Determination Of Chemical Composition In Pm2.5 Samples Collected In Urban And Semi-Urban Two Stations In Ankara

Abstract

Studies carried out in recent years have shown considerable number of deaths due to air pollution. In spite of this serious situation, studies on chemical composition of particulate matter are conducted only by a few research groups at air quality monitoring stations operated by the Ministry of Environment and Urbanization in Ankara with about 4.6 million residents.PM samples recommended to be studied in this research are collected daily at Gate B, Beytepe campus of Hacettepe Universty and garden of General Directorate of Public Health of Turkey located in Sıhhiye on quartz filters. The collected filter samples are cut into 1.5 cm2 pieces and these pieces will be analyzed in order to determine the contents of organic carbon (OC), elemental carbon (EC) and total carbon (TC) by thermal optic carbon analyzer developed by Sunset Lab (USA, Oregon).Obtained dataset were statistically evaluated and the analyzed parameters have been compared with similar previous studies in order to be able to provide basic information about urban air quality. The primary and secondary organic carbon (POC and SOC, respectively) were calculated using the EC and OC values. The results of this study revealed that PM2.5 and carbonaceous species pollution were serious during summer and winter especially at city center. PM2.5 mean concentrations at both locations in winter and summer are above the WHO, EU and EPA standard limits. There is not a big statistically difference between PM2.5 concentration at urban site between summer and winter. This shows that traffic is the dominant pollutant source and is not a season dependent factor. During the sampling period, OC was the parameter with the highest contribution to PM2.5 mass at all the samples. The OC concentration is approximately two times higher in winter. EC and OC concentrations are both higher at urban site indicating that this area is exposed to more intensive traffic and emissions. Organic carbon is emitted mostly from primary sources to the atmosphere of the city.