By Suzanne Rostler
NEW YORK, May 25 (Reuters Health) - Long-term exposure to radon, a naturally
occurring radioactive gas, can increase the risk of lung cancer, researchers
report.
Their study in the June 1 issue of the American Journal of Epidemiology
investigated exposure to radon in the homes of more than 400 women in Iowa who
were diagnosed with lung cancer and more than 600 women of the same age who did
not have lung cancer.
The women studied ranged in age from 40 years to 84 years and had all lived
in their home for at least 20 years. The study targeted women because they tend
to have less occupational exposure to radon, which is produced by the breakdown
of uranium in soil.
Researchers obtained radon readings by placing an average of 4 detectors
throughout people's homes.
Results show that average radon concentrations in basements were similar for
women with and without lung cancer. Nearly 60% of radon concentrations taken
from the basements of homes of both groups exceeded US Environmental Protection
Agency (EPA) recommendations of 4 picoCuries per liter, investigators found.
Further, a third of the first- and second-story living areas of lung cancer
patients and about 28% of these areas for other women exceeded recommended radon
levels.
But women who were diagnosed with lung cancer spent more time in areas of
their home with high concentrations of the gas.
"Overall, these results suggest that cumulative radon exposure is a
significant risk factor for lung cancer in women," conclude Dr. R. William Field
with the University of Iowa in Iowa City, and colleagues with St. John's
University in Collegeville, Minnesota and the University of Kansas in Kansas
City.
While he acknowledged that cigarette smoking causes the vast majority of
lung cancer deaths--more than 80% according to the American Cancer Society--he
stressed that radon continues to pose a significant environmental hazard.
In an interview with Reuters Health, Kristy Miller, a spokesperson for the
EPA, said it may not be possible to lower radon levels in the home below current
recommendations.
"We don't believe there is a magic number on radon where it is safe at a
certain level. We feel 4 (picoCuries per liter) is the best we can do," she
said.
Radon concentrations depend on how a home was built and the part of the
country in which a person lives, Miller explained. According to the study's
authors, Iowa has the highest concentrations of radon in the US due to glacial
deposits that occurred more than 10,000 years ago.
Concerned homeowners can have a contractor measure radon concentrations,
seal any cracks in the floor, particularly in the basement, and make sure the
home is well ventilated. Drain openings, which can allow radon to leak into a
home, should also be closed.
