Radon

Radon gas is a colourless, odourless, radioactive gas that is released during the decay of uranium in rocks and soils. Radon levels outdoors are generally low, but radon gas indoors poses more of a problem. The gas can enter buildings through cracks and openings in floors, leading to higher levels, especially in basements and lower floors. Over time, exposure to radon increases the risk of developing lung cancer. Health Canada estimates that over 3,000 Canadians die each year due to radon gas exposure (Chen et al., 2012). Smoking places people at higher risk from radon exposure, increasing the odds of developing lung cancer from 1 in 20 to 1 in 3 (Health Canada, 2010).
Radon levels indoors are influenced by:
- Geography, as uranium and radon levels vary naturally in soils across the country
- Household construction methods and architectural design
- Natural ventilation options and ventilation systems
The only way to know if radon is present indoors is to test. Health Canada recommends that all homes be tested (Health Canada, 2013) and those over 200 becquerels per meters cubed (Bq/m3) should be mitigated. This standard applies to public buildings as well, including schools, libraries and childcare facilities. Radon mitigation systems installed by certified professionals are very effective at reducing radon levels even when results far exceed the recommended guideline. A list of certified professionals by region is available at the Canadian National Radon Proficiency Program.
NCCEH Resources
- Introducing British Columbia’s new interactive radon map (Young, 2021)
This NCCEH guest blog provides an overview of the BC Centres for Disease Control’s new province wide radon resource that generates summaries and maps for BC communities and radon research initiatives.
- Radon: Public Health and Cancer Prevention (NCCEH, 2019)
This short animated video outlines steps that public health professionals can take to reduce radon gas exposure.
- Experiences with BC First Nations community-based radon testing: Successes and lessons learned (Neathway et al, 2018)
This article, published in Environmental Health Review, 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 (NCCEH, 2018)
Two NCCEH presentations 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 (NCCEH, 2017)
This NCCEH presentation was 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 (Phipps et al, 2017)
This article from Environmental Health Review 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 (NCCHPP, 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 (Nicol et al, 2015)
This NCCEH article published in the Environmental Health Review is aimed at providing information on radon risks and mitigation to public health inspectors.
- Radon and lung cancer (NCCEH, 2015)
Invited presentations to the House of Commons Standing Committee on Health (HESA) by NCCEH staff regarding radon and the risk of lung cancer.
Other Selected Resources
- Ontario Public Health Radon Initiatives (2021)
Radon testing and outreach occurs in many Ontario Public Health Units. Some examples of these programs and their findings can be viewed at: - Connecting the Dots to Reduce Radon Risk (CPHA, 2020)
This Nov 3rd 2020 presentation, hosted by the Canadian Public Health Association, highlights radon programming efforts that are on-going across Canada. Three speakers illustrate how public health professionals can get involved and help Canadian's reduce radon levels in their homes and workplaces.
- Take Action on Radon (2020)
This Health Canada funded program provides quick links to information and resources for radon testing and mitigation across the country. Take Action on Radon offers the “100 Test Kit Challenge” program which supports community access to free radon test kits as well as education and outreach.
- Radon: Quick summary (CAREX Canada, 2020)
This webpage includes resources on evidence, policies and guidelines pertaining to environmental and occupational radon exposure in Canada. It also links to summaries on radon testing initiatives in schools across the country.
- Environmental Scan of Radon Law and Policy: Best Practices in Canada and the European Union (Canadian Environmental Law Association, 2018).
This report is an analysis of existing radon policy initiatives at the domestic and international level. Recommendations are made to strengthen specific regulations to reduce radon exposure.
- Radon - online course for physicians (McMaster University, 2017)
This Continuing Medical Education (CME) course for physicians is offered through McMaster University. This program 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.
- Guide for radon measurements in public buildings and Radon reduction guide for Canadians (Health Canada)
These practical guides, developed by Health Canada, include topics such as how to test homes, buildings, schools, daycares, correctional facilities and hospitals. The guides include important information on hiring certified professional testers or mitigators.
- Radiation-Internalized a-particle Emitting Radionuclides. International Agency for Research on Cancer (IARC) Monograph on the Evaluation of Carcinogenic Risks to Humans Volume 100D (2012)
This IARC review provides an update to the evidence base linking occupational and environmental radon exposure to cancer.
- A citizen’s guide to radon: A guide to protecting yourself and your family (US Environmental Protection Agency, 2016)
A lay language guide, developed by the US EPA and Centres for Disease Control, about radon that is targeted to community members.
- 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 estimate was calculated, see the report and its technical supplement.
Peer-Reviewed Canadian Radon Literature
- A Summary of Residential Radon Surveys and the Influence of Housing Characteristics on Indoor Radon Levels in Canada. Health Physics (Chen, Sept 2021)
This article, based on more than 21,000 radon measurements taken in Canada, found that having a basement more than doubled the average radon exposure indoors. Homes with private wells also tended to have higher radon levels.
- Regional cost effectiveness analyses for increasing radon protection strategies in housing in Canada. Journal of Environmental Radioactivity. (Gaskin et al, Dec 2021)
This article provides compelling evidence in support of building code changes that prevent radon ingress in new homes. This work also found that efforts to remediate older homes was cost effective in higher radon regions across the country.
- Contribution of Childhood Indoor Radon Exposure to Lung Cancer Incidence among Young Adults: A Population-Based Ecological Study in Canada. Radiation environment and medicine (Chen et al, Feb 2021)
This article suggests that cumulative exposure to radon during childhood may be a leading cause of lung cancer in young adults and later in life.
- Younger North Americans are exposed to more radon gas due to occupancy biases within the residential built environment. Scientific reports (Simms et al, Mar 2021)
This article found that younger people who live in newer homes were receiving higher doses of radiation from radon gas. This exposure scenario is likely to lead to a greater future burden of lung cancer due to radon exposure.
- A comparison of consumer-grade electronic radon monitors. Journal of Radiological Protection (Warkentin et al, May 2020)
This study examined the accuracy and precision of consumer grade electronic radon detectors available in Canada
- A comparative study of radon levels in Federal buildings and residential homes in Canada (Whyte et al, 2019)
This study provides information about the Canadian government’s radon testing program in federal workplaces. The results are compared to residential radon results from other federal research initiatives.
- Radon exposure is rising steadily within the modern North American residential environment, and is increasingly uniform across seasons (Stanley et al, 2019)
This study of Canadian homes illustrates how housing characteristics can impact radon levels and examines radon variability.
- Indoor Radon in Microgeological Setting of an Indigenous Community in Canada (Sarkar et al, 2017).
This paper explores radon measurements in an Inuit community in Labrador.
- Canadian population risk of radon induced lung cancer: a re-assessment based on the recent cross-Canada radon survey (Chen et al., 2012)
This study undertook a re-assessment of Canadian population risk for radon-induced lung cancer, based on a cross-Canada radon survey.
- A cost-effectiveness analysis of interventions to reduce residential radon exposure in Canada (Gaskin et al. 2019)
This analysis highlights where efforts to reduce radon are most cost-effective and concludes that it is practical to reduce indoor radon and prevent lung cancer in Canada.
- A geospatial approach to the prediction of indoor radon vulnerability in British Columbia, Canada. (Branion-Calles et al 2016)
This paper presents a method useful for generating more accurate radon maps.
- Implementation of a radon measurement protocol and its communication plan by child care centre managers in Quebec. (Gagnon et al. 2016)
This intervention study demonstrates that childcare centre managers can test for radon in a cost-effective manner.
This list is not intended to be exhaustive. Omission of a resource does not preclude it from having value.