Risk Assessment of Heavy Metals in Soil Surrounding Manganese Tailings Pond Based on Source-oriented Analysis

To analyze the source apportionment, potential ecological risk, and health risk of heavy metals in soils surrounding a manganese tailings pond in Chongqing, a positive matrix factorization（PMF）model, potential ecological risk index, and health risk assessment model were used. Further, all three models were combined to explore the risks of heavy metals in soils by different pollution sources to determine the priority control factors. The results showed that except for the Cr concentration, the average values of Mn, Cd, As, Pb, Cu, Zn, and Ni concentration were higher than their corresponding background values. Using the PMF model analysis, mining, natural, agricultural, and industrial sources were identified as the determinants for the accumulation of heavy metals in soils, with contribution rates of 23.9%, 30.2%, 18.8%, and 27.1%, respectively. Using potential ecological risk index analysis, the ecological risk was predominantly categorized as strong risk, with the rate of 77.8%. The health risk assessment model analysis revealed that, the carcinogenic risks of adults and children were tolerable, whereas the non-carcinogenic risks were acceptable. According to the analysis results of the relationship among heavy metals, pollution sources, potential ecological risk, and health risks showed that agricultural sources were identified as the priority control sources, with Cd as the primary control factor. Mining sources and industrial sources were identified as secondary control sources, with Mn and As as the secondary control factors. © 2024 Science Press. All rights reserved.