Arsenic species in husked and polished rice grains grown at the non-contaminated paddy soils in Korea

There is an increasing concern over arsenic (As) contamination of paddy soil and rice with regard to food safety. This study was conducted to investigate total and inorganic As concentration in one hundred husked and polished rice samples collected at the non-contaminated paddy soil in Korea. Arsenic species in rice samples were extracted using 1% nitric acid (HNO₃) with a microwave oven and were measured using high performance liquid chromatography coupled with inductively coupled plasma-mass spectrometry. Mean concentrations of total As in husked rice and polished rice were 0.18 and 0.11 mg kg⁻¹, respectively. Also, average inorganic As concentrations in husked rice and polished rice were 0.11 and 0.07 mg kg⁻¹, respectively. These levels are lower than the standard guideline value 0.35 and 0.2 mg kg⁻¹ for inorganic As in husked and polished rice recommended by Codex Committee on Contaminants in Foods and Ministry of Food and Drug Safety, respectively. The mean of the inorganic As ratio for the total amount of As was 0.65 and 0.67 for husked rice and polished rice, respectively, and the range was from 0.08 to 1.0. For health risk assessment, the average value of cancer risk probability was 9.24×10⁻⁵ and ranged from 2.30×10⁻⁵ to 1.90×10⁻⁴. Therefore, human exposure to As through dietary intake of surveyed rice samples might considered to be a low health risk.