Distribution and risk assessment of multiple elements in rice from southeast China using Monte Carlo simulation

This study investigated the distribution of 24 elements in rice samples cultivated in Zhejiang, southeast China and estimated the health risks to local consumers using Monte Carlo simulation. The mean concentrations of the primary toxic elements As, Cd, Cr, Hg, Ni, Mo, Pb, and Sb were 0.094, 0.076, 0.046, 0.003, 0.218, 0.671, 0.018, and 0.002 mg kg-1, respectively. Correlation analyses revealed strong positive correlations between Ca-V, Ca-Fe, Se-Cd, Se-Hg, and Sr-Mo. Target hazard quotients (THQs) were adopted for non-carcinogenic risk assessment, and the THQs at the 50th percentile were all less than one, indicating that consumers experienced no deleterious effects from the consumption of rice containing these elements. The descending order for all age groups was THQ-Cd > THQ-As > THQ-Mo > THQ-Mn > THQ-Zn > THQ-Hg > THQ-Ni > THQ-Sb. When evaluating the THQ for multiple elements, the certainties of a hazard index greater than one for children, teens and adults were 74.0%, 81.1%, and 78.0%, respectively. Sensitivity analysis revealed that the Cd concentration and ingestion rate were the two principal factors contributing to the total risk. In addition, potential carcinogenic risk was indicated. These results suggest that the need for increased monitoring of toxic elements in rice.