Abstract: “Polycyclic aromatic hydrocarbons (PAHs) are semi-volatile organic compounds and present widely in ambient atmosphere. Due to the fact that PAHs are widely distributed in the environment and some species of them are carcinogenic, they are very important for human health and environment. High volume cascade impactor was used to collect the particulate matters according to particle size fractions between February 2013 and June 2014, in Istanbul. Particulate matters were collected according to size ranges >7.2 μm, 7.2 - 3 μm, 3 - 1.5 μm, 1.5 - 0.95 μm, 0.95 - 0.49 μm, <0.49 μm. 15 PAH species were analyzed in samples. Average of total PAH concentrations were found as 31.62 ng/m3. Total PAH size distribution was found between 0.95-1.5 μm. All investigated ring PAH species showed single modal distribution in size range of 0.95-1.5 μm. 4, 5 and 6-ring PAH species have high concentration in almost each size range. According to the obtained results, 4, 5, 6-ring PAHs are abundant on the particl”

Keywords: PAHs, particle size distribution, PM2.5, TEF