Affiliations: Department of Environmental Science, Sun Yatsen
University, Guangzhou 510275, China | Department of Geography, University of Hong Kong, Hong
Kong, China
Abstract: Levels of Cu, Ni, Zn, Pb and Cr were measured in soils and trees in
urban Guangzhou, China. Tree and soil samples were collected from the roadside,
urban parks and a university campus. Mean concentrations of Cu, Ni, Zn, Pb and
Cr in tree leaves were 28.3, 7.7, 142.1, 23.4, and 195.1 mg/kg respectively. In
a comparison of heavy metal concentrations in tree leaves between roads and
park locations, only Pb concentrations were significantly higher in the former.
Heavy metal concentrations were lower in the roots compared to leaves. It
indicated that heavy metal pollution of trees is mainly from air pollution. For
all top soil samples the mean concentrations of Cu, Ni, Zn, Pb and Cr were
24.3, 17.3, 121.5, 63.9 and 88.7 mg/kg, respectively. Heavy metal
concentrations in roadside soils were higher and their coefficient of variation
was higher than those in urban parks. Comparing heavy metal concentrations in
trees and soil between urban Guangzhou and Hainan Island, China, Cu, Ni, Zn, Pb
and Cr levels in soils and plants in urban Guangzhou were evidently affected by
the human impact. However the heavy metal content in the soil compared to some
international standards do not give cause for concern. Some observations on the
implications of the data for environmental monitoring are made.
Keywords: heavy metals, roadside, parks, plants, soil
