What can we learn about urban air quality with regard to the first outbreak of the COVID-19 pandemic? A case study from Central Europe

Abstract

Abstract. Motor vehicle road traffic in central Budapest was reduced by approximately 50 % of its ordinary level for several weeks as a consequence of various limitation measures introduced to mitigate the first outbreak of COVID-19 pandemic in 2020. The situation was utilised to assess the real potentials of urban traffic on air quality. Concentrations of NO, NO2, CO, O3, SO2 and particulate matter (PM) mass, which are ordinarily monitored in cities for air quality considerations, aerosol particle number size distributions, which are not rarely measured on-line continuously on longer run for research purposes and basic meteorological properties usually available were jointly evaluated. The largest changes occurred in the time interval of the severest limitations (partial lock-down in the Restriction phase from 28 March to 17 May 2020). Concentrations of NO, NO2, CO, total particle number (N6–1000) and particles with a diameter

Impact of the COVID-19 on the vertical distributions of major pollutants from a tower in the Pearl River Delta

“…The reduction in human activities due to the pandemic has greatly decreased primary pollutant emissions, with significant impacts on regional air quality ( Xing et al, 2020 ; Salma et al, 2020 ; Wang et al, 2021 ; Kim et al, 2021 ) and climate ( Gettelman et al, 2021 ), despite differences between regions. In South East Asia, the lockdown led to a notable decrease in aerosol optical depth over the region and in pollution outflow over oceanic areas.…”

Correlation between the Concentrations of Atmospheric Ions and Radon as Judged from Measurements at the Fonovaya Observatory

“…Since our data are for 2020, this may be a consequence of the lockdown associated with the coronavirus pandemic. There are publications reporting the change in the air composition due to the decrease in emissions [42][43][44][45]. However, the processes associated with the lockdown could affect only the annual variation in ions, while the features of the annual variation in radon are apparently explained by other causes.…”

Contrasting changes in reproductive success of birds in cities with reduced and increased human disturbance during the COVID-19 lockdown

“…However, while in Budapest the levels of NO 2 and NO X (two reliable indicators of tra c-related urban air pollution, measured during birds' rst-brood period) were substantially reduced during the lockdown compared to 2019 (Fig. S1) or longer reference periods (Salma et al 2020), in Veszprém the levels of both pollutants were similar in 2019 and 2020 (Fig. S1).…”

“…Besides inducing changes in human activity, the lockdown had other consequences that could have affected urban birds' breeding by different means, although we argue that these may be less likely in our case. For example, the reduction in vehicular road tra c during the lockdown was paralleled by reduced concentrations of air pollutants, resulting in improved air quality worldwide (Salma et al 2020) that could have bene cial effects on urban birds directly e.g. by affecting their oxidative stress physiology (Salmón et al 2018) or indirectly (via their arthropod food supply).…”