Radon, the cancer-causing gas

Radon is a cancer-causing radioactive gas. You can’t see, smell, or taste radon. But it may be a problem in your home. Studies performed at the University of Iowa have helped show that radon is the second leading cause of lung cancer and the leading environmental cause of cancer deaths in the United States. And Iowans are most at risk.

Home Radon Testing

Where does radon come from?

Radon gas is a radioactive gas that comes from the breakdown of naturally occurring radium-226 found in soils and rocks that surround the foundations of our homes and offices. Iowa has the highest average indoor radon concentration in the nation due to our glacial history. As the glaciers came over Iowa, they deposited finely ground rocks that contain radium. Because the rocks that make up our soils are so finely ground, they have a large surface area to emit radon gas.

Since the highest average radon concentrations are found in Iowa, Iowans are at even greater risk of radon-induced lung cancer compared to most Americans. In fact, about 400 Iowans die each year from radon exposure.

How does radon get into our homes?

Radon gas can enter even through small cracks in the foundation or openings in the foundation of homes like sump pumps or spaces around pipes. For some individuals with wells, radon in the well water can enter the home and become airborne during showering or dishwashing. The amount of radon from groundwater is generally small compared to the amount of radon that comes from the soil.

Why should you be concerned about radon?

  • People who breathe in high amounts of radon are at risk of lung cancer.
  • Iowa has the highest average radon concentrations in the U.S. The Environmental Protection Agency provides information on radon levels in other states.
  • Radon is most dangerous when it is trapped in an area with low ventilation, such as a home.

Who should test their home for radon?

Everyone should test their homes for radon, especially in Iowa where we have the highest average radon concentrations in the nation. And you can’t really predict the levels in your home based on your neighbor’s levels. Even if two homes on a street have low radon concentrations, the home between them may exhibit high concentrations. The only way to know is to test.

How can I test my home for radon?

Radon test kits can be purchased from a variety of local stores, including hardware stores or large discount stores.

Short-term radon test

One type of detector is known as a short-term test; it's usually placed for a few days to a week. Or, longer-term testing can be done for three months to a year. In the United States, more short-term tests are purchased since they provide a rapid indication of whether a home has the potential for elevated radon levels. Radon testing can also be performed by certified professionals. Regardless of who performs the testing, it should be done following EPA recommendations.

If we find high levels of radon in our home, what can we do?

If the test results indicate radon levels at or above 4 pCi/L (picocuries per liter), the EPA recommends doing a second test to confirm the initial findings. If the average of the two short-term radon tests is 4 pCi/L or greater, homeowners can take steps to reduce the radon concentration. The EPA notes that since there is no safe level of radon gas exposure, reducing radon to below 2 pCi/L also helps reduce the number of radon-related lung cancers.

Can homeowners or business owners take steps to reduce the radon concentrations themselves?

Usually it takes the assistance of a radon mitigation specialist to significantly reduce the radon concentrations long-term. Radon can be removed from homes or offices by installing a radon mitigation system, which vents the radon before it enters the building. Elevated radon levels in most homes and offices can be reduced to below 2 pCi/L by a radon mitigation system.

Radon mitigation systems

The cost of a typical radon mitigation system runs between $900 to $1,400.  Fortunately, radon reduction costs often are an eligible expense covered under a health flexible spending arrangement (FSA) if a homeowner has such a plan through their workplace. A list of certified radon testers and mitigators can be obtained from the Iowa Department of Public Health by calling their toll-free number at 1-800-383-5992.

Additional resource recommended by the EPA and created at the University of Iowa

Last reviewed: 
March 2018

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