AN EVALUATION OF THE RELATIONSHIP BETWEEN SELF-REPORT AND BIOCHEMICALMEASURES OF ENVIRONMENTAL TOBACCO-SMOKE EXPOSURE

To evaluate the relationship between self-reported exposure to environ mental tobacco smoke and saliva cotinine concentrations, we studied 18 6 nonsmokers. Each participant completed an exposure questionnaire, ke pt a daily exposure diary for 7 days, and provided a saliva sample for cotinine analysis. Salivary cotinine concentrations were measured usi ng gas chromatography/mass spectrometry. Of the volunteers, 30% lived with one or more smokers, and 84% were regularly exposed to smokers at work. Eighty-three percent of the volunteers had detectable saliva co tinine concentrations (greater-than-or-equal-to 0.5 ng/ml) (median = 1 .1; range = 0.5-7.4 ng/ml). Cotinine concentrations were related to ex posure in the household and at the workplace. Volunteers who lived wit h smokers had significantly higher cotinine levels (median = 1.0; rang e = <0.5-7.4 ng/ml) than those who did not (median = <0.5; range = <0. 5-4.7 ng/ml). Volunteers who reported regular exposure at work had hig her cotinine levels (median = 0.8; range = <0.5-7.4 ng/ml) than those who did not (median = <0.5; range = <0.5-3.0 ng/ml). Cotinine concentr ations were predicted by a regression equation that included the numbe r of smokers at home and work and the number of minutes of exposure re corded in the daily diary (r2 = 0.29). (C) 1994 Academic Press, Inc.