Nov. 14, 2017

Evict Radon fact sheet

University of Calgary study aims to gather data for medical research on the prevalence of carcinogenic gas in Alberta homes
A radon test device is smaller than a hockey puck and requires no electricity. Photo by Riley Brandt, University of Calgary
A radon test device is smaller than a hockey puck and requires no electricity. Photo by Riley Brandt

Who: Aaron Goodarzi, PhD and study principal investigator supported by the Alberta Real Estate Foundation.

What: We’re asking Albertans to join a provincewide campaign to Evict Radon and help gather data for medical research. Cumming School of Medicine researchers at the University of Calgary want to map household radon throughout the province and understand what type of homes are most at risk.

Why: Radon is a known carcinogen. According to the Canadian Cancer Society, radon is the second most frequent cause of lung cancer, after cigarette smoking and the leading cause in non-smokers. A recent study proved radon is prevalent throughout southern Alberta and in Calgary area homes. Researchers are now expanding their study to see whether those findings will be consistent in all areas of Alberta.  

Q: How can I join the study?
A: Sign up here We are accepting participants for the study until the end of January 2018. One thousand people who purchase 90-day tests will be selected by scientists for an additional free five-day radon testing device, to help understand how short term tests compare to the current gold-standard 90-day tests.

Q: Is there a cost?
A: Yes, study participants have to pay for their own 90-day radon testing kits. The cost is $60. Test kits will be shipped within a week of signing up, from now until the end of January.

Q: Is it hard to use the testing device?
A: No. A radon test device is smaller than a hockey puck and requires no electricity. You simply place it in the lowest level of the home where someone spends more than four hours a day. Radon West, the company supplying the radon tests, created an informational video on how to place the testing device.

Q: How long does the test take? 
A: To be reliable and accurate the radon test device must be placed inside a home for 90 days.

Q: What happens after the 90 days?
A: You repackage the kit in the box you received it in, affix the prepaid shipping label and post it to the central testing laboratories for North America. Participants will receive their confidential radon reading directly by email or post, together with advice from scientists about what their reading means and whether a mitigation procedure is recommended.

Q: Is the Evict Radon website the only place I can get information?
A: Free town hall information sessions will take place in Calgary and Edmonton in late November and early December 2017. Information on dates and locations can be found on the Evict Radon website and Facebook page. You can also email your questions to

Key Findings from the study testing Calgary and area homes:

  • 12.4 per cent (or one in eight) homes exceeded the 200Bq/m3 Health Canada maximum acceptable radon limit guideline.
  • Exceptionally high radon readings were observed across the region; all neighbourhoods are at risk. No areas contained homes entirely below Health Canada guidelines.
  • Newer homes built in the past 25 years had 31.5 per cent higher average radon levels compared to older homes built prior to 1992.
  • In southern Alberta, mitigation is highly effective, so there is a straightforward solution to the problem for homeowners at risk.


Q: What is radon gas?
A: Radon is a colourless, odourless, tasteless radioactive gas found naturally in the environment. Radon gas arises from the radioactive decay of radium, thorium and uranium-bearing soils and bedrock, and is prevalent across the prairies in North America.

Q: How does it get in my home?
A: Radon permeates through soil under high pressure towards low or negative pressurized areas such as basements. As homes are heated and the hot air rises, it creates a suction effect from the foundations to upper levels. The suction effect causes radon from the ground to be actively drawn up through foundations to accumulate within indoor air. 

Q: Why are homes with larger foundations at greater risk of higher radon concentrations?
A: Bigger homes mean a greater surface area upon which properties are in contact with the underlying soil, and therefore a greater surface through which to draw in radon. The concrete foundations of larger properties also undergo greater overall shrinkage as they cure (dry), generating larger gaps where the foundations meet the basement walls creating larger entry points for radon.

Q: Why are newer homes (built in past 25 years) at greater risk of higher radon concentrations than older homes?
A: Newer homes can have tighter air-sealing and may exhibit unbalanced air-exchange, which means there is less ventilation of interior air with the outside. Radon that is seeping into the home simply isn’t escaping as effectively as it does in “leakier” homes. 

Q: Is remediation effective?
A: Yes, remediation methods carried out by C-NRPP certified professionals (the Health Canada approved certification for radon mitigation and testing workers) are effective at reducing exposure, suggesting that radon testing and mitigation will be a successful cancer prevention strategy.