四川攀西地区典型金属采选与冶炼企业周边农用地重金属污染评价及来源解析OACSTPCD

The farmland around 16 typical mining and smelting enterprises in Panzhihua-Xichang area of Sichuan were taken as the research object,in order to evaluate the pollution situation in this area,and further explore the sources of heavy metals.Risk control standards for soil contamination of agricultural land and Nemerow pollution index were used to assess the pollution situation of the heavy metals,and principal component analysis and correlation analysis were performed to explore the sources of heavy metals.The results showed that:The proportion of sites for priority protection,safe utilization and strict control is 10.6％,59.1％and 30.3％.The evaluation of Nemerow pollution index revealed that this area has been seriously polluted.The result of evaluation with the geoaccumulation index method indicated that heavy metals ranked in order of their pollution degrees as follows:Cd＞Hg＞Zn＞Cu＞Pb＞Cr＞As＞Ni.The result of evaluation with the potential ecological risk index method showed that the potential ecological risk index at the level of slight,moderate,strong,very strong and extremely strong ecological risks was 7.6％,19.7％,21.2％,16.7％and 34.8％,respectively.The result of pollution source analysis indicated that Cd,Hg and Zn mainly came from enterprise emissions,Cr and Ni were probably influenced by geological background,and As and Pd were mainly affected by the combined action of geological background and enterprise emissions.