Secondhand smoke shown to damage lungs

In collaboration with the Press Association

A new study has provided more evidence that secondhand tobacco smoke causes lung damage.

Cigarette smoke has long been known to damage the lungs of smokers, but now researchers have been able to detect microscopic lung injury in non-smokers.

Study leader Dr Chengbo Wang, magnetic resonance physicist in the Children's Hospital of Philadelphia's radiology department, said: "It's long been hypothesised that prolonged exposure to secondhand smoke may cause physical damage to the lungs, but previous methods of analysing lung changes were not sensitive enough to detect it.

"With this technique, we are able to assess lung structure on a microscopic level."

The researchers used magnetic resonance imaging (MRI) to create images of the lungs of 60 adults between the ages of 41 and 79, 45 of whom had never smoked.

The non-smokers were divided into two groups - high exposure (consisting of individuals who had lived with a smoker for at least ten years) and low exposure.

The results showed that one in three of the non-smokers with high exposure to secondhand cigarette smoke had developed structural changes in the lungs.

Dr Wang said: "We interpreted those changes as early signs of lung damage, representing very mild forms of emphysema.

"These findings suggest that breathing secondhand smoke can injure your lungs."

It is hoped that the findings, which were presented at the annual meeting of the Radiological Society of North America in Chicago, will strengthen efforts to restrict exposure to secondhand smoke.

Dr Julie Sharp, Cancer Research UK's science information manager, said: "This research means that scientists can now reveal the lung damage caused by passive smoking in minute detail.

"We know that breathing in secondhand smoke can lead to cancer and other diseases - these results underline just how important smoke-free legislation is for protecting the health of non-smokers."