Impact of SARS-CoV-2 on Ambient Air Particulate Matter in Tehran

ABSTRACT As an international novel challenge, the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has the positive and negative indirect effects on the environmental issues, particularly ambient air pollution. Our study aims to determine the effects of SARS-CoV-2 pandemic on the ambient air PM10 and PM2.5 in Tehran city, by comparison of the air quality data recorded at twenty-two air quality monitoring stations during the outbreak period from 20/02/2020 to 02/04/2020 and the same period of last year (20/02/2019-03/04/2019). Contrary to expectations, the average concentrations of ambient PM2.5 and PM10 in Tehran markedly increased during the SARS-CoV-2 outbreak compared to the same period of last year. An increase of 20.5% and 15.7% was found for ambient PM2.5 and PM10 in Tehran during the first scenario (the first month of SARS-CoV-2 outbreak in Iran) between 20/02/2020 and 19/03/2020, whereas these figures experienced an increase equal to 23.5% and 20.0% during the second scenario (over the Nowruz New Year holidays), respectively. Overall, the average concentrations of ambient PM2.5 and PM10 has risen by nearly 20.5% and 16.5% during the outbreak compared to the same period of last year. The non-integrated decisions (non-closing down administrative centers) or recommendations in particular on decreasing the use of public transportation to prevent close contact have worsened the ambient air particulate matter status in Tehran over the SARS-CoV-2 outbreak, because Tehran citizens inevitably used the private cars. As a result, SARS-CoV-2 outbreak provided an exceptional opportunity to evaluate the direct/indirect influence of recommendations/decisions on emission sources and air quality policies on ambient air PM2.5 and PM10 in Tehran. Because of the significant association between high level of lethality by COVID-19 infection and ambient air pollution exposures, the rise of ambient air PM2.5 in Tehran during this outbreak could increase the lethality rate of SARS-CoV-2.