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What You Need to Know About Radon

Read Time: 2 minutes

Update January 2023
Originally Published January 2018

Person holding up instructions for radon test

Radon is a radioactive gas that forms when uranium in the soil breaks down. It can enter homes and buildings, but you can’t see, taste, or smell it. Radon is the second leading cause of lung cancer, as breathing it in can damage the cells in the lungs.

The only way to know if your home has radon is by testing. Testing is easy and inexpensive.

How common is radon?

In the Mountain West, radon is very common. In Utah and Wyoming, about one in three homes have radon, and almost two in five homes in Idaho and Montana test for high levels of radon. Additionally, many counties in Nevada experience high levels of radon.

What are the health risks of radon?

If you have high levels of radon in your home, radioactive gas particles can get trapped in your lungs when you breathe. As these particles break down, they can damage your lungs. This damage can lead to lung cancer over time. The risk of developing lung cancer from radon depends on a number of variables:

  • How much radon is in your home?
  • How much time do you spend in your home?
  • Have you smoked or do you currently smoke?

How do I test for radon?

You can test for radon in your home. Test kits look for elevated levels of radon—four picocuries per liter of air (pCi/L) or higher. Remember, if you move, you should test your new home for radon and re-test your home every few years.

Testing is easy and inexpensive. Follow these three steps:

  • Buy or find a radon test kit. Helpful resources include or
  • Do the test. Follow the instructions, mail your test kit, and receive your results several weeks later.
  • Fix the problem, if necessary. if the test results show high radon levels, you may need to take action. This may include a second test or a process called mitigation.

For more information, visit the Environmental Protection Agency or the Cancer Learning Center.

Cancer touches all of us.