Radon gas in homes: What you need to know

When you’re searching for a new home, you’re looking to check a lot of boxes. From budget and bedroom count to outdoor space, there’s a lot to consider. But one thing that likely isn’t top of mind, or even on your house-hunting checklist, is the presence of radon gas.

You can’t see, smell, or taste radon, but it’s the second leading cause of lung cancer and the Environmental Protection Agency (EPA) estimates it’s in one out of every 15 homes in the U.S. But don’t worry, that sounds scarier than it actually is. The presence of radon doesn’t have to be a deal breaker, especially if there’s a radon mitigation system in the home. It just helps to be prepared.

What is radon?

Radon is an invisible, odorless, tasteless gas that’s the byproduct of radioactive elements decaying underground. As substances like uranium and thorium deteriorate, they release radon gas that eventually reaches the surface.

Outside, radon becomes so diluted that it isn’t a health risk. Inside buildings, however, it can become concentrated and pose a higher risk of lung cancer. Radon exists in every state in America, but some areas have higher exposure risks than others. The EPA has an interactive map to help you identify if you’re house-hunting in a high-risk area.

Why should I worry about radon in homes?

Radon is carcinogenic and when it’s trapped indoors, it becomes concentrated enough to cause serious health problems. Because it’s heavier than air, radon tends to settle into basements and crawl spaces. However, HVAC systems often distribute it throughout the entire house.

The higher the concentration of radon gas in a home, the greater the chances of developing lung cancer — especially for those in smoking households. The EPA recommends that a home’s radon level remain below four picocuries per liter (pCi/L).

Is it okay to live in a house with radon?

Most houses contain some amount of radon, so it’s fine to live in a home with radon. However, because no amount of radon is exactly safe, the EPA recommends treating homes with radon levels as low as 2 pCi/L — half the amount considered outright dangerous.

The EPA estimates that the average radon gas concentration in a home is about 1.3 pCi/L (compared to 0.4 pCi/L outdoors), which shouldn’t pose an elevated risk of lung cancer to a home’s inhabitants.

How do I get a radon test?

When you’re touring homes or considering putting an offer, ask if it has been tested for radon recently. If it has been, ask for the results of the test. If it hasn’t, you can request that the seller perform a test. Your home inspector might be able to test when doing the standard home inspection but you may also have to call in a radon specialist depending on the inspector you or your lender choose. It’s wise to make a radon evaluation a contingent part of your purchase contract and negotiate with the seller to either make them pay for the test or split the cost.

Hiring a certified radon tester typically costs less than $200, but you can also perform a radon test yourself with a test kit. These consumer test kits range from $15 to $45, including the lab’s processing fee. With a professional test, you can expect results in as little as 48 hours.

What happens if a test reveals high radon levels?

If a test reveals high radon levels, it’s important to sort out the wording of your purchase contract. If your contract doesn’t specify who will pay for radon mitigation, you as a buyer can demand the seller pay for at least a portion of the mitigation. Radon mitigation efforts can cost anywhere from $800 to $1,800, so it’s worth discussing.

What is radon mitigation?

Radon is a common health hazard that’s easy to alleviate. If a test finds radon levels are above 4 pCi/L, bring in a professional radon mitigation contractor. Each state has a Radon Office that determines the necessary certifications for contractors, but not all states regulate mitigation. As a buyer, you should discuss with the homeowner and your real estate agent before agreeing on a contractor.

Once you’ve hired someone, they can work to reduce the amount of gas in your home and install mitigation systems to slow the accumulation of radon in the future. Mitigating radon includes actions like sealing gaps in service pipes and cracks in basement floors and walls to keep radon from seeping in. Sometimes, contractors will install a radon pipe under the basement to guide radon gas away from the house and into the outdoors. These radon mitigation systems are useful for limiting the frequency with which you’ll have to test for radon.

You’ll never eliminate radon entirely, but mitigation efforts can help lower levels and keep them low for a period of time.

Should I buy a house with a radon mitigation system?

Because radon is everywhere, radon mitigation systems don’t make much of a difference in a home’s value. It’s still going to get in eventually, but it’s a nice perk for a homebuyer if a seller has taken radon mitigation efforts recently. It will save them the time and cost of having to test shortly after moving in.

No radon mitigation system works forever, so you’ll still have to test down the line. Homes shift or settle over time, moving with the Earth, which means tiny cracks in your foundation can still form. Installing a radon detector is a good way to know when to test for radon.

To answer the question: Yes, you should buy a home with a radon mitigation system, but don’t worry too much if a home you love doesn’t have a system in place.

Radon is everywhere. Yes, it’s dangerous when concentrated and can increase your risk of lung cancer, but it’s easy to keep it under control. As a home buyer, make sure to ask what kind of testing and mitigation efforts the seller has taken and, if applicable, be ready to negotiate the cost of radon intervention.