Attention, non-smoking women married to smokers:
A new study, the largest of its type, found that living with a smoker significantly raised the risk of lung cancer in women who had never smoked.
Never-smokers married to smokers were 50 percent more likely to develop adenocarcinoma of the lung, the most common lung cancer in women. These women were also 30 percent more likely to develop other forms of lung cancer, according to the study.
The longer women lived with smokers, the greater their risk of developing lung cancer, the study found. Forty years with a two-pack-a-day smoker increased never-smokers' risk of developing lung adenocarcinoma by 70 percent.
The new research, published in the current issue of "Cancer Epidemiology, Biomarkers & Prevention" is the latest in a series of studies suggesting that other people's smoking can be harmful to non-smokers.
About 4 percent of women who develop lung cancer have never smoked, said Dr. Elizabeth Fontham, lead author of the new study.
"That's a good number of deaths that could be prevented by eliminating the exposure [to passive smoking], which isn't that difficult to do," said Fontham, associate professor of pathology at Louisiana State University Medical Center in New Orleans.
Previous passive-smoking studies have found a range of effects on non-smokers, from no detectable increase in lung cancer risk to a doubling of risk.
Fontham said the size and design of her study helped ensure that its findings are not a coincidence or a product of faulty data.
The study included 420 women from five cities. None of them had ever smoked.