How do pollutants change post-pandemic? Evidence from changes in five key pollutants in nine Chinese cities most affected by the COVID-19.

摘要: Under the COVID-19 global pandemic, China has weakened large-scale spread of epidemic through lockdown and other measures. At same time, with recovery social production activities, become only country which achieves positive growth in 2020 major economies. It entered post pandemic period. These measures improved local environmental quality. However, whether this improvement can be sustained is also a problem that needs to solved. So, study investigated changes five air pollutants (PM2.5, PM10, NO2, SO2, CO) nine cities most severely affected by during We emphasized when analyzing quality epidemic, we must consider not impact day short-term changesbut cumulative lag effect sustainable development. Through combination qualitative quantitative methods, it found concentration decreased significantly compared situation before epidemic. PM10 NO2 are falling most, downs 39% 46% respectively. During period, pollutant concentrations response 3-7 days. More specifically, related single pollutants, on shows significant correlation delayed for seven In multiple usually highest 3-5 This means policy environment lasted Besides, Wuhan, Jingmen Jingzhou have seen obvious improvement. did last. rebounded, rates reached 44% 87% September. When period from 2017 2019, decline rate been slower, even higher than average previous years. The research contributes China's economic "green recovery" plan but provides references governance countries.