Medical students’ awareness and beliefs regarding third-hand smoke

Abstract

Third-hand smoke refers to residual tobacco smoke contaminants that persist on indoor surfaces, dust, clothing, hair, and skin after smoking has ceased. This study assessed medical students’ prior awareness, perceived knowledge, and beliefs regarding third-hand smoke-related health effects and environmental persistence. This descriptive cross-sectional study was conducted among medical students at Gaziantep University Faculty of Medicine, Türkiye, between July and December 2024. Data were collected using a structured questionnaire administered online or face to face. Third-hand smoke awareness and perceived knowledge were assessed before a standardised third-hand smoke definition was provided, whereas beliefs were assessed after the definition using the validated Turkish version of the Beliefs About Third-Hand Smoke scale (score range: 1–5). Descriptive analyses, group comparisons, correlation analyses, non-parametric sensitivity analyses, and multivariable linear regression models were performed. Of 336 students who completed the questionnaire, four were excluded because they were younger than 18 years; the final analytical sample included 332 students. Most participants had not previously heard the term third-hand smoke (81.3%), only 3.0% reported previous third-hand smoke-related education, and 95.2% rated their third-hand smoke knowledge as insufficient. After a standardised third-hand smoke definition was provided, mean Beliefs About Third-Hand Smoke scale scores were above the scale midpoint for the total scale (3.91 ± 0.88), health subscale (3.90 ± 0.89), and persistence subscale (3.92 ± 0.94). In multivariable analyses, higher academic year was modestly associated with higher belief scores, whereas current smoking was modestly associated with lower total and health subscale scores. The explanatory power of the models was limited. Medical students in this single-centre study had limited prior awareness and education regarding third-hand smoke, while third-hand smoke-related belief scores were above the scale midpoint after a standardised definition was provided. Third-hand smoke may be considered as a brief topic within existing tobacco-control and environmental health education.