Frequency and risk factors related to smoking in cars with children present.

Objectives: Second-hand smoke (SHS) can attain high concentrations in cars. To protect children's health, nine Canadian provinces have enacted legislation prohibiting smoking in privately owned vehicles when children are present; Quebec is the only province with no such legislation. The objective of this study was to estimate the proportion of smokers in Quebec who smoke while travelling in a private vehicle in which children are present, and to compare the characteristics of smokers who do and do not smoke in cars.

Methods: In 2011-12, 754 daily smokers who recently travelled in a car with children completed a telephone survey in which they reported how frequently they smoked in a car, if there were smoking restrictions, and perceptions about the effectiveness of legislation prohibiting smoking in cars when children are present.

Results: Twenty-three percent of daily smokers smoked at least occasionally in their car when children were present. This proportion was higher among smokers who knew that there was no legislation in Quebec prohibiting smoking in cars, compared to smokers who believed that such legislation was already in effect (32% vs. 12%). Smokers with a university degree and those who reported that smoking was prohibited at home were less likely to expose children to SHS in cars. Most daily smokers (75%) believed that legislation would be effective.

Discussion: The results of this study suggest that legislation prohibiting smoking in cars is necessary to protect children from SHS, that such legislation would be effective, and that it may be relatively easy to implement.