Geochemical Characteristic of Heavy Metal in Zhouzhi Area and Analysis of Their Causes Based on Minimum Data Set

Zhouzhi County is an important kiwifruit base in Shanxi Province and even in China. 226 samples were collected from eight typical agriculture land, the contents of Cu, Pb, Zn, Cd, Ni, Cr, As, Hg, Sn, Co, Mn, V and Fe in soils were analyzed. The geochemical characteristic, potential ecological risk and origin of heavy metal elements in Zhouzhi County were investigated through constructing the minimum data set (MDS), based on correlation analysis, principal component analysis and Norm value calculation by using Cu, Pb, Zn, Cd, Ni, Cr and As. The results revealed that the single-factor pollution index was less than 1, and aggregate pollution index was 30.90, indicated the concentrations of heavy metals in soil meet the safety standard. The correlation analysis and the principal components analysis were made to discuss the cause of the heavy metals. It is believed that the first cluster including Cu, Ni, Cr, Co, Mn and V were mainly influenced by geological background; the second cluster including Pb, Zn and Cd were mainly related to human agricultural production; the third cluster including As, Sn and Hg were affected by geological background and human activities.