Prioritizing soil heavy metal control based on source-specific probabilistic ecological-health risk assessment in industrial development areas of Shouguang, a typical agricultural city in China

Heavy metal (HM) contamination caused by industrial expansion may have a major effect on the environmental quality and human health in agriculture-dominated towns and cities. Identifying priority control factors for HMs in soil is essential for risk reduction. In this study, Positive Matrix Factorization (PMF), Monte Carlo simulation (MCS), and risk assessment models were integrated to identify priority control sources and target HMs in the industrial growth zones of a typical agricultural city. The PMF model ascertained five sources of HMs: coal combustion and smelting activities, welding and plating sources, transportation emissions, agricultural sources, and general industry sources. Overall, the study region exhibited mild to moderate ecological risk, primarily driven by coal combustion, smelting activities, and general industry, which should be prioritized for control. Hg (mean Ei = 47.05) and Cd (mean Ei = 42.28) were identified as target elements, contributing 40.6% and 36.5% to the NCRI, respectively. The non-carcinogenic risk posed by HMs was negligible, but the carcinogenic risk was significant, with mean TCR values for adults and children of 9.64E−06 and 2.93E−05, respectively. With Cr as the target element, welding and plating sources were recognized as priority control sources for health hazards in FTSG, contributing 40.06% and 40.78% to adults and children, respectively. Overall, this research offers a theoretical basis for carrying out the evaluation and management of the risk of soil HMs in towns with agriculture-led industrial development.