Pollution assessment and source apportionment of heavy metals in soil from lead – Zinc mining areas of south China

Abstract

For the regulation and remediation of heavy metal-polluted soils in mining areas, it is important to study the spatial distribution of soil heavy metal accumulation, quantitatively describe the sources of soil heavy metals, and identify the main characteristic contaminants. Therefore, in this study, multivariate statistical and geostatistical analyses were combined with principal component analysis and positive matrix factorization to assess the spatial distribution of soil-contaminating heavy metals, to quantitatively describe the sources of soil heavy metal contamination in mining areas, and to identify the main contaminants in 15 Pb–Zn mining areas in six provinces of South China.The average concentrations of heavy metals were higher than the local soil background values. Mining soils were contaminated by multiple heavy metals, mainly Cd, Pb, and Zn. All the heavy metals have a strong spatial autocorrelation except for Sb. Cd and Zn mainly originated from smelting sources (24.0%), Pb mainly originated from transportation and mining sources (16.4%), As and Cu mainly arose from flux sources (25.0%), Cr, Ni, and Sb mainly originated from natural sources (34.6%). Overall, this study provides a solid research basis for the remediation and treatment of heavy metal-contaminated soils in Pb-Zn mining areas.