Radon is a naturally occurring, colorless, odorless radioactive gas that can seep into homes from the ground. It's considered the second leading cause of lung cancer in the United States, after smoking, according to public health agencies.
A short-term radon test typically uses a detector placed in the lowest livable level of the home for 48 hours under closed-house conditions. Results are reported in picocuries per liter (pCi/L).
Radon levels at or above 4 pCi/L are generally considered elevated. Because radon levels can vary by season and by home, some homeowners choose to follow up a short-term test with a longer-term test or periodic retesting.
Radon levels vary significantly by geography and even between neighboring homes, since it depends on local soil and geology as well as how the home is built. Many buyers choose to test as part of the home purchase process, and homeowners can test at any time — DIY kits are available, or a licensed inspector can test as part of a broader inspection.
Radon mitigation systems, typically involving a vent pipe and fan system, can meaningfully reduce indoor radon levels. A licensed contractor should handle installation.
As an Amazon Associate, Inspection.id may earn from qualifying purchases. See our Advertising Disclosure.