Health Risk Assessment of Exposure to Heavy Metals in Wheat Flour from Iran Markets: Application of Monte Carlo Simulation Approach

The significance of flour in the Iranian diet underscores the need to ensure its safety from chemical pollutants. This study aimed to evaluate the potential health risks posed by certain heavy metals, such as Fe, Zn, Cu, Al, Co, Hg, Cr, Ni, Pb, and Cd, in wheat flour available in the Iranian market. A total of 248 flour samples were collected from 11 provinces in Iran during the winter of 2021. The health risks associated with heavy metals in children and adults were evaluated using USEPA health risk assessment guidance for superfund part A and Monte Carlo Simulation. The average concentration of Fe, Zn, Cu, Al, Co, Hg, Cr, Ni, Pb, and Cd, was equal to 30.62 +/- 59.24, 4.94 +/- 13.64, 1.24 +/- 3.08, 2.85 +/- 4.98, 0.03 +/- 0.01, 0.12 +/- 0.03, 1.42 +/- 1, 0.23 +/- 0.05, 1.71 +/- 0.65, and 0.02 +/- 0.004 mg/kg dry weight, respectively. Analysis of Fe, Cr, Al, Hg and Cr in all flour samples showed that the average concentration of these metals were greater than the standards levels set by the WHO/FAO. The results of the non-carcinogenic risks (HI) showed that the hazard index values (children: 0.969 +/- 1.04, adult: 0.837 +/- 0.905) of heavy metals through the consumption of flour to both study population were acceptable. The results of the carcinogenic risks (CR) based on Cd, and Pb concentration showed that the CR values from ingestion of flour to the children and adults population were 1.45 x 10-5 +/- 5.08 x 10-5 and 1.26 x 10-5 +/- 4.40 x 10-5, respectively. The results of Monte Carlo simulation showed that conventional deterministic health risk evaluation could overestimate risk outcomes. Likewise, Cr has 68.8% and 69.1% probability of non-carcinogenic risk to children and adult, respectively, and 80% and 79.8% probability of CR for adults and children respectively for Pb, suggesting that Cr and Pb is a priority control heavy metals. Therefore, it is recommended to continuously monitor the levels of heavy metals in wheat and its derived food products to ensure food safety.