Heavy Metal Contamination, Source Apportionment, and Risk Assessment of Agricultural Soils Surrounding a Gold Mining Area in Northeastern Shandong Province, China

ABSTRACT Heavy metals (HMs) contamination in agricultural soil environmental systems poses a critical threat to ecosystem security, food safety, and public health. To investigate the pollution characteristics, sources, and ecological‐health risks of HMs in agricultural soils in a concentrated gold mining area, topsoil samples were collected from the vicinity of industrial squares, tailings ponds, and potentially affected zones. The concentrations of Hg, Cd, Cr, Ni, As, Pb, Cu, and Zn were determined. The geo‐accumulation index (I geo ), enrichment factor (EF), potential ecological risk index (RI), and human health risk assessment (HRA) model were employed to evaluate the contamination level and associated risks. Principal component analysis (PCA) and positive matrix factorization (PMF) were combined to quantitatively apportion the sources of HMs. The results indicated that, except for one sample each exceeding the standard for Cd and Hg near tailings ponds, the concentrations of the remaining HMs fell within the corresponding risk screening values. The I geo and EF results revealed that Cd exhibited the highest enrichment, with over 30% of samples showing moderate enrichment, whereas other elements remained at minimal enrichment levels. The PMF model identified five sources: natural parent material (51.62%), gold mining and smelting (15.19%), atmospheric deposition (Hg, 14.77%), a mixed source of natural background and mining activities (14.45%), and a localized minor anthropogenic mixed source (3.97%). The potential ecological risk was largely attributed to the accumulation of Cd and Hg. The comprehensive RI indicated that 76.67% of sites were at low risk and 23.33% at moderate risk. The non‐carcinogenic risk for both children and adults fell beneath the acceptable threshold (HI < 1), while the carcinogenic risks (especially for Cr and As) posed potential health threats, particularly concerning children. Overall, the agricultural soils are generally clean with localized contamination, and Cd and Hg are identified as the priority control elements.