Getting a radon test result above the Health Canada guideline of 200 Bq/m³ can feel alarming. But here's the important thing: radon is a solvable problem. Effective mitigation systems exist, they work well, and certified professionals across Canada install them every day.
First: Don't Panic
An elevated radon result doesn't require emergency action. The health risks from radon are associated with long-term exposure over years, not days or weeks. You have time to research your options and make a well-informed decision.
That said, Health Canada does recommend acting promptly. If your result is between 200–599 Bq/m³, the recommendation is to mitigate within 2 years. For results above 600 Bq/m³, the recommendation is within 1 year.
What the Guideline Actually Means
The 200 Bq/m³ guideline is Health Canada's action level ? the point at which they recommend taking steps to reduce radon. It's based on a balance between achievable reduction levels and health risk. Radon is the leading cause of lung cancer in non-smokers in Canada, responsible for approximately 3,200 lung cancer deaths annually, according to Health Canada.
The guideline doesn't mean that levels below 200 carry no risk. There is no known threshold below which radon exposure is completely without risk. However, 200 Bq/m³ represents the level at which Health Canada considers corrective action to be warranted.
Finding a Certified Mitigation Professional
The most important step is to hire a C-NRPP (Canadian National Radon Proficiency Program) certified radon mitigation contractor. C-NRPP certification ensures the professional has been trained in proper radon mitigation techniques and follows established protocols.
You can search the C-NRPP directory at c-nrpp.ca to find certified mitigators in your area. Get at least 2–3 quotes before deciding, and ask each contractor about their specific approach for your home's construction type.
How Radon Mitigation Works
The most common and effective mitigation method in Canada is sub-slab depressurization (SSD), also called active soil depressurization. Here's how it works:
- A small hole is drilled through the basement floor slab
- A PVC pipe is connected and routed to the exterior of the home
- A small, quiet fan creates negative pressure beneath the slab
- Radon gas is drawn from under the foundation and vented outside before it can enter your living space
Other methods include heat recovery ventilators (HRVs), which increase air exchange to dilute indoor radon, and sump pit covers with exhaust fans for homes with open sump pits. The best approach depends on your home's foundation type and construction, which is why Health Canada points homeowners to certified professionals for mitigation work.
How Effective Is Mitigation?
Professional radon mitigation systems are remarkably effective. Most SSD systems reduce indoor radon levels by 80% or more. A home with a result of 400 Bq/m³ could reasonably expect post-mitigation levels well below the 200 Bq/m³ guideline ? often below 100 Bq/m³.
What Does Mitigation Cost in Canada?
In most Canadian markets, a standard sub-slab depressurization system costs between $2,000 and $4,000 CAD, depending on factors like foundation type, accessibility, and your location. This is a one-time installation cost, with minimal ongoing expenses (the fan uses about the same electricity as a light bulb).
Some municipalities and provinces offer rebates or incentive programs for radon mitigation. Check with your local health authority for any available programs in your area.
Retest After Mitigation
After your mitigation system is installed, retest your home to confirm the system is working effectively. A post-mitigation long-term test (91+ days) will give you a reliable confirmation of your new radon level.
Need a retest kit? Order a RadonTest.ca kit ? we'll guide you through the process with reminder emails and results delivered with clear Health Canada context.
For process questions, visit our FAQ page. For mitigation options, use the C-NRPP directory.