Radon test kit

From Correspondent Dan Rutz

NEW YORK (CNN) -- 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.