Multivariate Statistical Analysis of Heavy Metals Contamination in Urban Topsoil and Pollution Assessment

319 space samples about the contents of As,Cd,Cr,Cu,Hg,Ni,Pb and Zn in the soil of different functional zones in some cities were analyzed,the results showed that the contents of As,Cd,Cr,Cu,Hg,Ni,Pb and Zn were heavier than that of the background values,especially for the contents of Hg,Cu,Zn and Cd.Factor analysis was applied to identify sources of these metals,it indicated that the concentrations of As,Cr,Cu and Ni were mainly associated with industrial regions,while that of Cd,Pb and Zn were mainly from traffic zone.Additionally,that of Hg was primarily originated from pesticide in the park.The Nemerow integrated pollution index(NIPI) for the eight heavy metals shows that the rank of the pollution from heavy to light was: industrial zone,traffic area,residential area,green area in the parks and mountainous area.