Radon and Indoor Air Quality in Fredericton Homes

What radon actually is (and why you cannot ignore it here)

Radon is a radioactive gas produced when uranium in soil and bedrock breaks down. You cannot see it, smell it or taste it. Outdoors it disperses into the open air and is essentially harmless. The problem starts when it seeps up through your foundation, gathers in a basement or lowest lived-in level, and you breathe it in day after day, winter after winter.

Here is the part locals should sit up for: New Brunswick is not average. Uranium is common in the bedrock and soils under much of the province, which means more radon working its way toward the surface. Combine that with the fact that we seal our homes tight against the cold for six months of the year, and you have close to a worst-case setup for radon to build up indoors. The Government of New Brunswick and NB Lung both flag radon as a genuine provincial health issue, not a scare story imported from somewhere else.

Radon is the second leading cause of lung cancer in Canada after smoking, and the leading cause among people who have never smoked. If you do smoke, the risk multiplies: living with high radon and smoking together is far more dangerous than either on its own. New Brunswick already carries one of the higher lung cancer rates in the country, so this is not abstract. The reassuring flip side is that radon is one of the few cancer risks you can measure with a cheap kit and fix with a fan.

Why Fredericton's geology stacks the odds

Radon is stubbornly local. Your house can test high while your neighbour's tests fine, because it depends on the specific ground beneath your foundation, the cracks and gaps in your slab, how your home draws air, and how you heat and ventilate it. That is exactly why a provincial map or a neighbour's result cannot answer the question for you.

That said, the regional picture is sobering. The Government of New Brunswick and NB Lung both state plainly that roughly 1 in 4 New Brunswick homes have radon above the 200 Bq/m3 guideline, and in some communities the share tested above the guideline runs considerably higher. Those are among the highest rates in the country. Fredericton and the surrounding communities sit squarely in radon country, and results vary street by street and even house by house, so testing is the only way to know where yours lands.

A few things make our housing stock especially worth testing. Basements are near universal here and are the most common lived-in low level. Many older Fredericton homes have fieldstone or block foundations, sump pits, and floor drains that give radon easy paths in. And our long heating season means we run those homes closed up and slightly depressurized, which can actively pull soil gas indoors. If you are already thinking about your furnace and envelope, our guide to heating your Fredericton home pairs naturally with a radon test, because the same air sealing that saves on heating can also trap gas.

How to test: free library kits vs professionals

You have three realistic routes, and for most homeowners the cheapest one is also perfectly credible. What matters is that the device is a long-term detector certified through the Canadian National Radon Proficiency Program (C-NRPP) and that you run it correctly.

The bargain of the province is the public library kit program. In the fall of 2025 the Government of New Brunswick and the New Brunswick Public Library Service rolled out free long-term radon test kits at all 63 public libraries in the province, including the Fredericton Public Library. The detectors are supplied and analysed by the Research and Productivity Council (RPC), a C-NRPP certified lab based in Fredericton at 921 College Hill Road (E3B 6Z9). Demand was strong enough that some branches ran out within a day of the launch, so call ahead or check availability before you make a trip. You borrow a kit at no cost, set the detector yourself in minutes, leave it untouched in place for the recommended period, then return it to the library. Results typically come back within four to six weeks of the detector reaching the lab. You can reach RPC's lab at 506-452-1212 (or toll free 1-800-563-0844) or [email protected].

NB Lung, headquartered downtown at 2-132 Main Street (E3A 1C7), also offers long-term test kits and runs a radon lending program. Its purchased kits bundle the detector, lab analysis and return handling, and buying one supports the charity's outreach, which is a fair trade if the free library stock is tapped out.

The third route is hiring a C-NRPP certified measurement professional, which makes the most sense during a real estate transaction or when you want a documented, defensible result. Here is how the options compare.

Prices and kit availability shift, so confirm current details with your library branch, RPC or NB Lung before you count on a number.

What the number means and when to act

Radon is measured in becquerels per cubic metre (Bq/m3). Canada's guideline is 200 Bq/m3. That is not a hard safety line where 199 is fine and 201 is dangerous. Radon risk is a sliding scale with no truly safe level, so lower is always better. The guideline is simply the point at which Health Canada says you should take action.

Read your result like this. New Brunswick's health authorities keep it simple: if a long-term test comes back over 200 Bq/m3, plan to mitigate within about a year, and the higher the number, the sooner you should act. Health Canada frames the timing in tiers that say the same thing in more detail: above 600 Bq/m3, fix it within a year, and between 200 and 600, within about two years. Under 200 no action is required, but if you land at, say, 150 and mitigation is affordable, driving it lower is still worthwhile, and it is worth retesting every five years or after major renovations. Because radon fluctuates with weather, seasons and how you run the house, one high result is a signal to act rather than to panic, and one low result on a short test is not a clean bill of health.

If you are house hunting, fold radon into your due diligence the same way you would a roof or a well. Our guide to buying a home in Fredericton and the notes on well water quality cover the other invisible things worth checking before you sign, and rural properties on wells are exactly the ones where soil gas tends to be worth a look.

Fixing a radon problem: mitigation and grants

Good news first: radon is one of the more fixable problems a house can hand you. The standard solution is active sub-slab depressurization, which sounds fancy but is basically a pipe drawing air from beneath your foundation slab and a quiet fan venting it above the roofline, so soil gas is pulled outside before it ever enters your living space. Done properly by a certified contractor, a system typically cuts radon by more than 80 percent and often brings a very high reading well under the guideline.

Expect a professional mitigation system to cost roughly $3,000 to $5,000 in New Brunswick, depending on your foundation, layout and how many suction points are needed. Older homes with rubble foundations or multiple slabs can run higher. Some newer homes may already have a radon rough-in stubbed into the slab, which can lower the cost considerably. Hire a contractor certified through the C-NRPP: this is not a job to hand to a general handyman, and a poorly designed system can move gas around without actually reducing it.

On money, there is real help. The Canadian Lung Association's Lungs Matter grant offers up to $1,500 toward mitigation. To qualify in New Brunswick you generally need a household income at or below the provincial threshold (recently $74,600) or a lung cancer diagnosis, plus a long-term C-NRPP test showing over 200 Bq/m3, and a quote from a certified mitigator. Crucially, the work cannot already be done when you apply, and funding is limited, so meeting the criteria does not guarantee approval. Provincial homeowner repair programs may also help lower-income owners, and NB Lung keeps a running list of what is available. If mitigation overlaps with a basement reno, our renovations, permits and trades guide is worth a read so you sequence the sub-slab work before you finish the floor.

Beyond radon: mould, moisture and ventilation

Radon gets the headlines, but it is one thread in the bigger story of how a Fredericton home breathes. Our climate swings from humid summers to bone-dry, sealed-up winters, and both extremes tax indoor air.

Moisture is the local villain. Spring melt and the occasional high river make damp basements a regular Fredericton reality, and where there is chronic damp, mould follows. Mould triggers allergies and asthma and, unlike radon, you can often see or smell it. The fixes are unglamorous but effective: keep basement relative humidity in the roughly 30 to 50 percent range, run a dehumidifier through the muggy months, fix leaks fast, grade soil away from the foundation, and make sure downspouts carry water well clear of the house. Anyone in a flood-prone pocket should read our spring flood guide alongside this one.

The other half of the equation is ventilation. Tight, energy-efficient homes save on heat but trap radon, moisture, cooking fumes and everyday off-gassing. A heat recovery ventilator (HRV) is the workhorse answer for our climate: it exhausts stale indoor air and brings in fresh outdoor air while recovering most of the heat, so you get ventilation without throwing your heating dollars out the window. Newer New Brunswick homes are often built with one, and they are worth running rather than switching off to save a few cents. An HRV alone will not reliably solve a serious radon problem (that still calls for sub-slab work), but it improves overall air quality and can help at the margins. Simple habits matter too: run bathroom and kitchen fans that vent outside, open windows on mild days, and change furnace and HRV filters on schedule.

Wood smoke, winter air and the whole picture

Plenty of Fredericton-area homes lean on a wood stove or fireplace, and on a cold February night there is nothing better. But wood smoke is a real source of fine particulate that irritates lungs, especially for kids, seniors and anyone with asthma. If you burn, burn smart: use seasoned, dry hardwood, keep the fire hot and bright rather than smouldering, have the chimney cleaned and inspected annually, and make sure the appliance is drawing properly so smoke goes up the flue and not into the room. A slow, smoky, dampered-down fire is both a health nuisance and a creosote hazard.

Two safety notes ride along with any combustion heating. First, install carbon monoxide alarms on every level and near sleeping areas: CO is a separate, faster-acting killer that a radon detector will not catch. Second, remember that a wood stove or a big exhaust fan can depressurize a tight house and actually pull more soil gas (and radon) indoors, another reason ventilation and radon get considered together rather than one at a time.

Zoom out and the message is simple. Test for radon and act on the number. Manage moisture so mould never gets a foothold. Ventilate deliberately, ideally with an HRV. Burn wood cleanly and back it with CO alarms. None of it is expensive relative to the payoff, and the same envelope choices that keep your heating efficient are the ones that make air quality a thing you manage on purpose instead of a thing that happens to you. For newcomers still learning how these houses behave in the cold, our first Fredericton winter guide is a good companion.