Soil gases are naturally occurring throughout Canada and some may pose a health risk if they are allowed to accumulate in our our buildings, mainly through leaks in basements and cellars.

Soil gases common in Canada include: Carbon Dioxide, Nitrogen, Oxygen, Methane and Radon.

Radon is of most concern since it is radioactive and has been linked to cancer. The gas is colourless and odourless that occurs naturally in the environment, from the natural breakdown of uranium in soils and rocks. Radon is measured in "becquerels" per cubic metre of concentration in ambient air.

Very low levels occur in the outdoors, but if trapped in houses, Radon may build up to the point of being a hazard - exposure to radon has been associated with an increased risk of lung cancer, depending on concentration and exposure time.

ADDITIONAL RESOURCE ON RADON: Canadian Centre for Occupational Health and Safety "Radon in Buildings".