NEW YORK (CNN) January 4, 1999 -- A new study into the effects of radon gas
suggests its cause-and-effect relationship with lung cancer may be
overestimated.
Unlike dioxin and other natural pollutants, radon gas is released naturally
into the environment when weak radioactive elements of rock and soil break
down into minuscule airborne particles, which often seep into homes.
"These particles can damage the cells in the lining of our lungs and
produce lung cancer," said Dr. David Brenner of Columbia University.
The Environmental Protection Agency has estimated that radon leads to
20,000 lung cancer deaths each year. But scientists are still uncertain how
much radon over how long a period causes cancer.
For years, much of the data available for making such estimates was based
on information collected from uranium miners, who spent far more time
underground and were exposed to much more radon than most people.
Effects less than expected
When Brenner and his colleagues at Columbia bombarded mouse cells with
low-dose radon, their results differed from earlier studies.
"This is the first time anyone has been able to look at the cancer risk
associated with single alpha particles going through cells, and what we saw
was the effects were in fact rather less than expected," said Dr. Brenner.
The Columbia University study will be published in the upcoming journal of
the Proceedings of the National Academy of Sciences.
Although more studies are needed, Brenner and other scientists believe the
EPA estimate of 20,000 deaths each year is too high.
"Its probably lower than that, but I doubt very much it's zero," Brenner
said. "It's a large number of Americans dying each year."
The EPA estimates 6 million U.S. homes have high levels of radon. Although
there are no laws regulating radon, the EPA suggests people test their
homes regularly and get rid of the harmful gas if the level reaches four or
above on a special scale.
"The best thing we can do is check our homes," said radon expert Terry
Howell. "It's very cost-effective and imposes no particular hardship on
anyone during the test process."
If a high level of radon is discovered, installing a specialized vent and
fan for less than $1,500 is usually all it takes to reduce the gas, Howell
said.
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John O. Erickson
john.erickson@hhss.state.ne.us