Dry deposition of polycyclic aromatic hydrocarbons in urban and rural sites of Western Greece

The dry deposition of 12 polycyclic aromatic hydrocarbons (PAHs) was measured at an urban (Kozani), an adjacent coastal (Vegoritis) and a continental background site (Petrana) located in the Eordea basin, western Greece. Mean dry deposition fluxes of 3917, 3346 and 5648 ng m−2 month−1 (0.13, 0.11 and 0.19 μg m−2 day−1) were found in Petrana, Vegoritis and Kozani, respectively. Differences among sites were attributed to their different impact from emission sources and to differences in prevailing meteorological conditions. The correlation of dry deposition fluxes with particle- and gas-phase PAH concentrations determined at the three sites during the same sampling periods was investigated. Dry deposition velocities (Vd) were calculated by dividing deposition fluxes with the corresponding average ambient PAH concentrations. The low Vd values obtained suggest that gas phase PAHs and fine particle associated PAHs dominate their dry deposition. The influence of air mass movements to dry deposition and atmospheric concentrations of PAHs in the area was also investigated.