Heavy Metals in Agricultural Soils from a Typical Mining City in China: Spatial Distribution, Source Apportionment, and Health Risk Assessment

This study investigated the spatial distribution, sources, and health risks of heavy metals (As, Cd, Cr, Cu, Hg, Ni, Pb, and Zn) in agricultural topsoils in Fuxin, China. One-hundred and thirty-eight topsoil samples were collected from Fuxin in August 2017. Except for Cu, Hg, and Pb, the mean concentrations of other heavy metals surpassed their respective background values. The mean concentration of Cd was nine times that of the background value. For the majority of heavy metals, contents in the Haizhou and Xihe areas and south of Fumeng County were significantly higher than those of other areas. The results of the geoaccumulation and potential ecological risk indexes revealed that Cd demonstrated moderate contamination. The Haizhou and Xihe areas were considerable risk areas, whereas heavy metals in other areas posed low risks. Results of the health risk assessment revealed that the non-carcinogenic risks caused by heavy metals were small-beer. The carcinogenic risks caused by Ni, Cr, and As surpassed acceptable levels. Based on the results of source apportionment, which is based on positive matrix factorization, agricultural sources contributed to half of the concentration of heavy metals; industrial and traffic sources contributed 32.12% and 14.97%, respectively.