[Spatial distribution and accumulation of heavy metal in arable land soil of China].

Based on the domestic and foreign published papers about soil heavy metal contents, the present study explored the spatial variations of heavy metal contents in agricultural soil in China. Totally, 173 studies on soil Pb, 138 on Cd, 156 on Cu, 139 on Zn and 140 on Cr were collected. Firstly, the abnormal values were selected and removed, then the spatial distributions were obtained through Kriging method and the average values in the provinces were calculated. Results show that the spatial distributions of heavy metals have obvious regional characteristics and the southwest part of China has relatively high heavy metal concentrations in soils. Compared with the background value of soil heavy metal concentrations, nearly all of the provinces have higher Pb, Cd, Cu and Zn concentrations. Pb and Cd have the most obviously higher values than the background values. The highest difference of Pb concentration is in Yunnan Province with 1.91 times of the background, and the highest Cd difference is in Liaoning Province with 23.04 times of the background; The highest Zn enrichment is in Yunnan, with 1.55 times of the background; and the highest Cu difference with 2.92 times of the background value.