Objectives: Children are highly vulnerable to damage from passive smoking as they are unable to avoid environmental tobacco, if present. Some reports have suggested that domestic exposure to environmental tobacco smoke can increase respiratory diseases in children. The aim of this study was to assess whether domestic passive smoking is associated with new respiratory events.
Methods: A descriptive, retrospective study was performed of 410 children aged less than 14 years old. The variables studied were: a) smokers in the household, b) the number of cigarettes smoked per day, c) school attendance, d) the number of siblings, e) previous respiratory diseases among parents and siblings, f) maternal smoking in pregnancy, and g) the number of respiratory events recorded in the previous year. Univariate, bivariate and multivariate analyses were performed.
Results: A total of 50.2 % of the children cohabited with smokers at home. The mean number of upper respiratory tract events per child living in environments free of tobacco smoke was 2.53 versus 3.52 when one of the household members smoked. For respiratory disease as a whole, an inverse association with age was found [OR = 0.83; (95 % CI: 0.76-0.90)] and a direct association was found with maternal smoking [OR = 4.56 (95 % CI; 1.84-11.34)]. With upper respiratory tract disease, the OR was 1.4 if the mother smoked 11-20 cigarettes/day, and was 1.9 if the number of cigarettes was > 20. With lower respiratory diseases, the odds ratio was 3.48 (95 % CI; 2.07-6.06) if the mother smoked.
Conclusions: Fifty percent of the children studied were exposed to environmental tobacco smoke in the home. Younger children were at higher risk. The major risk factor for respiratory disease was maternal smoking and the risk increased with the number of cigarettes smoked. Health education is essential to protect children from tobacco smoke exposure.