Variations of air pollutant response to COVID-19 lockdown in cities of the Tibetan Plateau

Abstract

Coronavirus Disease 2019 (COVID-19) accidentally appeared in Tibet on August 7, 2022, and broke the 920 consecutive epidemic-free days. The cities in Tibet completely kept lockdown to restrict the public to homes. It provided a valuable opportunity for understanding how variations of urban air pollutants responded to the COVID-19 lockdown in the special highland cities of the third polar. Compared with the global COVID-19 restrictions in 2020, a slightly negative O3 anomaly and greater PM2.5 and NO2 reductions were found. The study showed PM10 (−65%) < NO2 (−53%) < PM2.5 (−52%) < O3 (−15%) < CO (−11%)