E-cigarette use in vehicles: factors associated with secondhand exposure and behaviour from a US young adult sample in 2024

Background This study investigates factors associated with electronic cigarette (e-cigarette) use and secondhand exposure in vehicles among US youth and young adults. Methods Data were collected from an online panel survey of individuals (N=3482, aged 15–25 years) from July to December 2024. Analyses included those who reported using any tobacco product in the past 30 days and answered items measuring exposure to (N=2600) and/or use of e-cigarettes in vehicles (N=2366). Logistic regression models assessed predictors of e-cigarette use and exposure in vehicles, including demographic, psychosocial and tobacco use characteristics. Results Among all participants, 67.1% reported e-cigarette use in the past 30 days. Of those reporting current e-cigarette use (N=2336), 60.6% reported using their e-cigarette/vape while travelling by car in the past 30 days. Of those who answered the question measuring exposure to e-cigarette use in vehicles (N=2600), 69.3% reported being in a vehicle where someone was using e-cigarettes. Higher nicotine dependence and residence in small metro and non-metro areas were associated with greater odds of using e-cigarettes in vehicles. Just meeting basic expenses or meeting needs with a little left, household tobacco use and residence in small metro areas were associated with greater odds of secondhand e-cigarette exposure. Discussion Public health interventions should place a strong focus on education and increasing public awareness of the health consequences of e-cigarette use in vehicles to protect bystanders from secondhand e-cigarette exposure.