Comparison of Phase States of PM_2.5 over Megacities, Seoul and Beijing, and Their Implications on Particle Size Distribution.

ABSTRACT: Although the particle phase state is an important property, there is scant information on it, especially, for real-world aerosols. To explore the phase state of fine mode aerosols (PM_2.5) in two megacities, Seoul and Beijing, we collected PM_2.5 filter samples daily from Dec 2020 to Jan 2021. Using optical microscopy combined with the poke-and-flow technique, the phase states of the bulk of PM_2.5 as a function of relative humidity (RH) were determined and compared to the ambient RH ranges in the two cities. PM_2.5 was found to be liquid to semisolid in Seoul but mostly semisolid to solid in Beijing. The liquid state was dominant on polluted days, while a semisolid state was dominant on clean days in Seoul. These findings can be explained by the aer

SUBMITTER: Song M 

PROVIDER: S-EPMC9775198 | biostudies-literature | 2022 Dec

REPOSITORIES: biostudies-literature