Comparison of different methods for measuring dry deposition fluxes of particulate matter and polycyclic aromatic hydrocarbons (PAHs) in the ambient air

In this study, three methods (bucket, plate for downward flux and upward flux, and water vessel) were used to measure atmospheric dry deposition fluxes at three different heights (0.5, 1.5 and 12.5m) to estimate the deposition fluxes of mass and polycyclic aromatic hydrocarbons (PAHs) in TERC (Tsukuba), Japan. Ambient particles were also collected using a high-volume air sampler, and ambient particle size distributions between 0.01 and 13.1 mum were measured using a low-pressure cascade impactor to characterize the PAH levels and dry deposition. Settling velocities were calculated as the settling fluxes divided by the corresponding average ambient particle concentrations. In this research work, 'we describe how small particles dominate atmospheric dry deposition of PAHs and how bucket deposition fluxes and net (downward minus upward) fluxes decrease with height due to resuspension and/or vertical distribution of suspended particles' etc. (C) 2004 Elsevier Ltd. All rights reserved.