Radon & Your Health

Radon is an odourless, colourless, tasteless gas that occurs naturally in the environment. When radon is released from the ground outside, it is diluted and is not a concern. However, in buildings it can sometimes accumulate to high levels, which can pose a health risk.

Some facts about radon include:

  • Radon is the leading cause of lung cancer after smoking and causes 16% of lung cancer deaths each year.
  • Radon levels can only be determined by testing. An estimated seven per cent of buildings in Toronto, including homes, workplaces and schools, have levels of radon that may pose a health risk.
  • In Toronto, 10 deaths related to radon exposure could be prevented each year if radon levels were reduced below the Canadian radon guideline of 200 Bq/m3.

To test your home for radon, you have two options:

  1. Buy a do-it-yourself test kit
  2. Hire a professional.

Radon test kits can be purchased online or from many home improvement stores. The radon test kits include instructions on how to set up the test and to send it back to a lab for analysis once the testing period is over.

When purchasing a radon test kit, be sure that it is a long-term test kit (one that measures radon levels in your home for at least three months).

For more information, visit the Take Action on Radon website for a list of Health Canada-approved tests.

If the level of radon is higher than 200 Bq/m3 you can hire a professional who may use simple measures such as sealing a sump pump and/or opening and filling cracks in the foundation to lower radon levels.

Although Toronto Public Health does not fund or has a program supporting remediation, there are options available:

  • The Canadian Lung Association and Ontario Renovates Program may offer financial assistance for radon mitigation to eligible homeowners.
  • Radon discovery is also covered under Ontario’s New Home Warranty, and mitigation costs for homes under 7 years old are included.
  • Ontario’s 2024 Building Code require homes to adopt a proactive approach to address soil gas/radon by requiring new houses to have rough-ins for radon mitigation systems, effective January 1, 2025.