What You Should Know About Radon
About This SeriesWelcome to Know Your Home, our series on the practical side of homeownership. Buying and selling are only part of what it means to own a home. Just as important is understanding the house itself: how it works, what it needs, and what questions are worth asking along the way. We'll cover topics that matter whether you're actively in the market or settling into your new home.
We're starting with one that comes up often in our corner of New England: radon. If you've bought or sold a home around here, radon testing was probably part of the process. It's one of the most common items on a home inspection, and for good reason. We want to emphasize up front that radon is common, easy to test for, and very fixable. Let's walk through what it is and what to do about it.
Radon is common here, and it's manageable
Here's the reassuring part first: if your home has elevated radon, you're not alone, and the problem has a well-established solution. Radon shows up regularly in homes across Rhode Island and southeastern Massachusetts. Testing is simple and inexpensive, and when levels run high, a mitigation system reliably brings them back down. Thousands of local homeowners have already been through this. It's a routine part of owning a home here, not a cause for alarm.
So what is radon?
Radon is a naturally occurring gas that forms when radioactive materials like uranium break down in rocks, soil, and groundwater over time. It's odorless, colorless, tasteless, and invisible. Outdoors it disperses into harmless levels. Indoors, it can accumulate to higher concentrations. It usually enters a home through openings in the foundation, such as gaps around sump pumps, floor drains, or utility lines.
Why radon is worth taking seriously
Radon is measured in picocuries per liter of air (pCi/L), and the EPA sets 4.0 pCi/L as the action level. The EPA estimates the national average indoor concentration is about 1.3 pCi/L, while outdoor air averages around 0.4 pCi/L. The action level is the point at which the EPA recommends taking steps to reduce radon.
That threshold comes down to health. According to the EPA, radon is the leading cause of lung cancer among people who don't smoke, and the second leading cause overall after smoking. That's why the 4.0 marker exists, and why testing is worth doing rather than skipping.
The EPA breaks its guidance down like this:
- Below 2.0 pCi/L: Low risk, though no level is completely risk-free.
- 2.0 to 3.9 pCi/L: Consider reducing radon if possible.
- 4.0 pCi/L or higher: Take action to reduce radon levels.
This hits especially close to home. Rhode Island's current average radon level runs nearly three times the national average, and more than one in four homes tested in the state has a radon level the EPA considers a health risk. The national rate is closer to one in fifteen. Elevated radon is simply more common here than in much of the country, which is why testing here is so routine.
Why We TestRadon is the number one cause of lung cancer among non-smokers. More than one in four Rhode Island homes tests at or above the EPA's action level, with the state average running nearly three times the national number. A simple test is the only way to know where your home stands.
How radon is tested
A licensed professional or a do-it-yourself kit can measure radon. Test kits are widely available through the American Lung Association, major building supply stores, and other retailers. When buying a home, buyers often have a licensed professional handle radon testing as part of the overall home inspection.
There are two basic approaches: a short-term screening test that runs a few days, or a long-term test that runs anywhere from 90 days to a year. Because radon levels naturally fluctuate, a long-term test gives a more accurate picture of your home's year-round level. Either way, the takeaway is simple: an inexpensive test tells you something genuinely important about your home.
Pro TipTesting isn't a one-time event. RIDOH recommends retesting every three to five years, and especially after any remodeling, since changes to a home can affect how radon moves through it.
The good news: radon is fixable
If a test comes back high, professionals can reduce radon with a mitigation system. In Rhode Island, a Rhode Island Licensed Radon Mitigation Contractor should do this work, since they have the training to evaluate your home and choose the right approach.
A common setup in our area is an active sub-slab depressurization system, which uses a vent pipe and fan to draw radon out from beneath the foundation and release it safely above the roofline. For a single-family home, a professionally installed system typically runs $1,000 to $2,000, depending on the home's size and layout. More complex homes can cost more, so it pays to get more than one quote.
What's different across the state line
Radon behaves the same everywhere, but the rules around it differ between Rhode Island and Massachusetts.
In Rhode Island, real estate disclosure law requires sellers to tell buyers about prior elevated radon test results. If a home has been tested and mitigated, that history becomes part of the conversation.
Massachusetts has no equivalent statewide radon disclosure requirement, which puts more of the responsibility on buyers to test during their own inspection period. The health facts are identical on both sides of the line, and elevated radon is roughly as common in Massachusetts as in Rhode Island. The difference is mostly in the paperwork, and in who is expected to raise the topic.
A few practical takeaways
- Radon is common in our region, and testing is a normal part of buying, selling, or simply maintaining a home.
- The EPA action level is 4.0 pCi/L. At or above that, it's time to take action.
- Testing is inexpensive, whether with a kit or through a licensed professional.
- If levels run high, mitigation reliably fixes the problem, usually for $1,000 to $2,000.
- Rhode Island requires sellers to disclose prior elevated results; Massachusetts does not.
- Consider retesting every few years, especially after a remodel.
Frequently asked questions
Is radon actually dangerous, or is it overblown?
It's a real health concern. The EPA identifies radon as the leading cause of lung cancer among non-smokers and the second leading cause overall. That said, it's also very manageable. The risk comes from long-term exposure to elevated levels, which is exactly what testing and mitigation prevent.
How do I test my home for radon?
Buy a do-it-yourself kit at many building supply stores or through the American Lung Association, or hire a licensed professional. Buyers often include professional radon testing as part of their home inspection. A short-term test gives quick results, while a long-term test provides a more accurate year-round picture.
What does it cost to fix a radon problem?
For a typical single-family home, a professionally installed mitigation system usually runs $1,000 to $2,000. The exact cost depends on the size and layout of the home, so get more than one quote.
Do I have to tell buyers if my home has had radon?
In Rhode Island, yes. State disclosure law requires sellers to share prior elevated radon test results. Massachusetts has no comparable statewide requirement, though testing is still a standard part of most buyers' inspections.
A Quick NoteThe information here is meant for general education and isn't a substitute for professional advice, including medical advice. Radon levels vary significantly from one property to the next, and the only way to know your home's level is to test it. If you have questions or concerns, consult a qualified radon measurement professional or a licensed mitigation contractor.
This is the first in our Know Your Home series, and there's more useful information on the way. Whether you're buying, selling, or settling in for the long term, we're here to help you understand your home and make confident decisions about it.
Questions about radon, testing, or anything else on your mind as a homeowner? Get in touch with our team. We're always happy to help.
