We studied the concentration of 10 primary aromatic amines (AA), which are classified as suspected carcinogens, in indoor and outdoor air in Italy.. The measured AA included: aniline, o-toluidine, m-toluidine, p-toluidine, 2,3-dimethylaniline, 2,4-dimethylaniline, 2,5-dimethylaniline, 2,6-dimethylaniline, 2-naphtylamine and 4-aminobiphenyl. In the indoor environment (homes, offices and public buildings) the level of contamination (expressed as sum of 9 AA, excluding aniline) varied from 3 ng/m(3) (hospital ward) to 207 ng/m(3) (discotheque). In most indoor environments with no contamination from cigarette smoke the AA levels were below 20 ng/m(3), whereas in the presence of smokers higher values were observed. Aniline levels were more erratic (varying from 53 ng/m(3) (office of non-smokers) to 1929 ng/m(3) (discotheque) and were not related to cigarette smoke. The concentration range of AA (excluding aniline) in the outside air varied from 3 ng/m(3) (Siena) to 104 ng/m(3) (Brindisi); aniline concentration was extremely variable. Most samples of outdoor air had AA levels lower than 40 ng/m(3). In conclusion, AA are widespread air contaminants and attain a high concentration in heavily contaminated indoor environments, due to smoking and poor ventilation. AA occasionally attain a high level in outdoor air as well. Therefore, a strategy of reduction of the exposure to AA should consider the abatement of multiple sources of contamination. (C) 2001 Elsevier Science Ltd. All rights reserved.