[Gridded Atmospheric Emission Inventory of PCDD/Fs in China]

PCDD/Fs emission inventory is the basis for PCDD/Fs control, research on environmental fate behavior, and health risk assessment. In the present study, based on officially released PCDD/Fs emissions inventory for each industry in China in 2004, we estimated atmospheric PCDD/Fs emissions by sector in various provinces in 2016 by combining the emission intensity in the "Identification and Quantification of PCDD/Fs Emission Standards Toolkit" released by the United Nations Environment Program (UNEP) in 2013. Subsequently, using different gridding data for various sectors as surrogate data, we established atmospheric gridded emission inventory (1/4°×1/4° latitude by longitude) for PCDD/Fs in China. Finally, the uncertainty of PCDD/Fs emission inventory was analyzed. Results show that the atmospheric emissions of PCDD/Fs in China in 2016 were 10366 g, which was about two times higher than that in 2004. From the perspective of the emission sector, metal smelting is the largest emitter of PCDD/Fs in China, which released 5333 g, followed by waste incineration (2469 g), heating and power generation (1290 g), and mineral production (933 g). These four sectors accounted for 97% of China's total PCDD/Fs emissions. In spatial terms, China's atmospheric PCDD/Fs emissions are mainly concentrated in the Beijing-Tianjin-Hebei, Yangtze River Delta, and Pearl River Delta regions. PCDD/Fs emissions from the Beijing-Tianjin-Hebei and Yangtze River Delta regions originate mainly from steel smelting, and that from the Pearl River Delta region is mainly due to waste incineration.