北京市某区大气PM_(2.5)中金属元素质量浓度及其来源

Mass concentration and source analysis of metal elements in atmospheric PM_(2.5) in a district of Beijing

目的分析北京市某区大气可吸入颗粒物(PM_(2.5))中金属元素的来源及其所占比例,为控制污染源、防治大气污染和保护人群健康提供科学依据。方法在北京市某区城中心设置1个监测点,2017年每月10—16日进行PM_(2.5)采样,共采集样品168件,测定锑(Sb)、铝(Al)、砷(As)、铍(Be)、镉(Cd)、铬(Cr)、汞(Hg)、铅(Pb)、锰(Mn)、镍(Ni)、硒(Se)、铊(Tl)12种金属元素含量,并用SPSS 16.0进行因子分析。结果 2017年北京市某区PM_(2.5)质量浓度日均值为59.58μg/m^3,其中1、2、3月的PM_(2.5)质量浓度日均值高于其余月份。PM_(2.5)中金属元素平均质量浓度顺序:Al>Pb>Mn>Cr>As>Se>Sb>Ni>Cd>Hg>Tl>Be。PM_(2.5)中金属元素的来源分为3类:第1类为工业排放源,占47.25%;第2类为交通污染源和燃烧污染源,占19.89%;第3类为土壤尘等,占14.46%。结论北京市某区大气PM_(2.5)重金属元素主要来自工业污染,其次为交通污染。

[Objective]To analyze the source and proportion of metal elements in atmospheric PM2.5 in a district of Beijing,provide a scientific basis for controlling pollution sources,preventing and controlling air pollution and protecting people’s health.[Methods]A monitoring point was set up in the center of a district in Beijing. PM2.5 samples were collected from 10-16 every month in 2017,and totally 168 samples were collected. The contents of antimony(Sb),aluminium(Al),arsenic(As),beryllium(Be),cadmium(Cd),chromium(Cr),mercury(Hg),lead(Pb),manganese(Mn),nickel(Ni),selenium(Se) and thallium(Tl) were determined.SPSS 16.0 was used in factor analysis.[Results]The average daily mass concentration of PM2.5 in a district of Beijing was 59.58μg/m3,and the average daily mass concentration of PM2.5 in January,February and March was higher than that in the rest months.The average mass concentration of metal elements in PM2.5 ranked as the following order: Al>Pb>Mn>Cr>As>Se>Sb>Ni>Cd>Hg>Tl >Be. The sources of metal elements in PM2.5 included three categories: the first category was industrial emission source,accounting for 47.25%,the second category was traffic pollution source and combustion pollution source,accounting for 19.89%,and the third category was soil dust,accounting for 14.46%.[Conclusion]The heavy metal elements in atmospheric PM2.5 in a district of Beijing mainly come from industrial pollution,followed by traffic pollution.