Risk assessment of soil heavy metals in mining activity areas: a case study in Eastern Shandong Province, China

A total of 237 surface soil samples were collected during May and June 2021 within a mining activity area in Eastern Shandong Province, China. In this research, the soil heavy metal pollution risk and its sources were identified in the mining activity area. Overall, the soil was acidic in nature, and most of the sites were uncontaminated, except for a few that were slightly polluted. The heavy metals produced by mining activity were mainly Hg, Pb, and Cd, among which Hg was highly enriched, while Pb and Cd were slightly enriched, indicating high ecological risks for Hg followed by Cd in this region. Most of the heavy metals were not above the detrimental level for human health, but the As, Cr, and Pb contents require attention. The Ni and Cr heavy metals were mainly derived from natural sources, whereas As was derived from pesticides and fertilizers, Zn and Cu had mixed sources, and the heavy metal Cd may affect agricultural security to some extent. This study provides scientific support for implementing policies to control heavy metal pollution and its sources. These findings will also assist in protecting and restoring the ecological environment, promoting safer agricultural production, and providing a healthier life for residents within mining activity areas.