Soil Heavy Metal Pollution of Roadside Greenbelt in the North of Beijing

In order to gain an understanding of the soil environmental quality of roadside greenbelt,the concentrations and pollution indexes of soil heavy metals under different vegetation types near the ring roads were studied in North Beijing.The results showed that the concentrations of Zn and Pb in different roadside greenbelt soil were distributed unevenly,the coefficient of variation were 108.79% and 99.56%,respectively.The concentrations of soil Pb,Cu,Zn,Ni,Mn,Co in the North Second Ring Road were significantly higher than that in the North Fifth Ring,while no obviously difference of concentrations of soil heavy metals between the North Fourth Ring and North Fifth Ring soil was found.The pollution level of each heavy metal was different.Pb was in the cleanliness level,Cr and Cu were in the light pollution level,Zn and Co were both in the moderate pollution level,while the Ni and Mn were limited to the level of alert.Consequently,the soil heavy metal pollution index was 1.81,the soil environmental quality reached the extent of light pollution.