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Radon is an odorless, radioactive gas that results from the natural decay of uranium. Uranium is found in rock, soil, and water across the world. Radon typically moves up through the ground to the air above and into your home through cracks and other holes in your home’s foundation.

Radon gas decays into radioactive particles that can get trapped in your lungs when you breathe. As they break down, these particles release small bursts of energy that can damage lung tissue and lead to lung cancer. Radon is a Class A carcinogen meaning there is adequate human data to indicate that it causes cancer in people. 

Your chances of getting radon-induced lung cancer depend on how much radon is in your home, the amount of time you are exposed to it, and whether you are a smoker. Long-term radon exposure is the leading cause of lung cancer in non-smokers. There were an estimated 21,000 deaths in the U.S. last year due to radon-induced lung cancer.

Nearly 46% of all homes in Colorado are estimated to have elevated radon levels. The only way to know the radon level of your home is to test. It is inexpensive and takes only a few minutes of your time.

Webinar: "An Introduction to Radon Gas in Homes"
This webinar provides an overview of the key basic facts of radon - what it is, what it does to us, how we measure it, how we reduce our exposure, and resources for additional information.

Radon Testing

Testing Options

Short-term tests typically run from 3 to 7 days and require closed house conditions for the duration of the test. These kits work by capturing radon in charcoal which is then analyzed by the lab. These kits provide a quick snapshot of the radon present during the test and are usually a good indication of whether more comprehensive testing is needed. 

Long-term tests run from 90 days to a year and are conducted with the home under normal living conditions. These test kits typically are alpha track detectors which use a film that gets etched by alpha particles. The lab analyzes these kits by counting the number of alpha tracks. These tests give a more representative picture of the radon levels in a home over time.

Continuous or active radon monitors are electronic devices that integrate continuous radon measurements over time. They run constantly but usually require some type of periodic calibration. This is the type of test most commonly used by professional radon testers. The National Radon Proficiency Program (NRPP) maintains a list of certified radon professionals in Colorado that you can hire to test for you.

Kits Can Be Purchased At...

Most local hardware stores sell radon test kits.  You can also purchase kits online through the following suppliers:

Alpha Energy Laboratories
Air Chek

Hiring a Radon Measurement Contractor

Certified radon measurement contractors can be found at:  

As of July 1, 2022 all contractors conducting radon measurement and/or mitigation in Colorado must be licensed by the Colorado Department of Regulatory Agencies (DORA). Verify that the certified contractor you have selected is licensed by DORA.


Radon Mitigation

Reducing Radon

If your home has elevated levels of radon above the U.S. Environmental Protection Agency’s (EPA) recommended action level of 4.0 picocuries of radon per liter of air (pCi/L), then a radon reduction system (often referred to as a mitigation system) should be installed.

Fortunately, most mitigation systems cost no more than other common home repairs, ranging from $800 to $1,200.

The method of mitigation depends on the type of foundation your home has. Methods differ for basements, crawl spaces, engineered floors, slab on grade, or any combination of these foundations. 

Hiring a Radon Mitigation Contractor

As of July 1, 2022 all contractors conducting radon measurement and/or mitigation in Colorado must be licensed by the Colorado Department of Regulatory Agencies (DORA). Verify that the certified contractor you have selected is licensed by DORA.

When hiring a contractor:

  • Ensure the contract stipulates that the contractor will follow all EPA protocols regarding radon mitigation and will obtain all applicable local permits.
  • Consider using the EPA checklist for selecting a contractor.
  • Get bids from multiple contractors.
  • Obtain a guarantee that radon levels will be reduced to 4.0 pCi/L or below.
  • Ensure your contractor is bonded and has proof of liability insurance.


Installing a Mitigation System Yourself

If you decide to mitigate yourself, information about mitigation system installation and design is available in the manual Protecting Your Home from Radon, a Step-by-Step Manual for Radon Reduction by D. L. Kladder. It explains everything you need to know about fixing a radon problem in your home.

Financial Assistance for Mitigating Your Home

The Colorado Department of Public Health's Low Income Radon Mitigation Assistance (LIRMA) program can provide financial assistance to individuals with low-income status for radon mitigation. CDPHE can provide financial assistance up to $1,500 to individuals with low-income status for radon mitigation services. Homeowners must be a Colorado resident, occupy the property as their primary residence, and qualify as a low-income household. For more information, read the LIRMA Policy and Procedures Manual.(PDF, 520KB)