RISK ASSESSMENT OF HEAVY METALS IN FARMLAND SOILS NEAR MINING AREAS IN DAYE CITY, HUBEI PROVINCE, CHINA

We aimed to identify the status and evalute the potential risks of heavy metals in the farmland soils near the mining areas in Daye City, Hubei Province, China. Seventeen surface samples from this area were collected from depths of 0 cm to 20 cm to investigate the content of six major heavy metals, namely, Cu, Zn, Pb, Cd, Cr, and Ni, and evaluate the risk of these heavy metals in soils using single factor evaluation index and Nemero comprehensive evaluation index. The results revealed the sites were severely contaminated by Cu, Cd, and Zn. The pollution percentages of Cu, Cd, and Zn above the Class II standards defined by the National Soil Environmental Quality Standard (GB15618-1995) were 88.24%, 100%, and 58.82% respectively. The average concentration values for these elements were 259.7, 1.360, 241.1 mg/kg respectively. Light, moderate, and heavy pollution levels were observed in 17.65%, 35.29%, and 47.06% of the soils respectively according to the results by Nemero comprehensive evaluation index. No soil was clean or under warning limit. Correlation and Principal component analysis results revealed that mining activities were the main source of pollution. Therefore, the situation of the heavy metals pollution in the soils near the mining areas in Daye City were very serious and measures should be taken immediately to avoid further deterioration. The results presented here can provide data support and reference for regional soil quality management in Daye City.