Exposure assessment of arsenic speciation in different rice types depending on the cooking mode

Abstract

Total (Ast), inorganic arsenic (Asi=As(III)+As(V)) and dimethylarsonic acid (DMA) were determined in 37 commercial rice samples collected in France. Ast was measured by inductively coupled plasma-mass spectrometry (ICP-MS) whereas anion-exchange chromatography – ICP-MS was used for Asi and DMA determination. Ast in raw rice varied from 0.041 to 0.535mgkg−1 whereas Asi varied from 0.025mgkg−1 (polished Basmati rice) up to 0.471mgkg−1 (organic rice duo). The daily intake and associated health risk for different population groups as a function of age and gender was also assessed. The intake varied between 0.002 and 0.184μgkg−1 body weight for Ast and 0.002 and 0.153μgkg−1 body weight for Asi, which do not pose a chronic toxicity risk. Organic wholegrain rice may entail a risk for children in the case of sole consumption at the expense of polished rice. The impact of rice cooking/boiling in terms of the overall toxicological risk related to As species was also investigated. Pre-rinsing and boiling the raw rice by using an excess of water is the most efficient mode to obtain a significant Asi removal and further reduction of the toxicological risk for children, particularly for white rice varieties.