Another Study Links Secondhand Smoke to Lung Cancer

Long-term exposure to smoke increases lung cancer risk by as much as 32%

Parts excerpted from Reuters

NEW YORK, Dec 10 - Although it can hardly be considered news, a new study from Europe finds that people exposed to tobacco smoke pollution are much more likely to develop lung cancer than others.  The study was published in the December 10th issue of the International Journal of Cancer.

The findings are based on an analysis of data from 1,263 lung cancer patients who never smoked and 2,740 control subjects. The analysis focused on smoke exposure from three sources: spousal, workplace, and social settings.

People who were exposed short-term to spousal smoking were 18% more likely to develop lung cancer than people who were not exposed, noted lead author Dr. Paul Brennan, from the International Agency for Research on Cancer.  With long-term exposure to spousal smoking the excess risk was 23%.

People who were exposed short-term to smoke in the workplace had a 13% increased risk of lung cancer, the researchers state. Once again, with long-term exposure, the excess risk was higher, at 25%.

People who were exposed short-term to smoke in social settings had a 17% increased risk of lung cancer. With long-term exposure, this risk rose to 26%.

As expected, the greatest cancer risks were seen in subjects exposed to smoke from multiple sources.  For example, people with long-term exposure to smoke from all three sources were 32% more likely to develop lung cancer than non-exposed individuals.

Sensitivity analysis revealed that, if anything, the researchers' figures may underestimate the true risk associated with passive smoke exposure.

"Our pooled analysis provides more precise estimates of the effect of secondhand smoke on lung cancer risk than those previously obtained in individual studies and emphasizes the importance of protecting people from tobacco smoke," the investigators state.