上海市区街道灰尘重金属污染研究

对上海市区街道灰尘重金属的分布特征、赋存形态及其生物有效性进行了研究,结果表明,市区街道灰尘中Pb、Cu、Ni和Zn的平均含量分别为264、182、86和673 mg kg-1,远高于上海市土壤环境背景值;重金属含量空间分布差异较大,Cu、Pb和Zn污染中心区主要位于商业区和内环线附近,Ni污染中心区主要位于外环线附近;市区街道灰尘中Pb主要以铁锰氧化物结合态存在,Cu主要以有机物结合态存在,Ni主要以残渣态和铁锰氧化物结合态存在,Zn主要以残渣态存在;其生物有效性表现为:Ni≈Pb>Zn>Cu。

Heavy Metal Pollution in the Urban Street Dust of Shanghai City

The distribution character,speciation and bioavailability of the heavy metals in the urban street dust of urban area of Shanghai city were studied.The results showed that the average concentrations of Pb,Cu,Ni and Zn were 264,182,86 and 673mg kg-1 respectively,which were higher than the background concentrations of soil in Shanghai city.The spatial distribution of the heavy metals in urban street dust had much difference.The center areas of Pb,Cu and Zn pollution located in commercial area and near the inner circular route,while the center area of Ni pollution located near the outer circular route.Pb was present mainly in the Fe-Mn oxide fraction,Cu was predominantly associated with organic fraction,Ni was almost equally present in the residual and Fe-Mn oxide fraction,and Zn was present mainly in the residual fraction.The potential bioavailability of the heavy metals could be ordered as follows: Ni ≈ Pb>Zn>Cu.