According to the Virginia Department of Health, radon can seep into your home from exposed dirt such as a crawl space, plumbing cut-out or old cellar. It can also pass through openings in your foundation such as unsealed sumps, drains, joints, cracks and open top block walls (see diagram on cover). The highest levels of radon are typically found in the lowest livable areas of the home, such as basements or other rooms in direct contact with the ground.

All types of homes can have elevated radon levels, homes without basements, homes with basements, drafty homes, old homes, and new homes.

The Environmental Protection Agency (EPA) strongly recommends contacting a qualified professional to install a radon reduction (also called radon mitigation) system if your home radon level is at or above 4 pCi/L of air.

Levels between 2-4 pCi/l: Consider mitigation or periodic retest as indoor Radon levels vary by season and weather conditions.

Below 2 pCi/l: Consider bi-annual retest or whenever significant changes to the home structure or mechanical systems occurred.

The EPA recommends testing your home after any lifestyle changes, renovations, and every two years as part of routine home maintenance. If you've already installed a radon mitigation system due to the previously elevated levels, completing a radon test is the only way to verify that the radon mitigation system is working properly. Testing more frequently (once per year) may be advised.