Lung cancer photo

Lung cancer's gassy ally

Radon gas seeps into 4 to 8 million homes across the U.S., rising through the foundations from underlying soil and rock and mixing with inside air. The radioactive gas is odorless, colorless --and a cause of lung cancer. But how big a cause? Last week, a National Academy of Sciences report made possible the most authoritative answer yet.

The study's chief, Dr. Jacob Fabrikant of the University of California at Berkeley, calculated how exposure to levels of radon considered worrisome by the Environmental Protection Agency affects the odds of contracting lung cancer. His basic finding: Spending 12 hours a day in a house with excess radon boosts a person's cancer risk by about 50 percent.

Of 1,000 male nonsmokers exposed to excess radon, 16 will die of lung cancer, he estimates. That's 5 more than in a nonexposed group. Among 1,000 female nonsmokers, radon exposure ups lung-cancer deaths from 6 to 9. The statistics are much grimmer for smokers: Some 172 out of 1,000 male smokers exposed to excess radon will die of lung cancer--49 more than among nonexposed male smokers. For women smokers, radon pushes the toll from 60 to about 85.

Why radon and smoking are more lethal to men than to women is unknown. Why is radon more lethal to smokers? That, too, is not known. Some experts think smoke-damaged lungs trap the radioactive radon particles.

Homes with serious radon problems can be fixed by sealing cracks to prevent seepage and by improving ventilation. The EPA's Office of Public Affairs offers information booklets and a list of radon-detection companies. Now awaiting action in the House is a bill passed unanimously by the Senate last year that would provide $33 million to the states for radon education and pilot programs.

Photo: Areas of potentially high radon levels