Gas-particle partitioning and health risk estimation of polycyclic aromatichydrocarbons (PAHs) at urban, suburban and tunnel atmospheres: Use ofmeasured EC and OC in model calculations

Özet

Gas and particle phase ambient concentrations polycyclic aromatic hydrocarbons (∑13PAH) were determined aturban and suburban sites in Eskişehir and in a traffic-tunnel. Organic and elemental carbon (OC and EC) con-centrations of total suspended particles (TSP) were also measured. Atmospheric∑13PAH (gas+particle) con-centrations measured at suburban sites was found to be lower than that of tunnel and urban site. Concentrationsof TSP and OC/EC were highest in the tunnel. Fluorene, Phe, Flt and Pyr were the most dominant PAH com-pounds in gas phase samples for all three sampling locations, while BaA, Chr, BbF, BkF and BaP were found to behigher in particle phase.Gas-particle partitioning coefficients, (Kp) and particle-phase fractions (Φ) of PAHs were correlated withsupercooled vapor pressures (PLo). Non-linear curvefitting ofΦversus logPLowas found to be more robust thanlinear logarithmic regressions of log Kp versus logPLo. Kp of PAHs were estimated by octanol-air and soot-airpartitioning models and the results were compared with the experimental Kp values. Measured EC and OCconcentrations were used in model calculations. Use of measured carbon concentrations in model calculationsresulted much better estimations for tunnel samples. Gas-particle partitioning of PAHs for the majority of thecompounds were controlled by adsorption onto soot carbon and adsorption into the organic matter. Cancer risksassociated with inhalation and dermal contact were also estimated. Generally, the estimated cancer risks werebelow 1 × 10−5for urban and suburban sampling locations.