摘要
在北京市六环路以内北西-南东、北东-南西、东-西及南-北4条剖面上采集了街道灰尘样品,进行了20个元素的化学分析(K,Ca,Al,Fe,Ti,Mn,Cr,Ni,Cu,Zn,Cd,Pb,La,Ce,Y,Nb,As,Sb,Hg,OC),并通过统计分析对街道灰尘中这些元素可能的来源进行探讨.结果表明,比较街道灰尘中对人体有害元素含量与北京地区土壤背景值发现,只有As、Ti、Mn的含量低于土壤背景值,其它元素的含量都不同程度地高于土壤背景值,而Cd和Hg的最大值甚至达到了北京地区土壤背景值的250倍和64倍.可见这些元素的点污染现状相当严重.通过因子分析将20个元素变量减少为5个因子,可解释北京市街道灰尘的4种来源:①交通排放,特征元素为Zn,Sb,Pb,Cu;②与成土母质的地质背景有关的土壤颗粒的再悬浮和/或迁移;③工业污染,铁族元素组合Fe、Mn、Cr、Ti是典型的首都钢厂污染元素;④建筑材料及废弃物.而Hg和Cd因其多来源的复杂作用使得这2个严重污染环境的元素归属(分组)不明.
Street dust samples were collected along four transects inside the sixth ring road in B eijing. The concentrations of 20 elements （K, Ca, AI, Fe, Ti, Mn, Cr, Ni, Cu, Zn, Cd, Pb, La, Ce, Y, Nb, As, Sb, Hg, OC） in the fraction of the street dust smaller than 100μm were analyzed by optimized methods of AFS, ICP-MS and XRF. The levels of toxic elements were much higher than the background value of Beijing soil. Using factor analysis,5 factors were extracted from 20 element variables as the most important sources of street dusts on Beijing roads： namely, ①traffic emissions, characterized by Zn, Sb, Pb, Cu and OC ; ②resuspension and/or mobilization of geogenic soil particles; ③industrial pollution, e.g. Fe, Mn, Cr and Ti are typical pollutants from steel manufacture; ④construction materials and wastes.
出处
《环境科学学报》
CAS
CSCD
北大核心
2007年第7期1181-1188,共8页
Acta Scientiae Circumstantiae
关键词
街道灰尘
化学成分
因子分析
污染物来源
北京
street dusts
chemical composition
factor analysis
pollution sources
Beijing
