The Research On Green Space Soil Heavy Metals In Pudong District

Urban greenbelt is one of the most important places for public entertainment and it also serves to display beautiful landscape for modern life. The accumulation of heavy metal in soils can affect not only the growth, reproduction of various plants and animals, but also influence the health of human being. Therefore, it is of significant theoretical and practical importance to study the situation of heavy metal pollution, their distribution and the quality of soil environment.The soil collected from greenbelts in Pudong district was studied by field suvrey and laboratory chemical analysis. Elemental concentrations were determined by ICP-AES (Cd, Pb, Cu, Zn, Ni, Cr, As) and mercury analyzer (Hg). Physical and chemical parameters such as the pH, organic component and texture of soils were also quantified. The data obtained were then analyzed by ANOVA analysis, correlation analysis, principal component analysis and cluster analysis using SPSS.The results show that the soils collected from PuDong greenbelts were mainly comprised of loams, with relatively low organic component. The pH values of the soils range from 5.5 to 9, most alkaline. The upper soil layer was mixed with hazardous artificial additives, which is detrimental to the growth of green plants. Compared to the background value of shanghai urban soils, it can be found that overall heavy metal accumulation in the greenbelt soil is relatively higher. However, among many samples collected, 81.8% of samples have lower Hg component than the background value, and 93.5% have lower Cd component than the background value. For most samples, the Hg and Cd component of analysed samples were within the standard of first class soil. It can also conclude from data that the component of other heval metals such as As, Cr, Cu, Ni, Pb and Zn were within the standard of second class soil. Therefore, the heavy metal pollution of greenbelt soils in Pudong district is still at the stage of low pollution. Meanwhile, the data showed that there is irregular distribution of heavy metal in different layers of analysed soils.The research on heavy metal pollution in Longdong Road showed that Cu, As, Cd and Cr were mainly at the medium valence, very liable to absorbed and accumulated by various plants, so great attention should be paid to their potential hazardous effect to the ecological system.Multivaritate statistical analysis showed that compound pollutions such as Cd-Zn,Hg-Pb,As-Cd and Cr-Ni exist in the region surveyed. According to principal component analysis and cluster analysis, three sources might be responsible for the eight heavy metals mentioned above. The first, correlated with As, Cd and Zn, was originated from agricultural production. The second, correlated with Ni and Cr, was predominantly from natural sources. And the last, mainly consisted of Hg, Cu and Pb, came from the discharge from mobile vehicle.In order to lessen the hazardous effect caused by heavy metal pollution,it is vital to plant the greenbelt on the suitable soils. The soil quality evaluation and monitoring of the urban greenbelts in Pudong district can provide an important scientific foundation for the administrative decision from the government, and it can be used as a reference for greenbelt soil quality evaluation of other districts in Shanghai.