What is Radon?
Radon is a radioactive gas that comes from the breakdown of uranium in soil and rock. It is invisible, odourless and tasteless. When radon is released from the ground into the outdoor air, it is diluted and is not a concern. However, in enclosed spaces, like homes, it can accumulate to high levels and become a risk to the health of you and your family.
How does radon enter buildings?
Radium in the soil directly under a building is normally the major source of indoor radon. Less important sources of radium are in ground water and building materials.
The presence of uranium in soil and rock is an important indicator of places where radium and radon can be present. Because radon is a gas, a fraction of the radon produced in the soil can find its way into a building. The rest is trapped in the soil. In the air, radon decays to radon progeny that are solids, and are present in the building air as fine particles. Because radon is a gas, changes in the atmospheric pressure also affect its emission from the ground and its accumulation in the building air. The concrete floor and walls in the basement slow down the movement of radon from the soil into the building. However, cracks in the floor, wall slab joints, and the drainage system allow radon to enter a building.
What are the health effects of radon?
Inhaling radon progeny increases the risk of lung cancer. The link between the concentration of radon progeny in the air and the risk of lung cancer was first based on data from a study of lung cancer mortality among uranium miners and other workers exposed to very high levels of radon progeny.
How do you test for indoor Radon levels?
To provide a realistic estimate of indoor radon levels, all measurements are made in the lowest level of a building which 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. A small disc-like detector is placed in strategically identified areas and left in place for a period of 91 days during the heating season. The ratio of disks to space often determined by Health Canada guidelines. These disks are harmless to occupants.
If you would like more information regarding testing of your home, the local health unit is currently hosting information sessions.
Public Homeowner Information sessions
https://www.peterboroughpublichealth.ca/your-health/home-health-and-safety/radon/
Other resources
https://www.ccohs.ca/oshanswers/phys_agents/radon.html