Exposure to heavy metal contamination and probabilistic health risk assessment using Monte Carlo simulation: a study in the Southeast Iran.

Abstract

The rice contamination to heavy metals and its associated health risks have been less addressed in the southeast of Iran. In the present study, in the mentioned region, we assessed the concentration of nine elements in rice, and the health risk related to the measured elements was determined using the data which were gathered by a questionnaire. For this purpose, 36 samples of the 12 most widely consumed rice brands were collected. Using ICP-MS, the concentrations of Ni, Cr, Hg, Sr, Mn, Fe, Se, Ba, and Zn were measured in the studied samples as 0.599 ± 0.124, 0.483 ± 0.28, 0.0157 ± 0.005, 0.85 ± 1.307, 11.5 ± 1.97, 178.46 ± 67.27, 0.212 ± 0.083, 0.845 ± 0.62, and 8.416 ± 1.611mg/kg, respectively. We found that, regarding the other studies, the levels of Ni, Cr, Hg, Fe, and Ba were higher. Besides, using 258 distributed questionnaires among citizens, the daily rice consumption was determined to be 295.66 ± 171.005g/person/ day. Based on this consumption rate and Monto Carlo uncertainty simulation, Fe (0.741 ± 0.54mg/kg/day) and Se (8.95E-04 ± 6.33E-04mg/kg/day) showed the highest and lowest daily intake, respectively. Also, using Hazard Quotient (HQ), the non-carcinogenic risk effects of the surveyed elements were estimated. The obtained results of HQ revealed that Fe (2.48) and Mn (1.06) could pose non-carcinogenic health risks to consumers. Moreover, the calculated hazard Index showed that the overall health risk of the surveyed elements is in an unsafe range.