Industrial polycyclic aromatic hydrocarbons (PAHs) emissions embodied in domestic trade in China in 2012

Atmospheric Polycyclic Aromatic Hydrocarbons (PAHs) emissions cause non-negligible damage to human health and well-being. Effective regional cooperation is urgently required to mitigate PAHs emissions to maintain satisfactory air quality. This study quantified and tracked China's PAHs emissions flows embodied in interprovincial trade. A production-based emissions inventory of 16 U.S. EPA priority PAHs based on commercial energy consumption in China in 2012 was compiled using the emissions factor approach. Then, a multiregional inputoutput model was constructed to reveal consumption-based emissions and to track the PAHs emissions embodied in the trade of 27 major sectors across 30 regions in China. Key structural paths were also identified using structural path analysis (SPA). In 2012, the total industrial energy-derived PAHs emissions were estimated to be 47.7 tons of BaP-toxic equivalents (8032.7 tons of mass). Shandong, Hebei, and Hubei accounted for more than 24.0% of the production-side PAHs emissions in the whole country. Approximately 30.8% of China's PAHs emissions were embodied in goods consumed outside of the province in which they were produced. PAHs flow tended to start in the western regions and ended in the eastern regions along the coast. The results of the SPA showed that critical paths, such as from the Metallurgy sector to the Construction sector, embodied a large amount of emissions and had the potential to affect the performance of the entire system. By paying attention to the consumption-based accounting as well as the production-based accounting of emissions and by focusing on vital transfer paths, policymakers can devise effective and targeted environmental protection and sustainable development policies in China.