Atmospheric Concentrations and Phase Partitioning of Polycyclic Aromatic Hydrocarbons in Izmir, Turkey

Ambient air polycyclic aromatic hydrocarbon (PAH) samples were collected at a suburban (n = 63) and at an urban site (n = 14) in Izmir, Turkey. Average gas-phase total PAH (Sigma(14)PAH) concentrations were 23.5 ngm(-3) for suburban and 109.7 ngm(-3) for urban sites while average particle-phase total PAH concentrations were 12.3 and 34.5 ngm(-3) for suburban and urban sites, respectively. Higher ambient PAH concentrations were measured in the gas-phase and Sigma(14)PAH concentrations were dominated by lower molecular weight PAHs. Multiple linear regression analysis indicated that the meteorological parameters were effective on ambient PAH concentrations. Emission sources of particle-phase PAHs were investigated using a diagnostic plot of fluorene (FLN)/(fluorine + pyrene; PY) versus indeno[1,2,3-cd]PY/(indeno[1,2,3-cd]PY + benzo[g,h,i]perylene) and several diagnostic ratios. These approaches have indicated that traffic emissions (petroleum combustion) were the dominant PAH sources at both sites for summer and winter seasons. Experimental gas-particle partition coefficients (K-P) were compared to the predictions of octanol-air (K-OA) and soot-air (K-SA) partition coefficient models. The correlations between experimental and modeled K-P values were significant (r(2) = 0.79 and 0.94 for suburban and urban sites, respectively, p < 0.01). Octanol-based absorptive partitioning model predicted lower partition coefficients especially for relatively volatile PAHs. However, overall there was a relatively good agreement between the measured K-P and soot-based model predictions.