Distribution of Polychlorinated Dibenzo-p-dioxins and Dibenzofurans in the Atmosphere of Beijing, China

Zhi-Guang Zhou；Bin Zhao；Li Qi；Peng-Jun Xu；Yue Ren；Nan Li；Sen Zheng；Hu Zhao；Shuang Fan；Ting Zhang；Ai-Min Liu；Ye-Ru Huang；Li Shen

PCDD/Fs ； Atmosphere ； Beijing ； Seasonal and spatial variation ； Sources

Aerosol and Air Quality Research

14卷4期（2014 / 06 / 01）

1269 - 1278

英文

Air samples were collected from six locations during the periods of February, 2011–March, 2012 in Beijing city. Samples were analyzed using HRGC-HRMS according to HJ 77. 2-2008. The concentrations, congener profiles, seasonal variation, spatial distribution, and sources identified were investigated. The mass concentrations of 2,3,7,8-substituted PCDD/Fs is 1750 to 10380 fg/m^3 with an average of 3670 fg/m^3. The highest concentration was observed at site DS in February 2011 and the lowest was at site NS in July 2011. The TEQ concentrations of PCDD/Fs ranged from 35.0 to 751 fg I-TEQ/m^3, with an average of 251 fg I-TEQ/m^3. The dominant contributor to total TEQ value is 2,3,7,8-PeCDFs, with an average contribution of 40%. Low-chlorinated PCDDs were observed in all samples in winter. The concentration and profiles exhibit obvious seasonal variation. The PCDD/Fs at six sampling sites did not show obvious spatial variation. Seasonal variation of PCDD/F concentrations indicated that the emission sources may be different. Fossil fuel combustion and automobiles may be the main dioxins emission sources during the heating period, whereas, in non-heating period, the automobiles alone are the main emission sources.