A total of 62 urban soil samples were collected within the third ring road of Xi'an,covering industrial areas,traffic areas,mixed commercial and traffic areas,residential areas,cultural and educational areas,and parks.The concentrations of As,Co,Cr,Cu,Mn,Ni,Pb,and Zn in the soil samples were analyzed by using PW2403 X-Ray fluorescence spectrometer.The potential ecological risk of heavy metals in the urban soil was assessed by the modified potential ecological risk index.The health risk of human exposure to heavy metals in the urban soil was evaluated with the health risk assessment model of United States Environmental Protection Agency (US EPA).The results showed that the mean concentrations of As,Co,Cr,Cu,Mn,Ni,Pb,and Zn in the soil were 12.15,24.96,69.74,32.52,662.59,30.67,37.11,and 101.73 mg kg-1,respectively.They were higher compared with their background values in soil of Shaanxi,especially for Co,Pb,Cu,and Zn.The potential ecological risk was low for Pb,Cu,Ni,Cr,Zn,and Mn,but moderate for As and Co.The total potential risk of heavy metals in the soil belonged to moderate level.It was varied in soil with functional areas.The major pathways of human exposure to heavy metals in urban soil were ingestion through hand and mouth as well as dermal adsorption.The exposure doses of children through the two exposure pathways were higher than those of adults.Children and adult exposure to heavy metals in the urban soil presented cancer risk,while the risk of children was higher than that of adults.The cancer risk of human exposure to As,Cr,and Ni was in the acceptable range of 10-6-10-4,while it was higher than the standard value of 10-6.The risk of non-carcinogenic and carcinogenic risk of human exposure to heavy metals in the urban soils was different in these functional areas.
NETL
NSTL
维普
万方数据
