Abstract:

The exploitation of fluorite mines has triggered a serous soil pollution problem in Damao County, Inner Mogolia. Soil samples were collected from mining areas, quarries, earth dumping sites, inside and outside of gangue dumping sites and pastures around the mining areas in the region for analysis of Pb, Cr, Ni, Cu, Cd, Zn, As, and Hg. Heavy metal pollution degrees of the soils were analyzed and assessed based on soil pollution factor, Nemero index, soil pollution load index, and potential ecological risk index. Results show that the soils in all these places have gone beyond the Grade Ⅲ criteria of the Standard of Soil Environmental Quality (GB 15618-1995), in pollution of Cu, Cd, Zn, and As. In terms of single-factor pollution, Cd is the most serious and the most extensively distributed one. Pollution risks exist mainly inside the gangue dumping sites and in areas around the gangue and earth dumping sites, with Cd, As and Hg being the major pollutants. The gangue dumpling sites are the priority areas for pollution prevention and control. As a whole, soil pollution is relatively concentrated in the mining areas, and does not have much influence on people in the living quarters.

Key words: soil pollution, Nemero index, pollution load, ecological risk