Assessment of Heavy Metal Contamination in Paddy Soils from Daye Mining Area of Hubei Province, China

摘要

The occurrence and distribution of heavy metals (including copper (Cu), lead (Pb), zinc (Zn), cadmium (Cd), chromium (Cr), cobalt (Co), nickel (Ni) and manganese (Mn)) in paddy soils from the Daye mining area were investigated by atomic absorption spectrophotometry (AAS) using the flame and graphite furnace method. The pollution of all metals investigated was found in paddy soil samples from the Daye mining area. Additionally, Cu, Pb, Zn and Cd concentrations at the sampling sites near the quarries and mines located in the central and eastern part of Daye were higher than those at the other sampling sites. Hierarchical cluster analysis and principal component analysis (PCA) of the heavy metal concentrations showed that the mine might be an important contributor to heavy metals contamination. PCA analysis extracted two factors that explained 67% of the total variables. The source of Zn, Cd, Cu and Pb would be primarily the deposition of aerosol particles emitted by metal smelting, manufacturing and traffic, acid mine drainage and metal mine waste rock and long-term stockpiling of tailings. Ni and Cr were controlled by parent material in the soils. Evaluation of heavy metals contamination of paddy soils indicated that the Cd contamination was the most widespread, followed Cu, Ni, Zn and Pb.