ATS 2007, SAN FRANCISCO -- Children of smokers who dont show any signs of respiratory problems may still be experiencing damaging changes in their airways that could lead to lung disease later in life, according to a new study presented at the American Thoracic Society 2007 International Conference, on Sunday, May 20.

"Everyone knows that children of smokers have more respiratory problemsmore puffing, wheezing, cases of pneumoniabut until now we havent known if lung function is impaired in children of smokers who dont have any respiratory complaints or diagnosed lung problems," says researcher Bert Arets, M.D., Ph.D., of University Medical Center Utrecht in the Netherlands.

The study included 244 children ages 4 to 12 without any history of lung or airway disease. They were divided into four groups according to the smoking pattern of their parents: never smokers, smoking after birth but not during pregnancy, during pregnancy but not after birth, and both before and after birth. The researchers found that children of smoking parents had significantly reduced lung function similar to that seen in smokers. Smoking after birth appeared to be more harmful than smoking during pregnancy alone. The researchers have now expanded their study to include 2,000 healthy children of smokers.

Dr. Arets speculated that in the future, the growing number of smoking bans in public places might cause parents to smoke more in their own homes, thereby increasing the harm to the developing lungs of children. "We may see an increase in diminished lung function in children of smokers because of this trend," he said.