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Environmental and Workplace Health

How to Test for Radon?

Radon testing is relatively simple and inexpensive. Radon test devices can be purchased by phone or over the internet and are available at some home improvement retailers across Canada. For more information on do- it-yourself radon test kits contact Health Canada's Radiation Protection Bureau at radon@hc-sc.gc.ca or 613-946-6384.

You can also hire a certified radon measurement professional to come and test your home. Health Canada recognizes the Canadian certification program, Next link will take you to another Web site Canadian National Radon Proficiency Program (C-NRPP) offered through the American Association of Radon Scientists and Technologists (AARST), 1 800 269-4174. Lists of certified Canadian measurement and mitigation professionals are available through the Next link will take you to another Web site Canadian National Radon Proficiency Program.

The most popular long term radon detectors are the electret ion chamber and the alpha track detector. These devices are exposed to the air in a home for a specified period of time, and then sent to a laboratory for analysis. Radon is measured in units called "becquerels per cubic meter" (Bq/m³). It is not uncommon to see radon levels in a house change by a factor of two to three or more over a one-day period. Seasonal variations can be even more dramatic with the highest levels usually experienced during the fall and winter months when air circulation and ventilation is decreased. Since the radon concentration inside a home varies over time, measurements gathered over a longer period of time are generally considered to give a more accurate picture of the radon exposure. Health Canada recommends that homes be tested for a minimum of three months, ideally during the winter months as the radon concentrations are usually representative at this time.

When conducting the radon test yourself observe the manufacturer's instructions and the guidelines below when placing a radon detector in your home:

  • Make the measurement in the lowest lived-in area of your home. By lived-in we mean; where you or a member of your family spends more than 4 hours per day in that area.
  • Avoid taking measurements in the kitchen. The exhaust fan as well as humidity and airborne particles from cooking may affect the accuracy of some types of radon detectors. Also, avoid bathrooms since relatively little time is spent in this room.
  • Place the detector where it will not be disturbed during the measurement period but avoid small enclosed areas, such as a cupboard or closet.
  • Do not place the detector close to an outside wall or near a sump or floor drain.
  • Avoid locating the detector in drafts from heating or air conditioning vents, near windows or doors, or sources of heat, such as stoves, fireplaces or strong sunlight.
  • Place the detector a minimum of 50cm from any floor, wall or ceiling and more than 20cm from other objects.

Health Canada has developed standard protocols for radon testing in homes, schools and other large buildings. These protocols provide detailed instructions and guidance to radon testing companies and homeowners on how to perform a radon test. Health Canada recommends that homes be tested for a minimum of three months, ideally in the fall / winter timeframe. The cost of radon testing is approximately $50 to $100.

As part of the National Radon Program, Health Canada has completed a Cross-Canada residential radon survey in an effort to gain a better understanding of radon concentrations in homes across Canada.