Exposure to tobacco smoke in cars and in rooms: Trend comparisons among subpopulations of non-smoking u.s. adolescents

Introduction: Young people in the U.S. are exposed to environmental tobacco smoke (ETS) primarily in homes and in cars. Recently, researchers reported that the prevalence of U.S adolescents exposed to environmental tobacco smoke in cars (ETSC) decreased from 2000-2009; however, comparisons of trends across important subpopulations were not assessed. In addition, no studies have examined trends of exposure to ETS in rooms (ETSR). Methods: We used data from the 2000, 2002, 2004, 2006, and 2009 waves of the National Youth Tobacco Survey (NYTS), a nationally representative cross-sectional survey of U.S. middle and high school students. For ETSC and ETSR, we identified exposure trends from 2000-2009, and compared trends among genders and race/ethnicity subpopulations using binary logistic regression. Results: We identified significant downward linear trends in ETSC and ETSR exposures for all measured subpopulations of adolescents from 2000-2009, except for ETSC exposure among Native Hawaiians/Pacific Islander (NH/PI) students. Downward trends in both ETSC and ETSR exposures for male students were significantly steeper than downward trends for female students. For ETSC, the downward trend for Black students was significantly steeper than for White students. For ETSR, the downward trend for White students was significantly steeper than for both Hispanic and NH/PI students. Conclusions: Although prevalence of ETSC and ETSR exposure among non-smoking U.S. adolescents has declined from 2000-2009, the rates of decline were not equal across genders and racial/ethnic groups. Identification of these differing rates of exposure can help the public health community advocate for interventions focused on reducing adolescent ETS exposure.