Radon is a naturally occurring radioactive gas found in soil and rock throughout Maine. It can enter a home through cracks, gaps, and other openings in the foundation, collecting indoors — especially in basements and lower levels.
Because radon has no smell, taste, or color, testing is the only way to know if a home has elevated levels. In Maine, radon is one of the most common environmental issues found during real estate inspections.
Radon testing is an important step in understanding the full condition of a home — not just how it looks or functions, but how healthy it is to live in.
Health Risk — Radon exposure is the second leading cause of lung cancer in the U.S., after smoking.
Common in Maine — Much of Maine’s soil and bedrock contain uranium, which naturally produces radon gas.
Invisible but measurable — Because radon can’t be detected by sight or smell, testing is the only way to confirm if levels are within a safe range.
Impact on transactions — Many buyers, sellers, and lenders include radon testing as part of their due diligence, just like a water test or inspection.
Whether you’re buying, selling, or maintaining your home, knowing the radon level helps you make informed decisions — and, if necessary, plan for mitigation.
Radon in Air: The most common concern. It moves upward from the soil and can accumulate indoors.
Radon in Water: Found mainly in homes using private wells, radon can enter indoor air when water is used (for example, during showering or washing).
Both sources can be tested, and results are reported in picocuries per liter (pCi/L). The EPA recommends action if radon levels in air are 4.0 pCi/L or higher.
Radon testing is recommended:
During a real estate transaction, as part of the inspection process
Every 2–5 years for homeowners, since levels can change over time
After major renovations or foundation work
If you’ve never tested and the home has a basement, crawlspace, or slab-on-grade foundation
Testing ensures buyers and sellers have transparent information about potential risks before closing.
A radon test is a natural extension of a home inspection. While the inspection evaluates visible systems and structures, the radon test measures an environmental condition that can directly affect health and long-term property value.
Including radon testing during the inspection process provides a more complete understanding of the home, helping both buyers and sellers make informed decisions and negotiate with confidence.
U.S. Environmental Protection Agency (EPA): https://www.epa.gov/radon
Maine CDC — Radon in Drinking Water and Air: https://www.maine.gov/dhhs/mecdc/healthy-living/health-and-safety/drinking-water-safety/public-water-systems/information-for-consumers/drinking-water-contaminants/radon