Soil and surface dust heavy metal pollution state and assessment in Shanghai City

Spatial interpolation technique was applied to study the content level and the spatial distribution character of heavy metal pollution in soil and surface dust of Shanghai City. Geochemical maps of heavy metals (Cr, Cu, Pb and Zn) in the soil and surface dust were produced based on and adopting Hakanson suggested potential ecological risk index technique to assess the potential ecological risk of heavy metal in soil and surface dust, and utilizing geographical information system (GIS) technique to drawn up the spatial distribution map of assessment results. The soil and surface dust heavy metal pollution was serious in Shanghai City, all greatly exceeded the Shanghai soil background value, especially the average content of Pb in soil and surface dust reached 925.85 mg/kg and 4415.98 mg/kg respectively, exceeding the background value 37 times and 174 times; the potential ecological risk indexes of urban soil and surface dust were 244.69 and 1004.03, respectively, reaching respectively the middle ecological risk and very strong ecological risk.