Health risk assessment of heavy metals in drinking water reservoirs of Yasuj Iran using Monte Carlo simulation and sensitivity analysis

Heavy metals (HMs) in drinking water are a health hazard to humans as they induce a variety of diseases. In this study, the concentrations of HMs (As, Cd, Pb, Hg, Cu, and Zn) in 24 water samples collected from eight reservoirs of Yasuj (Iran) were analyzed using an inductively coupled plasma mass spectrometry. Potential carcinogenic and non-carcinogenic health risks due to the ingestion of HMs in the water samples were also assessed estimating hazard quotient (HQ), hazard index (HI) and cancer risk (CR). The average concentrations (μg/L) of HMs were found to be 2.53 (As), 0.33 (Cd), 13.94 (Cu), 2.97 (Pb), 0.99 (Hg), and 258.65 (Zn). All HMs had HQ values under 1 for all age categories, but the average value of HI estimated for infants was above safety limits at 1.21. The average values of CRs were estimated as 2.18×10 -4 (As) and 1.13×10 -4 (Cd). Monte Carlo simulation showed that HM concentrations are mostly acceptable, but that infants are in considerable health jeopardy. The study thus calls for continuous monitoring and risk mitigation measures to protect these vulnerable sections against the prospective long-haul impacts of heavy metal exposure via drinking water.