(HealthDay News) -- Using a special type of magnetic resonance imaging (MRI), U.S. researchers have identified structural damage to the lungs caused by secondhand smoke.
This is the first study to produce evidence of such a link, they added.
"It's long been hypothesized that prolonged exposure to secondhand smoke may cause physical damage to the lungs, but previous methods of analyzing lung changes were not sensitive enough to detect it," Chengbo Wang, magnetic resonance physicist at The Children's Hospital of Philadelphia, said in a prepared statement.
Wang's team used long-time-scale, global helium-3 diffusion MRI to study the lungs of seven current and former smokers and 36 people who'd never smoked. Of those 36 people, 18 had a high level of secondhand smoke exposure.
The results showed that 57 percent of smokers and 33 percent of the nonsmokers with high exposure to secondhand smoke appeared to have early signs of lung damage. In addition, 14 percent of smokers and 67 percent of nonsmokers with high exposure to secondhand smoke showed evidence of developing respiratory problems such as asthma or chronic bronchitis.
"These findings suggest that breathing secondhand smoke can injure your lungs," Wang said.
"Since legislation to limit public exposure to secondhand smoke is still being considered in many states, we hope that our work can be used to add momentum to the drive to pass such legislation."
The study was slated to be presented Monday at the Radiological Society of North America annual meeting, in Chicago.
The American Cancer Society has more about secondhand smoke.