Impact of the COVID-19 lockdown on the chemical composition and sources of urban PM_2.5.

ABSTRACT: The lockdown measures caused by the COVID-19 pandemic substantially affected air quality in many cities through reduced emissions from a variety of sources, including traffic. The change in PM_2.5 and its chemical composition in downtown Toronto, Canada, including organic/inorganic composition and trace metals, were examined by comparing with a pre-lockdown period and respective periods in the three previous years. During the COVID-19 lockdown, the average traffic volume reduced by 58%, whereas PM_2.5 only decreased by 4% relative to the baselines. Major chemical components of PM_2.5, such as organic aerosol and ammonium nitrate, showed significant seasonal changes between pre- and lockdown periods. The changes in local and regional PM_2.5 sources we

SUBMITTER: Jeong CH 

PROVIDER: S-EPMC8747944 | biostudies-literature | 2022 Jan

REPOSITORIES: biostudies-literature