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About Radon

Radon is a radioactive gas that cannot be seen, smelled or tasted. Radon gas is a natural substance that can be found in the dirt and rocks beneath houses, in well water and in some building materials. It can enter homes through soil, crawlspaces, foundation cracks, floors and walls. Once inside, it can sometimes become trapped in [Photo: radioactive sign]your home. All homes have some radon gas. Breathing high levels of radon can put you at risk for lung cancer. To see if your house has dangerous levels of radon, you should test it.

Radon is measured in picoCuries per liter of air (pCi/L). Radon levels inside houses below 4 pCi/L are considered acceptable. If your home has radon levels above 4 pCi/L, you should take action.

What can you do?

Test your home:


  • Use a 2-day test kit or 90-day test kit (90-day test kits take longer but the results are more accurate).
  • Follow test kit instructions closely.
  • You may also hire a professional to test for radon for you (Contact your state's radon office for a list of qualified testers).
Fix your home if you have unacceptable levels of radon: Hire a professional contractor.
  • Contact your state's radon office for guidance and assistance if you are thinking about fixing your radon problem yourself.
  • Re-test your home after repairs to make sure the problem was fixed.

Follow these additional tips:


  • Do not smoke in your house. Smoking increases the risk of lung cancer from radon.
  • Keep your home ventilated by opening windows and using fans and vents to circulate air. (This will only temporarily reduce radon levels.)
  • Seal cracks in floors and wall with plaster, caulk or other crack sealants.
  • You can cover the earth floor in crawl spaces with a high-density plastic sheet. A vent pipe and fan can be used to blow the radon from under the sheet and vent it to the outdoors

Whom can you call?

Indoor Air Quality Information Clearinghouse (to find a state radon contact) 1-800-438-4318

National Radon Hotline (to order a radon test kit) 1-800-767-7236

National Safety Council/EPA Radon Hotline (for questions about radon) 1-800-557-2366

Radon Fix-It Hotline 1-800-644-6999

Spanish Language Radon Hotline 1-800-725-8312