COMPARISON OF 3 METHODS FOR ESTIMATING ENVIRONMENTAL TOBACCO-SMOKE EXPOSURE AMONG CHILDREN AGED BETWEEN 12 AND 36 MONTHS

Background. The methods currently used for measuring environmental tob acco smoke (ETS) exposure among small children all have their limitati ons, The aim of this study was to compare the results of questionnaire assessments of children's ETS exposure with cotinine measurements in urine and nicotine measurements in hair, a new method for estimating a verage ETS exposure. Methods. Questionnaire information on ETS exposur e and a sample of hair were collected from 94 children aged 12-36 mont hs. A urine sample for cotinine analysis was obtained from 72 of the c hildren. Results. Nicotine was found in all hair samples and cotinine in all urine samples. Compared to children registered as unexposed by the questionnaire, hair nicotine levels were 12.4 times higher among c hildren exposed to more than 10 DNC (daily number of cigarettes) (P < 0.001) and 3.6 times higher among children exposed to 1-10 DNC (P < 0. 001). The median cotinine creatinine ratio (CCR) was 2.4 times higher among children exposed to more than 10 DNC compared to unexposed child ren (P < 0.001). No significant difference in median CCR was found bet ween unexposed children and children exposed to 1-10 DNC. The correlat ion coefficient was 0.64 between children's hair nicotine levels and D NC, 0.50 between CCR and DNC and 0.56 between children's hair nicotine levels and CCR. Conclusion. Nicotine measurement in hair is a practic al and valid method for estimating average ETS exposure in children. A n underreporting of ETS exposure was indicated.