The Status Assessment And Risk Evaluation Of Soil Heavy Metals Pollution In Huaibei Mining Area

Coal mining has changed the original soil environmental structure greatly, and when heavy metals content which could change with the process of coal mining beyond the soil environmental threshold, there will be a damage to soil eco-environment and human health. This study revealed the accumulation of heavy metals content and the correlation among those sources of heavy metals pollution by analyzing the present status of soil heavy metals pollution in Huaibei coal mining area; using nemerow index method, geoaccumulation index method, potential ecological risk index method and health risk assessment method to evaluate the heavy metal ecological impacts level in mining area and provide the scientific theory basic for heavy metal pollution control in mining area.The analysis results revealed that the environmental status of the whole research area is all right,and the heavy metals content which are under researched have attained the national standards for Grade II. Although the heavy metals content of the most sample points have not beyond the local background value of soil element, it shows a potential trend of pollution. The sources of Cu and Ni in the heavy metal pollution of Huaibei coal mining area are similar, maybe from the smelting of coal stone;the sources of Cr and Zn are similar,maybe from the mining of coal; the source of Hg pollution which maybe from natural soil forming factors is different from other heavy metal sources.The results of risk assessment revealed that the sample point7,9,14,15and16have shown slight pollution as the geoaccumulation index rating to1st grade and the ecological impacts reaching to intermediate level, there is a requirement for special attention on the soil pollution of heavy metals. The pollution levels of As,Zn,Hg and Cd are the most high,and it is in great request for the control of the sources of these four kinds of heavy metals. The total value of heavy metals health risk of these41sample points have reached3rd grade and the sample point8,10-15and19have got a larger value than the others, therefor the damage to human health which is caused by heavy metals pollution deserves a high attention from environmental protection authorities.