Identification of Heavy Metal Sources and Health Risk Assessment in Coal Mining Area Soils Using Mercury Isotopes and Positive Matrix Factorization (PMF) Model

This investigation focuses on anthropogenic impacts on metallic element distribution within coal mining ecosystems, particularly addressing soil contamination risks in the Linhuan region. Researchers conducted comprehensive sampling and analysis of surface soil contaminants, specifically quantifying mercury, copper, zinc, iron, aluminum, and lead concentrations. Through integrated application of receptor modeling (PMF) and mercury isotopic fingerprinting methodology, this study established a quantitative assessment framework for pollution source apportionment. The multi-technique approach enables precise identification of contamination pathways and proportional contributions from different anthropogenic activities in the mining environment. Coupled with a human health risk assessment model, the health risks associated with specific sources were evaluated. The results indicate that the concentrations of Hg, Cu, Zn, Fe, Al, and Pb in the soil of the study area are 9.49, 2.80, 4.01, 11.79, 6.32, and 1.03 times the soil background values, respectively, suggesting a certain degree of enrichment of these six heavy metals in the soil. The PMF source contribution results show that the soil heavy metals in the study area have three sources: natural soil formation, a mixture of coal combustion and traffic activities, and coal mining activities, with contribution rates of 31.23%, 31.59%, and 37.18%, respectively. The health risk assessment results for specific sources indicate that the non-carcinogenic risks of soil heavy metals in the local area require sufficient attention. Hg is the main cause of non-carcinogenic health risks for both groups, making it a priority element for controlling soil heavy metal health risks. Coal mining activities are the main source (52.4%) of non-carcinogenic risks, making them a priority control source for soil heavy metal health risks in the study area. These findings provide a theoretical basis for enhancing the refined management of heavy metal pollution and the prevention of health risks in soils of coal mining areas.