Contribution of water and cooked rice to an estimation of the dietary intake of inorganic arsenic in a rural village of West Bengal, India

Abstract

Arsenic contamination of rice plants by arsenic-polluted irrigation groundwater could result in high arsenic concentrations in cooked rice. The main objective of the study was to estimate the total and inorganic arsenic intakes in a rural population of West Bengal, India, through both drinking water and cooked rice. Simulated cooking of rice with different levels of arsenic species in the cooking water was carried out. The presence of arsenic in the cooking water was provided by four arsenic species (arsenite, arsenate, methylarsonate or dimethylarsinate) and at three total arsenic concentrations (50, 250 or 500 µg l⁻¹). The results show that the arsenic concentration in cooked rice is always higher than that in raw rice and range from 227 to 1642 µg kg⁻¹. The cooking process did not change the arsenic speciation in rice. Cooked rice contributed a mean of 41% to the daily intake of inorganic arsenic. The daily inorganic arsenic intakes for water plus rice were 229, 1024 and 2000 µg day⁻¹ for initial arsenic concentrations in the cooking water of 50, 250 and 500 µg arsenic l⁻¹, respectively, compared with the tolerable daily intake which is 150 µg day⁻¹.

Keywords:

• Arsenic speciation
• cooked food
• cooking water
• organic arsenic
• total arsenic.

Acknowledgements

The paper was produced with the financial assistance of the European Union (Development of a Low Cost Technology for In-situ Treatment of Groundwater for Potable and Irrigation Purposes, TIPOT, ASI/B7-301/2598/24-2004/79013), MEC (CTM2005-2425-E), and Caja de Ahorros del Mediterráneo (CAM-2006). The contents of this paper are the sole responsibility of UMH and can under no circumstances be regarded as reflecting the position of the European Union and/or CAM.