Second-hand smoke exposure in Canada: prevalence, risk factors, and association with respiratory and cardiovascular...

The aims of the present study were to estimate the prevalence of second-hand smoke exposure in Canada, to identify sociodemographic risk factors for second-hand smoke exposure, and to examine the relationship between second-hand smoke exposure and respiratory and cardiovascular diseases.

Data from the 2000/2001 Statistics Canada Canadian Community Health Survey (n=130,880, aged 12 years or older) were analyzed. Second-hand smoke exposure was based on self-report within the past month. The presence of chronic health conditions was also based on self-report. Because ex-smokers would be expected a priori to have poorer health than never-smokers, the analysis was stratified by previous smoking status.

Approximately 25% of never-smokers and 30% of ex-smokers self-reported recent second-hand smoke exposure. The following factors were identified as risk factors for second-hand smoke exposure: men; residences in Quebec, Atlantic Canada and the Territories; younger ages; nonimmigrant status; low education and income levels; social assistance receipt; and households without children younger than 12 years of age. After controlling for potential confounders, both never- and ex-smokers exposed to second-hand smoke had significantly higher odds of self-reporting asthma (20% to 30%) and chronic bronchitis (50%) than those not exposed to second-hand smoke. Among ex-smokers, those exposed to second-hand smoke also had significantly higher odds of self-reporting hypertension (20%) than those not exposed to second-hand smoke. No associations were observed between second-hand smoke exposure and emphysema or heart disease.

Self-reported recent second-hand smoke exposure in Canada in 2000/2001 was high, and was associated with asthma, chronic bronchitis and hypertension in never- and ex-smokers. Potential causal associations and public health implications warrant additional research.