Urban Air and Passive Tobacco Smoke. Risky Conditions for Youth in the Onset of Oxidative StressAbstract Number:1936 Roberto Bono*, Roberta Tassinari, Valeria Bellisario, Massimiliano Bugiani, Marco Pazzi, and Pavilio Piccioni Roberto Bono* University of Turin, Italy, E-mail Address: [email protected] Search for more papers by this author , Roberta Tassinari University of Turin, Italy, E-mail Address: [email protected] Search for more papers by this author , Valeria Bellisario University of Turin, Italy, E-mail Address: [email protected] Search for more papers by this author , Massimiliano Bugiani Unit of Respiratory Medicine, National Health Service (ASL TO2), Turin, Italy, Italy, E-mail Address: [email protected] Search for more papers by this author , Marco Pazzi University of Turin, Italy, E-mail Address: [email protected] Search for more papers by this author , and Pavilio Piccioni Unit of Respiratory Medicine, National Health Service (ASL TO2), Turin, Italy, Italy, E-mail Address: [email protected] Search for more papers by this author AbstractThe urban pollution and the passive exposure to tobacco smoke are associated with several pathological conditions, expecially for adolescents, which can be preceeded by the formation of oxidative stress. The purpose of this study was to clarify the role of some factors in the oxidative stress status of population of healthy adolescent not-smokers living in North-Western Italy.Methods. To assess the levels of oxidative stress, the 15 F2t-isoprostane (15 F2t-IsoP) concentrations were measured in the urine of 390 adolescents (12 ? 1,0 years) and, to verify their role in this biosynthesis, some independent variables were quantified: a) the urbanization of three areas where the selected subjects live and attend school: Turin (6.700 inhabitants/km2), Chivasso (507 inhabitants/km2), Casalborgone (93,3 inhabitants/km2); b) the level of urinary cotinine to assess the intensity of passive exposure to tobacco smoke, c) the characteristics of the subjects.Results. The mean levels of 15 F2t-IsoP [ng/mg CREA] in the three sites were significantly different (p<0.0001) one to each other: Turin 7.2 - 4.0; Chivasso 6.4 - 5.4; Casalborgone 4.8 - 3.0. Furthermore, the MLR showed 15 F2t-IsoP positively correlated to passive exposure to tobacco smoke (urinary cotinine): p < 0,0001 C.I. 0,119-0,197 and level of urbanization (Turin vs Chivasso vs Casalborgone p < 0.0001 C.I. 0,152-0,561), but negatively to age. Adjusted by residence, the univariate analysis showed a positive and direct role of tobacco passively smoked in the distribution of 15 F2t-IsoP values. At the same time, when the sample was adjusted by the variable ‘urinary cotinine’, the linear regression revealed a significant, positive and directly relationship between the 15 F2t-IsoP values and the sites of residence.Conclusions. Both passive exposure to tobacco smoke and level of urbanization of the place where the guys live show an independent and direct role in the onset of oxidative stress.