What is radon gas?
Radon is an invisible, odourless, tasteless, and radioactive gas that forms from the breakdown of uranium in rock and soil. It’s found everywhere on the earth’s surface, although the levels of radon in the soil vary from region to region. Radon is also sometimes present in groundwater.
How can radon affect your health?
Radon is known to cause health problems.
Radon is the leading cause of lung cancer among non-smokers. International health agencies have recognized radon as a carcinogen. In Quebec, 10–16% of lung cancer deaths are attributed to radon, which amounts to over 1,000 deaths a year in the province. Smokers are at a higher risk of developing lung cancer from radon. The gas doesn’t directly cause breathing difficulties, however, nor is it known to cause issues such as chronic bronchitis, asthma, allergies, or birth defects.
Radon can seep into a house through dirt floors, drains, crawlspaces, joints, faucets, cracks in the foundation walls or concrete slab, and openings around vent pipes and service lines. Upon inhalation into the lungs, radon breaks down into radioactive particles that release small burst of energy. This energy is absorbed by lung tissue which damages the lung cells. Damaged cells can become cancerous when they reproduce.
Radon gas is harmless outdoors, as it quickly becomes diluted by the fresh air.
How to detect radon
Homeowners can purchase a radon gas detector from a local hardware store or have a professional perform tests.
Radon is measured in becquerels per cubic meter (Bq/m³), which are a gauge of radioactivity. The detector will give you two readings: a short-term reading (usually a seven-day average) and a long-term reading (an average of all measurements taken). Radon levels can change from day to day and month to month in the same space.
Place the detector in the basement or in an area on the lowest floor of the home where people usually spend more than four hours a day. Place the device at height of no more than 6 feet. Don’t place the device in humid areas (above 85%), or within 3 feet of ventilation sources such as vents, fans, windows, or doors. An influx of fresh air will skew the results.
Health Canada recommends that radon levels within living spaces do not exceed 200 Bq/m³.
If the reading is higher, Health Canada recommends corrective action:
- For a reading of between 200 Bq/m³ and 600 Bq/m³, take corrective action within two years.
- For a reading greater than 600 Bq/m³, take action within one year.
We will look at corrective measures below.
Implications for homebuyers and sellers
Sellers
As a seller and a homeowner, you should have your home tested for radon, even though you are not legally required to do so. A prospective buyer may ask about the radon levels in your home.
However, readings above 200 Bq/m³ constitute a material latent defect which you and your real estate agent or broker would be obligated to disclose to potential buyers. Additionally, if you’re unable to provide the results of a radon test, the buyer may reduce their offer price or hold back funds until the house is tested.
Buyers
As a buyer, you should ask the seller if they have long-term radon gas readings and request a copy of the results. If the seller has tested, ask where in the house they got readings, especially if the house has a basement. If the house hasn’t been tested, make sure that tests get done before you close the deal.
It’s also wise to start running long-term tests after you move in, just to be safe.
