Characteristics of heavy metal pollution in soil and dust of urban parks in Shanghai

The contents of heavy metals in soils and dust of urban parks in Shanghai were studied, and the spatial distribution of heavy metals was also analyzed. The results showed that the average contents of Pb(55.06 mg·kg-^-1), Zn(198.54 mg·kg^-1), Cu(44.57 mg·kg^-1), Cr(77.01 mg·kg^-1), Cd(0.40 mg·kg^-1) and Ni(31.17 mg·kg^-1) in soils were lower than them in the dust, which were 416.63 mg·kg^-1, 906.29 mg·kg^-1, 235.89 mg·kg^-1, 162.59 mg·kg^-1, 1.58 mg·kg^-1 and 92.19 mg·kg^-1 respectively. The heavy metals in soils except Ni and all the six heavy metals in dust were higher than the background values in Shanghai more or less. The heavy metals average contents in dust in the parks of city central area were lower than them in the parks of city surrounding area, and the heavy metals in soils have similar spatial distribution patterns except for Zn. However, in different districts, the distribution of heavy metals in the soils and dust were not regular. Pearson correlative analysis and principal component analysis indicated that the heavy meals accumulation of the soils and dust were induced by anthropogenic input, furthermore traffic and industry were the main pollution sources.