Environmental tobacco smoke exposure among children: findings from the Swiss Paediatric Airway Cohort

<bold>Introduction:</bold> Environmental tobacco smoke (ETS) exposure has negative effects on children’s health. Globally, around 40% of children are affected, with population prevalence estimates in Switzerland ranging 27-47%. We studied prevalence of parental smoking and smokers’ characteristics among children in the Swiss Paediatric Airway Cohort (SPAC). <bold>Methods:</bold> In SPAC, we invited families with children aged 0-17 years referred for respiratory symptoms to pulmonary outpatient clinics in Switzerland since 2017. Parents filled in a questionnaire with questions on smoking. We used descriptive statistics and logistic regression analysis. <bold>Results:</bold> We included 4062 children (median age was 9 years [IQR 5-12], 60% male). At enrolment, 1246 (31%) children were exposed to self-reported parental smoking. Of these, 631 (16%) were exposed exclusively to paternal smoking, 234 (6%) maternal, and 381 (9%) to both smoking parents. Mothers who smoked were more likely to have attained lower education levels (primary OR 2.6 95%CI 1.9-3.8, secondary OR 2.5 95%CI 2.0-3.0 vs tertiary education), have a full-time job (OR 1.6 95%CI 1.2-2.2 vs part-time job) and have a single child (OR 1.6 95%CI 1.2-2.1 vs >2 children). Fathers who smoked were more likely to have a migration background (OR 1.6 95%CI 1.3-1.9), have attained lower education levels (primary OR 2.7 95%CI 2.0-3.7, secondary OR 2.8 95%CI 2.3-3.3 vs tertiary), and be unemployed (OR 1.9 95%CI 1.2-3.0 vs full-time job). <bold>Conclusions:</bold> We found that one-third of SPAC participants were exposed to ETS, with more fathers reporting smoking compared with mothers. ETS is significantly influenced by socio-economic factors. Funding: SNSF 320030_212519