Spotlight on Health

Radon – The second leading cause of lung cancer in Canada. Are you at risk?

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© All Rights Reserved. Radon Reduction Guide for Canadians. Health Canada, 2013. Adapted and reproduced with permission from the Minister of Health, 2017.

Article submitted by: Dr. Farhan M. Asrar 

November is Radon Action Month and if you have not heard of Radon or not sure if this really matters to you then read on.

What is Radon?

  • Radon is a colourless and odourless radioactive gas that is formed naturally from the breakdown of uranium in the soil.

Is Radon exposure common and why does this matter to me?

  • “Radon represents almost 50 per cent of a person’s lifetime radiation exposure”
  • All homes have some level of radon.
  • Radon can build up to levels that can pose a health concern.
  • For Ontario, 8.2 per cent of homes had levels of radon above the Canadian guideline.

How can Radon enter my home?

  • Radon can enter homes through any opening which contacts the soil: through cracks or foundation gaps, floor drains, etc.

What are the health concerns?

  • Radon is the second leading cause of lung cancer.
  • In Canada, 16 per cent of lung cancers deaths are attributable to radon (around 3,200 deaths each year)
  • Smokers exposed to high levels of radon have a significantly higher risk of developing lung cancer (compared to the risk of either factor individually).

What are the risks of causing lung cancer?

  • The risk of lung cancer depends on the level of radon, duration of exposure, and if you smoke.
  • The risk of developing lung cancer from exposure to high radon (800Bq/m3) alone is one in 20. BUT in smokers exposed to high levels of radon, the risk increases to one in three!

What can I do about it?

  • Educate yourself and tell others about Radon
  • If you smoke, then quit!
  • Test your homes (to know if levels are above the Canadian guideline or not)
  • Health Canada recommends testing your home for a minimum of three months, preferably during the winter.
  • Get your own test kit or hire a professional. Test kits can cost between $30 to $60 and can be bought from hardware stores or online.
  • High levels of radon in homes can be fixed at a reasonable cost
  • When hiring a professional to reduce high levels of radon, Health Canada recommends hiring professionals certified through the Canadian National Radon Proficiency Program (C-NRPP).

Where can I get more information?

  • Talk to your doctor about Radon



Canada. Health Canada. Radon [Internet]. Ottawa, ON: Health Canada; 2017 [updated 2017 Sep 21]. Available from:  Accessed: 2017 Sep 26.

Health Canada. It’s your health: radon. Updated. Ottawa, ON: Health Canada; 2012 Sep. Available from: Accessed: 2017 Sep 26.

Bush K ; Canada. Health Canada. Radon: is it your patient’s homes? Presented at: College of Family Physicians of Canada Air Quality Health Index (AQHI) Train the Trainer Project; 2017.

Canada. Health Canada. Cross-Canada survey of radon concentrations in homes : final report. Ottawa, ON: Health Canada; 2012. Available from: Accessed: 2017 Sep 26.

© All Rights Reserved.  Radon.  Health Canada, 2017. Adapted and reproduced with permission from the Minister of Health, 2017.


About the contributor:

Dr. Farhan M. Asrar is Assistant Professor with the Dept of Family and Community Medicine (DFCM), University of Toronto and Cross-Appointed with the Dalla Lana School of Public Health. He is also Research Lead for the Credit Valley and Summerville Family Medicine Teaching Units, Mississauga, Ontario (Trillium Health Partners & DFCM, UofT). Dr. Asrar served as member of the OCFP’s Environmental Health Committee (EHC) and was the founder and editor of its provincial EHC newsletter.

Dr. Asrar is a CFPC AQHI Trainer under the CFPC Train-the-Trainer Project which is an educational outreach program (organized by the CFPC and funded by Health Canada) that educates health professionals on Safe Environments, including climate change and health, the Air Quality Health Index and Radon.


Posted on September 25, 2017 in newsletter

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