Spatial distribution of tin in top soils of Yangtze River delta and influencing factors

In this paper, concentrations of tin and related elements in top soils (0~20cm) of Yangtze River delta were analyzed, and the distribution of Sn in soils was studied. It is found that soil Sn concentration of Yangtze River delta was by far higher than that of its background value of China. The average Sn concentration in the studied soils is 8.35mg/kg. It is indicated that in large and medium-sized cities and some developed regions, the concentrations of tin are much higher than those of other areas. In the same sedimentary environment of agrotype, Sn content of the above areas is higher than that of the whole country, showing characteristics of high background. Researches show that the factors caused by human activities are much more important than other factors. The enrichment of tin in the surface soil is in a serious condition, and 90.39% area shows enrichment tendency, with the strong concentration area characterized by concentration coefficient large than 2 possessing 44.03%. In addition, Ag, Bi, Hg, P, Pb, Sb, Se, TOC and some other elements also have some influence on the distribution of Sn.