Radon gas is the leading cause of lung cancer among non-smokers and is responsible for approximately 16% of lung cancer deaths in Canada.1,2 Radon is colourless and odourless, so testing is the only way to know if radon levels are elevated and if remediation is required. Many organizations are working to assess radon exposure in homes and raise awareness about the importance of testing. Given that children and staff spend a considerable amount of time indoors in schools – where radon levels can accumulate to high levels – the CAREX Canada team has prioritized radon exposure in Canadian schools.
Led by Associate Professor Anne-Marie Nicol, CAREX revisited its investigation of radon testing efforts in schools across Canada. Staff contacted ministries of Health and Education, and the Offices of the Chief Medical Officer in each province and territory. Subsequently, staff also contacted individual school boards’ Superintendents or Chairs in an effort to determine where school testing has occurred, if schools with elevated levels were remediated, and what challenges were encountered in testing or remediating.
Key findings from this investigation include:
- All public schools in Saskatchewan, New Brunswick, Nova Scotia, Prince Edward Island, and Yukon have been tested for radon.
- British Columbia, Alberta, Manitoba, Ontario, and Newfoundland have low rates of radon testing in schools.
- Quebec has a collaborative approach to radon testing in schools led by the ministries of Education and Health, which is a product of the Inter-sectoral Committee on Radon.
- Over 500 schools across the country expressed interest or developed plans to test for radon in 2018.
- In some provinces, new schools are built to facilitate remediation should they report elevated levels of radon.
- Some school buildings, such as those in some regions in the Northwest Territories and Nunavut, are constructed above ground on piles and therefore, may not require radon testing.3
- Only Prince Edward Island and Yukon make all school testing results openly available to the public.
A more detailed summary for each province and territory is provided at the bottom of this page.
Why radon exposure matters: CAREX Canada has a carcinogen profile on radon, available here. Radon is a radioactive gas released when uranium, found naturally in rocks and soil, decays. This gas emits radioactive particles that can attach to the surface of aerosols, dust, and smoke and are easily inhaled into the lungs, causing damage to DNA that can develop into cancer.4 CAREX Canada risk estimates for indoor air carcinogens show that radon gas is the highest priority exposure in Canadian settings.5 The gas can enter and accumulate in buildings through unfinished floors, wall slab joints, sump pumps, windows, and cracks and openings in foundations.6The US EPA estimates that one in five schools in the US have elevated radon levels.7
What is being done about this exposure: As part of their Cross-Canada Survey of Radon Concentrations in Homes, Health Canada has tested many dwellings across the country. The results of this survey are visualized in maps available on the CAREX Canada website.8,9 These maps illustrate how some provinces have higher overall levels than others. In order to minimize health risks, Health Canada recommends that all buildings, including homes and schools, be tested and remediated to ensure they have less than 200 becquerels per cubic metre (Bq/m3) of radon gas.10 Health Canada also recently released an updated guide to school testing.11
Without a national school testing mandate however, provinces approach the issue of radon testing in unique ways. In some provinces and territories, the agencies responsible for testing in schools include ministries of Health, Education, Infrastructure, Transportation, and Labour. Where there is no provincial government involvement, school districts assume the responsibility of testing and remediation. These programs are often assisted and supported by external organizations, such as school board associations, health authorities, and teachers’ unions.
Due to changes in building codes across Canada, newly constructed government buildings, including schools, are designed and built with a radon mitigation “rough-in” system that can be activated if it is found that radon levels are above Health Canada’s guideline. Even with a radon mitigation “rough-in” system, schools still need to be tested for elevated levels of radon. Radon testing in schools continues to increase, and CAREX staff found that over 500 schools across the country expressed interest or developed plans to test for radon in 2018.
For a full list of CAREX resources on radon exposure in workplaces and communities, please visit our Radon Resources page.
Additionally, Alberta Infrastructure developed a technical specification for rough-in systems for radon mitigation. When a new building is completed, the building owner is responsible for bringing in a certified C-NRPP professional to determine the radon levels in the building. If results are above the Health Canada guideline, building owners must activate the radon ventilation system. This program was initiated due to Health Canada’s and Alberta Health’s recommendation to test all publicly occupied buildings for radon.
CAREX staff contacted all 85 public school boards in Alberta to investigate radon testing efforts. Only 61 (3%) schools reported testing for radon, and 198 (8%) confirmed that radon testing has not been done. Ninety-five schools reported they would be interest in, or are planning to begin testing in 2018. Radon testing efforts are unknown or unreported for 2,129 of the 2,388 schools in Alberta.
Occasionally, Alberta Infrastructure’s Building Environment Unit supports remediation efforts by providing technical specification documents and connecting school boards to certified C-NRPP technicians and third-party organizations for remediation options. Ongoing efforts include updates to the program based on changes and advancements in radon testing, mitigation technology, and alternative solutions proposed by industry professionals.
CAREX staff contacted all 60 public school districts in BC to obtain a more accurate understanding of current testing efforts. We found that 133 (8%) public schools have been tested for radon, and 283 (18%) public schools have not. Data were unreported or unknown for 45 school districts, which account for 1,150 (73%) public schools. Most school districts that reported radon testing in schools had levels below 200 Bq/m3. In schools that reported levels over 200 Bq/m3, remediation was either completed or is underway.
A number of districts asked us how they could initiate testing. Seven school districts, totalling 134 public schools, reported they would be interest in, or are planning to begin testing in 2018.
As part of the initial sampling, the Government of Saskatchewan recommended adopting a radon actionable level guideline more closely aligned with the World Health Organization’s radon guidelines of 100 Bq/m3. As a result, the Government of Saskatchewan considered that any school with levels over 112 Bq/m3 is at an elevated risk. Any such school must be retested to measure the true radon level in the building before assessing the need for remediation. The results of the 1990 initiative concluded that 79 of the schools tested had levels of above 112 Bq/m3.
When the Health Canada guideline was modified from 800 Bq/m3 to 200 Bq/m3 in 2007, the Ministry of Education embarked on follow-up testing in all schools. The province was able to remediate and retest all buildings that recorded radon levels above 200 Bq/m3, and once again reduce the overall radon risk in Saskatchewan schools following the Health Canada guideline.
The province’s commitment to minimize radon exposure in schools has led to ample retesting in schools of concern. The Ministry of Education is also conscious of health risks from extended and elevated radon exposure, and builds new schools with ventilation and structural considerations that reduce exposure.
CAREX staff contacted all 39 public school boards in the province. Of these, 76 (8%) schools confirmed testing for radon, and 33 (3%) schools confirmed testing had not been done. Of the schools that reported testing, none were above the Health Canada guideline. Thirty-two school boards, which oversee 831 (88%) public schools, did not provide any data.
Following the Ministry’s direction, CAREX staff contacted all 84 public school boards in the province. Of the schools contacted, 854 (18%) schools reported that they have tested for radon and 1,230 (25%) schools confirmed that they have not tested for radon. Of the schools that had tested, two school boards overseeing 601 schools indicated that they had remediated schools with levels above Health Canada’s guideline. They did not provide the actual number of schools with elevated readings.
Several school boards identified that they have not tested for radon because it is not mandatory but, if required to do so, they would. In 61 school boards, accounting for 2,807 (57%) schools, radon testing was not reported or is unknown.
In 2009, the CIQR piloted a testing program in 65 schools. As a result, a province-wide initiative was launched to test all 3,600 public and private education buildings starting in August 2011. Following this initial probe, the MEES strongly recommended that all schools test for radon and report findings. The information was forwarded to the CIQR in July 2014.
Ultimately, the Institut national de santé publique du Québec (INSPQ) gathered all reported radon information and collated the results, with 57% of schools complying with the radon testing recommendation. The INSPQ identified 124 tests that presented radon levels above the Health Canada guideline. Education material on the effects of radon and potential mitigation strategies were sent to all participants. Emphasis was placed on clear communication to inform participants of prior radon efforts and results from radon test measures.
A secondary outcome of this program was an increase in residential radon testing. As well, the MEES recommended that all newly constructed schools or school expansion projects be designed with methods indicated in the province’s Building Code to mitigate underground hazards, such as radon. The MEES is also encouraged to send reminders to school board managers of the remaining schools that did not initially participate in the 2014 provincial testing initiative, to promote future testing efforts.
New Brunswick’s Office of the Chief Medical Health Officer states that no provincial legislation or regulation requires radon testing in all schools; however, there is a province-wide radon testing protocol based on Health Canada’s guideline. Schools that were remediated or recorded levels of radon above the guideline are retested annually, as are schools that were recently renovated. Retesting in Fall 2017 and Winter 2018 is planned for 49 mitigated schools. Testing schedules extend to Winter 2021. New Brunswick identified cost as a key challenge in continuing its testing program.
The Department of Transportation and Infrastructure created new mandatory clauses in the 2010 edition of the Design Requirements Manual. The Manual contains requirements that are common in all provincial building projects, including specifications for Educational Facility Design. Included in Division 31, Earthwork, is 31.21.00 “Off-Gassing Mitigation,” where Clause 18.104.22.168 states: “Where Phase 1 Environmental Assessment indicates a presence of Radon, TPH or other radioactive waste at contaminating levels, or as directed by the Department, provide for design and installation of a vapour extraction system.” Clause 22.214.171.124, states: “Unless recommended by the Phase 1 Environmental Assessment, or directed by the Department, design a vapour extraction system for radon as a passive system with provision for future activation”.
These additions ensure that any new educational facilities require an environmental assessment for the presence of radon, and if elevated levels are present upon completion of construction, remediation efforts are implemented. With the addition of Clause 126.96.36.199 in the Design Requirement Manual, any newly constructed school will be designed with “a vapour extraction system for radon as a passive system with provision for future activation.”
Prince Edward Island
In Phase 1, 56 schools were tested by June 2008. All results and remediation guidelines are publicly available in the Radon Survey at Selected Sites Across Prince Edward Island report. The report identified 11 schools that required remediation.
In 2009, Phase 2 tested all remaining schools, and retested the schools that had been remediated. The results were again made publicly available in the Phase 2 – Radon Survey at Selected Sites Prince Edward Island report. The retesting was done to confirm that remediation had been required in these specific buildings. In Phase 2, three more schools recorded radon levels above the Health Canada guideline. This led the ministries of Health and Education to begin mitigation efforts in all schools that recorded levels above the federal guideline more than once. As a long-term impact of this program, the Government of PEI is now testing and mitigating to reduce radon levels in any new construction of school buildings.
Newfoundland and Labrador
Like PEI, the Yukon has made all recorded radon levels in school buildings publicly available online. The current results indicate that three facilities have recorded levels above the Health Canada guideline. The Government of Yukon stated that it is following through with mitigation action in these three schools.
A future consideration for Yukon’s testing program includes radon testing year-round in all schools to ensure accurate readings of annual radon levels, which can then inform any mitigation action.
The Northwest Territories’ Ministry of Infrastructure indicated that schools are tested where concerns about radon have been raised. Ministry records show that one school reported levels above the Health Canada guideline, and this school has since been remediated for radon.
- Health Canada. What are the health effects of radon? (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.
- US Environmental Protection Agency. Building Radon Out (2001) (PDF)
- ATSDR. Toxicological Profile for Radon (2015)
- Setton E, Hystad P, Poplawski K, Cheasley R, Cervantes-Larios A, Keller CP, Demers PA. “Risk-based indicators of Canadians’ exposures to environmental carcinogens.” Environ Health 2013;12(1):15.
- Health Canada. Radon: Is it in your home? (2014)
- US Environmental Protection Agency. Radon in Schools (2016)
- Health Canada. Cross-Canada Survey of Radon Concentrations in Homes – Final Report (2012)
- CAREX Canada. Radon: Provincial Tables and Maps (2011)
- Health Canada. How to test for radon? (2014)
- Health Canada. Guide for Radon Measurements in Public Buildings (2016)