Impacts of condensable particulate matter on atmospheric organic aerosols and fine particulate matter (PM 2.5 ) in China

[摘要] Condensable particulate matter (CPM) emitted from stationary combustion andmobile sources exhibits high emissions and a large proportion of organiccomponents. However, CPM is not generally measured when conducting emissionsurveys of PM in most countries, including China. Consequently, previousemission inventories have not included emission rates for CPM. Here, weconstruct an emission inventory of CPM in China with a focus on organicaerosols (OAs) based on collected CPM emission information. Results show thatOA emissions are enhanced twofold after the inclusion of CPM in a newinventory for China for the years 2014 and 2017. Considering organic CPM emissions andmodel representations of secondary OA (SOA) formation from CPM, aseries of sensitivity cases have been simulated here using the three-dimensionalCommunity Multiscale Air Quality (CMAQ) model to estimate the contributionsof CPM emissions to atmospheric OA and fine PM (PM 2.5 , particulate matter withaerodynamic diameter not exceeding 2.5  µ m) concentrationsin China. Compared with observations at a Beijing site during a haze episode from 14 Octoberto 14 November 2014, estimates of the temporal averageprimary OA (POA) and SOA concentrations were greatly improved after includingthe CPM effects. These scenarios demonstrated the significant contributionsof CPM emissions from stationary combustion and mobile sources to the POA (51 %–85 %​​​​​​​), SOA (42 %–58 %), and total OAconcentrations (45 %–75 %). Furthermore, the contributions ofCPM emissions to total OA concentrations were demonstrated over the 2 majorcities and 26 other cities of the Beijing–Tianjin–Hebei region (hereafter referred to as the “BTH2  +  26 cities”) in December 2018, with average contributions of up to 49 %, 53 %, 54 %, and 50 %for Handan, Shijiazhuang, Xingtai, and Dezhou, respectively.Correspondingly, the inclusion of CPM emissions also narrowed the gapbetween simulated and observed PM 2.5 concentrations over the BTH2  +  26cities. These results improve the simulation performance of atmospheric OAand PM 2.5 and may also provide important implications for the sources ofOA.

[学科分类] 医学（综合）