General Radon Information

Montana specific radon and radon level information can be found throughout this site. You will be able to find information about certified radon inspectors in Montana, as well as detailed radon level information for every county in Montana.

Radon is a radioactive gas that comes from the soil. Radon usually does not present a health risk outdoors because it is diluted in the open air. Radon can, however, build up to dangerous levels inside a house. Exposure to radon gas it the second-leading cause of lung cancer (after smoking) in the United States. About 14,000 people die each year from radon-related lung cancer.

Radon is produced from the natural breakdown of the uranium found in most rocks and soils. As it further breaks down, radon emits atomic particles. These particles are in the air we breathe. Once inhaled, they can be deposited in our lungs. The energy associated with these particles can alter cell DNA, thus increasing the risk of lung cancer.

In 1997, Mike Vogel, Montana State University Extension housing specialist conducted a study for the Montana Department of Environmental Quality in cooperation with the American Lung Association of Montana. It followed a 1992 study of 830 homes that had found 40 percent of Montana homes with high radon.

Sam Sperry of the Montana Vital Statistics Bureau says that Montanans have about 55.2 lung cancer deaths per 100,000 people compared to 67.5 per 100,000 average throughout the United States. The national average background level of radon in outdoor air is between 0.2 and 0.7 picoCuries per liter (pCi/L). For indoor air, the national average is 1.3 pCi/L, but in Montana the average is 5.9 pCi/L.

Nationally, research indicates that lung cancer due to radon may cause about 15,000 deaths per year. Most lung cancer risk is associated with smoking tobacco, says Vogel, but most studies show that the risk of lung cancer from smoking increases more than 25 percent for a person who lives in a radon environment.

Cigarette smokers should keep their exposure to radon as low as possible. Smokers have eight times the risk from radon as non-smokers. People with young children should be more concerned with the possible consequences of radon exposure 20 years from now than someone in their late sixties or seventies. Families with a hereditary predisposition of cancer should be more concerned about radon exposure than families who don't have any history of cancer.

No level of radon is considered absolutely safe. However, the radon levels in a home should be reduced as much as possible. The amount of radon in the air is measured in picoCuries per Liter of air, or pCi/L. The EPA recommends fixing your home if the results of one long-term test or the average of two short-term tests taken in the lowest lived-in area of the home show radon levels of 4 pCi/L or higher. The higher the radon level, the more quickly you should have your home fixed.

Basically all counties in Montana have a high percentage of homes with over the EPA "action level" of radon. County comparisons of radon levels from this study are not appropriate, says Vogel, because of differences in the number of homes studied in each county. Some counties had as few as one test done and others had as many as 2,000 tests.

"Virtually all Montana counties with over 150 tests had between 28 and 65 percent of those tests show more radon than the EPA action level," says Vogel.

Montana law based on EPA guidelines requires a disclosure clause in a home buy-sell agreement that describes radon and the fact that some Montana buildings have radon levels higher than EPA guidelines. Because of that, potential home buyers often ask about the radon level, though radon testing is not mandatory.

"You won't know whether your home has radon until you test," says Vogel. "Houses side-by-side have been tested that have radically different radon levels." Minimizing the radon concentration generally involves pulling the air from under the foundation where radon can accumulate above the soil, and venting it outside. This design is also used for crawl-space radon correction.

There are two type of kits that can be purchased. The first is a short-term test kit (2-7 days) and the other is a long-term test kit (3 12 months). If a short-term test is used, you should consider running a second test later and the two tests averaged to obtain a more accurate reading.

Fortunately, there are extremely effective means of keeping radon out of your home. Qualified contractors can typically mitigate radon problems for a cost similar to that for may common home repairs such as painting or having a new water heater installed - anywhere from $800 to $2,500.