Risk Assessment of Heavy Metals in Soils of a Lead-Zinc Mining Area in Hunan Province (China)

Eighty-two soil samples were collected, and As, Pb, Cd, Zn, Cu and Ni were analysed for their concentrations, potential ecological risks and human health risks. The average concentrations of As, Pb, Cd and Zn exceeded their corresponding limits prescribed by the Chinese National Soil Environmental Quality Standard III, while Cu and Ni were far less than prescribed. The potential ecological risk index results indicated that Cd showed severe potential ecological risk. The human health risk assessment indicated that 80.49 % of the soil samples expressed acceptable non-carcinogenic risks, while 19.51 % of the soil samples expressed unacceptable non-carcinogenic risks. The research area represents unacceptable carcinogenic risks, the major contributor of the risk being As. Of the soil samples, 34.15 % posed acceptable carcinogenic risks, and 65.85 % posed unacceptable carcinogenic risks.