Environmental Tobacco Smoke Exposure Among Children by Urinary Biomarkers and Parent Report

Objective: The goal of this study was to describe environmental tobacco smoke (ETS) exposure using urinary biomarkers and its correlation with parent report, among children presenting to emergency room. Methods: This is a case control study among children aged 3 to 12 years at a tertiary pediatric emergency department in Israel. Children with respiratory (case) or gastrointestinal (control) symptoms were recruited and their accompanying parent completed a short survey. Urine samples were obtained and analyzed for nicotine, cotinine trans-3’-hydroxycotine. Clinical data were extracted from medical records. We compared tobacco exposure using urinary biomarkers, parent report, and Pearson's product-moment correlation, including 95% confidence intervals, between cases and controls. Results: Forty-nine cases with respiratory symptoms and 96 controls with gastrointestinal symptoms were enrolled in the study. Parent-reported ETS exposure in the previous month was higher in the cases compared to control (71.4% vs 57.3%), although the difference was not statistically significant. The mean values of detectable biomarkers did not differ by between cases and controls. However, there was a correlation between urinary biomarkers and reported ETS exposure (0.278–0.460 for various biomarkers) only among cases. Conclusions: The majority of children in this study had detectable nicotine urinary biomarkers, regardless of their symptoms. However, correlation between parental report and urinary biomarkers was only found among children with symptoms potentially related to ETS. These findings imply that parents of children without respiratory symptoms may underestimate exposure. Efforts to educate parents and caregivers on the risks associated with exposure to ETS should be intensified, regardless of illness.