[Distribution and Source-specific Ecological Risk Analysis of Soil Heavy Metals in South Hunan Province]

Area of Science:

• Environmental Science
• Geochemistry
• Risk Assessment

Context:

• Soil heavy metal pollution poses a significant threat to ecosystems and human health.
• Hunan Province, a region with extensive industrial activities, faces challenges in managing soil contamination.
• Understanding the spatial distribution and sources of heavy metals is crucial for effective environmental management.

Purpose:

• To investigate the spatial distribution patterns of heavy metals (Cd, Hg, As, Pb, Zn, Ni, Mn, Tl, Sb) in southern Hunan Province.
• To assess the ecological risks associated with soil heavy metal pollution.
• To identify and quantify pollution sources using multivariate statistics, GIS, and the positive matrix factorization (PMF) model.

Summary:

• Mean concentrations of soil metals exceed background values, with Cd, Hg, Pb, and Sb showing significant pollution.
• High heavy metal concentrations are concentrated near industrial zones, particularly black and nonferrous metal processing areas.
• Primary sources include industrial activities (29.06%), atmospheric deposition (22.05%), nonferrous metal mining (20.65%), and industrial/transportation sources (14.73%).

Impact:

• Cd and Hg are identified as critical elements requiring prioritized control measures to mitigate ecological risks.
• Industrial activities and atmospheric deposition are major contributors to health risks.
• The findings provide a basis for developing strategies to manage heavy metal contamination in Hunan Province.