LANSING -- Radon gas is the second-leading cause of lung cancer -- after cigarette smoking -- in the United States, and state and Upper Peninsula 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 that is undetectable to human senses. "It increases your risk of lung cancer, and the bad thing is that it doesn't give you a warning," Hendershott said.

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 has 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 UP have cause to worry, too.

"The highest radon level ever documented in Michigan is in Marquette County," Hendershott said. The house, located in Republic, tested at about 100 times the recommended EPA action level.

Health departments in Delta and Marquette counties use January -- National Radon Action Month as designated by the EPA -- to educate their residents on the dangers of radon and to provide testing kits.

"We have radon test kits that are available for sale and now we're working on a project with the local school districts." Said Dianne Mathews, the director of environmental health for the Delta County Public Health Department.

The health department gives local students kits to test their homes and analyze the results to determine what areas in the county have the highest radon levels and what percentage of houses have elevated radon levels.

"We don't have a large number of recent test results," Mathews said. "But according to our data, 14 percent of houses in Delta County are above the EPA guideline and 6 percent in Menominee County."

Despite the contaminated house in Republic, Marquette County is a low-risk zone, according to the EPA, but that doesn't keep health officials from being cautious.

"We did over 70 tests in Marquette, free of charge," said Fred Benzie, the county's environmental health director.

"The federal government gives money to the state for testing and promoting awareness," said Benzie. "We got $13,500, and we spent $8,000 in December alone."

The county administers the tests because it makes the results more reliable. "You really have no quality assurance control unless you do it yourself," Benzie said.

Once testing confirms that radon is a problem in a home, there are few options to consider. "The recommendation is that if the first measurement comes back above 4 picocuries, they test again," Benzie 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. "Radon-resistant construction is a smart thing people can do to avoid radon," said Benzie.

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