Air Quality During The COVID-19 Epidemic in China

Abstract At the end of 2019, the COVID-19 emerged in Wuhan, China. It has since put global public health institutions on high alert. People reduced their traveling, and production has stopped nationwide during the epidemic. This paper explores the effect of these COVID-19-derived changes on the air quality in China. Air quality data of 367 cities around China were included. The daily air pollutants concentration (AQI,CO, O3, NO2, SO2, PM10, and PM2.5) were collected. We compared the air quality changes between three periods (23.1.2019-23.3.2019, 22.11.2019-22.1.2020, and 23.1.2020–23.3.2020). To compare, we calculated the daily average number of cities with pollution, and the trend in air quality index change. Furthermore, Air quality in the top 50 cities with confirmed cases and Wuhan was analyzed. During the period between 23.1.2020 and 23.3.2020, the number of cities with excellent air quality was significantly higher than that in another two periods. The concentrations of PM2.5, PM10, NO2, SO2, CO, and O3 decreased significantly during the COVID-19 epidemic. The most significant decreases were in PM10 and NO2. The number of cities with good air quality in the later period was significantly higher than that a year before. The air quality has improved significantly during the COVID-19 outbreak, The reason for this change may be human activities such as reduced transportation and production stoppage.