Environmental Tobacco Smoke and Urinary Cotinine in a Group of Adolescent.

Cotinine, a metabolite of nicotine, can be measured in urine in a noninvasive way. This procedure permits its use in large-scale epidemiological studies. The aim of this pilot study was to evaluate the relationship between environmental tobacco smoke exposure and urinary coti-nine in 148 school children (14 years old). The subjects were randomly chosen from a larger study group of 460 school children. The data on exposure were based on a questionnaire. Cotinine levels for the two extremes of passive exposure (no exposure vs. living with a smoking mother and other smokers) demonstrated a statistically significant difference (P = 0.0069) as did exposure for smokers vs. nonsmokers (P = 0.0001). This validation will allow us to consider the answers to the questionnaire relative to tobacco smoke exposure as an independent variable in the near-complete analysis of the larger study of the 460 students for all the parameters considered.