长沙市环境空气中BTEX的污染特征及健康风险  

POLLUTION CHARACTERISTICS AND HEALTH RISKS OF BTEX IN AMBIENT AIR OF CHANGSHA

作　　者：邹利林 姚运先[2] 蒋利华[2] 王真真[2] 张洲[1] ZOU Lilin;YAO Yunxian;JIANG Lihua;WANG Zhenzhen;ZHANG Zhou(Changsha Center for Mineral Resources Exploration,Guangzhou Institute of Geochemistry,Chinese Academy of Sciences,Changsha 410013,China;Hunan Provincial Engineering Center of VOCs Monitoring Technology,Changsha Environmental Protection College,Changsha 410004,China)

机构地区：[1]中国科学院广州地球化学研究所长沙矿产资源勘查中心,长沙410013 [2]长沙环境保护职业技术学院湖南省挥发性有机物VOC监测技术工程中心,长沙410004

出　　处：《环境工程》2022年第1期102-109,共8页Environmental Engineering

基　　金：湖南省重点研发计划项目(2018SK2039);湖南省自然科学基金项目(2019JJ50704);中国科学院战略性科技先导专项(A类)(XDA23010303);湖南省环保科研课题(湘财建指[2017]83号)。

摘　　要：BTEX(苯、甲苯、乙苯、二甲苯等)是对空气质量和人体健康具有重要影响的挥发性有机物。为研究长沙市城市大气BTEX污染特征,选择2个典型城市站点(采样点S和W)于2017年8月进行了连续采样分析。结果显示:2个采样点BTEX平均浓度分别为(9.84±5.44),(6.35±4.68)μg/m^(3);其中间/对-二甲苯是占比最高的组分,分别为32.3%和26.7%,其次是甲苯,贡献比例分别为20.6%和22.8%。BTEX及主要组分浓度日变化呈“U形”特征,即7:00—8:00浓度较高,之后逐渐降低,至13:00—14:00出现最低值,然后上升,至16:00—17:00浓度高值,可能受光化学反应及排放强度等因素影响。由BTEX相关性及苯、甲苯、乙苯比值分析发现,长沙市城市大气BTEX主要受机动车排放、工业及溶剂排放等影响。BTEX非致癌风险危害商值(2.89×10^(-4)-9.35×10^(-2))均<1,表明对暴露人群尚不存在明显的非致癌风险;但空气苯暴露的致癌风险评价值(6.41×10^(-6),5.34×10^(-6))却较高,表明苯可能对居民健康存在潜在的致癌风险。BTEX(benzene, toluene, ethylbenzene, xylenes, etc) are volatile organic compounds which have great impact on air quality and human health. To study pollution characteristics of BTEX in Changsha, ambient samples were collected and analyzed consecutively at two typical urban sites(site S and W) during August 2017. The results showed that the averaged concentrations of BTEX were(9.84±5.44) μg/m^(3) at site S and(6.35±4.68) μg/m^(3) at site W, respectively;and m, p-xylenes were the most abundant species among BTEX with contributions of 32.3% and 26.7%, respectively, followed by toluene with contributions of 20.6% and 22.8%, respectively. Diurnal variations of major BTEX species showed a “U” pattern with lower concentrations during 13:00—14:00 and higher concentrations during 7:00—8:00 and 16:00—17:00, which might be influenced by variation of photo-chemistry reactivity and source emission. The correlations among BTEX and relative proportions of benzene, toluene and ethylbenzene suggested that traffic-relate sources, industrial sources and solvent emissions were the major sources of ambient BTEX in Changsha. The non-carcinogenic hazard quotients of BTEX(2.89×10^(-4)-9.35×10^(-2)) were all lower than 1, indicating no obvious adverse carcinogenic hazard risk on the exposed population. However, the carcinogenic hazard risk values of benzene(6.41×10^(-6) and 5.34×10^(-6)) were higher, implying the potential cancer risks due to ambient benzene exposure in the study region.

关 键 词：BTEX 污染特征 来源 健康风险 长沙市 

分 类 号：X51[环境科学与工程—环境工程]