The environmental impact of Notte Bianca (White Night) holidays held during September 2007 in Rome, Italy, was investigated by measuring aerial concentrations of several genotoxic, psychotropic or source-dependent organic pollutants. Chemical characterization of airborne particulates collected concurrently at Montelibretti RM (semi-rural locality lying approximately 30 km NE of Rome centre) was used as a reference. n-Alkanes, polynuclear aromatic hydrocarbons (PAH) and nitrogen/oxygen-containing polyaromatic compounds (PAC) did not seem to undergo important enhancements during the holiday celebration, whilst recreational drugs peaked downtown (87 vs 41 pg m(-3), on the average, of cocaine, and 5.0 vs. 2.6 ng m(-3) of nicotine). By contrast, a simultaneous raising of aerial drugs was not detected at Montelibretti.