Radon Testing: Do You Need It?

Whether you live in a newly constructed home or you just bought a home built some years ago, the U.S. Environmental Protection Agency (EPA) recommends periodic radon testing.  This usually happens during a sale or purchase of a home, but you can always have tests performed or purchase a kit and do it yourself at any time.  We’ve included information directly from the EPA below, to help you answer the question: Does my home need to be tested for radon?  You’ll see helpful links throughout the post that will connect you with state radon offices, provide in depth reports about radon and risk assessments, as well as information about radon in water.  You can opt to complete testing on your own, by purchasing a test kit at your local hardware store, or by visiting this site (provided by the EPA website), where you can order online: http://sosradon.org/test-kits .

The EPA updated its estimate of the lung cancer risks from exposure to radon in indoor air. “EPA Assessment of Risks from Radon in Homes” [EPA 402-R-3-003]. was based on the National Academy of Sciences’ (NAS) report on the “Health Effects of Exposure to Radon” (BEIR VI, 1999). The Agency now estimates that there are about 21,000 annual radon-related lung cancer deaths, an estimate consistent with the NAS Report’s findings. Download the risk assessment (PDF, 98 pp., 526 K).  This Guide answers important questions about radon and lung cancer risk. It also answers questions about testing and fixing for anyone buying or selling a home.

What is Radon?

Radon is a cancer-causing, radioactive gas. You cannot see, smell, or taste radon. But it still may be a problem in your home. When you breathe air containing radon, you increase your risk of getting lung cancer. In fact, the Surgeon General of the United States has warned that radon is the second leading cause of lung cancer in the United States today. If you smoke and your home has high radon levels, your risk of lung cancer is especially high.

  • If you are buying a home or selling your home, have it tested for radon.
  • For a new home, ask if radon-resistant construction features were used and if the home has been tested.
  • Fix the home if the radon level is 4 picocuries per liter, or pCi/L,  or higher.
  • Radon levels less than 4 pCi/L still pose a risk, and in many cases, may be reduced.
  • Take steps to prevent device interference when conducting a radon test.

Radon is estimated to cause thousands of lung cancer deaths in the U.S. each year.

* Radon is estimated to cause about 21,000 lung cancer deaths per year, according to EPA’s 2003 Assessment of Risks from Radon in Homes (EPA 402-R-03-003). The numbers of deaths from other causes are taken from the Centers for Disease Control and Prevention’s 2005-2006 National Center for Injury Prevention and Control Report and 2006 National Safety Council Reports.



Testing for Radon

Testing is the only way to find out your home’s radon levels. EPA and the Surgeon General recommend testing all homes below the third floor for radon.

Fixing a Radon Problem

If you find that you have high radon levels, there are ways to fix a radon problem. Even very high levels can be reduced to acceptable levels.

If You Are Selling a Home…

EPA recommends that you test your home before putting it on the market and, if necessary, lower your radon levels. Save the test results and all information you have about steps that were taken to fix any problems. This could be a positive selling point.

If You Are Buying a Home…

  • EPA recommends that you know what the indoor radon level is in any home you consider buying. Ask the seller for their radon test results. If the home has a radon-reduction system, ask the seller for information they have about the system.
  • If the home has not yet been tested, you should have the housed tested.
  • If you are having a new home built, there are features that can be incorporated into your home during construction to reduce radon levels.
  • The radon testing guidelines in this Guide have been developed specifically to deal with the time-sensitive nature of home purchases and sales, and the potential for radon device interference. These guidelines are slightly different from the guidelines in other EPA publications which provide radon testing and reduction information for non-real estatesituations.

This Guide recommends three short-term testing options for real estate transactions. EPA also recommends testing a home in the lowest level which is suitable for occupancy, since a buyer may choose to live in a lower area of the home than that used by the seller.

1. Why Should You Test for Radon?

a. Radon Has Been Found In Homes All Over the U.S.

Radon is a radioactive gas that has been found in homes all over the United States. It comes from the natural breakdown of uranium in soil, rock and water and gets into the air you breathe. Radon typically moves up through the ground to the air above and into your home through cracks and other holes in the foundation. Radon can also enter your home through well water. Your home can trap radon inside.

Any home can have a radon problem. This means new and old homes, well-sealed and drafty homes, and homes with or without basements. In fact, you and your family are most likely to get your greatest radiation exposure at home. That is where you spend most of your time.

Nearly 1 out of every 15 homes in the United States is estimated to have an elevated radon level (4 pCi/L or more). Elevated levels of radon gas have been found in homes in your state. Contact your state radon office for information about radon in your area.

b. EPA and the Surgeon General Recommend That You Test Your Home

Testing is the only way to know if you and your family are at risk from radon. EPA and the Surgeon General recommend testing all homes below the third floor for radon.

You cannot predict radon levels based on state, local, and neighborhood radon measurements. Do not rely on radon test results taken in other homes in the neighborhood to estimate the radon level in your home. Homes which are next to each other can have different radon levels. Testing is the only way to find out what your home’s radon level is.  In some areas, companies may offer different types of radon service agreements. Some agreements let you pay a one-time fee that covers both testing and radon mitigation, if needed. Contact your state radon office to find out if these are available in your state.


 More helpful links and contact information if you need more details about radon and remediation.



MD State Certified labs for radon testing in well water: 1-800-426-4791 or 1-410-527-3712 (see above for other state radon offices)


Link to certified labs qualified to test for radon (you can inquire if the labs test well water): http://www.epa.gov/radon/radontest.html


Link to radon professionals who test for radon in air: http://www.epa.gov/radon/radontest.html


1-800-SOS-RADON (1-800-767-7236)*National Radon Hotline Purchase radon test kits by phone.


1-800-55RADON (1-800-557-2366)*National Radon Helpline Get live help for your radon questions.


1-800-644-6999*National Radon Fix-It Line For general information on fixing or reducing the radon level in your home.


1-800-426-4791Safe Drinking Water Hotline, operated under contract to EPA. For information on testing, treatment, radon in water, and drinking water standards.


*Operated by Kansas State University in partnership with EPA