Geographical variation and human health risk assessment of arsenic contamination in locally produced unpolished and polished rice from the Mekong Plain and coastal region of Cambodia

Abstract

Arsenic (As) is widespread in the environment. It poses serious health risks, particularly through rice, which can accumulate up to 10 times more arsenic than other cereal crops because of flooded growing conditions. Rice is the main staple food in Cambodia; therefore, this study assessed arsenic contamination in 110 polished and 100 unpolished rice samples collected from Kandal, Kampot, and Kep Provinces. Total As was measured via acid digestion and inductively coupled plasma mass spectrometry. The As concentrations in polished and unpolished rice ranged from 0.11 to 0.55 and from 0.09 to 0.89 mg/kg, respectively. Based on estimated iAs fractions, EU maximum permissible levels were exceeded in a substantial proportion of rice samples, particularly those from Kandal. Among the rice cultivars, Sen Kro Ob (Kandal), Phka Rumduol (Kampot), and Phka Mlis (Kep) presented the highest arsenic concentrations. The health risk assessment identified potential concerns, with hazard quotients (HQ) exceeding 1 and incremental lifetime cancer risk (ILCR) exceeding 1.0 & times; 10(-)4 across rice types. Compared with males, females presented higher estimated risks in the scenario-based assessments, primarily because of lower average body weights despite similar rice consumption levels. Overall, arsenic exposure risk varies by geographic origin, rice type, and cultivar. Continued monitoring and targeted risk communication are recommended to mitigate long-term health impacts.