What is Radon? 

Radon is a naturally occurring, radioactive gas created from the decay of uranium in minerals present in rock, soil and water. Radon is present in every indoor environment – i.e. homes, schools and workplaces. The question is, to what degree? You cannot see, smell or taste radon, therefore the only way to know the radiation level you are being exposed to is to conduct a simple radon test. Though naturally occurring in the environment, radon poses a threat in enclosed spaces, where it has the potential to accumulate to high levels1. This threat is due to radon’s extremely radiative nature, having the ability to emit alpha radiation as it decays. Once inside the lungs, radon decay products can genetically damage delicate lung cells –potentially leading to the development of lung cancer when these cells reproduce. Radon is one of the most deadly and overlooked health risks today.

Radon and Lung Cancer

Radon is the leading environmental cause of lung cancer, the leading cause of lung cancer in non-smokers and the second leading cause of lung cancer in smokers2. In addition, exposure to radon and tobacco use together can significantly increase your risk of lung cancer1. Research shows that if you are a lifelong smoker and also exposed to high levels of radon, your risk of getting cancer increases from 1 in 10 to 1 in 31. According to Health Canada, the risk of lung cancer is dependent on the levels of radon present in the environment and how long a person is exposed to those levels. Despite the imminent danger radon presents, most Canadians are unaware of radon gas and the significant health risk it poses. The Environmental Protection Agency (EPA) and US Surgeon General estimate that approximately 21,000 lung cancer deaths are attributable to radon exposure every year in the USA. Health Canada recently increased its estimate of radon induced lung cancer deaths to approximately 16% of all lung cancers or approximately 3,200 Canadians that die annually from radon exposure. The World Health Organization (WHO) similarly estimate around 14% plus of all lung cancer deaths globally are radon induced. This represents approximately 189,000 of the 1.4 million people that die annually from this disease.

How Radon gets into the home

When radon is present in an outdoor environment, the air is able to dilute the gas to non-threatening levels1. The concern of radon rises when it becomes trapped in enclosed spaces, such as the family home. The more enclosed or poorly ventilated a space is, the higher radon levels can accumulate. For instance, radon levels are usually highest in basements or crawl spaces as they are nearest to the source and are often poorly ventilated1. According to Health Canada, the difference in air pressure from inside vs. outside the home draws air and other gases, including radon, from the soil into your home1. Radon is able to enter a home through any opening where the house contacts the ground – cracks in the foundation floor and walls, construction joints, gaps around service pipes, support posts, window casements, floor drains, sumps or cavities inside walls1


Reproduced with the permission of Natural Resources Canada 2008, courtesy of the Geological Survey of Canada
Reproduced with the permission of Natural Resources Canada 2008, courtesy of the Geological Survey of Canada
Testing for Radon 

According to the Canadian Association of Radon Scientists and Technologists, it is important to test for radon in all buildings as ”no area is radon free”3. This includes both newly built homes (to be done during the first heating season of the house) as well as older homes3

How to detect Radon in your environment 

Since you cannot taste, smell or see radon gas, radon detection technology has been developed to test and monitor radon levels in homes and workplaces. There are two basic ways to test for radon: short term and long term. Short term tests must be a minimum duration of 48 hours up to 91 days3. Long-term testing can be from 91 days to one year3.

What’s the difference between short-term and long-term testing?

Radon gas levels in a home are not the same every day. Weather changes, how often windows and doors are opened and closed, the type of air conditioning/heating systems, and lifestyle all contribute to the level of radon gas in your home each day. A short-term test may show unusually high or low levels due to the weather and activity in your home. The overall purpose of a short term test is to provide quicker results than a long term test is able to provide, which can be useful for various situations3.A long-term test will average your exposure to radon levels over a period of time, and experts agree that this gives a more conclusive test result. Not only does this type of testing provide you with the most accurate information on how your home’s radon levels can put you at risk for lung cancer, but Health Canada also recommends a long term test should be done before making a decision to mitigate1.

How do I buy a Radon test kit? 

If you are concerned about radon, there are kits available that allow you to test for radon levels in your home. There are different methods used to measure radon. One method involves alpha track technology. The detector is placed in your home from one month to one year (Health Canada recommends that homes be tested for a minimum of three months in the lowest lived-in level of the home, ideally during the winter1). It is then sent for analysis and a report is returned to you. Another method continuously tests for radon using an electronic radon gas detector. This has the advantage of a numeric display and audible alarm for high radon levels. The cost of a radon test ranges from $30 to $601. For more information on radon testing and how to buy one, visit https://takeactiononradon.ca/test/radon-test-kits/

When to hire a professional

If your radon test kit result is above the Canadian guideline of 200 Bq/m3  it is recommended you hire a certified radon professional to determine the best and most cost effective way to reduce the radon levels present in your home4. Health Canada highlights the importance of making sure that the contractor is certified as a radon mitigation professional by the Canadian National Radon Proficiency Program (C-NRPP)4. You can hire a radon mitigation professional by visiting https://takeactiononradon.ca/test/find-a-radon-mitigation-professional/

How to reduce radon levels in the home

If the radon test kit result is above the Canadian guideline of 200 Bq/m3 , there are steps both you and the radon mitigation professional can do to reduce radon levels in your home. Health Canada recommends the following; 

  • Radon Mitigation System: Can be installed in less than a day and in most homes will reduce the risk of radon levels by more than 80%4
  • Sub Slap Depressurisation: Typically done by a contractor, this method works by ventilating the basement sub-flooring by installing a small pump to draw the radon from below the concrete slab to the outside before it is able to enter your home1
  • Increasing the mechanical ventilation via a heat recovery ventilator (HRV) in order to allow an exchange of air1
  • Sealing all cracks and openings in foundation walls, floors, pipes, and drains1
Patient Story 

Janet and Alan Whitehead

In 2008 Janet Whitehead was diagnosed with lung cancer at the age of 54 and immediately underwent successful surgery to remove her upper left lobe, one third of her lower left lobe and tumors in her right lobes. Janet had never smoked and subsequently learned that her lung cancer was apparently radon induced. Janet was exposed to exceptionally high levels of radon gas, in a former home in Ottawa, where the family lived for 5 years.
Janet and Alan WhiteheadFollowing Janet’s diagnosis and surgery, the family reached out to the present occupant of the house, to advise them of her situation and their suspicions and encourage them to test the home for radon. The results were alarming with indoor radon concentrations in the living area and bedrooms measuring 3,250 Bq/M3, which is equal to 20 times the Health Canada guideline and 30 times the WHO guideline. Janet says “had we known about radon when we were living in Ottawa in 1992-97 and that the area is in a geologically high radon potential zone, we would have tested our home for radon and fixed the problem at that time. To put our situation into perspective, exposure to 400 Bq/M3 of radon for 8 hours is considered by radiation scientists to be equivalent to smoking a pack of cigarettes every day. I now worry about my husband and 3 children who were also exposed and I would encourage everyone to test their homes, schools and workplaces for radon. This is one deadly form of cancer which is totally preventable.”
The story has a positive outcome – the current occupant of their former home in Ottawa, on receiving their advice, immediately had the house tested and then mitigated, reducing the radon levels to less than 100 Bq/M3 and giving the occupants peace of mind. Janet is determined to be a lung cancer survivor and together with her husband Alan, is an advocate and passionate about raising radon awareness and education in Canada to save lives.

Helpful links
For more information on radon including health risks, guidelines and how to test for radon, please visit the following sites:

Financial Support for Home Radon Mitigation - https://www.lung.ca/lungs-matter-radon-mitigation-support
Health Canada - Radon - https://www.canada.ca/en/health-canada/services/radon.html
Home Radon Test.ca - https://www.homeradontest.ca/order/create
Purchase a Radon Test Kit - https://takeactiononradon.ca/test/radon-test-kits/
Hire a Radon Professional  - https://takeactiononradon.ca/test/find-a-radon-mitigation-professional/
Help promote awareness -  https://takeactiononradon.ca/join/
Canadian Association of Radon Scientists and Technologists – Steps to Reduce Radon - https://carst.ca/StepsToReduceRadon#Step1
WHO – Radon - https://www.who.int/health-topics/radon#tab=tab_1
Canadian lung association - https://www.lung.ca/lung-health/air-quality/indoor-air-quality/radon
Canadian Cancer Society – Radon - https://cancer.ca/en/cancer-information/reduce-your-risk/know-your-environment/radon
Health Canada. “Radon: Is it in your home?” Canada.ca, Government of Canada, 7 Nov. 2017, www.canada.ca/en/health-canada/services/environmental-workplace-health/reports-publications/radiation/radon-your-home-health-canada-2009.html.
2 “Radon and Cancer" Canadian Cancer Society, www.cancer.ca, www.cancer.ca/en/prevention-and-screening/reduce-cancer-risk/make-informed-decisions/know-your-environment/radon-and-cancer/?region=on.
“Steps to Reduce Radon.” CARST, www.carst.ca/StepsToReduceRadon.
Health Canada. “Radon .” Canada.ca, Government of Canada, 31 July 2019, www.canada.ca/en/health-canada/services/radon.html.