Smoke-Free Car Legislation and Student Exposure to Smoking

Policies protecting children from exposure to secondhand smoke (SHS) may help prevent SHS-related negative health outcomes in children and discourage them from intending to smoke in the future. In this study, we assess the impact of California's 2007 smoke-free vehicle law on changes in middle and high school students' reported exposure to smoking in cars. Secondary aims included assessing the association of student-reported exposure to smoking in vehicles and lifetime asthma diagnosis and future intentions to smoke.

Population-weighted data from the California Student Tobacco Survey and the National Youth Tobacco Survey were used to evaluate California and national trends, respectively. Weighted logistic regression models using California Student Tobacco Survey 2011 data assessed the association between the number of days of exposure to smoking in cars and student-reported lifetime asthma diagnosis as well as intention to smoke in the future.

The proportion of California students reporting exposure to smoking in cars in the last 7 days declined <1% annually from 2001 through 2005, but declined 12% annually from 2007 to 2011. National trends did not show comparable declines after 2006. Students reporting exposure to smoking in vehicles were more likely to report having ever been diagnosed with asthma and intending to smoke in the future than students who were not exposed to SHS.

These findings support the legislative intent that public policies that are designed to protect children from exposure to smoking in vehicles will yield better adolescent health outcomes and a lower risk of future adolescent cigarette smoking.