Comparison of air pollution before and during COVID-19 pandemic in 30 metropolitan cities and Zonguldak Province in Türkiye

The SARS-CoV-2 virus, which causes coronavirus disease (COVID-19), belongs to the family of airborne coronaviruses and primarily affects the upper respiratory tract. Since March 11, 2020, individuals and governments worldwide have implemented personal, local, regional, and global restrictions to slow the spread of the pandemic and minimize the loss of life. In Türkiye, various restrictions were also enforced, with the most stringent measures applied in 30 metropolitan cities and Zonguldak. This study examines the impact of these restrictions on air pollution parameters in 31 cities in Türkiye. To answer the question “Did the restrictions reduce air pollution?”, the study evaluates pollutant levels from 2019 to 2022 and provides recommendations for reducing air pollution, drawing lessons from the impact of restrictions in Türkiye and other regions around the world. During the study, annual assessments showed a decreasing trend in PM₁₀ and SO₂ concentrations, while CO and NO₂ levels showed an increasing trend. Assuming that the mobility-reducing measures adopted during the pandemic (e.g. remote working) will be extended over time, it is predicted that the pandemic period will serve as a step towards reducing air pollution. This study can act as a roadmap for potential future pandemic periods, and its findings can serve as a reference for developing sustainable living practices.