Study on distribution characteristics of chromium and nickel in root soils around a typical abandoned alunite mining area

Abstract

The exploitation of alunite resources results in the exposure of heavy metals to the surface surrounding, enrichment in soil and potential health risks to human beings. This study investigated the heavy metal pollution of root soils in a mining district surrounding a typical abandoned alunite mining area in Anhui province of China. Up to 10 root soil samples were collected in 20 sampling sites, and the concentration of Cr and Ni were determined. The results show that the root soils contained acceptable levels of Cr and Ni occurring in the ranges of 46.2-503.5 and 12.8-44 mg/kg, respectively. According to the National Soil Environment Quality Standards, few samples had Cr and Ni contents exceeding the risk screening values. However, due to the regional differences of background values, the geoaccumulation indices of Cr indicate slightly to extremely contaminated. Based on the calculation of potential ecological risk index, all the root samples were considered as low health risk level. These findings indicate the possible need for deeply and comprehensively investigation of heavy metals at alunite ore mines.