Samplings of atmospheric particulate matter (PM) from 0.25 to 10 µm were performed between the months of March and April 2007, simultaneously in urban and rural areas of Londrina City (Paraná State, Brazil). Results indicated that the fine fraction (PM2.5) represents a significant portion of the PM10 mass (70 and 67% in urban and rural areas, respectively). Dicarboxylic acids were found in larger concentration, contributing to the PM2.5 fraction with 78% in urban and 69% in rural areas, being oxalate and succinate the most abundant species. Mass size distribution of oxalate in urban site was presented as the dominant mode, with peaks at 0.25-0.5 µm. Acetate-to-formate mass ratio indicated the primary vehicular emissions as dominant source of carboxylic acids in Londrina. Moreover, backward trajectories indicated the transport of pollutants from São Paulo State to Londrina region.
size-segregated particulate matter; carboxylic acids; PM2.5; urban and rural aerosols
