Two-dimensional Monte Carlo simulation improves source-specific health risk assessment accuracy of soil heavy metals...

Human health and well-being are negatively affected by exposure to heavy metal (HM)-polluted soil. Accurate assessment of the health risks associated with soil HMs remains a daunting challenge, particularly in legacy mining regions. Herein, we assessed carcinogenic and non-carcinogenic risks to children, adult females, and adult males in a polymetallic mine legacy region using one- and two-dimensional Monte Carlo simulations (1D-MCS and 2D-MCS, respectively). The 2D-MCS method provided more accurate evaluations than the 1D-MCS method and reduced carcinogenic risks (95 % quantiles) by 35.83 %, 39.85 %, and 41.21 % for children, adult females, and adult males, respectively. Further, while Pb-Zn mining and smelting were the largest contributors to soil HM accumulation, the associated carcinogenic risks for children were lower than those linked to Cu and Au mining and smelting. Notably, the carcinogenic risks from individual sources were negligible for adults. By combining nighttime light data and spatial autocorrelation analysis, we identified priority areas for targeted risk management located to the north and northwest. Overall, our findings improve the accuracy of source-specific health risk assessments for soil HMs. This will assist decision-makers in developing targeted interventions and management strategies to prevent over-remediation and unnecessary resource expenditure while protecting vulnerable populations.