Occurrence and concentration levels of Nitro-PAH in the air of three Brazilian cities experiencing different emission impacts

Nitrated Polycyclic Aromatic Hydrocarbons (NPAH) were determined in the suspended particulates collected in Sauo Paulo (Brazil) and three other cities lying in the Sauo Paulo State, (namely, Araraquara, Piracicaba and Paulinia), during August 2002 and July 2003. Sao Paulo samples represented a big difference between two groups of days, one of which characterized by heavy injection of pollutants released by industrial and agricultural activities. Most NPAH congeners identified in the atmosphere were among those usually associated to diesel exhaust, with the three important exceptions of 2-nitrofluoranthene, 2- and 4-nitropyrene. Daytime reactions seemed to promote decomposition of primary fluoranthene and pyrene. Trends of NPAH at all sites seemed to be associated to regional transport of polluted air through air masses passing over sugar cane plantations of Sao Paulo State.