Chemical characterization of polar organic markers in aerosols in a local area around Bologna, Italy

In both seasons the most abundant compound is levoglucosan, as the major by-product from biomass burning. The abundances of dicarboxylic acids exhibit a seasonal pattern with higher winter concentrations (mean total concentrations are 60 ng m−3 and 23 ng m−3, in winter and summer, respectively). The distribution profiles and the diagnostic ratios of these markers allowed to estimate the contribution of primary emission sources (power plants, vehicular circulation, biomass burning) associated with secondary constituents from both biogenic and anthropogenic precursors. The distinct seasonal pattern of abundances suggests, overall, the dominant role of secondary formation of particulate organics in summer, and the highest strength of primary emissions in winter.