The objectives of this study were the determination of: (a) benzene (B), toluene (T) and xylene (X) air pollution in three sites of the Piedmont region (north-western Italy), (b) the relationship between BTX pollution in indoor, outdoor and personal air measured for a group of non-smoking university students, (c) the influence of environmental tobacco smoke on the level of BTX exposure for indoor air environments. Results indicate (i) a direct relationship between human density and level of contamination and higher toluene pollution, (ii) an indoor/outdoor ratio of > 1 for all the three aromatics, (iii) a similar level of personal and indoor air contamination. Human exposure to BTX air pollution has been found to depend principally on indoor air contamination, not only on home pollution, but also, probably on many other confined environments.