NOCO Spotlight
Colorado has some of the highest radon risks in the United States, and modern energy-efficient homes can raise additional concerns when ventilation is inadequate.
Radon is a health threat that cannot be seen, smelled, or tasted, and more Colorado homeowners are paying attention to it. The state is known for its mountain scenery and outdoor lifestyle, but its geology also creates an indoor air quality concern that homeowners should not overlook.
According to the Colorado Geological Survey, roughly half of Colorado homes have radon levels of concern. Radon is also the second leading cause of lung cancer in the United States, behind cigarette smoking. As new residential construction places more emphasis on energy efficiency and airtight building techniques, understanding how radon builds up inside a home matters more than ever.
Radon is easy to detect with simple testing, and proven mitigation systems can significantly reduce exposure.
What Is Radon, and Why Is It Dangerous?
Radon is a naturally occurring radioactive gas produced by the breakdown of uranium in soil, rock, and groundwater. As uranium decays, radon moves upward through the soil and can enter a home through small openings, including:
- Cracks in concrete foundations and basement floors
- Gaps around plumbing and utility penetrations
- Sump pits and floor drains
- Crawl spaces and construction joints
Once inside, radon can accumulate in enclosed living spaces, particularly basements and lower levels. Unlike carbon monoxide, radon causes no immediate symptoms that would alert occupants to its presence. The health risk comes from long-term exposure.
The Centers for Disease Control and Prevention (CDC) estimates that radon contributes to about 21,000 lung cancer deaths each year in the United States. It is the leading cause of lung cancer among people who do not smoke, and the combination of radon exposure and smoking increases the risk further.
Why Does Colorado Have Such High Radon Levels?
Colorado's geology is the main reason. Much of the state sits on granite and other formations that contain naturally occurring uranium, and as that uranium breaks down it releases radon into the surrounding soil. The Colorado Geological Survey has detected radon throughout the state.
Elevated radon levels are not limited to mountain communities or older houses. Homes in Denver, Colorado Springs, Fort Collins, Boulder, Loveland, Greeley, and communities throughout the Front Range can all have elevated indoor radon concentrations.
Radon levels can also vary significantly between neighboring properties. A low reading at one house says nothing about the house next door, so testing each home individually is the only reliable way to know its radon level.
Do Energy-Efficient Homes Increase Radon Exposure?
Many new Colorado homes include advanced insulation, high-performance windows, and thorough weather sealing. These features lower energy costs and improve comfort, but tighter construction also reduces natural air exchange. When a home is not adequately ventilated, radon entering from the soil can accumulate indoors instead of being diluted by outdoor air.
The National Cancer Institute notes that radon concentrations can be higher in tightly sealed, well-insulated homes. In other words, an energy-efficient home is not automatically a home with healthy indoor air. Properly designed mechanical ventilation and radon-resistant construction address this without sacrificing efficiency.
New homes are not inherently more dangerous than older ones. Radon levels depend on the underlying geology, foundation design, air pressure, ventilation, and whether a radon control system is installed. If you are buying a newly built home in Colorado, ask the builder about radon-resistant construction features.
How Much Radon Is Considered Unsafe?
The Environmental Protection Agency (EPA) measures radon in picocuries per liter of air (pCi/L) and recommends the following:
| Radon Level | EPA Guidance |
|---|---|
| Below 2.0 pCi/L | Lower exposure; continue periodic testing |
| 2.0–3.9 pCi/L | Consider reducing radon levels |
| 4.0 pCi/L or higher | Take action to reduce radon levels |
There is no known completely safe level of radon exposure. The EPA recommends fixing homes at or above 4.0 pCi/L and considering mitigation between 2.0 and 4.0 pCi/L.
How Can Colorado Homeowners Protect Their Families?
Reducing radon exposure is achievable for most homeowners.
- Test your home. Affordable test kits are widely available, and licensed professionals can perform radon measurements. Test when buying a home, after major renovations, or if your home has never been tested.
- Understand your results. If a short-term test shows elevated levels, follow EPA guidance for a confirmation test and next steps.
- Consider a professional mitigation system. The most common approach uses a vent pipe and a continuously running fan to draw radon from beneath the foundation and exhaust it safely outdoors.
- Retest after mitigation. Confirm the system has lowered indoor radon levels, then retest about every two years and after any significant changes to the home.
- Hire a licensed Colorado radon professional. Colorado requires professionals who perform radon measurement and mitigation to hold a state license. Verify credentials before hiring.
What Does Radon Mitigation Cost in Colorado?
Most Colorado radon mitigation projects cost roughly $1,000 to $2,500, although complex installations can cost more. Price depends on the home's foundation type, basement layout, crawl space access, system design, and installation requirements.
A properly designed system provides long-term reduction in indoor radon levels, which makes a professional evaluation a worthwhile investment. When comparing quotes, ask for written estimates and details on system warranties, post-installation testing, and ongoing maintenance.
Finding Radon Mitigation Professionals in Colorado
Choosing a qualified contractor is one of the most important steps in addressing elevated radon. RadonMitigationCostColorado.com is a Colorado-specific resource that offers:
- Radon testing and mitigation guidance for homeowners
- Typical mitigation costs and the factors that affect pricing
- A directory of Colorado radon professionals organized by city
- Tips for evaluating contractor qualifications
- A way to request a radon mitigation quote
Homeowners can also review the site's Colorado radon mitigation cost guide before requesting estimates. Before hiring anyone, verify the contractor's current Colorado license and ask for references, a written estimate, and details on the proposed system.
A Safer Colorado Home Starts With Testing
Radon is not a new problem in Colorado; it is a naturally occurring hazard that has been present for generations. As communities grow and building methods change, testing and mitigation remain important for every homeowner, whether you live in a historic home, a new subdivision, or a mountain property.
The only way to know your home's radon level is to test. For more on radon testing, mitigation costs, and finding qualified professionals in your area, visit RadonMitigationCostColorado.com.
