Selenium in selenium-rich rice sold in China and risk assessment.

Selenium-rich rice samples of 52 brands were bought from supermarkets on line in China and analysed for Se with ICP-MS. The Se concentration of Se-rich rice in China ranged from 0.012 ± 0.001 to 0.558 ± 0.057 mg/kg with an average of 0.090 ± 0.092 mg/kg. Rice samples with Se concentrations below 0.04 mg/kg accounted for 36.5% of the total samples. Se concentrations between 0.04 and 0.3 mg/kg accounted for 61.6%. Taking the upper tolerable limit of 400 μg/d as the risk standard, the risk of selenium intake by selenium-rich rice was low and the risk index was far less than 100%. With the upper intake limit of 100 μg/d and the adequate intake of 70 μg/d as the risk standard, the maximum intake risk index was higher than 100%, indicating a certain risk in the consumption of selenium-rich rice.