Pollution Characteristics and EcologicalRisks of Heavy Metals in Soil Neara Pb-Zn Mine in Northeast China

The heavy metal pollution in the surrounding environment of the Chaihe Pb-Zn Mine in Liaoning Province has become quite severe, yet our understanding of the chemical speciation and potential ecological risks of metals in the soil of its adjacent areas remains inadequate.Consequently, this study collected 28 soil samples from the vicinity of the Pb-Zn mine and analyzed the concentrations and speciation of Cr, As, Cu, Pb, Zn, Ni, and Cd in the soil.The results indicated that compared to background values, Cd was the metal with the highest level of exceedance, followed by Pb and Zn, with over-standard multiples of 62.33, 39.11, and 13.69, respectively.Notably, the average percentage of exchangeable Cd fractions reached 24.95%, suggesting a high bioavailability of this metal.This finding is echoed by the risk assessment code results, which indicated that Cd posed a high risk at 53.57% of the sampling sites and a medium risk at 39.29% of the sites.Furthermore, the risk index calculations revealed that the potential ecological risk in the study area was extremely severe, with cadmium and lead being the primary sources of risk.In conclusion, the contamination of Cd, Pb, and Zn in the soil surrounding the Chaihe Pb-Zn Mine is severe and requires urgent remediation measures.