Evaluation of Heavy Metal Pollution in Soils from Nanjing Qixiashang LeadZinc Mines

The characteristics and status of heavy metal contamination in soils from Nanjing Qixiashang leadzinc mines were investigated and evaluated. Different sampling methods and evaluation criteria were selected for different soil types mainly from open mining area, vegetable field and scenic spot of Qixia Temple. The quincunx sampling mode was selected for the first two types of soils and the random sampling mode was used for soils at Qixia Temple. The national standards for soil environment quality （GB 15618—1995）was used for the evaluation with the Grade Ⅱ standard for vegetable field soil and the Grade Ⅲ standard for mining area and scenic spot soils. The survey results showed that the soils in the mine area, Qixia Temple and vegetable field were contaminated seriously by Pb, As, Cd and Zn, and the soils in some areas were also polluted by Cu slightly, but no contamination from Cr was found. The Nemerow (multi-factor comprehensive pollution) indexes were all greater than 3, indicating that these three types of soils were suffered from severe contamination, especially in the concentrating mill, mine outlet and tunnel exhaust port, and the pollution level was gradually declined with the distance increase from the mining area.