Source apportionment and dynamics of PM_2.5 across regions during and after the coronavirus 2019 pandemic.

ABSTRACT: The coronavirus disease 2019 (COVID-19) pandemic was reported to improve air quality. However, the effects of lockdown on PM₂.₅ and its chemical components based on source-specific characteristics remain unclear. This study evaluated and compared the components of PM₂.₅ across three target sites-Seoul, Ansan-Siheung, and Wonju-based on source distribution patterns during the pandemic and post-pandemic periods. The results revealed that total ion concentrations decreased by 7-19% at the target sites, while trace element concentrations increased by 19-29% in the post-pandemic period. Carbon concentrations showed region-specific trends. Components associated with secondary formation, such as SO₄²⁻, NO₃⁻, and NH₄⁺, decreased, whereas natural-origin components, such as Cl⁻, Na⁺, Mg²⁺, and Ca²⁺,

SUBMITTER: Park SY 

PROVIDER: S-EPMC12223244 | biostudies-literature | 2025 Jul

REPOSITORIES: biostudies-literature