Arsenic (As) is a ubiquitous environmental contaminant. Chronic exposure to As in drinking water has impaired and threatened the health of millions of people worldwide. Recently, unsafe level of As has been found in groundwater in the Mekong River basin of Cambodia. This book provides a comprehensive investigation of both field survey and laboratory analysis on arsenic contamination in groundwater and foodstuffs and its associated health risks of people residing in the Mekong River basin of Cambodia. Three chapters on health risk assessment of As intake indicate that As accumulation in Cambodian people is mainly through groundwater drinking pathway. And, As in rice can be an additional source of As ingestion. One chapter suggests the use of As in hair, fingernail and toenail as exposure biomarkers providing an early warning stage of the arsenicosis development. This book should be helpful for the initiation of the future and current preventive interventions and should be especially useful to researchers, scientists and professionals in Environmental Health, Science and Engineering or anyone else who are interested in implementing a project in the Mekong River basin of Cambodia.