Has COVID-19 Lockdown Affected on Air Quality?—Different Time Scale Case Study in Wrocław, Poland

Tomasz Turek,Ewa Diakowska,Joanna A Kamińska

doi:10.3390/atmos12121549

Tomasz Turek, Ewa Diakowska + Show 1 more

Open Access

https://doi.org/10.3390/atmos12121549

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Abstract

Due to the COVID-19 pandemic, there are series of negative economic consequences, however, in limiting mobility and reducing the number of vehicles, positive effects can also be observed, i.e., improvement of air quality. The paper presents an analysis of air quality measured by concentrations of NO2, NOx and PM2.5 during the most restrictive lockdown from 10 March to 31 May 2020 on the case of Wrocław. The results were compared with the reference period—2016–2019. A significant reduction in traffic volume was identified, on average by 26.3%. The greatest reduction in the concentration of NO2 and NOx was recorded at the station farthest from the city center, characterized by the lowest concentrations: 20.1% and 22.4%. Lower reduction in the average concentrations of NO2 and NOx was recorded at the municipal station (7.9% and 7.7%) and the communication station (6.7% and 10.2%). Concentrations of PMs in 2020 were on average 15% and 13.4% lower than in the reference period for the traffic station and the background station. The long-term impact of the lockdown on air quality was also examined. The analysis of the concentrations of the pollutants throughout 2020, and in the analyzed period of 2021, indicated that the reduction of concentrations and the improvement in air quality caused by the restrictions should be considered as a temporary anomaly, without affecting long-term changes and trends.

Highlights

Lockdown caused by the COVID-19 pandemic outbreak caused a series of negative economic and social consequences
The situation of the global pandemic in 2020 and resulting lockdowns have created a unique opportunity to test this hypothesis on the real data
In this study we focused on NO2, NOx and PM2.5, which are measured at hourly intervals

Summary

Introduction

Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations. Lockdown caused by the COVID-19 pandemic outbreak caused a series of negative economic and social consequences. Restrictions in movement, reduction in the number of active vehicles and the general population fluctuations resulted in many changes—. Including environmental ones [1,2,3]. In limiting people’s mobility and reducing the number of vehicles in motion, positive effects can be seen. One of them is improvement of air quality. The situation of the global pandemic in 2020 and resulting lockdowns have created a unique opportunity to test this hypothesis on the real data

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