Effects of tobacco smoke exposure on lung growth in adolescents.

A longitudinal study on exposure to tobacco smoke among adolescents was carried out in Turin (North-Western Italy) in January-February 1992 and in January-February 1993. In 1992, 394 schoolchildren aged 14-16 years were enrolled in a study protocol which consisted in answering a standardized questionnaire, measurement of urinary cotinine and testing of lung function (flow-volume curve--[FVC] and forced expiratory volume in I sec.--[FEV1]). In 1993, 333 schoolchildren from the same group repeated the survey. By comparison to urinary cotinine, findings obtained showed a reduction of increase, from 1992 to 1993, of -0.57% (p = 0.082) for FVC, and -0.66% (p = 0.05) for FEV1. Assuming that the systematic selection bias did not seem to have occurred, findings, obtained from a multiple regression analysis, showed that active and passive exposure to tobacco smoke, as measured by urinary cotinine, had a significant effect on lung growth (as measured by FEV1) in adolescents; this effect, though small, was dose-related.