Objectives: Secondhand smoke (SHS) exposure is an important cause of morbidity in children. We assessed the impact of family rules about smoking in the home and car on SHS exposure prevalence in students in grades six to 12.
Methods: We studied never-smoking young people (n = 1,698) in the random sample cross-sectional South Carolina Youth Tobacco Survey, a 2006 survey of middle and high school students in South Carolina.
Results: Overall, 40% of the students reported SHS exposure in either the home or car in the past week; among these, 85% reported exposure in cars. Subsequent analyses focused on students who lived with a smoker (n = 602). Compared with those whose families prohibited smoking in the home or car, SHS exposure prevalence was 30% (p < 0.0001) higher for households with smoke-free rules for only one place (home or car) and 36% (p < 0.0001) higher for households with no rules. Compared with students from households with strict rules, SHS exposure prevalence was 48% greater (p < 0.0001) among those with only partial rules against smoking in the home or car, and 55% (p < 0.0001) greater among those from households with no rules. Similarly, compared with students with strict family rules for home and car that were adhered to, SHS exposure prevalence was significantly higher (p < 0.0001) among students when only one or no rules were followed.
Conclusions: Young people from families that made and enforced strong rules against smoking in homes and cars were much less likely to report SHS exposure. Parents would be wise to endorse and enforce strong smoke-free policies for both homes and cars.