ATMOSPHERIC CONCENTRATIONS OF INORGANIC POLLUTANTS (NO2, SO2 AND OZONE) IN ESKİŞEHİR: SPATIAL AND VERTICAL VARIATIONS, WEEKDAY-WEEKEND DIFFERENCES

Abstract

Atmospheric concentrations of inorganic pollutants ($NO2$, $SO2$ and ozone) were measured at three different sampling sites inEskişehir. Samples were collected between 25th of March and 8th of April 2016 by using passive sampling method. During twoweeksampling study, each week was divided to three sub-periods to investigate weekday and weekend differences of thepollutant concentrations. One-time vehicle counts during morning, noon and evening hours for both weekday and weekendperiods were inspected. The highest $NO2$ concentrations were measured at the sampling site having urban, traffic and residentialcharacteristics. Positive relationship between $NO2$ concentrations and traffic density was observed. Reverse trend wasdetermined for ozone. Ozone concentrations were higher at the sampling site far from the city center. Spatial variations of $SO2$concentrations were similar to those of $NO2$. Weekday $NO2$ concentrations were higher than weekend concentrations whilehigher ozone concentrations were observed in weekend. Weekend and weekday $SO2$ concentrations were quite similar at allsampling sites. Beside spatial variations, vertical variations of each pollutant were also investigated. $NO2$ concentrationsdecreased with the elevation and reverse case was observed for ozone with increasing concentrations at the same elevationrange. $SO2$ concentrations increased with the elevation due to chimney gas emissions.