How COVID-19 Impacted PM 2.5 and Air Quality in China's Main Cities

The air quality in modern cities is one of the topics that people are very concerned about, due to its impact on people's health and production. There have been many studies on air quality improvement and transmission mechanisms, showing that proper measures can improve air quality efficiently. Under the unexpected COVID-19 time, lots of measures were taken by the government, and the question of whether those strict measures have somehow influenced the local air quality remains This article mainly combines some relevant policies and behaviors during the outbreak of COVID-19 to explore whether this epidemic has an impact on emissions, and to observe whether the sub-index PM2.5 representing air quality is changed. Based on assessing the cause of air pollution in each city and evaluating the policy implemented to prevent COVID-19 from spreading, the topmost effective policies that reduce air pollution are preventing residents' transportation, reducing deliveries, and shutting down heavy industry factories.