Social disparities in children's exposure to secondhand smoke in privately owned vehicles

Introduction Secondhand smoke (SHS) can quickly attain high concentrations in cars, posing health risks to passengers and especially to children. This paper assesses whether there are social disparities in children9s exposure to SHS in privately owned vehicles. Methods On weekday mornings and afternoons from September to November 2011, trained observers were stationed at 100 selected street intersections in Montreal, Canada. For each car transporting at least one passenger aged 0–15 years travelling through the intersection, observers recorded the estimated age of the youngest child in the car, whether any occupant was smoking and the licence plate number of the car. Licence plate numbers were linked to an area material deprivation index based on the postal code of the neighbourhood in which the car was registered. Results Smoking was observed in 0.7% of 20 922 cars transporting children. There was an apparent dose–response in the association between area material deprivation level and children9s exposure to SHS in cars. Children travelling in cars registered in the most disadvantaged areas of Montreal were more likely to be exposed to SHS than children travelling in cars registered in the most advantaged areas (unadjusted OR=3.46, 95% CI 1.99 to 6.01). Conclusions This study revealed social disparities in children9s exposure to SHS in privately owned vehicles.