Geochemical features and potential environmental implications of heavy metals in mining-impacted sediments, south...

The present study was initiated to investigate the geochemical features and associated pollution risks of selected heavy metals in sediments near an active copper sulfide mines, south China. These results indicated that legacy contamination in sediments were mainly Cd (11.9 mg/kg), Cu (0.106%), Pb (0.189%), Zn (0.0958%), and As (0.158%). Furthermore, the geochemical variability of most elements, ranging from 5.66% for K₂O to 24.99% for Cd, was relatively lower. On the spatial scale, the variation patterns of multi-elements did not show a decreasing trend. The multivariate statistical analysis revealed that the significant enrichment of the studied elements was mostly related to the geochemical background and anthropogenic sources. Besides that, the stable climate might have positive influences on the leachability patterns of heavy metals in sediment profiles. According to the results of the potential ecological risk index (PERI), Cd, Cu, Pb, and As were identified as the riskiest elements due to their rather higher contribution ratios to pollution risk. In response to continuous exposure risks, the significant enrichment of these mining-derived elements should be preferentially concerned. Finally, some reasonable action is proposed for aquatic environment protection. Graphical abstract.