Private space second-hand smoke exposure and the mental health of non-smokers: A cross-sectional analysis of Canadian adults

Introduction: The aim of this paper was to examine the association between exposure to second-hand smoke (SHS) among non-smokers, in the home and the vehicle, and poor mental health outcomes (mood disorder, anxiety disorder, poor/fair mental health, and high stress). Methods: Data were drawn from the 2010 Canadian Community Health Survey, a representative sample of 62,909 Canadians 12. years and older. Measures of SHS exposure are drawn from self-reported daily or near daily exposure in the home or in the vehicle. Mental health indicators include self-reported diagnosed mood and anxiety disorders, and self-report measures of overall mental health and experiences of stress. Associations between SHS exposure and poor mental health among non-smokers were examined in a series of logistic regression models. Additional analyses stratified on respondent's smoking status, physical health, and gender. Results: Analyses revealed that SHS exposure among non-smokers was associated with increased anxiety disorders, poor/fair mental health, and high stress, with no association to mood disorders. Stratified analyses demonstrated that associations between SHS and poor mental health are contextualized by respondent's gender, physical health, and smoking status. Conclusions: Beyond changes to physical health, SHS exposure in private spaces was negatively associated with the mental health of non-smokers. Public health efforts to reduce SHS exposure in private spaces are warranted. Findings also reveal additional targets for decreasing and eliminating the societal burden of mental health disorders. Further research is needed to examine causality and to explore associations between SHS exposure and specific mental health outcomes.