Spatial and temporal look at ten-years air quality of Istanbul city

Abstract

This study is aimed to investigate spatial and seasonal variations of air pollutants in Istanbul between 2007 and 2017. Target air pollutants were carbon monoxide, particulate matter, sulfur dioxide, nitrogen oxides, and ozone. Air quality data of the city of Istanbul were obtained from 31 continuous air quality monitoring stations located at the Anatolian and the European Sides of the city. Spatial and temporal variations of the air pollutants were assessed by statistical methods (p < 0.05). According to the results of this study, all air pollutants showed seasonal variations and all parameters were found to be higher during the heating periods than other periods (p < 0.05), except for ozone. The annual average values of carbon monoxide, particulate matter with diameter of less than 10 µm, sulfur dioxide, ozone, and nitrogen dioxide (except for nitrogen dioxide levels measured in 2017) concentrations were below the national limit values in all stations between 2007 and 2017. In terms of yearly variation of the air pollutants, carbon monoxide and ozone showed statistically significant increasing trends (p < 0.001). Overall, once ten-years average air quality data were compared with current air quality limit values which was effective since 2019, PM and NO2 may have limit exceedance problems in the next years. Moreover, levels of particulate matter with diameter of less than 2.5 µm were measured at 3 air quality monitoring stations, exceeded both World Health Organization and European Union limit values. Furthermore, positive correlations were found among the air pollutants (p < 0.001).