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Radon is a radioactive gas found naturally in the environment. It is produced by the decay of uranium found in soil, rock or water. Radon is invisible, odourless and tasteless and emits ionizing radiation. As a gas, radon 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 floors, or gaps around pipes and cables.

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. In the open air, the amount of radon gas is very small and does not pose a health risk.

A two year study from 2009-2011, conducted by Health Canada's National Radon Program, found that 99% of homes that were tested in Porcupine Health Unit area were in the acceptable range below 200 Bq/m3.

If you are interested in further details of the study, view the Cross-Canada Survey of Radon Concentrations in Homes - Final Report.

What are the Health Effects of Radon?

Radon gas breaks down or decays to form radioactive elements that can be inhaled into the lungs. In the lungs, decay continues, creating radioactive particles that release small bursts of energy. This energy is absorbed by nearby lung tissue, damaging the lung cells. When cells are damaged, they have the potential to result in cancer when they reproduce.

Exposure to high levels of radon in indoor air results in an increased risk of developing lung cancer. The risk of cancer depends on the level of radon and how long a person is exposed to those levels.

Exposure to radon and tobacco use together can significantly increase your risk of lung cancer. For example, if you are a lifelong smoker your risk of getting lung cancer is 1 in 10. If you add long term exposure to a high level of radon, your risk becomes 1 in 3. On the other hand, if you are a non-smoker, your lifetime lung cancer risk at the same high radon level is 1 in 20.

How can Radon get into my Home?

The air pressure inside your home is usually lower than in the soil surrounding the foundation. This difference in pressure draws air and other gases, including radon, from the soil into your home.

Radon can enter a home any place it finds an opening where the house contacts the soil: cracks in foundation walls and in floor slabs, construction joints, gaps around service pipes, support posts, window casements, floor drains, sumps or cavities inside walls.

How radon enters a house

How do I Test my Home for Radon?

There are two options for testing a house for radon: to purchase a do-it-yourself radon test kit or to hire a radon measurement professional. If you choose to purchase a radon test kit, you must closely follow the instructions on how to set up the test.

If you choose to hire a service provider to perform the radon test in your house, it is recommended that you ensure they are certified and will conduct a long term test for a minimum of 3 months.

Where can I get a Radon Test Device?

Radon test kits may be purchased over the phone, on the internet or from home improvement retailers. 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. The cost of testing ranges from $25 to $75. For information on radon testing go to:

Where in my Home should I Perform the Test?

To provide a realistic estimate of the radon exposure of your family, all measurements should be made in the lowest lived-in level of the home. That means the lowest level that is used or occupied for more than four hours per day. For some, this may be a basement with a rec room, for others it will be the ground floor. If you only use your basement once a week to do laundry, for example, there is no need to test on that level - your exposure time will not be long enough to create health effects.

How can I Reduce the Amount of Radon in my Home?

If your radon test result is above the guideline of 200 Bq/m3, you can take the following steps to help reduce the level of radon:

  • Ventilate the basement sub-flooring by installing a small pump to draw the radon from below the concrete slab to the outside before it can enter your home (commonly known as Sub Slab Depressurisation typically performed by a contractor).
  • Increase the mechanical ventilation, via a heat recovery ventilator (HRV), to allow an exchange of air.
  • Seal all cracks and openings in foundation walls and floors, and around pipes and drains.

If you want to hire a contractor, Health Canada recommends that the contractor be certified as a radon mitigation professional from an accredited organization.

See Radon Reduction Guide for Canadians for more information on reducing radon in your home.