广州大气细颗粒物中半挥发性有机污染物的快速筛查

Screening of semi-volatile organic pollutants in urban fine particulate matter in Guangzhou,China

本研究利用Compound Composer软件,对广州主要城区、若干企业和市政设施周边大气中的细颗粒物(PM2.5)中的半挥发有机污染物种类进行了筛查和半定量分析。样品中共检出了10大类161个化合物,其中主要以增塑剂和正构烷烃化合物为主。在大部分采样点中,增塑剂类化合物浓度最高,平均浓度为179 ng/m^3,占总检出污染物的15%~77%;正构烷烃的平均浓度为148 ng/m^3,占总检出污染物的12%~40%。源解析表明人为源贡献超过了80%。检出的农药类化合物包含了杀虫剂、杀菌剂和除草剂,其中以杀虫剂的种类最多且浓度最高(平均65.1 ng/m^3)。增塑剂、正构烷烃和农药均在市中心地区具有较高的浓度。有6种阻燃剂被检出,绝大部分为磷酸酯类化合物。阻燃剂及部分化工原料在点源采样点浓度高于城市背景点,显示为工业活动的排放。本研究为后续城市大气颗粒物重点有机污染物分析以及颗粒物的健康影响研究打下基础。

In this study,semi-volatile organic pollutants in atmospheric fine particulate matter(PM2.5)with an aerodynamic diameter of less than 2.5μm collected from the seven urban sites and five potential point-source sites in Guangzhou City,were screened and semi-quantified using a Shimadzu GC-MS and Compound Composer Database.A total of 161 compounds(10 categories),were detected in these samples.Plasticizers and n-alkanes were the major chemicals.The concentration of plasticizers was the highest in most of the sites with a mean concentration of 179 ng/m^3 and accounted for 15%-77%of the pollutants in PM2.5 mostly resulting from their widespread use in both commercial and industrial products.The mean concentration of n-alkanes was 148 ng/m^3,accounting for 12%-40% of the pollutants.Source categorization revealed that over 80%of n-alkanes were derived from anthropogenic sources.About 48 kinds of chemicals including pesticides,insecticides,bactericides,and herbicides were found in the samples,and insecticides were predominant(with a mean of 65.1 ng/m^3).The concentration of plasticizers,n-alkanes,and pesticides from the sites in the urban areas were higher than those at the point-source sites,indicating that the point-source sites probably had minimal industrial activities.The six flame retardants test conducted on PM2.5 were dominated by organophosphates.The concentration of flame retardants and some of the industrial chemicals at point-source sites were higher than those observed from the urban sites,indicating the presence of industrial emissions.This study provides important information for further studies on particle-bound organic pollutants,and has potential health implications of PM in the study area.