Radon is a naturally occurring radioactive gas that can be present in any home, regardless of age, size, or location. Because radon is invisible and odorless, testing is the only reliable way to know whether elevated levels are present.
Including radon testing during the home inspection process helps buyers understand an important health-related risk before moving forward.
What Radon Is
Radon forms naturally as uranium breaks down in soil and rock beneath the ground. From there, it can enter homes through foundation cracks, crawlspaces, sump pits, and openings around plumbing or utility penetrations.
Once inside, radon can accumulate to elevated levels, particularly in lower areas of the home.
Health Risks Associated With Radon
Long-term exposure to radon is a serious health concern. According to the U.S. Environmental Protection Agency (EPA), radon is the second leading cause of lung cancer in the United States, responsible for thousands of deaths each year.
The EPA provides detailed information for home buyers and sellers on radon risks and testing:
https://www.epa.gov/radon
Why Radon Is Not Identified in a Standard Inspection
A home inspection evaluates visible and accessible components of a property, but radon itself cannot be seen, smelled, or detected through visual observation. A home can appear to be in excellent condition and still have elevated radon levels.
Because of this, radon testing is a separate process that uses specialized monitoring equipment to measure indoor air concentrations over a defined period.
When Radon Testing Is Typically Performed
Radon testing is commonly performed during the home inspection phase of a real estate transaction or before the expiration of a builder’s warranty in new construction homes.
Testing at the time of purchase allows buyers to address elevated levels before moving in and before finalizing negotiations.
Understanding Radon Test Results
Radon levels are measured in picocuries per liter of air (pCi/L). The EPA recommends taking corrective action when radon levels are 4.0 pCi/L or higher. Even levels below this threshold may still warrant mitigation depending on individual risk tolerance.
The EPA explains radon action levels and what they mean for homeowners here:
https://www.epa.gov/radon/what-epas-action-level-radon-and-what-does-it-mean
What Happens If Radon Levels Are High
If elevated radon levels are identified, mitigation systems can often be installed to reduce concentrations effectively. These systems typically involve venting radon gas from beneath the home to the exterior.
Radon mitigation is a well-established process and is generally considered a manageable issue when identified early.
Why Testing Is Worthwhile
Radon testing provides information that cannot be obtained through any other part of a home inspection. Because health risks increase with prolonged exposure, identifying elevated levels before occupancy is an important step in protecting long-term well-being.
Testing does not assume a problem—it verifies whether one exists.
Radon is a hidden risk that can only be identified through testing. Including radon testing as part of the home inspection process helps buyers make informed decisions with a clearer understanding of indoor air quality and health considerations.