The Effects of COVID-19 Measures on Air Pollutant Concentrations at Urban and Traffic Sites in Istanbul

Abstract

Since December 2019, most countries have been working to stop the spread of SARS-CoV-2, the virus responsible for COVID-19. These measures, which include restricting movement, have environmental consequences. This study assessed the impact of COVID-19 measures on air pollutant concentrations measured in urban areas and traffic stations on both the European and Asian sides of Istanbul during March 2020. Significant reductions in pollutants: 32-43% (PM10), 19-47% (PM2.5), 29-44% (NO2), 40-58% (CO) and 34-69% (SO2) were calculated. The clearest reductions at the traffic stations were in NO2 which originates primarily from vehicle exhaust. The reduction of NO2 at the traffic station on the European side was found higher comparing the Asian side. The average concentrations of NO2, PM2.5, PM10 and CO during peak traffic hours were significantly (p < 0.01) decreased under COVID-19 measures. The results indicate that due to the measures taken in Istanbul and across Turkey and to control the spread of the virus, anthropogenic activities such as industry, vehicle traffic and sea transport have decreased, and consequently, air pollution has been significantly reduced. These pollutant levels demonstrate the anthropogenic contribution to air pollution and can inform clean air actions in Istanbul and in others cities throughout the world.