Assessment of Population Exposed to Groundwater Arsenic in As-affected Areas of Cambodia

Background: High As levels in Cambodia’s groundwater were first reported in a small scale, but country-wide survey in 2001 and since then a number of studies have been undertaken to identify the spatial extent of the problem, release mechanisms and intake pathways. An exposure risk study was first published in 2008 but was done only for Kandal Province.

Aims: This study aims to i) characterize the current water use pattern of people living in at risk areas; and ii) quantify the size of the population exposed to harmful levels of arsenic through the consumption of groundwater in the highly arsenic affected areas of Cambodia.

Methodology: This study consisted of questionnaire development, site selection and questionnaire application for 998 residents in 50 villages of Kandal, Kampong Cham, and Prey Veng provinces.

Results: The questionnaires revealed that rain water is the main source of water during the rainy season while tube well and surface water are relatively important sources of water for both the rainy and dry seasons. The proportion of population exposed to As levels over 50 ppb is 6.3% in the surveyed villages. We conclude that surface water is still an important source for rural Cambodians, thus household water treatment and storage (HWTS) programs should be further implemented to avoid the substitution health effect from As instead of microbial contamination. Regular monitoring programs should be considered since tube well water is still being used in those areas.