CAREX Canada's resources on exposure to radon gas
October 24, 2016 (Vancouver, BC) – CAREX Canada is a national project that estimates Canadians’ exposures to cancer-causing agents in workplaces and communities. One of those agents is radon, a colourless and odourless gas that is the leading cause of lung cancer among non-smokers. Health Canada estimates that radon is responsible for approximately 16% of lung cancer deaths in Canada, which translates to more than 3,200 lung cancer deaths per year.1,2
Radon concentrations vary depending on local geology, soil, and building characteristics. The highest concentrations of radon are found in areas with uranium and thorium ore deposits and granite formations. In these areas, radon seeps out of the ground into surrounding air, water, and soil. This becomes a hazard if the radon gas gets indoors. Radon has been found in public buildings, schools, hospitals, and new and older homes in many places across Canada. A summary of the ways that radon can infiltrate a home are illustrated below.
CAREX Canada's resources on radon
CAREX Canada has developed the following resources to help organizations better understand exposures to radon in their area:
Profile: Our carcinogen profile for radon provides general information about radon and why it was classified as a carcinogen, lists the regulations and guidelines related to radon exposure in Canada, describes how exposure takes place in workplace and community environments, and offers a series of resources on how to reduce exposure. The radon profile is available here.
Maps: Our maps summarize radon measurements from Health Canada’s Cross Canada Radon Survey (Phase 1 and 2). These maps highlight the percentage of home radon measurements in each health region above the Health Canada guideline of 200 Becquerel per cubic metre (Bq/m3). These maps are available here.
Environmental exposure estimates: Our estimates use lifetime excess cancer risk an indicator of Canadians’ exposure to known or suspected carcinogens in the environment. Risk estimates for indoor air carcinogens show that radon gas is the highest priority exposure in Canadian settings. The full estimate is available here.
Radon in schools research: Our team contacted ministries of Health and Education, Offices of the Chief Medical Officer, and/or school boards in each province and territory in an effort to determine where school testing has occurred in Canada, if schools with elevated levels were remediated, and what challenges were encountered in testing or remediating. A summary of this effort is available here.
Occupational exposure estimates: These new estimates use a method tailored for assessing radon exposure in workplaces. They take into account groups such as indoor and underground workers. Results show that approximately 188,000 Canadians are occupationally exposed to radon. The largest industrial groups exposed are elementary and secondary schools, provincial and territorial public administration, and depository credit intermediation. The full estimate is available here.
First Nations Environmental Health Resources: We collaborated with four First Nations groups to develop a series of resources to help better understand local concerns, and use that understanding to identify priorities for reducing or eliminating exposures to carcinogens in the environment. A common concern across several groups was exposure to radon gas in homes. We developed a briefing note that explains why radon levels are naturally higher in some areas of Canada, how exposure occurs, and what can be done about it. We also developed brochures on radon monitoring and interpreting monitoring results. These resources are available here.
What to do about it?
The only way to know if radon gas is present is to test for it. Data from Health Canada’s most recent survey (2011) revealed that 42% of Canadian households had heard of radon, but only 5% of those households had tested for radon (up from 3% in 2009).3 Because radon levels vary over time, Health Canada recommends using a long-term detector and testing for a minimum of three months, over the winter months if possible when homes tend to be sealed and ventilation is low.4 If a worker has concerns about radon levels in a workplace, he/she can request a radon test.
Radon testing is available through certified service professionals; lists of these are available through the Canadian Association of Radon Scientists and Technologists (CARST)5 and the Canadian National Radon Proficiency Program (C-NRPP).6 Homeowners can also purchase do-it-yourself kits through local Lung Associations or hardware stores, and follow the guidelines outlined by Health Canada for how to properly conduct a radon test.
Health Canada recommends4 that the higher the radon concentration, the sooner steps should be taken to remediate the issue:
The specific methods used to remove radon from existing buildings depend on several factors, including building construction and soil type. The most effective of these methods is called “active sub-slab depressurization”, where a remediator installs a pipe through the floor slab of the foundation. This pipe is attached to a fan that runs continuously to draw radon gas out from beneath the home, to the outdoors where it is effectively diluted.
For new buildings, the National Building Code of Canada encourages builders to prevent radon from entering homes by implementing what’s called a “roughed-in radon reduction system” during construction.4 This involves laying a polyethylene barrier under the slab, sealing the slab perimeter and all areas where pipes run through the slab, and installing airtight coverings for sump pit covers. Other remediation approaches are summarized on Health Canada’s Radon Reduction Guide for Canadians page.4
How is CAREX addressing Canadians' exposures to radon?
- Providing evidence and data visualizations to the Canadian Environmental Law Association to support their Radon Tax Credit Proposal and Radon Policy Challenge (calling for a coordinated policy response to radon exposure). These projects are in follow-up to their Radon in Indoor Air: A review of Policy and Law in Canada report, which remains a huge asset to the network of groups working to reduce radon exposure across the country.
- Supporting the BC Teachers’ Federation (BCTF) and the BC Confederation of Parent Advisory Councils in advocating for radon testing in schools to protect teachers and students. As part of our work with the BCTF, we developed a fact sheet outlining how exposure is taking place, what past test results show, and what other provinces are doing about this issue. This fact sheet is available here. We are offering a webinar as part of Radon Awareness Month on radon testing in schools across Canada. Details can be found on our Training page.
- Working with the Canadian Association of Radon Scientists and Technologists (CARST) and the Canadian National Radon Proficiency Program (C-NRPP) to organize workshops that facilitate dialogue among a broad group of stakeholders, including public health professionals, radon testers and remediators, real estate agents, firefighters and RCMP, and home inspectors. More information about the workshop held in Nova Scotia in May 2016 can be found here.
- Presenting at events hosted by the Canadian Cancer Society National office, as well as Saskatchewan and BC divisions. This includes a presentation at the Saskatchewan legislature, where MLAs were encourage to measure levels in their own homes. This work is featured in our 2014-15 Annual Report.
CAREX Canada is working with various partners in order to raise awareness, facilitate networks, and support action on addressing exposure to radon gas. These efforts involve giving presentations, organizing workshops, providing evidence, and more. Examples include:
- Health Canada. What are the health effects of radon? (Last updated September 2012)
- Chen J, Moir D, Whyte J. Canadian population risk of radon induced lung cancer: a re-assessment based on the recent cross-Canada radon survey. Radiat Prot Dosimetry 2012;152(1-3): 9-13.
- Statistics Canada. Households and the environment survey, knowledge of radon and testing, Canada and provinces: CANSIM Table 153–0098. (2015)
- Health Canada. Reduction guide for canadians. (2014)
- Canadian Association of Radon Scientists and Technologists (CARST). CARST Website: Member list. (2015)
- Canadian National Radon Proficiency Program (C-NRPP). C-NRPP Website. Find a professional. (Last updated 2016)