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Weekend Effect of Air Pollutants in Small and Medium-sized Cities: The Role of Policies Stringency to COVID-19 Containment

Abstract

Although the pattern of air pollutants has been extensively studied during the COVID-19 pandemic, the weekend effect has been rarely investigated. In order to understand the impact of policies stringency as well as the interruption-recovery pattern, the aim of the study was to investigate the levels of air pollutants (O, NO, SO, PM, PM) and PM/PM ratio before and after the COVID-19 pandemic in four cities in the state of Rio Grande do Sul, Brazil, evaluating the weekend effect at these two scenarios and also identifying how the restriction measures applied locally had an impact on this effect. For this, daily data from two years of monitoring of air pollutants were collected and the weekend effect was calculated based on the levels from Monday to Friday (weekday) and Saturday and Sunday (weekend). There was a positive weekend effect for almost all criteria air pollutants in the four cities, and an intrinsic relation between the weekend effect and the restriction measures adopted. A negative weekend effect was observed in the scenario characterized by less restrictive and more permissive policies for daily and occupational activities. Conversely, when more stringent measures were implemented, this trend was reversed and higher intensities of positive weekend effect were observed as restrictions increased. In conclusion, the COVID-19 perturbation to air quality changed as regions tighten and loosen restrictions on human mobility. These insights that can guide responsible authorities about future strategies and policies for air quality control.

References
1.
Sicard P, De Marco A, Agathokleous E, Feng Z, Xu X, Paoletti E . Amplified ozone pollution in cities during the COVID-19 lockdown. Sci Total Environ. 2020; 735:139542. PMC: 7237366. DOI: 10.1016/j.scitotenv.2020.139542. View

2.
Yousefian F, Faridi S, Azimi F, Aghaei M, Shamsipour M, Yaghmaeian K . Temporal variations of ambient air pollutants and meteorological influences on their concentrations in Tehran during 2012-2017. Sci Rep. 2020; 10(1):292. PMC: 6962207. DOI: 10.1038/s41598-019-56578-6. View

3.
Tavella R, Santos J, de Moura F, da Silva Junior F . Better understanding the behavior of air pollutants at shutdown times - results of a short full lockdown. Int J Environ Health Res. 2022; 33(12):1525-1532. DOI: 10.1080/09603123.2022.2105310. View

4.
Sharma S, Zhang M, Anshika , Gao J, Zhang H, Kota S . Effect of restricted emissions during COVID-19 on air quality in India. Sci Total Environ. 2020; 728:138878. PMC: 7175882. DOI: 10.1016/j.scitotenv.2020.138878. View

5.
Berman J, Ebisu K . Changes in U.S. air pollution during the COVID-19 pandemic. Sci Total Environ. 2020; 739:139864. PMC: 7442629. DOI: 10.1016/j.scitotenv.2020.139864. View