Abstract

To investigate geochemical characteristics of soil and atmospheric environments by anthropogenic source, we have analyzed and determined heavy metal concentrations of the surface soils beneath roadside trees and leaves of Platanus occidentalis from 52 points in Seoul during autumn 2001. For comparison of the contents of heavy metal for the soil and leaf, we have analyzed heavy metal contents of the surface soils beneath roadside trees and leaves from 2 points in rural area of Yesan during the same time period. The composition of heavy metals of soils are relatively high for Cd, Co, Cr and Ni in industrial area (IA, Industrial Area) and high for Cu, Pb and Zn in heavy traffic area (HTA, Heavy Traffic Area). The heavy metal contents of rural area in Seoul are higher than those in Yesan. The differences of chemical compositions between the washed and unwashed leaves are high for Cd, Cu, Pb and Zn in the HTA. The element couples of Cd-Co, Cr-Ni and Pb-Zn for the soils had shown a good correlation and their contamination sources could be similar. The relationship for Pb-Cu and Cu-Zn showed good correlation in Platanus leaves. The relationship between soils and unwashed leaves show a good correlation for Cr, Cu, Pb and Zn but low correlation for Cd, Co, Fe, Mn and Ni. It is thought that the Cr, Cu, Pb and Zn were derived from contaminants of soils, whereas Cd, Co, Fe, Mn and Ni were originated from atmospheric source. From the spatial variations of elements for soils and leaves, Ni and Cr were dominant in the soils of IA and Cd, Cu and Zn were dominant in those of HTA. The Contamination by Cd-Pb and Cu-Zn in unwashed leaves were analyzed to show similar patterns. Using the enrichment factors (EF) of heavy metals in unwashed leaves, the EF sequences were to be Cu, Zn, Pb, Mn, Co, Ni, Cd and Cr. We identified that Cu, Zn, Pb and Mn were most problematic of environmental hazard in Seoul.

Keywords roadside tree leaves, roadside soil, heavy metals, enrichment factor, Seoul