摘要
工业生产和交通排放的增加导致了城市大气重金属污染,并威胁城市居民的健康.苔藓是常用的大气重金属污染指示植物之一,具有分布广、成本低、效果直观等优点.该研究利用藓袋法(泥炭藓)监测广州市大气重金属Cd、Cr、Cu、Pb、Zn的污染水平并评价其污染风险.结果表明:与暴露前泥炭藓的重金属含量相比,暴露后的Cd、Cu、Pb、Zn的几何平均值分别是其暴露前的1.2、2.3、1.4和2.3倍,而Cr元素在暴露期间稍微下降(0.9倍).工业区的泥炭藓中Cd、Cu、Pb、Zn几何平均含量普遍较高;与风景区和居民区相比,商业区的Cu、Pb、Zn含量较高.聚类分析和主成分分析结果显示,工业活动和交通污染源是广州大气重金属污染的主要来源.利用污染因子法对4个功能区的泥炭藓样品的重金属污染情况进行评估,其中重金属污染程度为极高和高的监测点主要受工业生产及其重金属废弃物排放的影响(Cu、Pb、Zn);中度污染的监测点主要受到交通污染源影响(Cu、Zn);低污染的监测点都是远离工业排放源和交通源.该研究结果证明藓袋法(泥炭藓)在城市大气重金属污染监测中具有较高的适用性.
Abstract
The increasing emissions of industrial production and transportation have resulted in serious atmospheric heavy-met-al pollution,posing threats to the health of urban residents.In this paper,the bryophyte is recommended to monitor the pollu-tion,which features wide distribution,low cost,and being able to get intuitive results.Thus,a kind of moss(Sphagnum palustre)bag was applied to monitoring the concentrations of atmospheric heavy metal(incl.Cd,Cr,Cu,Pb and Zn)in Guangzhou City,and accordingly the pollution degree and health risks were evaluated.The results obtained from the monitoring showed that in comparison with the pre-exposure to the atmospheric heavy metal pollution,the post-exposure geometric mean values of con-centrations of Cd,Cu,Pb and Zn contained in the mosses were 1.2,2.3,1.4 and 2.3 times higher than,respectively,however Cr concentration decreased slightly(0.9 times);and in general,the geometric mean values of concentrations of Cd,Cu,Pb and Zn were comparatively high in industrial areas,while in commercial areas,the concentrations of Cu,Pb and Zn were found to be higher than the scenic and residential areas.Principal component analysis(PCA)and cluster analysis(CA)revealed that in-dustrial activities and traffic emission were the main sources of atmospheric heavy metal contamination of Guangzhou City.Following the heavy metal pollution status-quo investigation with moss,four functional areas were assessed using the contami-nation factor,which indicated that in the monitoring sites showing heavy metals(Cu,Pb,Zn)pollution was high/very-high,the emissions mainly came from coal combustion,industrial metal production and processing activities,while those showing mod-erate(Cu,Zn)pollution,the pollutants came from traffic sources,and the monitoring sites where heavy metal contamination level was low,were utterly distant from industrial emission sources and traffic pollution sources.In conclusion,the moss bag(Sphagnum palustre)is rather adaptive to monitoring atmospheric heavy metal contamination in urban areas.
维普
万方数据