摘要
采用高分辨气相色谱/高分辨质谱法对珠三角地区2019年11月冬季期间和2020年8月夏季期间大气环境中17种氯取代二噁英的现状水平进行了测定,并在此基础上对其空间分布、指纹特征、指示性单体和区域迁移特征也进行了分析.结果表明,夏季和冬季二噁英的浓度平均值分别为1.40 pg·m^(-3)和5.14 pg·m^(-3),而毒性当量(以I-TEQ计)平均值分别为0.087 pg·m^(-3)和0.076 pg·m^(-3).同时,9个城市夏季和冬季二噁英的空间分布不一致,这可能由各地区采样期间的气象条件和排放源的影响导致.OCDD、1,2,3,4,6,7,8-HpCDD、OCDF和1,2,3,4,6,7,8-HpCDF是夏季和冬季的主要指纹特征单体;而2,3,4,7,8-PeCDF和1,2,3,4,7,8-HxCDF是主要的毒性贡献单体,且贡献率越大,其与总毒性当量的线性相关性越强.由后向轨迹模拟结果发现,夏季受东南偏南季风影响,气团由海上迁移至陆地,导致夏季二噁英浓度较低,且高浓度区域主要受本地排放源影响;而冬季受东北季风影响,福建和广东东部地区携带污染物的气团发生陆源迁移到珠三角区域,导致冬季二噁英浓度较高,且高浓度区域受外源污染输入和本地源综合影响.
The current situation of 2,3,7,8-chlorine-substituted PCDD/Fs was examined using high-resolution gas chromatography/high-resolution mass spectrometry(HRGC/HRMS)in winter and summer ambient air from November 2019 to August 2020 around the Pearl River Delta.Further analysis was carried out on the spatial behavior,fingerprint features,indicated monomers,and regional migrations.The results revealed that the mean mass values were 1.40 pg·m^(-3) and 5.14 pg·m^(-3),whereas the average toxic equivalent quantities(measured by I-TEQ)were 0.087 pg·m^(-3) and 0.076 pg·m^(-3) in summer and winter,respectively.Simultaneously,there were differences in the spatial distribution of PCDD/Fs among nine cities between summer and winter,which might have been caused by meteorological conditions and emission sources during the sampling period.OCDD,1,2,3,4,6,7,8-HpCDD,OCDF,and 1,2,3,4,6,7,8-HpCDF were the major congeners;moreover,2,3,4,7,8-PeCDF and 1,2,3,4,7,8-HxCDF were the primary toxic contributors,in which the stronger linear correlation indicated a greater contribution.According to the simulated results of back trajectory,air masses influenced by the south-southeast monsoon migrated from the ocean to land and caused the lower mass concentration in summer;simultaneously,the highly contaminated districts were mainly affected by local emission sources.However,the air masses carrying pollutants influenced by the northeast monsoon migrated from Fujian and eastern Guangdong province to the Pearl River Delta,which caused the higher concentration in winter,and external and local emission sources influenced the highly contaminated regions.
作者
付建平
谢丹平
黄锦琼
杨艳艳
冯桂贤
周长风
廖海婷
青宪
张漫雯
吴明亮
张素坤
FU Jian-ping;XIE Dan-ping;HUANG Jin-qiong;YANG Yan-yan;FENG Gui-xian;ZHOU Chang-feng;LIAO Hai-ting;QING Xian;ZHANG Man-wen;WU Ming-liang;ZHANG Su-kun(South China Institute of Environmental Sciences,Ministry of Ecology and Environment,Guangzhou 510655,China)
出处
《环境科学》
EI
CAS
CSCD
北大核心
2022年第5期2355-2362,共8页
Environmental Science
基金
广东省环保专项资金项目(PM-zx443-201703-132)。
