Pollution characteristics, source analysis and risk assessment of heavy metals in soil around a gold mine in Jiaodong Peninsula

This paper is the result of environmental geological survey engineering.

Objective This paper collected 34 surface soil samples to analyze and determine the concentrations of eight heavy metal, including Hg, Cd, As, Pb, Cu, Cr, Zn, and Ni. The objective was to characterize the heavy metal pollution in the soil around a gold mine, identify the sources of heavy metals in the soil, and conduct a risk assessment.

Methods Correlation analysis and principal component analysis were used to explore the sources of heavy metals in the soil. Single pollution evaluation and geo−accumulation index method were employed to determine the degree of pollution. Potential ecological risk assessment and human health risk assessment methods were utilized to evaluate the risks.

Results (1) Only three point source pollutions were found in the study area: one for Hg contamination and two for Cd contamination. (2) Nickel, chromium, and arsenic mainly originated from soil parent materials, while lead, cadmium, zinc, and mercury primarily came from mining activities. Copper was derived from both soil parent materials and agricultural activities. (3) Some localized areas demonstrated high potential ecological risks, mainly due to Hg and Cd, while other elements posed minimal risks. (4) Human health risk assessment indicated that the heavy metal elements in the soil did not pose significant health risks to humans.

Conclusions The soil around the gold mine was influenced by mining activities and exhibited localized pollution, albeit at a low level. The risks were manageable, but monitoring and assessment of heavy metals in this area should be strengthened.