Nitrated-PAH in urban air of Italy as indicators of motor vehicle emission and light-induced reactions

The precence of particle-bound nitrated PAH (NPAH) in the atmosphere has been observed in urban areas of Italy. Milan appeared to be the most polluted city. Sites of different nature were investigated in Rome and its outskirts. Particle-bound NPAH were modulated not only in concentration, but also in-situ generation mechanisms influencing the site. Despite that, direct release from motor vehicles was found less important than degradation of PAH with respect to the presence of NPAH in the atmosphere. Concentrations of NPAH seemed to be capable to affect ambient air quality, due to strong mutagenicity of selected congeners.