Source Apportionment and Ecological-Health Risks Assessment of Heavy Metals in Topsoil Near a Factory, Central China

Soil heavy metals pollution caused by industrial activities poses a great threat to the environment and human health and has become an increasingly concern worldwide. In this study, heavy metals/metalloid (Pb, As, Zn, Cu, Cr, Ni, Fe, Mn) in the topsoil around a factory, central China were investigated to identify their sources and to assess the potential ecological-health risks. A total of 106 soil samples were collected and analyzed in the study area. Statistical analysis and Positive Matrix Factorization (PMF) model revealed that Pb, As, Zn and Cu were main contaminants in the topsoil of the study area, which mainly originated from three sources: industrial fume emitted by factory entering the soil through dry deposition (41.3%), natural sources (52.1%), and sewage leakage (6.6%). Self-Organizing Map (SOM) indicated that the sampling sites could be grouped into four clusters. Potential ecological and human health risks were evaluated for each cluster. It was found that the potential ecological risks and the non-carcinogenic risks were relatively high in the southeast of the factory due to the soil pollution associated with the main wind direction, and the carcinogenic risks were relatively high in the northeast of the factory affected by the discharge of As-containing wastewater. The high-risk areas identified in this study could provide a priority for future control and treatment of heavy metals pollution.