Effect of current emission abatement strategies on air quality improvement in China:A case study of Baotou,a typical industrial city in Inner Mongolia

The national Air Pollution Prevention and Control Action Plan required significant decreases in PM_（2.5） levels over China.To explore more effective emission abatement strategies in industrial cities,a case study was conducted in Baotou to evaluate the current national control measures.The total emissions of SO_2,NO_X,PM_（2.5） and NMVOC（non-methane volatile organic compounds） in Baotou were 211.2 Gg,156.1 Gg,28.8 Gg,and 48.5 Gg,respectively in 2013,and they would experience a reduction of 30.4%,26.6%,15.1%,and 8.7%,respectively in 2017 and 39.0%,32.0%,24.4%,and 12.9%,respectively in2020.The SO_2,NO_Xand PM_（2.5） emissions from the industrial sector would experience a greater decrease,with reductions of 37%,32.7 and 24.3%,respectively.From 2013 to 2020,the concentrations of SO_2,NO_2,and PM_（2.5） are expected to decline by approximately 30%,10% and 14.5%,respectively.The reduction rate of SNA（sulfate,nitrate and ammonium）concentrations was significantly higher than that of PM_（2.5） in 2017,implying that the current key strategy toward controlling air pollutants from the industrial sector is more powerful for SNA.Although air pollution control measures implemented in the industrial sector could greatly reduce total emissions,constraining the emissions from lower sources such as residential coal combustion would be more effective in decreasing the concentration of PM_（2.5） from 2017 to 2020.These results suggest that even for a typical industrial city,the reduction of PM_（2.5） concentrations not only requires decreases in emissions from the industrial sector,but also from the low emission sources.The seasonal variation in sulfate concentration also showed that emission from coal-burning is the key factor to control during the heating season.

Screening the emission sources of volatile organic compounds （VOCs） in China by multi-effects evaluation

Volatile organic compounds （VOCs） play important roles in the atmosphere via three main pathways： photochemical ozone formation, secondary organic aerosol production, and direct toxicity to humans. Fewstudies have integrated these effect, s to prioritize control measures for VOC.s sources. In this study,we developed a multi-effects evaluation methodology based on updated emission inventories and source profiles, by combining the ozone formation potential （OFP）, secondary organic aerosol potential （SOAP）, and VOC toxicity data. We derived species-specific emission inventories for 152 sources. The OFPs, SOAPs, and toxicity of each source were estimated, the contribution and sharing of source to each of these adverse effects were calculated. Weightings were given to the three adverse effects by expert scoring, and then the integrated effect was determined. Taking 2012 as the base year,solvent use and industrial process were found to be the most important anthropogenic sources, accounting for 24.2% and 23.1% of the integrated effect, respectively, followed by biomass burning, transportation, and fossil fuel combustion, each had a similar contribution ranging from 16.7% to 18.6%. The top five industrial sources, including plastic products, rubber products, chemical fiberproducts, the chemical industry, and oil refining, accounted for nearly 70.0% of industrial emissions. Beijing, Chongqing, Shanghai, Jiangsu, and Guangdong were the five provinces contributing the largest integrated effects. For the VOC species from emissions showed the largest contributions were styrene, toluene, ethylene, benzene, and m/p-xylene.