title: Arsenic geochemistry of groundwater in Southeast Asia.
abstract: The occurrence of high concentrations of arsenic in the groundwater of the Southeast Asia region has received much attention in the past decade. This study presents an overview of the arsenic contamination problems in Vietnam, Cambodia, Lao People's Democratic Republic and Thailand. Most groundwater used as a source of drinking water in rural areas has been found to be contaminated with arsenic exceeding the WHO drinking water guideline of 10 μg·L(-1). With the exception of Thailand, groundwater was found to be contaminated with naturally occurring arsenic in the region. Interestingly, high arsenic concentrations (> 10 μg·L(-1)) were generally found in the floodplain areas located along the Mekong River. The source of elevated arsenic concentrations in groundwater is thought to be the release of arsenic from river sediments under highly reducing conditions. In Thailand, arsenic has never been found naturally in groundwater, but originates from tin mining activities. More than 10 million residents in Southeast Asia are estimated to be at risk from consuming arsenic-contaminated groundwater. In Southeast Asia, groundwater has been found to be a significant source of daily inorganic arsenic intake in humans. A positive correlation between groundwater arsenic concentration and arsenic concentration in human hair has been observed in Cambodia and Vietnam. A substantial knowledge gap exists between the epidemiology of arsenicosis and its impact on human health. More collaborative studies particularly on the scope of public health and its epidemiology are needed to conduct to fulfill the knowledge gaps of As as well as to enhance the operational responses to As issue in Southeast Asian countries.
authors.affiliation: School of Environmental Science & Engineering and International Environmental Analysis & Education Center (IEAEC), Gwangju Institute of Science and Technology (GIST), Gwangju 500-712, South Korea. kwkim@gist.ac.kr
authors.forename: Kyoung-Woong
authors.initials: KW
authors.lastname: Kim
authors.forename: Penradee
authors.initials: P
authors.lastname: Chanpiwat
authors.forename: Hoang Thi
authors.initials: HT
authors.lastname: Hanh
authors.forename: Kongkea
authors.initials: K
authors.lastname: Phan
authors.forename: Suthipong
authors.initials: S
authors.lastname: Sthiannopkao
mesh_terms: D001151:Arsenic / Q000032:analysis*; D020261:Arsenic Poisoning / Q000209:etiology*; D001210:Asia, Southeastern; D060766:Drinking Water / Q000009:adverse effects / Q000032:analysis*; D060587:Groundwater / Q000032:analysis*; D006197:Hair / Q000737:chemistry; D006801:Humans; D014874:Water Pollutants, Chemical / Q000032:analysis
chemical_list: D060766:Drinking Water; D014874:Water Pollutants, Chemical; D001151:Arsenic