Associations of childhood and current secondhand smoke exposure at home with current secondhand smoke exposure at work: A cross-sectional analysis of the Singapore multiethnic cohort

Abstract

INTRODUCTION Relationships between secondhand smoke exposure (SHSE) in various temporal and physical settings are not fully studied despite its adverse impacts on human health, especially in multi-ethnic Asian populations. We investigated associations of childhood and current SHSE at home (SHSEhome) with current SHSE at work (SHSEwork) in Singapore and its relation to sources of daily smokers at home. METHODS This cross-sectional study identified 925 healthy, never smoker working adults from the Singapore Multi-Ethnic Cohort (2004-2010). Firstly, the multiple logistic regression model estimated the adjusted odds ratios (AORs) of SHSEhome. Subsequently, sources of daily smokers entered through an additional model building process using the former as a base. RESULTS Current adults (AOR=2.05; 95% CI: 1.28-3.29) and childhood SHSEhome (AOR=1.43; 95% CI: 0.93-2.19) had a positive and no association with current SHSEwork, respectively. These findings persisted when smoker identity-related variables entered the model: child (AOR=3.56; 95% CI: 1.19-10.64) for current daily smokers; father (AOR=2.30; 95% CI: 0.94-5.64) and sibling (AOR=2.97; 95% CI: 1.55-5.68) for childhood. Compared to no childhood SHSEhome, only those living with their fathers and siblings who smoked daily at home had significantly higher odds of reporting current SHSEwork (AOR=3.70; 95% CI: 1.88-7.30). CONCLUSIONS Current SHSEhome was a risk factor for current SHSEwork, with risks elevated among those who smoke daily at home and living with their children. Childhood SHSEhome becomes a risk factor when daily household smokers include fathers and siblings. Deformalizing smoking could consider interpersonal dynamics of daily smokers at home with family members in different temporal settings, to reduce SHSEwork.