Long-term exposure to lung irritants such as industrial dust
and chemical fumes.
Preterm birth that leads to lung damage (neonatal chronic lung disease).
Inherited factors (genes),
alpha-1 antitrypsin deficiency. This is a rare condition in
which your body may not be able to make enough of a protein (alpha-1 antitrypsin) that
helps protect the lungs from damage. People who have this disorder and who smoke
generally start to have symptoms of emphysema in their 30s or 40s. Those who
have this disorder but don't smoke generally start to have symptoms in their