Smokers benefit from mountain air.

• Position: Your Life

Here is another potential reason to live up in the mountains: lung cancer rates in both smokers and nonsmokers are lower in higher-elevation counties in the western part of the U.S., suggesting that oxygen may promote the incidence of lung cancer, according to a study coauthored by a student at the University of Pennsylvania School of Medicine, Philadelphia.

While lung cancer primarily afflicts smokers, 10% to 15% of cases arise in nonsmokers and more than 80% of smokers never develop lung cancer.

Controlling for smoking, education, and numerous other variables associated with higher rates of cancer, the study has found that, for every 1,000-meter rise in elevation, lung cancer incidence in the population living in that area decreases by 7.23 cases per 100,000 individuals. (The 260 counties in 11 states studied have a median lung cancer rate of 56.8 cases per 100,000 people.) The researchers did not find similar pronounced effects for elevation on colorectal, breast, or prostate cancer, all of which also are prevalent in the U.S.

Previous studies have pointed to an inverse relationship between elevation and lung cancer rates, and more recent findings have raised the...