Children who are regularly exposed to tobacco smoke appear to be at increased risk of developing early emphysema later in life, according to new research.

This finding "suggests that a child's lungs may not recover completely from early tobacco smoke exposure, even if they never smoke themselves. I was surprised that we could detect a difference so many years later," lead researcher Dr. Gina Lovasi, from Columbia University, New York, told Reuters Health.

Environmental tobacco smoke (ETS) is known to be associated with a variety of serious health problems, but it had not previously been associated with the development of emphysema over the life course, according to study results presented Tuesday at the international conference of the American Thoracic Society in San Diego, California.

Although other studies have looked at the long-term effects of early tobacco smoke exposure, the present study "is the first to use CT scans from a large sample of relatively healthy adults to look for emphysema-like patterns and to link those with childhood tobacco smoke exposure," Lovasi explained.

She and colleagues analyzed data form a diverse group of 3964 adults, around 60 years of age, focusing on 1781 adults who never smoked. They asked them whether they ever live with a regular cigarette smoker who smoked in your home.

The results showed that adults who had lived with a regular smoker as a child were much more likely to have evidence on CT scans of early emphysema than their peers without this history.

"From other studies, we already know that tobacco smoke has a range of negative health effects for adults and children," Lovasi said. "What our study adds is that damage done in childhood could persist for decades, or even get worse over time. Yet our study is still too preliminary to offer a clear message to the practicing clinician or the general public."