The Variation in Chemical Composition and Source Apportionment of PM_2.5 before, during, and after COVID-19 Restrictions in Zhengzhou, China.

ABSTRACT: Despite significant improvements in air quality during and after COVID-19 restrictions, haze continued to occur in Zhengzhou afterwards. This paper compares ionic compositions and sources of PM_2.5 before (2019), during (2020), and after (2021) the restrictions to explore the reasons for the haze. The average concentration of PM_2.5 decreased by 28.5% in 2020 and 27.9% in 2021, respectively, from 102.49 μg m^-3 in 2019. The concentration of secondary inorganic aerosols (SIAs) was 51.87 μg m^-3 in 2019, which decreased by 3.1% in 2020 and 12.8% in 2021. In contrast, the contributions of SIAs to PM_2.5 increased from 50.61% (2019) to 68.6% (2020) and 61.2% (2021). SIAs contributed significantly to PM_2.5 levels in 2020-2021. Despite

SUBMITTER: Huang J 

PROVIDER: S-EPMC10819188 | biostudies-literature | 2024 Jan

REPOSITORIES: biostudies-literature