Homeowner radon guide
What Is Radon?
Radon is a naturally occurring radioactive gas that can move from soil and rock into buildings. You cannot see, smell, or taste it, so testing is the practical way to learn the level in a specific home.
What homeowners need to know
Levels can vary between neighboring homes and over time. Long-term exposure increases lung-cancer risk. EPA recommends action at 4 pCi/L or higher and suggests considering action between 2 and 4 pCi/L; 4 pCi/L is not a safe-versus-dangerous boundary.
What to do
Test with a properly placed device, follow its instructions and state requirements, discuss elevated results with a qualified professional, and retest after mitigation and periodically afterward.
What to do next
Use the cost estimator for planning or search for professionals whose recorded service area matches your ZIP code.
Content reviewed 2026-08-20. Educational information only; testing and a property-specific assessment are still required.