Ecological risk assessment of heavy metals in soils around mining area: comparison of different assessment methods

Abstract

The farmland soil around the mercury mining area of Xunyang mansion was investigated and analyzed, and different methods were used to evaluate the soil. The results show that the contents of chromium, nickel, cadmium and mercury in Gongguan mercury mining area are 97-1113 mg / kg, 76-601 mg / kg, 0.415-1.458 mg / kg, 1.050-5.273 mg / kg, all of which exceed the standard values. The results show that the mercury pollution in Gongguan mercury mining area is extremely serious; the Nemero pollution index method shows that the soil near the Gongguan mercury mining area has been polluted in different degrees, and the crops near the mining area have the tendency to pollute heavy metals; the potential ecological risk index method shows that the heavy metal mercury in Gongguan mercury mining area presents a very strong risk level. The evaluation results of different evaluation methods are quite different. Therefore, in the follow-up evaluation, the appropriate evaluation method should be selected according to the purpose of evaluation.