乌鲁木齐市大气细颗粒物(PM2.5)污染成分特征

目的了解上海市虹口区大气PM_2.5污染状况及其重金属含量的特征。方法2015—2016年，在上海市虹口区某建筑物楼顶采用滤膜称重法采集大气PM_2.5，每次连续采样24 h，分析PM_2.5日平均质量浓度及其重金属含量特征。结果大气PM_2.5质量浓度范围为0.008~0.246 mg/m³，平均值为0.052 mg/m³，超标率为25.0%。PM_2.5质量浓度变化规律为冬季＞春季＞夏季＞秋季，2016年低于2015年。大气PM_2.5中重金属含量平均值依次为钾＞铁＞钙＞锌＞铝＞铅＞锰＞铜＞钒。结论该采样点大气PM_2.5污染较严重，超标率较高。重金属浓度变化具有季节规律，冬春季节明显高于夏秋季。

Chemical characterization and source apportionment of indoor and outdoor fine particulate matter (PM2.5) in retirement communities of the Los Angeles Basin

ObjectiveTo investigate the characteristics of the PM_2.5 pollution and heavy metal content in the atmosphere of Hongkou District of Shanghai.MethodsFrom 2015 to 2016, PM_2.5 mass concentration was monitored by membrane gravimetric method on the roof of a building in Hongkou District of Shanghai.Air samples were continuously taken for 24 h each time thus to calculate the daily average mass concentration and the heavy metal content.The data obtained were used to analyze seasonal characteristics.ResultsThe atmospheric PM_2.5mass concentration was in the range from 0.008 mg/m³ to 0.246 mg/m³, with the average being 0.052 mg/m³ and the exceeding-limit ratio reaching 25%.The PM_2.5mass concentration in winter was the highest, with spring, summer and autumn in decreasing sequence, and was found to be higher in 2015 than in 2016.The average mass concentration of heavy metals in atmosphere were K>Fe>Ca>Zn>Al>Pb>Mn>Cu>V.ConclusionThe PM_2.5 pollution at the sampling spot in Hongkou District of Shanghai is quite serious with higher rate of exceeding the PM_2.5 standard value.And its mass concentration variation has seasonal regular patterns, it is obviously higher in winter and spring than in summer and fall.