HEAVY METAL CONTAMINATION AND ECOLOGICAL RISK ASSESSMENT OF SOIL AROUND QUANDIAN COAL MINE, HENAN PROVINCE OF CHINA

In order to understand the heavy metal contamination of soils around of Quandian coal mine, Henan province of China, soil samples around the coal mining area were collected and measured the concentration of heavy metal (Zn, Mn, Pb, Cr, Cu), the contamination levels and ecological risk were evaluated using the geo-accumulation index, enrich factor and potential ecological risk index. The results show that the Zn, Mn, Pb, Cr and Cu concentrations are 70.0 similar to 99.0 mg/kg, 352.0 similar to 451.0 mg/kg, 30.0 similar to 50.0 mg/kg, 34.5 similar to 68.0 mg/kg and 31.0 similar to 60.0 mg/kg, and the mean values of Zn, Pb and Cu exceed the background values. According to the results of Igeo and EF, Zn, Mn and Cr have uncontaminated to minor enrichment levels, and Pb and Cu have moderately contaminated to minor and moderate enrichment levels. The rank of potential ecological risk coefficient is Cu > Pb > Cr > Zn > Mn. The mean values of potential ecological risk index is 23.79, suggesting low comprehensive ecological risk in soil samples. Pb and Cu are account over 85% contribution to RI, suggesting Pb and Cu are the main polluting elements and special attention should be paid on Pb and Cu contamination in soils around Quandian coal mine.