Read this first. This is general information for Quebec homeowners, buyers, sellers, landlords, and tenants, drawn from public sources: Health Canada, the Government of Quebec (Ministère de la Santé et des Services sociaux), the Institut national de santé publique du Québec (INSPQ), Take Action on Radon, and the Canadian National Radon Proficiency Program (C-NRPP). It is not medical, legal, or warranty advice. Radon results are reported against Health Canada's guideline of 200 Bq/m³; RadonTest.ca coordinates testing logistics and does not interpret individual results or provide any health assessment.
See the radon gas map — measured results for every surveyed area, searchable by postal code.
The essentials at a glance
- November is Radon Action Month in Canada. There is "no better time to start measuring the levels of this gas in your home" (Public Health Agency of Canada, Data Blog, 2019).
- In Quebec, the Ministère de la Santé et des Services sociaux (MSSS) issues this reminder every year: measuring radon in a home "is simple and inexpensive," and it should ideally be done between November and April (Government of Quebec / MSSS, quebec.ca, 2022).
- Radon is the leading cause of lung cancer among people who have never smoked, and the second leading cause overall after smoking; it is linked to roughly 16% of lung cancer deaths, or more than 3,000 deaths (~3,200) per year in Canada (Health Canada, 2025).
- In Quebec, an estimated one in six lung cancer deaths is associated with radon (Government of Quebec / MSSS, 2022).
- Canada's guideline is 200 Bq/m³ (annual average). No level is risk-free; if your result reaches or exceeds 200, Health Canada recommends taking action within a year — and sooner if the level is high (Health Canada, 2025).
- A valid test is a long-term test of at least 91 days, on the lowest lived-in level, in a room occupied more than 4 hours a day, ideally during the heating season — and November marks its start (Health Canada, measurement guide, 2025).
- The only way to know your level is to test: the campaign exists precisely to prompt you to do so (Take Action on Radon, 2025).
What is "Radon Action Month"?
Every November, Canada marks Radon Action Month (also called Radon Awareness Month). The idea is simple: to remind the public that radon is a real, invisible, and preventable risk, and to encourage them to take action — that is, to test their homes. As the Public Health Agency of Canada puts it, "November is Radon Action Month. There is no better time to start measuring the levels of this gas in your home and to make sure the air you and your family breathe is healthy" (Data Blog, 2019).
The national campaign is led by Take Action on Radon, an initiative funded by Health Canada and run with its partners in the health and cancer-prevention community. On its website, Take Action on Radon dedicates an entire section to Radon Action Month and invites individuals, cities, and municipalities to take part (Take Action on Radon, 2025). It's also the time of year when landmarks light up purple and many communities launch their testing programs — the wrap-up of the 2025 campaign specifically noted these efforts (Take Action on Radon, December 2025).
In Quebec, the event is echoed at the highest level. Every November, the Ministère de la Santé et des Services sociaux (MSSS) publishes an official reminder: "November is Radon Action Month." The Ministry describes radon as "a carcinogenic, colourless, and odourless radioactive gas found naturally in the soil," and notes that "measuring the radon concentration in a home is simple and inexpensive, and it should ideally be done between November and April" (Government of Quebec / MSSS, quebec.ca, 2022).
The message is amplified on the ground by several public-health players — the Quebec Lung Association (Poumon Québec), which has run a radon awareness program for years, along with regional CISSSs and CIUSSSs that send reminders to their populations in November. In other words, this isn't a commercial operation: it's a public-health campaign, backed by federal and Quebec authorities, whose sole purpose is to get more people to test their homes.
Why November? The heating season begins
The date isn't chosen at random. For most of Quebec, November marks the start of the heating season — and that's exactly the period when a long-term test is most representative.
Here's why. During the fall and winter, windows and doors stay closed, reducing the natural ventilation that dilutes radon in the summer. At the same time, heating creates a slight negative pressure indoors (the "stack effect") that draws soil gases — including radon — in through cracks and openings in the foundation. The result: indoor levels generally peak from about October to April. That's why Health Canada recommends measuring radon during the heating season, which gives "the most representative reading" of your true annual average. We break down this seasonal science — closed windows, the stack effect, higher winter readings — in our article When is radon testing season in Canada?
There's also a very practical reason to start in November rather than wait. A valid long-term test runs at least 91 days (about three months), plus the lab analysis time. If you place your detector at the beginning of November, you capture the heart of the heating season and get your result over the winter or in early spring — well before the buying and renovation season. Radon Action Month therefore falls at the ideal point in the calendar: it's the natural kickoff for a test that will cover the entire period when levels are highest.
A word to avoid a common misunderstanding: you can test in any season. Health Canada has clarified that if your result reaches or exceeds 200 Bq/m³, you should act — regardless of the season, with no need to retest — and that a result below the guideline obtained outside the heating season is worth confirming during the heating season. November is the best time to start, but the worst choice is to keep putting it off. For the details of these rules, see Health Canada's updated radon testing guidance.
What to do during the month: test your home
Radon Action Month asks just one thing, but it's a decisive one: get the radon in your home measured. Here's how to do it right.
1. Get a long-term radon detector. The alpha-track kit you receive in the mail is a radon detector — a small passive device that records your exposure over the full length of the test. It's the type of test Health Canada recommends for making a decision. Short "spot" tests lasting a few days aren't suitable for deciding whether to fix a home.
2. Put it in the right place. The detector goes on the lowest lived-in level of your home, in a room occupied more than four hours a day — a bedroom, living room, family room, or office, but not a bathroom, kitchen, laundry room, or closet. Place it at breathing height, out in the open, away from drafts, vents, windows, and heat sources. Our guide Where to place your radon test kit covers the exact heights and clearances.
3. Leave it in place for at least 91 days, then send it back. Don't move it or change your daily habits during the test — live normally, since that's what makes the average reliable. After at least 91 days (you can go up to 12 months), return the detector to the laboratory for analysis.
4. Act on your result. Your report shows your concentration in becquerels per cubic metre (Bq/m³), compared with Health Canada's guideline of 200 Bq/m³.
- If your result reaches or exceeds 200 Bq/m³, Health Canada recommends taking corrective measures to reduce radon within a year — and sooner if the level is high. A home reading several hundred Bq/m³ warrants acting faster than a home just above the guideline. (Health Canada sets its timelines according to the concentration; our guide What to do if your radon level is above 200 Bq/m³ summarizes them.)
- If your result is below 200 Bq/m³, no corrective measures are recommended. Keep in mind, though, that no level is entirely risk-free: the lower, the better.
The good news: a high result is a problem that can be fixed. The standard method in Canada — active soil depressurization — reduces radon by more than 80% in most homes, according to Health Canada, and a C-NRPP-certified professional can usually install it in a day. Radon poses a long-term risk, not an immediate hazard: you have time to plan properly, without putting it off indefinitely.
Radon in Quebec: what the data reveals
Do you really need to test in Quebec? Yes — and the numbers explain why.
Radon is present in the soil everywhere in the province, but to widely varying degrees depending on the local geology. The Institut national de santé publique du Québec (INSPQ) has shown that radon-emission potential depends heavily on the uranium content of soils and rocks: in areas where the intensity of the soil's gamma radiation is lowest, a relatively modest share of buildings exceeds the reference thresholds, whereas in the most radiogenic areas, more than half of buildings may exceed the 200 Bq/m³ guideline (INSPQ, Radon in Quebec). Some regions therefore have a markedly higher prevalence than others.
But here's the crucial point, stressed by every authority: high radon in your area tells you nothing definite about your home — and neither does the absence of known cases among your neighbours. Two neighbouring homes can show very different values depending on the soil, the foundation, and the ventilation. As the Public Health Agency of Canada notes, "there are homes with high radon levels in every region of Canada" (2019). Big cities are no exception. That's exactly why a regional map, however useful for awareness, never replaces a measurement: the only way to know your home's level is to test it.
The public-health burden is real in Quebec. The Government of Quebec notes that "in Quebec, one in six lung cancer deaths is associated with radon" (MSSS, 2022) — a proportion that mirrors Health Canada's national estimate of roughly 16% of lung cancer deaths. Behind these percentages are ordinary homes, in ordinary neighbourhoods, where a three-month test would have revealed a high level that's easy to fix. Radon Action Month exists to turn that fact into concrete action.
Make November your starting point
Radon Action Month isn't just a symbol on a public-health calendar: it's a useful reminder that falls at exactly the right time. November marks the start of the heating season — the window when a long-term test is most representative — and there's plenty of time to place a detector, let it measure for 91 days, and receive your result before spring.
If you've ever thought "I should get my home tested" without ever following through, this is the month to do it. The step is simple, inexpensive, and carries no risk, and it answers a question no regional average can answer for you: what is the radon level in my home?
Order your RadonTest.ca kit → — analysis by a C-NRPP-certified laboratory (with a fully-in-Canada analysis option), tracked round-trip shipping, and your result delivered with clear Health Canada context.
Frequently asked questions
Is Radon Action Month really in November? Yes. In Canada, November is Radon Action Month (also called Radon Awareness Month). It's a public-health campaign backed by Health Canada and led by Take Action on Radon; in Quebec, the Ministère de la Santé et des Services sociaux issues the reminder every year (Government of Quebec / MSSS, 2022; Public Health Agency of Canada, 2019).
Who's behind the campaign in Quebec? In Quebec, the official reminder comes from the Ministère de la Santé et des Services sociaux (MSSS), on quebec.ca. The national Take Action on Radon campaign, funded by Health Canada, coordinates the activities, and organizations such as the Quebec Lung Association along with regional CISSSs and CIUSSSs relay the message (Government of Quebec / MSSS, 2022; Take Action on Radon, 2025).
Why test in November rather than in summer? Because November marks the start of the heating season, when homes are closed up and heating draws more soil gas indoors: indoor radon levels then generally reach their peak (from about October to April). Health Canada recommends testing during this period to get the most representative reading. Starting in November also leaves time to complete a 91-day test before spring (Health Canada, measurement guide, 2025).
How long does the test need to run? At least 91 days (about three months), and up to 12 months if you prefer a longer period. Health Canada recommends a long-term test, not a "spot" test lasting a few days, because radon fluctuates enormously from day to day and season to season (Health Canada, measurement guide, 2025).
Where should I place the detector? On the lowest lived-in level of your home, in a room occupied more than four hours a day (bedroom, living room, office), at breathing height and away from drafts, vents, windows, and heat. Avoid bathrooms, kitchens, laundry rooms, and closets. See our guide Where to place your radon test kit.
What should I do if my result is above 200 Bq/m³? If your long-term result reaches or exceeds Health Canada's guideline of 200 Bq/m³, Health Canada recommends taking corrective measures to reduce radon within a year — and sooner if the level is high. Call in a C-NRPP-certified mitigation professional. Active soil depressurization reduces radon by more than 80% in most homes (Health Canada, 2025). See What to do if your radon level is above 200 Bq/m³.
My area doesn't have many known cases — should I still test? Yes. Homes with high concentrations are found in every region of Quebec and Canada, and two neighbouring homes can show very different results. A regional map can't tell you whether your home is affected; only a test can (Public Health Agency of Canada, 2019; INSPQ).
Is there a risk-free level of radon? No. There is no radon level that is entirely risk-free: the lower the concentration, the better. The 200 Bq/m³ guideline is not a boundary between "acceptable" and "harmful" — it's the action threshold at which Health Canada recommends fixing the home (Health Canada, 2025). To dig deeper, see What radon level is acceptable in Canada?
Order your RadonTest.ca kit → — analysis by a C-NRPP-certified laboratory (with a fully-in-Canada analysis option), tracked round-trip shipping, and your result delivered with clear Health Canada context.
Sources
- Public Health Agency of Canada — Radon Action Month in Canada (Data Blog, Health Infobase): "November is Radon Action Month"; radon = 2nd leading cause of lung cancer after smoking; more than 3,000 deaths per year; active soil depressurization ≈ 90%; "there are homes with high radon levels in every region of Canada." Published 2019-11-21. https://health-infobase.canada.ca/datalab/radon-blog.html
- Government of Quebec / Ministère de la Santé et des Services sociaux (MSSS) — November is Radon Action Month: "one in six lung cancer deaths is associated with radon" in Quebec; measuring "is simple and inexpensive"; "ideally… between November and April." Published 2022-11-01. https://www.quebec.ca/en/housing-territory/healthy-living-environment/residential-radon
- Health Canada — Government of Canada radon guideline (200 Bq/m³, annual average; corrective measures within one year, sooner if the level is high; no level is risk-free). Modified 2025-09-24. https://www.canada.ca/en/health-canada/services/health-risks-safety/radiation/radon/government-canada-radon-guideline.html
- Health Canada — Radon: What you need to know (radon = leading cause of lung cancer among non-smokers and 2nd overall; ≈ 16% of lung cancer deaths; > 3,000 / ~3,200 deaths per year; "1 in 5 homes" has a high level). 2025 edition. https://www.canada.ca/en/health-canada/services/environmental-workplace-health/reports-publications/radon-what-you-need-to-know.html
- Health Canada — Guide for radon measurements in residential dwellings (long-term test of at least 91 days; lowest lived-in level; room occupied > 4 h/day; heating season from about October to April; placement rules). Modified 2025-12-22. https://www.canada.ca/en/health-canada/services/publications/health-risks-safety/guide-radon-measurements-residential-dwellings.html
- Health Canada — Reducing radon levels in your home (active soil depressurization; reduction of "more than 80%"; installed in less than a day; using a C-NRPP-certified professional). Modified 2025-10-09. https://www.canada.ca/en/health-canada/services/health-risks-safety/radiation/radon/reducing-levels-home.html
- Take Action on Radon — Home and Radon Action Month section (national campaign funded by Health Canada; participation of cities and municipalities; wrap-up of the 2025 campaign). Modified 2025-09-25. https://takeactiononradon.ca/learn/radon-action-month/
- Institut national de santé publique du Québec (INSPQ) — Radon in Quebec: Health Risk Assessment and Critical Analysis of Intervention Strategies (geological variability of prevalence; share of buildings exceeding thresholds by radiogeochemical zone). https://www.inspq.qc.ca/en/node/2413
Laboratory analysis is carried out independently by a C-NRPP-certified laboratory. Results are reported against Health Canada's guideline of 200 Bq/m³. RadonTest.ca coordinates only the kit logistics and sample submission — it does not interpret or alter the laboratory results and does not provide medical, legal, or warranty advice. Information attributed to Health Canada, the Government of Quebec (MSSS), the Public Health Agency of Canada, the INSPQ, and Take Action on Radon is summarized from the public sources listed above; confirm any details subject to change (campaign dates, program availability) with the responsible organization.