南昌市地铁PM2.5时空分布及金属特征研究

Spatial and temporal distribution of PM2.5 and characteristics of metals in Nanchang metro

为有效预防PM2.5污染、深入了解南昌市地铁PM2.5特征,选取不同背景区域的地铁站,探讨地铁PM2.5分布规律及其中金属元素污染情况。结果表明:(1)车厢PM2.5最高,其次是站外入口、站台,售票口最低。站台和售票口PM2.5相关性较高(r=0.668,p=0.001),可能有相近的来源。相对湿度对车厢内PM2.5影响很大,而客流量变化与车厢内PM2.5日均值变化趋势相关性不显著。(2)站台和车厢PM2.5中Fe元素比其他采样区域高3.6~34.7倍,站外入口最低。Cr、As、Cd、Hg、Pb元素最大值均出现在车厢,其次是站外入口,最小值出现在售票口和站台。(3)车厢中各金属元素污染较重,Fe元素污染指数达11.17,为强污染,Cr、As、Hg、Pb元素为中度污染,Cd元素为轻污染。

To effectively prevent PM2.5 pollution and give an insight to the characteristics of PM2.5 in Nanchang metro,the spatial and temporal distribution of PM2.5 and its heavy metal characteristics in three metro stations with different background regions were studied.The results showed that:(1)the highest concentrations of PM2.5 appeared in carriage,followed by in entrance of station,platform and ticket counter.A strong correlativity(r=0.668,p=0.001)between ticket counter PM2.5 and platform PM2.5 indicated similar sources.(2)The Fe content of PM2.5 in platform and carriage was 3.6-34.7 times higher than that in other regions,and the lowest was in entrance of station.The maximum values of Cr,As,Pb,Cd and Hg all appeared in the carriage,followed by entrance of station,ticket counter and platform.(3)The metal elements pollution was serious in the carriage,the pollution index of Fe was11.17,indicating high contamination level.Cr,As,Hg and Pb showed moderate contamination levels and Cd were lightly contaminated.