Radon - What You Need to Know


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ISBN: 978-0-660-08393-3
Cat.: H129-75/2017E-PDF
Pub.: 100484

Organization: Health Canada

What is Radon?

  • Radon is a radioactive gas that comes from uranium in the ground that can get into your home undetected. You can’t see it, smell it or taste it.
  • All homes have some level of radon. The question is how much and the only way to know is to test.
  • In confined spaces like a house, radon can build up to high levels and over time become a health risk.

The current Canadian guideline for radon is 200 becquerels per cubic meter (200 Bq/m3).

Diagram - Text description

This is a diagram of radon movement indoors as well as outdoors. Because radon is a gas, it can move freely through the soil enabling it to escape to the atmosphere or seep into buildings. When radon escapes from the bedrock into the outdoor air, it is diluted to such low concentrations that it poses a negligible threat to health. However, if a building is built over bedrock or soil that contains uranium, radon gas can be released into the building through cracks in foundation walls and in floor slabs, construction joints, gaps around service pipes and support posts, floor drains and sumps, cavities inside walls, and the water supplies. When radon is confined to enclosed or poorly ventilated spaces, it can accumulate to high levels. Radon levels are generally highest in basements and crawl spaces because these areas are nearest to the source and are usually poorly ventilated.

Radon: What You Need to Know

What are Health Risks?

  • Radon exposure is the number two cause of lung cancer, after smoking. 16% of lung cancers are estimated to be from radon exposure, resulting more than 3,200 deaths in Canada each year.
  • People who smoke and are exposed to radon have an even higher risk of lung cancer.
  • The health risk from radon is long-term not immediate. The longer you are exposed to high levels of radon, the greater your risk.

How Do I Test My Home For Radon?

  • Testing for radon is easy and inexpensive.
  • Testing can be done by purchasing a do-it-yourself radon test kit or by a measurement professional that is certified under the Canadian National Radon Proficiency Program (C-NRPP).
  • Radon levels in a home can vary significantly over time so you need to do a long term test, for 3 months, ideally during the fall or winter time.
  • Go to TakeActiononRadon.ca/test to find a test kit or certified professional.

My Home Tested Above the 200 Bq/M3 Limit, What Now?

  • Techniques to lower radon levels are effective and can save lives. Radon levels can be reduced by more than 80% for about the same cost as other common home repairs such as replacing the furnace or air conditioner.
  • The higher the radon level in your home, the sooner it needs to be fixed.
  • Hire a certified radon mitigation professional to help you find the best way to reduce the radon level in your home. The most common radon reduction method is active soil depressurisation (ASD).
  • Go to c-nrpp.ca to find a certified mitigation professional.
  • Only a small percentage of Canadian homes will have radon levels above the guideline, the only way to know is to test


For more information on radon, visit canada.ca/radon or www.takeactiononradon.ca

 © Her Majesty the Queen in Right of Canada, represented by the Minister of Health, 2017

Cat.: H129-75/2017 (Print)
Cat.: H129-75/2017E-PDF
ISBN: 978-0-660-08393-3
ISBN: 978-0-660-08391-9
Pub.: 100484

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