Cotinine Elimination and Its Use as a Biomarker in Young Children Involuntarily Exposed to Environmental Tobacco Smoke

Abstract

Quantitative relationships between urinary cotinine excretion and environ mental tobacco smoke (ETS) exposure in young children have not been deter mined. The objectives of this research were to: (1) determine the cotinine t ½ in young children up to 3 years of age using urinary cotinine excretion data and (2) establish correlations between urinary cotinine excretion and ETS expo sure in young children. In 44 young children involuntarily exposed to ETS at home, urinary cotinine excretion data were collected for 6 days out of the home, and the cotinine t½ was determined. The median cotinine t½ was 54.7 h, and 50% of the t½ values were between 38.2 and 85.6 h. Air nicotine concen trations in the home were used to measure ETS exposure. The best predictor of home air nicotine concentration was a model with sex and the zero time creat inine corrected urinary cotinine concentration (R2 = 0.23).