Volume 14, No. 4, June 2014, Pages 1269-1278 PDF(634 KB)
Distribution of Polychlorinated Dibenzo-p-dioxins and Dibenzofurans in the Atmosphere of Beijing, China
Zhi-Guang Zhou1,2, Bin Zhao1, Li Qi2, Peng-Jun Xu2, Yue Ren2, Nan Li2, Sen Zheng2, Hu Zhao2, Shuang Fan2, Ting Zhang2, Ai-Min Liu2, Ye-Ru Huang2, Li Shen3
1 State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
2 State Environmental Protection Key Laboratory of Dioxin Pollution Control, National Research Center for Environmental Analysis and Measurement, 1 South Yuhui Rd, Chaoyang District, Beijing 100029, China
3 Ontario Ministry of the Environment, 125 Resources Road, Toronto, ON M9P 3V6, Canada
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/m3 with an average of 3670 fg/m3. 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/m3, with an average of 251 fg I-TEQ/m3. 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.
PCDD/Fs; Atmosphere; Beijing; Seasonal and spatial variation; Sources.