Radon levels vary significantly across Canada, influenced by local geology, soil composition, and building practices. Health Canada's Cross-Canada Survey of Radon Concentrations tested over 14,000 homes and revealed some striking regional differences. Here's what the data shows ? and why every Canadian home should be tested regardless of where it's located.
The National Picture
According to Health Canada's most recent survey data (2024), approximately 17.8% of Canadian homes have radon levels above the national guideline of 200 Bq/m³. That translates to nearly 2 million homes across the country where occupants may be exposed to elevated radon without knowing it.
Note: An earlier Health Canada Cross-Canada Survey reported approximately 7% of homes above the guideline. The higher 2024 figure reflects expanded testing and updated methodology.
The national average radon concentration was approximately 77 Bq/m³, but this number masks enormous variation between ? and within ? provinces.
Province-by-Province Breakdown
Saskatchewan consistently shows the highest radon levels in Canada. The Cross-Canada Survey found that approximately 35% of homes tested in Saskatchewan exceeded 200 Bq/m³. The province's uranium-rich geological deposits in the Canadian Shield and prairie soils are a significant contributing factor.
Manitoba also has notably elevated radon levels, with roughly 26% of homes above the guideline. Winnipeg in particular has been identified as a city with significant radon concerns.
New Brunswick is another province with higher-than-average radon, with approximately 20% of homes exceeding 200 Bq/m³. The province's geology, including granite and shale bedrock, contributes to higher soil radon concentrations.
Ontario has varied radon levels depending on the region. While the provincial average is moderate, certain areas ? particularly those with Canadian Shield geology in central and eastern Ontario ? have higher concentrations. Overall, approximately 8–10% of Ontario homes may exceed the guideline.
British Columbia shows lower overall averages, but pockets of elevated radon exist, particularly in the interior regions. Approximately 10% of BC homes tested above the guideline.
Alberta has moderate levels overall, with approximately 12% of homes above 200 Bq/m³. Southern Alberta and areas near the foothills tend to have higher concentrations.
Atlantic Provinces (Nova Scotia, PEI, Newfoundland & Labrador): Generally show lower averages, but individual homes can still have significantly elevated levels. Testing is the only way to know for certain.
Why Your Neighbour's Result Doesn't Predict Yours
One of the most important things to understand about radon is that levels can vary dramatically between houses on the same street. Factors that influence a specific home's radon level include:
- Foundation type and condition ? cracks, gaps around pipes, and sump pits provide entry points
- Soil permeability ? sandy soils allow more radon to migrate than clay
- Building ventilation ? tighter homes may trap more radon indoors
- Water sources ? well water can contain dissolved radon in some regions
Two homes side by side, built in the same year, can have radon levels that differ by a factor of 10 or more. Provincial averages and maps are useful for understanding general risk, but they cannot tell you what your home's level is.
Why Every Home Should Be Tested
Health Canada recommends that every home in Canada be tested for radon, regardless of location, age, or construction type. This is because:
- Radon is colourless and odourless ? you cannot detect it without a test
- Provincial averages don't predict individual home levels
- Even in low-risk provinces, individual homes can exceed 200 Bq/m³
- According to Health Canada, radon is the leading cause of lung cancer in non-smokers in Canada
The only way to know your home's radon level is to test it. A long-term test of 91+ days during the heating season gives the most reliable picture of your home's annual average.
Test your home today. Order a RadonTest.ca kit ? includes the detector, lab analysis by our C-NRPP and ISO 17025 certified lab partner, Lex Scientific, email reminders, and results delivered with clear Health Canada context. Visit our FAQ for common questions.