Second hand smoke & emphysema risk
Children exposed to second hand smoke face a higher risk of early emphysema when they become nonsmoking adults, because their 
lungs might not recover totally from secondhand smoke exposure.
Emphysema is a long-term, progressive disease of the lungs that primarily causes shortness of breath. To judge the hypothesis that mechanical stress to alveolar walls may cause progressive damage after an early-life exposure to environmental tobacco smoke, researchers conducted chest CT scans on 1,781 non-smokers (aged between 45 and 85 years) from six communities in the United States. About half of them grew up in homes with at least one smoker.
Differences were found on CT scans between the lungs of participants who lived with a smoker as a child and those who did not. Childhood environmental smoke exposure was associated with 2.8 higher risk of early emphysema.
Some known harmful effects of tobacco smoke are short-term, and the above findings suggests that effects of tobacco smoke on the lungs may also persist for decades.
The researchers didn’t find a link between childhood exposure to tobacco smoke and lung function. However, emphysema may be a more sensitive measure of damage compared with lung function in this relatively healthy cohort.
