Probabilistic health risk assessment of heavy metals in rice produced in Mazandaran province, Iran

The purpose of this study was to assess the health risk of the heavy metals (HMs) (arsenic [As], cadmium [Cd], chromium [Cr], copper [Cu], iron [Fe], lead [Pb], Manganese [Mn], and zinc [Zn]) in rice produced in Mazandaran province (Amol and Mahmoudabad), Iran. A number of 60 rice samples were randomly collected and analyzed for the HMs by ICP-MS. The non -carcinogenic and carcinogenic health risks of the HMs were probabilistically assessed based on Monte Carlo simulation in terms of hazard quotient/index (HQ/HI) and incremental lifetime cancer risk (LTCR), respectively. The average concentration of HMs in rice grains in the studied areas was ranked as follows: Fe > Zn > Mn > Pb > Cu > Cr > As > Cd. THQ Sigma mi showed that noncarcinogenic risk for area residents was largely related to Pb (1.77), As (0.59), Fe (0.57) and Cr (0.41). The average HI values of the HMs in rice produced in Amol and Mahmoudabad were assessed to be 2.42 (1.10-4.14) and 1.91 (0.43-3.9), respectively. The average LTCR values of the HMs in rice were in the following order: Cd (3.46 x 10(-4 )[1.34 x 10(-4 )to 6.96 x 10(-4)] for Amol and 3.97 x 10(-4) [1.35 x 10(-4) to 9.57 x 10(-4)] for Mahmoudabad) > As (8.60 x 10(-5 )[1.47 x 10(-5) to 2.42 x 10(-4)] for Amol and 1.04 x 10(-4 )[6.17 x 10(-6) to 2.83 x 10(-4)] for Mahmoudabad) > Cr (5.71 x 10(-5 )[2.88 x 10(-5) to 9.61 x 10(-5)] for Amol and 4.75 x 10-5 [1.59 x 10(-5) to 8.69 x 10(-5)] for Mahmoudabad). The average total LTCR value of the HMs in rice was within the acceptable range (10(-6) to 10(-4)). The findings showed that exposure to the HMs via rice consumption could threaten human health, and an appropriate strategy to reduce concentrations of the HMs in rice is needed.