What Is Radon and Why Is Testing for This Deadly Element Often Needed for a Home Closing?

Have your home tested for this radioactive gas and take corrective measures if it is found

Many homebuyers in North Carolina are required to test for radon before closing. But what is radon and why is testing a critical safety step? Radon is a naturally occurring radioactive gas that can accumulate in homes. It is the second-leading cause of lung cancer in the United States. Testing is simple, and mitigation methods can keep your indoor air safe for you and your family.

Radon and lung cancer risk

Radon is an invisible, odorless gas produced by decaying uranium in soil and rock. Low levels of radon are in outdoor air, but it can concentrate to dangerous levels when it seeps into homes. Long-term exposure to radon increases lung cancer risk. The U.S. Environmental Protection Agency estimates more than 21,000 Americans die each year from radon-related lung cancer. In North Carolina, many counties fall into moderate or high radon zones, so testing is important statewide.

Radon testing is affordable

Testing is the only way to know if radon is present and at what level. You can hire a certified professional for an accurate reading or use a do-it-yourself kit. Home improvement stores across North Carolina, including major retailers and independent hardware shops, carry test kits for under $25. Short-term tests run 2–7 days and give a snapshot, while long-term tests run 90 days to a year for a year-round average. Follow up any high result with a second test or professional service.

If your result is four picocuries per liter (pCi/L) or higher, the U.S. Surgeon General and EPA recommend corrective action. In North Carolina, contact the NC Radon Program for a list of qualified mitigation contractors and possible cost-share programs.

If you have high radon levels

A professional mitigation system uses a vent pipe and fan to pull radon from beneath the foundation and exhaust it outdoors. Installation in North Carolina typically ranges from $800 to $1,500, similar to many common home improvements. A contractor will choose the best method for your home’s construction, soil conditions, and radon level.

Selling a home with elevated radon

Under North Carolina law, sellers must disclose known environmental hazards, including radon. A buyer can request mitigation before closing or walk away if high levels are found. Many lenders also require a radon test and proof of mitigation. Addressing radon before listing your home protects your sale and benefits buyer health.

Homebuying checklist

• Ask the seller for past radon test results and mitigation records.
• Order an independent test during inspections to confirm current levels.
• Compare multiple mitigation bids if levels exceed four pCi/L.
• Negotiate remediation costs or price adjustments with the seller.
• Consult local contractors who understand North Carolina building codes.

New construction tips

Builders can install radon-resistant features, such as gas-permeable layers, vent pipes, and junction boxes, at minimal cost during framing. Ask your builder about these options when planning a new home in North Carolina.