Impact of COVID – 19 Restrictions on Air Quality Levels on Samsun, Turkey

The outbreak of the novel coronavirus SARS-CoV-2 (hereafter COVID19) has changed the daily routines of people around the world. The first case of COVID19 was confirmed on December, 2019 whilst, it was confirmed on 11 March 2020 in Turkey. After the number of cases reached 4500 per day by 10 April, the government declared more restrictive lockdown measures for 31 metropolitan cities and it was implemented for the following weekends, national and religious holidays. The change in concentrations of PM₁₀, CO, NO_x and NO₂ during this measures with respect to pre – lockdown period and for different level of measures for Samsun, the biggest city of Karadeniz Region were investigated in this study. The daily mean concentrations of PM₁₀, CO, NO_x and NO₂ obtained for the Tekkekoy station due to data completeness greater than 95 percent for all pollutants. Average CO, NO_x and NO₂ concentrations during lock down period, declined with respect to pre-lock down period whilst PM₁₀ increased 5 percent. The average concentrations of all the pollutants decreased when the level of restrictions increased during COVID19 lockdown period. The number of days exceed WHO limit for PM₁₀ were decreased during lockdown period of 16 days with respect to pre-lockdown period of 19 days. The relationship between concentration levels and mobility change was also investigated.