Disparities and Trends in Indoor Exposure to Secondhand Smoke among US Adolescents: 2000-2009

Introduction: Secondhand smoke (SHS) exposure causes disease and death among nonsmokers. With a plethora of smokefree legislation implemented and a steady decrease in cigarette consumption noted over the past decade in the U.S., this study assessed trends in indoor SHS exposure among U.S. adolescents in grades 6-12 during 2000-2009. Methods: Data were obtained from the 2000-2009 National Youth Tobacco Survey -a national survey of U. S. middle and high school students. SHS exposure within an indoor area within the past seven days was self-reported. Trends in indoor SHS exposure during 2000-2009 were assessed overall and by socio-demographic characteristics, using the Wald's test in a binary logistic regression. Within-group comparisons were performed using chi-squared statistics (p<0.05). Results: The proportion of U.S. middle and high school students who were exposed to indoor SHS declined from 65.5% in 2000 to 40.5% in 2009 (p<0.05 for linear trend). Significant declines were also observed across all population subgroups. Between 2000 and 2009, prevalence of indoor SHS exposure declined significantly among both middle (58.5% to 34.3%) and high school (71.5% to 45.4%) students. Prevalence of indoor SHS exposure was significantly higher among girls (44.0% in 2009) compared to boys (37.2% in 2009) during each survey year. Similarly, prevalence of indoor SHS exposure during 20002009 was highest among non-Hispanic whites (44.2% in 2009) and lowest among non-Hispanic Asians (30.2% in 2009). During each survey year, prevalence was highest among the oldest age group ($ 18 years) and lowest among the youngest (9-11 years). Also, prevalence was significantly higher among current cigarette smokers (83.8% in 2009) compared to nonsmokers (34.0% in 2009). Conclusion: Significant declines in indoor SHS exposure among U.S. middle and high school students occurred during 2000-2009. While the results are encouraging, additional efforts are needed to further reduce youth indoor SHS exposure.