Source apportionment of potentially toxic elements (PTEs) in soils of the Huayuan Manganese Mining Area using PCA-IDW and PMF.

Under the long-term influence of mining activities, PTEs in surface soils of mining areas pose serious threats to human health. To investigate the pollution risks of PTEs in surface soils induced by manganese mining, this study takes the surface soils of a mining area as the research object. By integrating a coupled principal component analysis-inverse distance weighting (PCA-IDW) model with a positive matrix factorization (PMF) model, we conducted sampling, analysis, and source apportionment of PTEs in surface soils.The results indicate the following: Cd, Pb, and Zn are the core pollutants in the mining area, with mean concentrations significantly exceeding regional background values and reaching heavy to moderately heavy pollution levels. Elements such as V, Cr, and Ni are mainly controlled by geological background inputs and do not exhibit notable contamination. Source apportionment reveals that PTEs pollution in the mining area is dominated by mining-related activities (approximately 65% contribution in the PMF model), which release Cd, Pb, and Zn primarily through waste rock accumulation, tailings leakage, and leaching of beneficiation wastewater. High-value zones are concentrated around active mining operations and the tailings reservoir. Traffic emissions constitute the secondary source (about 20% contribution), arising from tire wear, fuel leakage, and ore spillage from ore-transport vehicles, with pollution showing a linear distribution along transportation corridors within the mining area. Contributions from residential activities are minor (less than 5%), introducing only slight inputs through scattered coal combustion and leachate from domestic waste within the mining area and having no significant influence on overall pollution levels.This study precisely quantifies the differential contributions of three internal pollution sources, providing scientific support for targeted control of PTEs in surface soils of mining regions and facilitating refined pollution management in mining areas.