StressFree Environmental Services | Radon Education
Understanding your radon test shouldn't require a science degree. Learn what your measurement means, how EPA recommendations apply, and what to consider next.
Understanding Your Measurement
Radon is measured in picocuries per liter, abbreviated pCi/L. The higher the concentration, the greater the potential risk from long-term exposure.
The EPA recommends fixing a home when the confirmed radon level is 4.0 pCi/L or higher, and considering reduction when levels are between 2.0 and 4.0 pCi/L.
This graphic illustrates EPA recommendation ranges, not a linear measurement scale. No radon concentration is completely risk-free.
Your result is below the EPA's range for considering radon reduction. This does not mean the air is entirely free of radon or risk.
The EPA recommends considering radon reduction when levels fall between 2.0 and 4.0 pCi/L.
The EPA recommends taking action to reduce radon when the confirmed concentration is 4.0 pCi/L or higher.
The appropriate response to an initial test depends on the testing method, result, and whether the measurement is part of a real estate transaction. In some situations, additional testing is recommended before deciding on mitigation.
Reading Your Report
The radon concentration is important, but a useful test report also documents how, when, and where the measurement was collected.
Reviewing the supporting information helps you understand the conditions under which the test was performed.
Report Components Explained
Measurement Duration
Radon concentrations fluctuate. The duration of a measurement affects what the result can tell you.
Short-term tests typically measure radon over a period ranging from a few days to 90 days, depending on the method.
They are commonly used in real estate transactions because results can be obtained within a shorter period.
A short-term result may not fully represent a home's annual average radon concentration.
Long-term tests measure radon for more than 90 days.
Because radon levels vary with weather, seasons, and building conditions, longer measurements generally provide a better estimate of the long-term average.
They may be useful when a property owner wants additional information outside a time-sensitive transaction.
Elevated Radon Results
An elevated radon measurement deserves attention, but it does not mean you need to make an uninformed or rushed decision.
The next step depends on the result, test type, and circumstances. When reduction is indicated, qualified mitigation professionals can evaluate appropriate systems.
Real Estate Transactions
A higher radon result does not automatically mean a home cannot be purchased or sold. It provides information the parties can use when discussing next steps.
Review the reported concentration, the testing conditions, and whether mitigation or additional testing should be considered.
Understand the result and discuss appropriate corrective options with qualified professionals.
Help clients understand the testing information and coordinate with appropriate professionals while observing contractual deadlines.
After Radon Mitigation
A newly installed radon mitigation system should be followed by testing to determine whether radon concentrations have been successfully reduced.
Continued periodic testing helps verify that the system remains effective.
Long-Term Awareness
Radon levels can change over time, even in homes that previously tested low.
Radon Facts
Radon concentrations can differ significantly between neighboring homes. A nearby result does not establish your home's concentration.
Both new and older homes can have elevated radon concentrations. Age alone does not determine radon levels.
Radon can occur in buildings with basements, crawlspaces, or slab foundations.
Radon concentrations can change due to seasonal and building conditions. Periodic retesting is recommended.
Frequently Asked Questions
No radon concentration is completely risk-free. The EPA recommends fixing homes with confirmed levels of 4.0 pCi/L or higher and considering reduction between 2.0 and 4.0 pCi/L.
Picocuries per liter is a unit used to express radon radioactivity in a volume of air.
Yes. Radon levels fluctuate with weather, season, ventilation, and building conditions. Different measurement periods can produce different results.
The EPA action level is a recommendation threshold, not a precise boundary between safe and unsafe air. Risk generally increases with concentration and duration of exposure.
Follow-up testing depends on the initial result, measurement method, and whether the test was performed during a real estate transaction. Follow the applicable EPA confirmation recommendations.
Many properly designed systems can substantially reduce radon, sometimes below 2.0 pCi/L. Actual performance depends on the building and system. Post-mitigation testing is needed to verify the result.
No. Radon testing measures radon. Mold assessment and other indoor environmental evaluations involve different methods.
Visit the U.S. Environmental Protection Agency's Radon Information Center for homeowner guidance, testing information, and recommendations.
StressFree Radon Testing
Whether you're purchasing a home, selling a property, or simply checking your indoor environment, StressFree can help you take the next step toward understanding your radon levels.
Metro Detroit and surrounding Southeast Michigan communities.
