Beliefs about thirdhand smoke and voluntary smoking bans in homes and cars: a cross-sectional study in Türkiye, 2023

BACKGROUND: In this study, conducted in Ankara, Türkiye in 2023, the prevalence and determinants of voluntary smoking bans implemented by adults in their homes and vehicles were investigated, as were their relationship with beliefs about THS. METHODS: This cross-sectional study used convenience sampling and included adults aged ≥ 18 years who presented to a university hospital in Ankara in June 2023. Data were collected using a 33-item questionnaire administered via face-to-face interviews. Beliefs about thirdhand smoke were measured using the Turkish-validated Beliefs About Thirdhand Smoke (BATHS) scale, which includes health effects and environmental persistence subdimensions. Complete smoking bans in homes and cars were defined as dependent variables. Adjusted Odds Ratios (aOR) with 95% Confidence Intervals (CI) were calculated using logistic regression. Home models were adjusted for age, income, smoking status, secondhand smoke exposure, and the presence of a smoker in the home; car models were additionally adjusted for gender, education, and the presence of a child in the home. RESULTS: A total of 57.4% of the participants reported enforcing a complete smoking ban at home and a total of 63.2% reported enforcing a complete smoking ban in their cars. Each 1-point increase in the total BATHS score was significantly associated with smoking bans at home (aOR = 1.043, 95% CI: 1.018-1.068) and in cars (aOR = 1.044, 95% CI: 1.015-1.074). In the absence of smokers at home, the ban is enforced more frequently (home: aOR = 8.91, car: aOR = 8.34). Nonsmokers are more likely to enforce the ban at home (aOR = 1.57) and in cars (aOR = 2.02). A higher level of education increases the likelihood of enforcing a smoking ban in vehicles (aOR = 1.93). Individuals who have not been exposed to secondhand smoke in the past 30 days are more likely to enforce the smoking ban in cars (aOR = 2.15). CONCLUSION: Beliefs about THS predict voluntary smoking bans in private settings. By highlighting the role of THS awareness as a predictor of smoke-free private settings, the study suggests that integrating THS education into tobacco control strategies could help protect nonsmokers and reduce exposure in private environments where public smoke-free laws are not enforced.