千岛湖沿湖城镇街道灰尘重金属分布特征及风险评价

Distribution Characteristics and Risk Assessment of Heavy Metals in Urban Street Dust Along the Qiandao Lake

本文以千岛湖沿湖城镇街道灰尘为研究对象,对其街道灰尘的重金属污染及风险情况进行分析评价.结果表明,该城镇街道灰尘中Ni、Pb、Cu、Zn、Cr等5类主要重金属均在污染范围中,其中Pb、Zn处于轻污染,Ni、Cu属于中污染,而Cr属于重污染;各类重金属均有不同程度的地质积累,其中Pb和Cr的积累程度相对较高;不同功能区街道灰尘中重金属含量差别较大,交通区(环湖北路)和商贸区(新安大街、新安北路)的街道灰尘重金属含量相对较高;各类重金属元素含量均在夏季出现峰值,除Pb元素外其余4类重金属元素均在粒径越小的灰尘中含量越高.

This paper focused on the analysis and evaluation of heavy metal pollution and risks in the urban street dust along the Qiandao Lake. The results showed that the average content of Ni, Pb, Cu, Zn and Cr were beyond the standard. Pb and Zn were at a light pollution level, Ni and Cu were at a medium pollution level, while Cr was at a heavy pollution level. All kinds of heavy metals had different degrees of geological accumulation, especially Pb and Cr were at a relatively high degree. The content of heavy metals varied enormously in street dust of different functional areas, and it was relatively high in traffic area （ Lake North Road） and business district （ Xin＇ an Avenue, Xin＇ an North Road）. The content of heavy metals in urban street dust peaked in the summer. Other four heavy metals except Pb had higher content when the particle size of street dust was smaller.