Arsenic hazard in Cambodian rice from a market-based survey with a case study of Preak Russey village, Kandal Province

This study comprises a market-based survey to assess the arsenic (As) hazard of Cambodian rice, encompassing rice from seven Cambodian provinces, comparisons with rice imported from China, Vietnam and Thailand, and assessments of 15 rice varieties. Rice samples (n = 157) were collected from four large markets in Kandal Province and analysed for As using inductively coupled mass spectrometry. The mean As concentration for Cambodian rice (0.185 µg g−1, range 0.047–0.771 µg g−1) was higher than that for imported rice from Vietnam and Thailand (0.162 and 0.157 µg g−1, respectively) with mean As concentrations highest in rice from Prey Veng Province resulting in a daily dose of 1.77 µg kg−1 b.w. (body weight) d−1. Between unmilled rice varieties, Cambodian-grown White Sticky Rice had the highest mean As concentration (0.234 µg g−1), whilst White Sticky Rice produced in Thailand had the lowest (0.125 µg g−1), suggesting that localised conditions have greater bearing over rice As concentrations than differences in As uptake between individual varieties themselves. A rice and water consumption survey for 15 respondents in the village of Preak Russey revealed mean consumption rates of 522 g d−1 of rice and 1.9 L d−1 of water. At water As concentrations >1000 µg L−1, the relative contribution to the daily dose from rice is low. When water As concentrations are lowered to 50 µg L−1, daily doses from rice and water are both generally below the 3.0 µg kg−1 b.w. d−1 benchmark daily limit for a 0.5 % increase in lung cancer, yet when combined they exceeded this value in all but three respondents.