A new study has found that children of smokers who don't show any signs of respiratory problems may still be experiencing damaging changes in their airways that could lead to lung disease later in life.
The study was conducted by a team of researchers led by Bert Arets at University Medical Centre Utrecht in the Netherlands.
As part of the study, researchers analysed 244 children ages 4 to 12 without any history of lung or airway disease.
The children were divided into four groups according to the smoking pattern of their parents - never smokers, smoking after birth but not during pregnancy, smoking during pregnancy but not after birth, and smoking both before and after birth.
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.
"Everyone knows that children of smokers have more respiratory problemsómore puffing, wheezing, cases of pneumoniaóbut until now we haven't known if lung function is impaired in children of smokers who don't have any respiratory complaints or diagnosed lung problems," Arets said.
The researchers have now expanded their study to include 2,000 healthy children of smokers.
Researchers 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," Arets said.