Radon is an invisible, odorless radioactive gas that forms naturally in the soil and can seep into homes and buildings through cracks in foundations, sump pits, crawlspaces, and other openings. While you can’t see or smell radon, long-term exposure to elevated levels is a well-established cause of lung cancer. The good news is that radon exposure is preventable—and that’s where a radon mitigation system comes in.
What is a radon mitigation system?
A radon mitigation system is a professionally installed setup designed to reduce the concentration of radon gas inside a building. Rather than trying to eliminate radon at its source underground, the system works by redirecting the gas away from occupied spaces and safely venting it outdoors before it can build up indoors.
How the system works
Most homes are mitigated using a method called sub-slab depressurization, the most common and effective approach for basements and slab-on-grade foundations.
First, a small access point is created beneath the home’s foundation. This allows radon gas that naturally accumulates in the soil below the building to be collected. A network of PVC piping is then installed, running from beneath the foundation up through the structure or along an exterior wall.
At the heart of the system is a continuously operating radon fan. The fan creates gentle suction, pulling radon gas from beneath the home into the piping system. From there, the gas is vented safely into the outdoor air above the roofline, where it quickly disperses and poses no health risk.
Importantly, the fan is placed outside the living space—typically in an attic, garage, or on the exterior of the home—so it does not introduce radon back indoors.
How effective is mitigation?
When properly installed, a radon mitigation system can reduce indoor radon levels by up to 99 percent. The system operates 24 hours a day and uses very little electricity—often comparable to running a standard light bulb. Once installed, homeowners are advised to retest periodically to ensure the system continues to perform effectively.
What mitigation does—and does not—do
A mitigation system does not stop radon from forming underground, nor does it rely solely on sealing cracks or gaps in the foundation. While sealing can support the system’s efficiency, mitigation works by controlling exposure, not by eliminating radon at its natural source.
When is mitigation recommended?
Mitigation is strongly recommended when radon testing shows levels at or above 4.0 picocuries per liter (pCi/L), the EPA’s action guideline. Many public-health experts and advocates also encourage mitigation at lower levels, especially for families with children or individuals at higher risk.
A quiet system that saves lives
Radon mitigation systems are unobtrusive, reliable, and proven. Most importantly, they address one of the leading environmental causes of lung cancer—often without homeowners ever hearing or noticing the system at work. In that quiet, constant operation lies their greatest value: protecting health by making homes safer places to live.