Dietary exposure and health risk assessment of heavy metal in grains of Shaanxi Province

OBJECTIVE: To investigate heavy metal contamination of grains, and to assess the health risk of the contamination on local inhabitants. METHODS: The contents of 6 heavy metals of grains were detected, according to the food contamination monitor plan of Shaanxi Province. The levels of heavy metal contamination on grains were evaluated by pollution indices. Health risks associated with the daily dietary intake of heavy metals were assessed using USEPA health risk assessment model. RESULTS: 562 grain samples were randomly collected from 94 representative sites in Shaanxi Province. The contaminations of Cd and Pb were more seriously than the other metals. The pollution indices of Cd, As, Cr, Hg, Ni and Pb in 4 kinds of grains were less than 0.7, they were safe to eat. The dietary expose doses of Cd, As, Cr, Hg, Ni and Pb were also at the level of safety. The individual health risk of heavy metal pollution was 3.08 x 10(-4)/year for Cr, which was exceed the standard (5.0 x 10(-5)/year) of Inernational Commission on Radiological Protection (ICRP). The individual health risks of the other five metals were lower than the standard of ICRP. CONCLUSION: The most of grains are considered safe to eat for consumers, excepting a few samples are polluted by lead and cadmium. The individual health risk of Cr is higher than the standand of ICRP.