Heavy Metal Pollution In Highway Of Chongming Island

Interest in the levels of heavy metal pollution associated with highway has risen in these years,Influenced by such causes as automobile exhaust gas et al.The dust,soil,vegetable and green belt on the roadside have accumulated a large amount of heavy metals,and become a potential danger.The pollution that heavy metals make to the atmosphere,water and soil will bring direct or indirect threat to human heath .this article takes the study to heavy metal pollution in the corse of highway constmtion and opreation in order to put forward some advices and to control the pollution,which has significantly realistic and scientific meaning.On the Study of soil ,dust and vegetable on the roadside in ChongMing,327 sorts of samples are gathered .on the anlysis of 2003 effective data,make the analysis and reserch to the contant and spresding characters of heavy metals Zn,Cd,Cu,Pb,Cr in these samples.Meaniwhile,the pollution degree and ecological risk of these heavy metala are valued ,which provides reliable sicentific basis of the enviroment pollution control,highway management and city planning of Chong Ming.The main conclusions of this study can be summed up as follows: 1. The average content of Cr,Cu,Cd,Pb and Zn in soil of Chong Ming is110.3,18.7,0.34,29.4 and 95.1 mg/kg respectively, which is respectively 1.4,1.3,2.1,1.5 and 1.2times of the soil background values. With the method of potential ecological risk index to assess the heavy metal pollution in soil,the results show:Cd is at middle pollution level,the others is light level,the spatial distribution of each heavy metal has much difference and the partial pollution is serious,for instace the peak contents happen in Zhang Jia in Bei Yan and Shen Jia in Chen Hai,Heavy metals accumulate manily Which belong to serious particel pollution district and need strenged management and precaution, that on the sides of disdence of 20～50m ,Its content is higher than roadside. In soil the forecast of Pb in 20 years,warns us that the content is becoming without proper control become more and more serious.2.The average content of Cu,Zn,Cr,Pb and Cd in road dust is 37.05,164.13,114.44,41.66 and 0.36 mg/kg respectively,which is respecively 2.0,2.15,1.39,2.16 and 2.12 times of the soil background values,The content is higher than that in soils,Zn and Pb are more serious .The spatial distribution of each heavy metal has much difference and the partial pollution is serious,The peak contentshappen in E Gu ,Ge Long and Shen Jia ,with the method of geoaccumulation index to assess the heavy metal pollution in the road dust,it is found that Pb and Cd are at higher pollution level.3. Vegetables on the roadside have some heavy metals,Pb is the most serious, itscontent exceed limit of the national standards, The vegetables on the sides of road have more Pb than that on roadside, The spatial distribution has much distribution has much diffirence, the particle pollution is serious, the peak content happen in the distance of road with the range of 0～50m, it is similar for the character the spatial distribution of Pb in soil.4. The invistgate shows that serious pollution happens in heavy motor-running rare.so the amount of running motrors on some road shuold be restricted and keep the road expedicte .which pollution has already existed or will wxit,green belt should be widen, which trees and shrub are plants that can absorb extra heavy metals can be planted so as to keep ecological system on the roadside.