More Than Half of Larimer County Homes Exceed Radon Safety Levels; Free Tests Available
More than half of tested Larimer County homes exceed the EPA's radon safety threshold. In response, county health officials are distributing free test kits in January to help residents assess their risk from a naturally occurring gas linked to lung cancer even in non-smokers.
Larimer County Department of Health and Environment and CSU Extension are urging residents to test homes during January, Radon Action Month, and are offering free short-term radon test kits while supplies last.
Radon enters homes through small openings in foundations and crawl spaces. Prolonged radon exposure poses serious health risks. The gas is the second leading cause of lung cancer in the United States, resulting in approximately 500 annual lung cancer deaths in Colorado.
Of 18,512 radon tests conducted in Larimer County from 2005–2024, nearly 55 percent exceeded 4 picocuries per liter (pCi/L)—the EPA's action level. According to Colorado Environmental Public Health Tracking data, the county shows a median of 4.6 pCi/L and a maximum test result near 1,147 pCi/L.
"Testing is the only way to know if you and your family are at risk for serious health impacts," says Lea Schneider, environmental health planner and air quality manager for Larimer County Department of Health and Environment.
Free short-term test kits—with prepaid postage—are available at five Larimer County locations while supplies last:
- Larimer County Department of Health and Environment, Fort Collins (1525 Blue Spruce Drive, 2nd Floor)
- Larimer County Department of Health and Environment, Loveland (200 Peridot Avenue)
- Estes Park Town Hall (170 MacGregor Avenue)
- Red Feather Lakes Library (71 Firehouse Lane)
- Berthoud Community Library District (236 Welch Avenue)
Residents can also order kits online through the Larimer County CSU Extension website.
"Testing for radon during the winter provides the most accurate assessment of your home's safety. When windows and doors are sealed to retain heat, ventilation is restricted, allowing radon concentrations to peak. Additionally, frozen soil can block the gas from escaping outdoors, forcing it to seek an exit through your home. This is often intensified by the 'stack effect,' where rising warm air creates a vacuum that draws radon up into your living spaces," says Christa Timmerman, Larimer County CSU Extension Health and Wellbeing Specialist.
Homeowners with mitigation systems should retest every two years to confirm they're working. High radon levels can be effectively mitigated for the price of a typical home repair, and Colorado's low-income radon mitigation assistance program helps qualified households afford fixes.
For local radon data and resources, visit www.larimer.gov/radon.