title: Arsenic in groundwater and sediment in the Mekong River delta, Vietnam.
abstract: A study of groundwater and sediment during 2007-2008 in the Mekong River delta in Vietnam (MDVN) revealed that 26%, 74%, and 50% of groundwater samples were above the US EPA drinking water guidelines for As (10 microg/L), Mn (0.05 mg/L), and Fe (0.3 mg/L). The range of As, Fe, and Mn concentrations in the MDVN were <0.1-1351 microg/L, <0.01-38 mg/L, and <0.01-14 mg/L, respectively. Elevated levels of As were found in groundwater at sampling sites close to the Mekong River and in wells less than 60-70 m deep. An inverse relationship was found between As and Mn concentrations in groundwater. Sediment samples from An Giang and Dong Thap had the highest As concentrations (18 mg/kg and 38 mg/kg, respectively). Arsenic sediment occurred mainly in the poorly crystalline Fe oxide phases. Reductive dissolution of the Fe oxide phase is not necessarily the dominant mechanism of As release to groundwater.
authors.affiliation: Department of Environmental Science and Engineering, Gwangju Institute of Science and Technology (GIST), Republic of Korea.
authors.forename: Thi Hanh
authors.initials: TH
authors.lastname: Hoang
authors.forename: Sunbaek
authors.initials: S
authors.lastname: Bang
authors.forename: Kyoung-Woong
authors.initials: KW
authors.lastname: Kim
authors.forename: My Hoa
authors.initials: MH
authors.lastname: Nguyen
authors.forename: Duy Minh
authors.initials: DM
authors.lastname: Dang
mesh_terms: D001151:Arsenic / Q000032:analysis*; D004784:Environmental Monitoring; D005618:Fresh Water / Q000737:chemistry*; D019015:Geologic Sediments / Q000737:chemistry*; D014744:Vietnam; D014874:Water Pollutants, Chemical / Q000032:analysis*; D014881:Water Supply / Q000032:analysis
chemical_list: D014874:Water Pollutants, Chemical; D001151:Arsenic