Emission inventory of air pollutants and chemical speciation for detailed anthropogenic sources based on local measurements in the Yangtze River Delta region, China

In this study, a high-resolution air pollutant emission inventory for the Yangtze River Delta (YRD) region was updated for 2017 using emission factors and chemical speciation based mainly on local measurements. The inventory included 424 non-methane volatile organic compounds (NMVOC) and 43 particulate matter species (PM2.5) from 259 specific sources. The total emissions of SO2, NOx, CO, NMVOCs, PM10, PM2.5, and NH3 in the YRD region in 2017 were 1,552, 3,235, 38,507, 4,875, 3,770, 1,597, and 2,467 Gg respectively. SO2 and CO emissions were mainly from boilers, accounting for 49% and 73% of the total. Mobile sources dominated NOx emissions contributing 57% to the total. NMVOC emissions, mainly from industrial sources, made up 61% of the total. Dust sources accounted for 55% and 28% of PM10 and PM2.5 emissions respectively. Agricultural sources accounted for 91% of NH3 emissions. Major PM2.5 species were OC, Ca, Si, PSO4 and EC, accounting for 9.0%, 7.0%, 6.4%, 4.6% and 4.3% of total PM2.5 emissions respectively. The main species of NMVOCs were aromatic hydrocarbons, making up 25.3% of the total. Oxygenated volatile organic compounds contributed 21.9% to the total NMVOC emissions. Toluene had the highest comprehensive contribution to ozone (O3) and secondary organic aerosol (SOA) formation potentials, while other NMVOC included 1,2,4-trimethylbenzene, m,p-xylene, propylene, ethene, o-xylene, ethylbenzene. Industrial process and solvent use sources were the main sources of O3 and SOA formation potential, followed by motor vehicles. Among industrial sources, chemical manufacturing, rubber & plastic manufacturing, appliance manufacturing and textile made significant contributions. This emission inventory should provide scientific guidance for future control of air pollutants in the YRD region of China.