Impact of fireworks burning on air quality during the Spring Festival in 2021-2022 in Linyi, a central city in the North China Plain.

ABSTRACT

The management of fireworks has been strengthened during the Spring Festival in 2022 compared with that in 2021 in Linyi, a central city in the North China Plain. Online measurements of the chemical components of PM2.5 were conducted during the Spring Festival in 2021-2022 to assess the influence of fireworks burning (FB) on air quality. Remarkable achievements have been made in improving air quality during FB period (FBP) in 2021-2022 attributing to the stringent regional emission reduction measures, fireworks control, and favorable meteorological conditions with the concentrations of PM2.5, water-soluble ions, and carbonaceous aerosols decreasing by 73.6%, 78.8%, and 73.5%, respectively. The PM2.5 concentrations increased by 96.3% during FBP compared with those during non-FB period (NFBP) in 2021, while the opposite phenomenon was observed in 2022 with PM2.5 concentrations decreasing by 56.2% because of the favorable meteorological condition during FBP in 2022. As indicators of FB, the Cl-, K+, and Mg2+ concentrations showed an increasing trend during FBP compared with that during NFBP, both in 2021 and 2022, but had little effect on other components. The contribution of FB to PM2.5 decreased from 68.4% in 2021 to 15.7% in 2022 based on the relative ratio method, indicating the various measures conducted by all districts and counties in Linyi helped achieve near zero fireworks emissions by 2022. Besides, the contribution of FB to PM2.5 showed a straight-line upward trend from 1900 on New Year's Eve, reached its peak (76.1%) at 300 on Lunar New Year's Day, while the highest value was only 35.0% during FBP in 2022, indicating the implementation of fireworks ban measures in Linyi achieved a good effect on pollution peak cutting. This study has emphasized the necessity of FB restricting during special holidays.