Significant Reduction in Fine Particulate Matter in Beijing during 2022 Beijing Winter Olympics

To investigate the air quality improvement during 2022 Beijing Winter Olympic Games (WOG), continuous hourly observations of fine particulate matter (PM_2.5) and chemical fractions were performed in Beijing from January to March 2017-2022. Benefiting from the aggressive mitigation measures, significant reductions in the PM_2.5concentrations and chemical species in Beijing were observed during WOG. During strict control period, six sources of PM_2.5in Beijing were identified with positive matrix factorization model including secondary source (SS), industrial emissions (IEs), vehicle emissions (VEs), coal combustion (CC), fireworks burning (FB), and dust. Additionally, an obvious decline was observed in the sources of PM_2.5, and no contribution of FB was quantitatively identified in 2022. Based on the multiple linear regression analysis, it found that meteorological parameters accounted for 46.1% of the total variation in the PM_2.5concentration, while source control measures accounted for 53.9% of the total variation, indicating that aggressive mitigation measures played a more important role in the decline in the PM_2.5concentration than meteorological conditions. This study could provide valuable insight into achieving air quality improvement and formulating policies in developing countries plagued by heavy air pollution.