Babies exposed to secondhand smoke have higher risk of developing allergies.
New research released today has found that babies exposed to secondhand smoke are almost twice as likely to develop allergies to inhaled allergens such as animal hair as infants who are not exposed to tobacco smoke. Children whose parents smoke are almost 50% more likely to be allergic to certain foods. 
The findings are based on parental survey responses from more than 4000 families about their children’s allergies and environmental factors to which they were exposed before and after birth. These included parental smoking, pet dander (animal hair and dead skin) and foodstuffs.
One in 12 mothers smoked throughout pregnancy and one in 8 smoked during part of the pregnancy. The researchers found no evidence that smoking while pregnant affected a child’s risk of becoming sensitised to a certain allergen. But there was a dose-response effect for exposure to secondhand smoke during the first weeks of life and markers for sensitisation.
Furthermore, the effect of secondhand smoke exposure was stronger among children with non-allergic parents than among those with parents who had allergies.
Amanda Sandford, Research Manager of the health campaigning charity ASH, said:
“This study provides yet more evidence of the need to ensure that babies and young children are not exposed to tobacco smoke. Whilst the development of some allergies may not be fully understood, this research shows that one way of substantially reducing the risk is by banning smoking in the home.
The study adds to the already substantial body of evidence of the harmful impacts of secondhand smoke on children, particularly in the early years of development.  Simply restricting smoking to certain rooms does not offer enough protection to infants and families should therefore make every effort to make their homes smokefree to give their children the best possible start in life. ”
Notes and links:
 Lannero E et al. Exposure to environmental tobacco smoke and sensitisation in children. Thorax 2007
 Going smoke-free. The medical case for clean air in the home, at work and in public places. Royal College of Physicians, London, 2005