How Does Radon Testing Work?
Radon is an invisible, odorless radioactive gas that naturally occurs in soil and rock. It can enter homes and buildings through cracks in the foundation, gaps around pipes, or even well water. Long-term exposure to high radon levels is the second leading cause of lung cancer in the U.S., according to the EPA. That’s why accurate radon testing is so important.
Radon detectors measure tiny radioactive particles—called radon decay products—that form when radon gas breaks down. Passive tests like charcoal canisters trap radon in a filter, which is later analyzed in a lab. Alpha-track detectors use a special film that records tiny marks from these particles over time, while continuous radon monitors (CRMs) use electronic sensors to track radon levels hour by hour. All of these methods are equally reliable, but each is best suited for different situations. They all work by detecting the byproducts of radon’s decay—a process that’s also what makes radon dangerous. (Learn more in our upcoming post: How Radon is Dangerous.)
Short term Tests
Short-term radon tests typically last from 2 to 90 days and are ideal for getting quick results. They’re often used during real estate transactions or as an initial screening to see if further testing is needed. These tests can be completed with charcoal canisters, alpha-track devices, or continuous radon monitors.
long Term tests
Long-term radon tests measure levels for 90 days or more, giving the most clear picture of year-round exposure. Short-term tests are still reliable and often the best choice when quick results are needed, while long-term tests smooth out seasonal changes for a more complete, long-term average.
