Radon is an invisible, odourless radioactive gas that can be found in homes across Canada. It is produced naturally in the ground as uranium breaks down. The resulting gas can seep through cracks in the foundation, pipe openings, sump pits, and other openings into your home. Although it is present in almost all homes, levels can range from safe to hazardous even within the same neighbourhood. Over time, breathing in hazardous levels may cause lung cancer.

The role of the TBDHU is to:

  • Raise awareness about this gas and its possible health hazards.
  • Provide information about testing.
  • Partner with and support local organizations to promote radon gas awareness and testing.
  • Monitor overall radon levels in the area.
  • Provide recommendations related to public health and further research.


Radon and You

Radon in Oliver Paipoonge and Marathon

In 2017/2018, the TBDHU conducted a study of homes in the communities of Oliver Paipoonge and Marathon. The full report is available for download: The Prevalence of High Residential Radon in Two Communities Within Thunder Bay District

The study found that 65% of homes in Oliver Paipoonge had high levels of radon. This is significantly higher than the Ontario average of 5%. For those who live in Oliver Paipoonge, there is a very high probability that they are living with high radon levels. Residents of Oliver Paipoonge should immediately test their homes for radon, and reduce radon levels to the lowest practical level.

In the town of Marathon, the study found that 17% of homes had high levels of radon. While this result is lower than Oliver Paipoonge, it is still over three times the provincial average. All Marathon residents should test their home for radon and reduce radon levels to the lowest practical level.


Radon in Thunder Bay

In 2014/2015 the Thunder Bay District Health Unit conducted a study of City of Thunder Bay homes and found that 16% of the houses tested had radon levels higher than Health Canada guidelines. This result is well above the Canadian average of 6.9% and the Ontario average of 4.6%. The number of homes with high radon levels varied widely in different wards of the city with McIntyre at 43%, Neebing at 30%, Red River at 15%, Current River at 13%, Northwood at 5%, and McKellar at 2%. No homes in Westfort were found to have high levels of radon.

The complete TBDHU report was released in November 2015: The Prevalence of High Residential Radon in Thunder Bay (PDF)


Testing for Radon Levels in Your Home

The only way to know if you have radon in your home is to test with an inexpensive and easy-to-use kit. This small unit (often a puck-like disc but there are different kinds) sits in a key area of your basement. The instructions include directions on where to place the kit for the most accurate readings. Over time (it’s recommended you test over a three-month period), radon gas will seep into the test kit, where it is recorded.

Winter months are the best time to test when doors and windows are more likely to be closed and there is less air movement in the house.

After three months, simply follow the mailing directions included with the kit. A special lab analyzes the kit to determine how much radon was in your home during the test period. The current Canadian guideline for radon in indoor air for dwellings is 200 Becquerels (a measurement of radioactivity) per cubic metre. If your test comes back higher than this, you should find ways to reduce those levels (see below).

Long-term kits are available at many hardware stores or you can get one locally from EcoSuperior Environmental Programs for $50.00 (include lab fee and postage).

For more information on testing, visit Take Action on Radon.


What to Do if You Have High Levels of Radon

Current Health Canada guidelines recommend that if your test indicates a radon level of 200 Becquerels per cubic metre or higher, you should address the problem within two years, and within one year if levels are higher than 600 Becquerels per cubic metre.

There are several ways to reduce radon levels in your home depending on a variety of factors. Health Canada strongly recommends hiring a professional contractor certified under the Canadian National Radon Proficiency Program (C-NRPP). However, it is also possible for homeowners with the right skills to reduce radon themselves.

Find out more in the Radon Reduction Guide for Canadians (Health Canada) (PDF)

Find a certified radon professional (C-NRPP)


Mike Holmes on Radon:

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