Arsenic in rice: state of knowledge and perceptions in Cambodia

This research paper examines arsenic contamination in Cambodian rice, finding that the increasing use of groundwater for dry season irrigation facilitates the uptake of naturally occurring arsenic into rice grains. While arsenic in drinking water is a known issue, the document highlights a significant lack of awareness and data regarding rice as an exposure pathway. It identifies Kandal and Prey Veng as high-risk areas and notes that Cambodian rice can have higher arsenic levels than rice from Thailand or Viet Nam. The authors recommend improving surface water irrigation and diversifying crops to reduce reliance on contaminated groundwater.

• Groundwater in the Lower Mekong and Bassac River basins of Cambodia contains naturally occurring arsenic pockets with concentrations reaching or exceeding 500 µg/l, posing significant human health risks.
• Rice consumption is a major arsenic exposure pathway in Cambodia, particularly in provinces like Kandal and Prey Veng. In Kandal, inorganic arsenic intake from food (primarily rice) has been found to exceed the benchmark dose lower-confidence limit for a 0.5% increased incidence of lung cancer (BMDL0.5).
• The intensification of rice farming, specifically the use of shallow tube wells for dry season irrigation, increases arsenic uptake because underground arsenic deposits (arsenite) become available under flooded anoxic conditions and are readily absorbed by rice plants.
• While public health concerns regarding arsenic in drinking water are well-established in Cambodia, there is limited awareness and attention among stakeholders regarding rice as a primary exposure pathway.
• There is a critical lack of traceability in the rice supply chain, making it difficult to determine the risk of arsenic exposure for consumers. Much of the rice grown in the Mekong River region is sold in Phnom Penh and nearby towns, where rice consumption may be the primary arsenic exposure route.
• Proposed mitigation strategies to reduce arsenic uptake include using surface water irrigation instead of groundwater, cultivating rice in aerobic conditions (such as alternate wetting and drying), using low-accumulation cultivars, and shifting to non-rice crops during the dry season.
• Economic concerns regarding the impact of arsenic contamination on rice exports appear to be a higher priority for stakeholders than the associated public health risks, given the importance of rice to Cambodia's GDP.

APA

Pravalprukskul, P., Aung, M. T., & Wichelns, D. (2018). Arsenic in rice: state of knowledge and perceptions in Cambodia. Stockholm Environment Institute. https://www.sei.org/wp-content/uploads/2018/11/181109b-gill-may-rice-arsenic-wp-1809f.pdf

Chicago

Pravalprukskul, Pin, May Thazin Aung, and Dennis Wichelns. Arsenic in rice: state of knowledge and perceptions in Cambodia. Stockholm Environment Institute, 2018. https://www.sei.org/wp-content/uploads/2018/11/181109b-gill-may-rice-arsenic-wp-1809f.pdf.

Wikipedia

{{cite report |last1=Pravalprukskul |first1=Pin |last2=Aung |first2=May Thazin |last3=Wichelns |first3=Dennis |title=Arsenic in rice: state of knowledge and perceptions in Cambodia |publisher=Stockholm Environment Institute |date=November 2018 |url=https://www.sei.org/wp-content/uploads/2018/11/181109b-gill-may-rice-arsenic-wp-1809f.pdf |access-date=17 August 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{pravalprukskul2018arsenic, author = {Pravalprukskul, Pin and Aung, May Thazin and Wichelns, Dennis}, title = {{Arsenic in rice: state of knowledge and perceptions in Cambodia}}, institution = {Stockholm Environment Institute}, year = {2018}, month = nov, url = {https://www.sei.org/wp-content/uploads/2018/11/181109b-gill-may-rice-arsenic-wp-1809f.pdf}, urldate = {2026-08-17}, note = {Indexed by Climate Insights Directory} }