Radon

What is Radon?

Radon is an invisible, odorless radioactive gas. It forms when uranium in soil breaks down naturally. Radon is everywhere, and Colorado has higher levels than other regions.

Radon enters homes through cracks and openings in basements, crawl spaces and slabs. Radon levels vary from house to house. They depend on the age, quality and upkeep of the home, along with other factors.

Watch 'What is Radon?' Video

This webpage is not intended to be a source of medical or legal advice. For medical matters, please contact a medical professional. For legal matters, please contact a licensed attorney.

Health Risks of Radon

When you breathe radon, it breaks down into radioactive particles that damage your lungs and can cause cancer. Radon is a class 'A' carcinogen. This means there is enough human data to show it causes cancer in people.

Your chances of getting radon-induced lung cancer depend on:

• How much radon is in your home
• How long you are exposed to it
• Whether you smoke

Long-term radon exposure is the leading cause of lung cancer in non-smokers. About 21,000 people in the U.S. die each year from radon-induced lung cancer.

Testing for Radon

There are three types of radon tests:

1. Short-term tests run three-seven days. They need closed-house conditions during the test. These kits give a quick snapshot of radon levels and show if you need more testing.
2. Long-term test kits run 90 days to a year. You use them with normal living conditions. These tests show radon levels in your home over time.
3. Continuous radon monitors are electronic devices that check radon levels all the time. They run constantly but need to be checked and adjusted regularly.

The City of Fort Collins sells discounted radon test kits at the Fort Collins Senior Center, 1200 Raintree Drive:

• Short-term kits: $6
• Long-term kits: $20

Fort Collins residents can get a free short-term test kit through the Healthy Homes program.

If you live outside city limits, order a test kit from the Colorado Department of Public Health and Environment (CDPHE).

Short-term test kits are time sensitive. Mail them immediately after sealing. If you don't follow instructions, the lab may reject your results. Read and follow all instructions carefully.

Watch our how-to video to conduct your short-term test correctly.

Radon Testing Tutorial (English)

Tutorial sobre la prueba del radón

Radon Mitigation

The EPA recommends fixing radon levels of 4 pCi/L or higher (pCi/L = picoCuries per liter of air). About half of all Fort Collins homes tested have radon at this level. Levels below 4 pCi/L still pose a risk and can usually be reduced. The target level for radon systems is 2 pCi/L.

Fixing radon involves sealing basements or crawlspaces, then installing a system. A passive system vents radon through a pipe from soil to roof. It works like a chimney to create suction from on the soil. An active system adds a fan to the passive system to pull radon from soil.

The National Radon Proficiency Program keeps a list of certified radon professionals in Colorado. The City recommends consulting them for any radon project.

Find a Certified Radon Professional 

The CDPHE Low Income Radon Mitigation Assistance program provides financial help for radon fixes. You must be a Colorado resident, live in the property as your main home and qualify as low-income.

Radon in Real Estate and Rentals

Colorado law requires home sellers to tell buyers if they know the radon levels in their home. They use the Sellers Property Disclosure form.

Colorado also requires sellers to give buyers the Radon in Real Estate & Rental Transactions brochure published by CDPHE.