There may be a colourless, odourless toxic gas in your home without you realizing it. Radon, a radioactive element that seeps up from the earth itself is something many homeseekers in B.C. may not be aware of, but it’s worth knowing what it is and how you can handle it to protect your health and the value of your home.
What is radon and why is it dangerous?
Radon is a colourless, odourless radioactive gas with the atomic number 86 (Rn). It’s released from the ground and can accumulate indoors, posing significant health risks. Inhaling radon can damage lung tissue and it’s the leading cause of lung cancer among non-smokers, with even higher risks for smokers.
Radon enters homes through cracks and openings in the foundation, particularly in basements and lower levels. Unlike in outdoor environments where it can disperse, indoor spaces can trap radon, leading to dangerously high concentrations.
How much radon is too much radon?
Because it exists naturally, low levels of radon are everywhere. Usually, outdoor levels of radon are around 5 – 15 Bq/m³. “Bq” stands for becquerel, a unit used to measure radioactive decay, or disintegration, of a radioactive element, one disintegration per second. The “m³” stands for metres cubed. So, 1 Bq/m³ is one disintegration per second per cubic metre.
The Government of Canada sets an “action level” at 200 Bq/m³. If your home has radon levels above this point, take action to lower them. But even if there are lower levels of radon than this indoors, if they’re consistently above outdoor levels, it may still be a good idea to do something.
According to Health Canada, the following recommendations apply:
- At levels between 200 – 600 Bq/m³: Take steps to reduce radon levels within two years.
- At levels greater than 600 Bq/m³: Take steps to reduce radon levels within one year.
What areas of B.C. have high levels of radon?
The B.C. Centre for Disease Control has created a map illustrating areas in British Columbia and the percentage of homes in those regions with radon levels exceeding 200 Bq/m³. For instance, around 1% of homes in Vancouver and Richmond exceed this threshold, while areas near cities like Kelowna and Penticton show over 30% of homes with elevated levels.
However, it's crucial to understand that radon levels can vary significantly from one home to another, even within regions known for low radon levels. The only reliable way to determine the radon level in your home is through testing.
Keep in mind that radon is naturally occurring everywhere, so no home in Canada is entirely free of it. Even if your neighbours have low radon levels, you may still have elevated levels. Additionally, both new and older homes can experience high radon levels.
How do I measure the levels of radon in my home?
Although radon is invisible and odourless, there are effective methods to measure its concentration in your home. Radon levels can vary due to several factors, such as the opening and closing of windows and doors, the amount seeping up from the ground, and more. Therefore, it’s important to take multiple measurements and calculate an average over time.
The Government of Canada advises measuring radon levels over a period of three to 12 months. Plus, radon levels are often higher in winter when doors and windows are typically closed.
You can measure radon levels yourself or hire a professional for the task.
To measure radon levels yourself:
- Start by purchasing a radon test kit.
- Make sure it’s a long-term test kit. That is, ensure it’s for more than 90 days.
- After you receive the kit, follow the manufacturer’s instructions on how to use it and get test results.
To have a professional test your home for radon:
- Find a radon measurement professional in your area.
- Ask the professional to set up a test in your home. Ensure it’s a long-term test for more than 90 days.
- Follow the professional’s instructions on how to prepare your home for the test.
Testing is not a one-and-done scenario, though. Health Canada recommends testing once every two years. This will ensure that radon levels are still within acceptable limits throughout the time you’re living in your home.
How do I mitigate radon in my home?
If radon levels in your home exceed 200 Bq/m³, you can take steps to mitigate the issue, with the most common method being active soil depressurization (ASD). This involves drawing air from beneath the foundation and venting it outside, typically requiring the installation of a pipe and fan after drilling a hole in the foundation. It's important to seal any cracks in the foundation, but sealing alone is insufficient without an ASD system. New homes built after 2024 in BC in certain areas may have a radon mitigation rough-in, which includes a vent pipe, to facilitate future mitigation if testing determines it’s needed.
For homes with crawl spaces, encapsulation with a plastic sheet and a similar venting system can be used. In strata complexes, residents must work with their strata board to address high radon levels, which might require a special levy. Renters should inform their landlords about high radon levels, as landlords are obligated to maintain a safe living environment under the B.C. Residential Tenancy Act.
Radon mitigation is generally straightforward, with professional installation taking a short time. Costs range from $3,000 to $11,000, typically averaging on the lower end. The Canadian Lung Association also offers grants of up to $1,500 for eligible low- to moderate-income applicants and those diagnosed with lung cancer.
What should I do about radon when buying or selling a home?
Homeseekers should ask the listing agent or seller about any long-term radon testing conducted on the property and its results. Note that a week-long subject removal or three-day rescission period is insufficient for accurate long-term radon testing. While there is no requirement for sellers or agents to perform these tests, radon levels above 200 Bq/m³ are considered a material latent defect and must be disclosed if known. Some home inspectors may offer radon testing, but it's important to ensure it’s a long-term test for accurate results.
Potential buyers can check local maps for areas with high radon prevalence, but this doesn't guarantee similar levels in the specific home. It’s advisable to conduct a long-term radon test shortly after moving in to determine if mitigation is needed.
For sellers, conducting a long-term radon test before listing the home can be beneficial. If elevated levels are found, installing a radon mitigation system may increase the home's appeal. Conversely, if levels are safe, this information can be a positive selling point for prospective buyers.
Although radon may sound scary, testing is simple to carry out and if levels in your home are found to be high, it’s not complex to mitigate. Doing so will help safeguard your health and the resale value of your home.
Attribution: This radioactive gas may sound scary, but it’s relatively simple to deal with.
