Production and consumption-based primary PM2.5 emissions: Empirical analysis from China's interprovincial trade

Cross-regional trade activities not only facilitate the exchange of products but trigger the transfer of pollutants. In this study, China's production-based PM2.5 emissions were estimated by compiling sectoral resolution PM2.5 emission inventories. Integrated with a multiregional input-output model, the consumption-based PM2.5 emissions from 30 provinces in 2012 were calculated. Only approximately 14% of the PM2.5 emissions were induced by consumers' direct usage, while 86% of the emissions were triggered by upstreaming production processes, as quantified by simulation in the structural path analysis model. For specific sectors, 'other services' play an important role in direct usage, while 'nonmetal products', 'petroleum refining', 'metallurgy', 'coal mining' and 'chemical industry' are the dominant PM2.5 emission sectors in subsequent supply chains, which has implications for optimization of the industrial structure as well as for improving energy utilization efficiency to a reasonable level for production processes. Furthermore, this study investigated consumption-based PM2.5 emissions transfer from original to destination provinces, which varied from 9%similar to 84%. Most of the consumption PM2.5 emissions dominant provinces located in east coastal of China, outsourcing PM2.5 emissions to Central and Western China, such as Inner Mongolia, Shanxi, Guizhou and Hebei, each accounted for more than 50% of their total PM2.5 emissions. In addition, all provinces except Xinjiang present spatial connections with surrounding provinces through close trade cooperation. The findings of this research provide a solid foundation for identifying different provinces' responsibility for air pollutant control and proposing insightful observations to help policymakers to formulate associated cross-regional PM2.5 emissions reduction and control measures.