LANSING -- Radon gas is the second-leading cause of lung cancer -- after cigarette smoking -- in the United States, and state and Crawford County health officials are using the winter months as a time to educate those who are at risk.

"It's important that everybody test their houses," said Sue Hendershott, the indoor radon specialist for the Michigan Department of Environmental Quality.

The decomposition of uranium in certain kinds of soil leads to the release of radon, a radioactive gas.

"It really has to do with the glacial shift and how much of that rock is near the surface," said Jane Schneider, a health educator for the health district that covers 10 counties including Crawford County.

Radon is also undetectable to human senses, and there are no symptoms associated with breathing it in, aside from cancer.Hendershott said, "It increases your risk of lung cancer, and the bad thing is that it doesn't give you a warning."

The American Lung Association estimates that radon causes up to 22,000 lung cancer deaths each year in the United States, and it accounts for 12 percent of all cancer- related deaths.

According to the U.S. Environmental Protection Agency (EPA), the average Michigan indoor radon level is twice as high as the U.S. average.

"Approximately one in eight homes in Michigan have a higher radon level than the action standard set by the EPA," Hendershott said."All existing homes need to be tested."

The "action standard" she is refers to is 4 picocuries, a measurement of gas levels.Homeowners can test their radon levels with kits sold or given away by state and county health departments.

Most of the areas identified as high risk in Michigan are in the southern part of the state, including Hillsdale, Washtenaw and Lenawee Counties. But areas in northern Michigan and the Upper Peninsula have to worry, too.

"It is estimated that hundreds of homes in Crawford County and surrounding area have elevated radon levels," said a report by the Air Quality Control Agency.

The county health department uses January, designated as National Radon Action Month by the EPA, to educate its residents on the dangers of radon.

Schneider said, "The health department provides testing kits free for the month of January, but the kits are only $5 normally."

She warned that every home is at-risk no matter how it is built. "There's a real myth out there that if you don't have a basement there's no possibility of radon poisoning."

Radon can actually be a problem in any building, from schools to office buildings. But there are ways to ensure that radon will not be a problem after it is discovered.

"If radon is found in a home, it's a fairly easy fix," Schneider said.

To rid a house of high radon levels, a ventilation system can be installed in the basement, and cracks in the foundation wall can be sealed.

New homes can be built so they will never have a radon problem.

A ventilation system is built in from the basement to roof during the construction of a new house. If done early, the system cost is minimal -- between $350 and $500.

Hendershott said, "It will be a problem until all homes are built with radon-resistant construction."

© 2003, Capital News Service, Michigan State University School of Journalism