Pollution characteristics, risk assessment and source comparative analysis of potentially toxic elements in soils of three superlarge antimony ore areas in the Zijiang River, Hunan, China

The soils pollution of potentially toxic elements (PTEs) in the antimony (Sb)-ore area has seriously threatened residents' health and ecological safety. Although there have been many studies on soil PTEs pollution assessment in Sb mining, most of them focus on a single Sb-ore area, which makes it difficult to quantitatively assess the contribution of natural and anthropogenic sources. Herein, the pollution characteristics and risks of 11 PTEs in soil of three superlarge Sb ore areas in the Zijiang River were compared for the first time. Firstly, the concentration, distribution and correlation of PTEs were analyzed by surveying and sampling. Then, the geological accumulation index, enrichment factor and pollution load index were used to comprehensively evaluate the pollution degree of PTEs. Further, the ecological risk and risk flow were investigated through potential ecological risk index, initial risk index and network environment analysis. Additionally, human health risk assessment model was introduced to assess the non-carcinogenic and carcinogenic risks of PTEs to males, females and children under different exposure routes, with children facing the highest risk (hazard quotient of all PTEs up to 26.90). Finally, combined with Pearson and positive definite matrix factors, the sources of PTEs were analyzed, including geology, industry, transportation and agriculture, and the contributions of them were determined. This work can offer a new approach for large-scale environmental pollution assessment in mining areas, and also provide scientific basis for achieving environmental protection and sustainable resource development in mining areas.