ASSESSMENT OF HEAVY METAL POLLUTION IN SURFACE SOILS FROM URBAN PARKS AND SQUARES: A CASE STUDY FROM CHINA

Assessing the concentration of potentially harmful heavy metals in the case of soils in urban parks and squares that are used for leisure, sporting or recreational activities is imperative in order to evaluate the potential risks to residents and tourists. The concentrations of heavy metals (Pb, Cr, Cu, Ni, Zn, and Cd) in urban soils of 7 parks and 5 squares of Changchun, Northeast China, were measured based on different functional areas. The median concentrations of Pb, Cr, Cu, Ni, Zn and Cd in the investigated urban soils are 52.26, 63.00, 31.40, 16.02, 118.05 and 0.084 mg kg 1, respectively. The values of Pb, Cu and Zn are significantly higher than their background values of Changchun topsoil that average 20.46, 17.96 and 59.47 mg kg(-1). The integrated pollution index (IPI) of these six metals ranged from 1.17 to 3.65, with the highest UPI in the recreation area of the Children's Park. The results of multivariate statistical analysis (principal components analysis and hierarchical cluster analysis) indicated that Cr and Ni concentrations were mainly of natural origin, while Pb, Cu, Zn and Cd were derived from anthropogenic activities. The findings presented here show that the difference of functional areas in parks and squares is an important factor in determining the extent of heavy metal, and the level of pollution in some soils of recreation areas in parks and outside areas in squares was very high.