Analysis on the Influence and Cause of a Heavy Pollution Process on Air Quality in Baoding during COVID-19

Abstract

Due to the outbreak of the novel coronavirus, China had implemented a strict home isolation policy after the Spring Festival, and human activities in many areas had been prohibited. However, Baoding still suffered heavy air pollution during February 2020, especially in February 8-13. The results showed that the concentrations of pollutants in February 2020 had a decrease from February 2019. The reduction of human activities during the epidemic significantly decreased the concentration of air pollutants and improved air quality. In addition, compared with non-pollution period (February 22-29), the PM2.5 concentration during pollution period (February 8-13) increased the most visibly. The analysis of OC and EC shows that there was a certain amount of civil coal combustion during the heavy pollution period; K+ and Mg2+ in PM2.5 revealed the huge influence of fireworks and firecrackers in Baoding. The backward trajectory and potential source analysis indicated that Baoding was influenced by air masses from southwest during the heavy pollution period, and the potential source areas were mainly distributed in southwest of Baoding. It can be seen that the impact of pollutants in the superimposed area of local emission and transportation with unfavorable meteorological condition in Baoding.