized in the study areas compared to Bangladesh and West Bengal. This difference probably relates to arsenic contaminated tube-well water only being used substantially over the past 7 to 10 years in Vietnam and Cambodia. Because symptoms of chronic arsenic poisoning usually take more than 10 years to develop, the number of future arsenic related ailments in Cambodia and Vietnam is likely to increase. Early mitigation measures should be a high priority
Description:	SCIENCE OF THE TOTAL ENVIRONMENT Volume: 372 Issue: 2-3 Pages: 413-425 Published: JAN 1 2007 ; TNS07661
URI:	http://repository.vnu.edu.vn/handle/VNU_123/31876
ISSN:	0048-9697
Appears in Collections:	Bài báo của ĐHQGHN trong Web of Science