长沙市街道灰尘中重金属空间分布特征与风险评估

长沙市街道灰尘中重金属空间分布特征与风险评估(6800字)
摘 要:本文的主要目的是调研长沙市主要街道灰尘中典型重金属含量水平，分析其污染现状及特征，从而进行风险评估，旨在为街道清扫及长沙市灰尘重金属污染治理提供数据支持。研究表明，长沙市主要街道灰尘中典型重金属Pb、Cd、Cu、Zn存在不同程度的污染风险，各重金属外源部分均占极大比重。其中Pb含量超过湖南省土壤背景值20倍。火车站附近街道灰尘中Pb含量最高达到1019.35mg/kg。指数分析得出，Pb呈重度污染，Cd、Zn呈中度污染，Cu呈轻度污染。长沙火车站附近重金属污染程度高于长沙汽车东站。火车站附近街道灰尘重金属含量较高主要与人流、车流量较高有关。
关键词: 长沙市；街道灰尘；典型重金属；危害

HEAVY METALS POLLUTION AND ITS ASSESSMENT IN URBAN STEET DUST OF CHANGSHA
Abstract:The main purpose of this paper is to survey the typical heavy metal content of dust in Changsha main streets, analyze its basic characteristics and then give risk assessments of it, which can further provide information to street sweeping and pollution-shooting of the city. Studies have shown that typical heavy metal such as Pb, Cd, Cu, Zn, especially for their edging areas, are enduring different degrees of pollution respectively. Pb content of it reaches more than 20 times of the background value of Hunan soil. Pb content around the train station can up to 1019.35mg/kg. The following conclusions can be made under exponential analyzing: Pb was heavily polluted, Cd and Zn moderately polluted, Cu slightly polluted. Heavy metal pollution situation is more serious then south Changsha bus station ones and mainly because Changsha Railway Station have more flow of people and vehicles.