Threat of Arsenic Occurrence in the Vietnamese Mekong Delta

Abstract

The occurrence of high dissolved Arsenic (As) levels mobilized from geogene sources in pore water has been reported worldwide. High elevations of Arsenic concentration in groundwater have posed threats to human's health and implication for groundwater use. Previous studies on As-rich groundwater around the world have been in the literature. Particularly, Arsenic occurrence in the Red River and Mekong River deltas of Vietnam has recently drawn much attention from scientists. The purpose of this paper is to review Arsenic contamination in alluvial plains of Asian deltas of Bangladesh and Vietnam. Further, an additional evidence of Arsenic occurrence in the Mekong Delta region will be reported through our recent survey in An Phu district, An Giang province of the Vietnamese Mekong Delta. Thirty six (36) groundwater samples and two (02) cores of sediment were collected in the rainy and dry seasons of 2014. The investigated results show that Arsenic concentration in groundwater resources in the study area is much higher than the WHO and Vietnam drinking water standard (10μg/L), ranging from 208 to 1,523μg/L. In addition, the arsenic concentration in groundwater in the dry season tends to be higher than in the rainy season. Arsenic concentration in sediment cores increases with depths, reaching to 210 ppm at 25m depth.