Understanding Radon: Risks and Prevention

This month we’d like to talk about Radon gas which is a topic that is increasingly coming up in real estate transactions. Below we briefly discuss what radon is, how it can affect you, and what can be done about it.

Radon is a naturally occurring radioactive gas produced by the breakdown of uranium found in soil, rock, and water. It is invisible, odourless, and tasteless, meaning it cannot be detected by human senses alone. While radon released outdoors is diluted and generally not a concern, it can accumulate to dangerous levels within enclosed spaces like homes. Soil gas is the primary source of indoor radon, entering buildings through cracks in foundation walls, floor slabs, construction joints, and openings around pipes or sumps.

The health consequences of prolonged radon exposure are significant. The International Agency for Research on Cancer identifies radon as a group 1 carcinogen. It is the leading cause of lung cancer among non-smokers in Canada and the second leading cause overall, estimated to be responsible for 16% of lung cancer cases, The health risk depends on the concentration and duration of exposure; breathing in radioactive particles released by radon decay damages lung cells, and this risk is significantly higher for individuals who also smoke.

To avoid the dangers of radon, testing is essential, as levels can vary widely even between neighbouring homes. Health Canada recommends a long-term test of at least 91 days, ideally during the heating season, to determine the average annual level, If results exceed the guideline of 200 Bq/m3, corrective action is required. Mitigation strategies include sealing entry points and hiring certified professionals to install active soil depressurization systems, which exhaust soil gases before they enter the home. Furthermore, new building codes often require rough-ins for these systems to facilitate future radon reduction.