January is National Radon Action Month.


MARSHFIELD, Mo.– While you wait for the spring thaw, consider testing your home for harmful radon gas, says Bob Schultheis, a University of Missouri Extension natural resource engineering specialist.

Radon is a naturally occurring gas produced by the breakdown of radium and uranium in rocks and soils. Long-term exposure to high levels of radon is the second-leading cause of lung cancer, and the leading cause among nonsmokers. Radon enters the home through cracks and openings in floors and walls, and through floor drains and sumps. Energy-efficient or poorly ventilated homes are more likely to have higher radon levels, Schultheis noted.

“Testing in Missouri has shown that all counties have radon, and 18 percent of all homes have radon levels above the level considered dangerous,” he said.

The radon levels can vary greatly from one home to the next, so the Environmental Protection Agency recommends all homes be tested for radon.

Winter is a good time for testing because doors and windows need to be kept closed as much as possible during a radon test.

Missouri residents can get a free radon test kit from the Missouri Department of Health and Senior Services (www.health.mo.gov/living/environment/radon/testkit.php). Low-cost kits are also available from hardware stores and home improvement centers. These test kits are typically placed in the lowest lived-in level of the house for two to seven days, and then mailed to a lab for analysis. Depending on the lab, you might receive test results by mail or access them online.

While there is no level of radon that is considered absolutely “safe,” the EPA has set an “action level” of 4 picocuries per liter of air (“curie” is a unit of measure for radioactivity). If your house tests at 4 pCi/L or higher, EPA recommends a second, long-term test—three to 12 months—to verify the initial results.

If you decide you need to take action on radon in your house, take the time to carefully evaluate your options, Schultheis said. The dangers of radon come from long-term exposure—years, even decades.

Sometimes fixing the problem may be as simple as sealing cracks in the foundation, he said. In other cases, reducing radon to acceptable levels might involve installing a system that uses a vent pipe and fan to pull radon from under the foundation and vent it through the roof.

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