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Radon in the Home

Topics: Contaminants and Hazards, Indoor Air, Radiation

Radon is a colourless, odourless gas that is released from the degradation of uranium naturally present in rock and soil. Radon levels outdoors are generally low; however, radon can enter buildings and homes through cracks and openings in the foundation and levels can become much higher indoors, especially in basements and lower floors.

  • Long term exposure to radon increases the risk of lung cancer. Health Canada estimates that over 3,200 Canadians die each year due to radon gas exposure (Chen et al., 2012).
  • Exposure to radon is the leading cause of lung cancer for non-smokers. For smokers, radon exposure greatly increases the risk of developing lung cancer from 1 in 20 to 1 in 3 (Health Canada, 2010).
  • Currently, Government of Canada guidelines state that dwellings and public spaces including schools, daycare and libraries, do not exceed 200 becquerels per meters cubed (bq/m3) (Government of Canada, 2009). The World Health Organization recommends 100 bq/m3 (WHO, 2016).
  • Radon levels in homes are influenced by such factors as geography (which determines the amount of uranium and radon in soil) and household construction methods, architectural design, ventilation systems and the specific materials used to build a home (Branion-Calles et al., 2016; Levesque et al., 1997; Stanley et al., 2017).
  • It is impossible to predict levels of radon without measuring it. Health Canada recommends that all Canadians have their homes tested for radon (Health Canada, 2013).
  • Radon mitigation methods are very effective at reducing radon levels, even when results far exceed the recommended guideline.
  • Radon mitigation should be done by a certified professional. A list of certified professionals is available at the Canadian National Radon Proficiency Program.

NCCEH Resources

  • Experiences with BC First Nations community-based radon testing: Successes and lessons learned (2018)
    This academic paper, published in Environmental Health Reviews, describes a multi-year home radon testing program in First Nations communities in British Columbia. The article outlines key elements, such as developing local champions and clearly identifying funding issues that led to a very high rate of homes being tested and mitigated.

  • Inuit and Metis radon research across the country (2018)
    Two presentations were provide an historical overview of radon testing conducted in First Nations, Inuit and Metis communities across Canada.  Resources uncovered include a 1993 federal testing program of homes as well as a more recent federal program that included testing in administration buildings, schools and other public spaces in first nations communities.

  • Radon and child care facilities (2017)
    This was a presentation made at the Canadian Institute of Public Health Inspectors National Annual Education conference by NCCEH staff in conjunction with an environmental health officer from the British Columbia Interior Health Authority.

  • Call for action on radon in childcare settings (2017)
    This paper in Environmental Health Reivew is co-authored by NCCEH staff and outlines the rationale for implementing regulations to govern the testing of radon in child-care settings across Canada.
  • Public health ethics: A case for environmental health (2016)
    The National Collaborating Centre for Health Public Policy, in conjunction with the NCCEH and the INSPQ, hosted a webinar to discuss the ethical dimensions involved in testing for radon in childcare facilities.
  • Radon: Public health professionals can make a difference (2015)
    The NCCEH paper in the Environmental Health Review, authored by Nicol AM, Rideout K, Barn P, Ma L and Kosatsky T, aimed at providing information on radon risks and mitigation to public health inspectors.
  • From communication to mitigation, the challenges of managing radon exposure in Canada (2015)
    This presentation was given by NCCEH staff to BC Lung’s Annual Radon Workshop. The presentation outlines a theoretical framework that supports radon outreach and behavior change.
  • Radon and lung cancer (2015)
    Invited presentations to the House of Commons Standing Committee on Health (HESA)  by NCCEH staff regarding radon and the risk of lung cancer.
  • Residential indoor radon testing (2009)
    The advantages and disadvantages of short-term and long-term testing methods are reviewed.

Other Selected Resources

  • Reducing the risk from radon: A guide for health care providers (, 2018)
    The Conference of Radiation Control Program Directors, Inc., in collaboration with the U.S. Environmental Protection Agency, has developed a new guide for health care providers. This guide was designed to help health care providers inform patients about exposures to radon. This guide has the latest information on the science behind the risk estimates, sample guidance for use in health care settings and the role of health care providers in reducing the burden of radon.
  • Radon - online course (McMaster University, 2017)
    This Continuing Medical Education (CME) course for physicians is offered through McMaster University. This course is designed to help answer patient's questions about the health risks of radon and the need to test their home and reduce their family’s exposure based on Health Canada’s national radon awareness program.
  • Guide for radon measurements in public buildings (Health Canada, 2016)
    This updated guide focuses on public buildings including workplaces, schools, daycares, hospitals and correctional facilities.
  • Canadian National Radon Proficiency Program (2016)
    This is the certification program that establishes guidelines and resources for training professionals on radon testing and mitigation services. A list of certified radon professionals across Canada is provided.
  • A citizen’s guide to radon: A guide to protecting yourself and your family (US EPA and the US Centres for Disease Control, 2016)
    An easy to read overview of radon gas, why it is important to test and how to test.
  • Environmental burden of cancer in Ontario (Public Health Ontario, 2017)
    This useful report estimates that radon contributes to between 1,080 to 1,550 new cases of cancer every year in Ontario alone. For more information and an explanation of how this was calculated, see the report and its technical supplement.
  • Radon: Quick summary (CAREX Canada, 2017)
    This page includes resources on evidence, policies and guidelines pertaining to environmental and occupational radon exposure specifically in Canada. This page also links to summaries on radon testing in schools across the country.
  • Radon reduction guide for Canadians (Health Canada, 2014)
    This homeowner’s guide to reducing radon exposure includes topics such as dealing with contractors and the remediation options that are available.
  • Radon: Is it in your home? (Health Canada, 2014)
    Information is provided for Health Professionals including fact sheets designed for patients.
  • Cross-Canada survey of radon concentrations in homes (Health Canada, 2012)
    This two-year survey measured radon concentrations in 18,000 homes across Canada, with results stratified by province and by health region in Canada.

Peer-Reviewed Literature


This list is not intended to be exhaustive. Omission of a resource does not preclude it from having value.

Last updatedNov 25, 2018