Abstract
Introduction: The novel coronavirus disease 2019, namely COVID-19, has been known as a global pandemic by the World Health Organization (WHO). To prevent of COVID-19 spread, most countries including Iran have implemented many preventive measures. This study aimed to evaluate the effect of implementation (Phase-01)/non- implementation (Phase-02) of the traffic plan on confirmed cases, suspected cases, and mortality cases by COVID-19 as well as on air quality in Tehran. Materials and methods: Daily data of confirmed COVID-19 cases, suspected COVID-19 cases, mortality COVID-19 cases, air pollutants concentration and meteorological variables were obtained from 26 February, 2020 to 5August, 2020 in Tehran megacity and data were compared during the period’s implementation /non-implementation of traffic plan in Tehran. Results: Our results showed that the non-implementation of traffic plan has been effective in reducing the number of daily confirmed cases, suspected cases and mortality by COVID-19. Also, the average concentration of PM10, PM2.5, NO2 , O3 , SO2 and CO have reduced significantly during nonimplementation traffic plan phase. Conclusion: Our findings indicate that there is a significant association between non-implementation traffic plan and reduce risk of COVID-19 infection.