STUDY ON THE POTENTIAL ECOLOGICAL RISK ASSESSMENT OF TOXIC ELEMENTS BASED ON GEOCHEMICAL DATA:An Example from Aohan Qi, Inner Mongolia

With growing environmental pollution, various pollutants enter the human bodies in different ways to threaten human health. Heavy metals are the dominant pollutants in soil. Among them, Hg, Cd, Pb, Cr and metalloid As have significant biotoxicity, while Zn, Cu, Ni, Co and Sn are with moderate biotoxicity. This paper adopts the 1:50 000 water and soil geochemical survey data of Aohan Qi sheet to evaluate single element pollution level with single factor pollution index. With the toxicity response coefficients of heavy metal elements, the potential risk areas of toxic elements are assessed. The result shows that the potential ecological risk elements in the study area are mainly Cd, Pb and As, of which Cd is the most harmful. The major potential pollution factors are human geological factors, such as quarries, mining sites and garbage dumps, and primary geological environmental factors.