Bioaccessibility and Health Risk of Mercury in Rice of Nonmercury Contaminated Sites Using an In Vitro Method

摘要

Mercury (Hg) intake through rice has been proved as the main pathway for Hg exposure to inland Chinese residents. To evaluate the risk of Hg exposure through rice consumption, 49 rice samples were collected in three provinces of China. Total mercury (THg) concentration in rice samples ranged from 1.9 to 15.3 μg/kg (mean 4.4 ± 2.3 μg/kg), which was lower than the Chinese national standard. In vitro experiments were applied to obtain bioaccessibility of THg in rice and results showed that the range of bioaccessibility was 1.0–11.4%, which was much lower than the data reported in fish studies. Estimated daily intake (EDI) was calculated to assess the potential health risk. When considering bioaccessibility, the EDIbio was far below the reference dose. Overall, our results suggest that consuming rice planted in non-Hg contaminated sites might not cause severe Hg poisoning for inhabitants in their daily diet.