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Independent Environmental Monitoring Program: Elliot Lake historical mine sites

Publication date: August 30, 2019

Rio Algom Limited and Denison Mines Limited are licensed by the Canadian Nuclear Safety Commission (CNSC) to operate historical mine sites in Elliot Lake, Ontario. Uranium mining was conducted in the area for approximately 40 years, from the late 1950s to the mid-1960s, and again from the early 1970s until the early 1990s, when most of the mines ceased operations.

The results of the Independent Environmental Monitoring Program (IEMP) for 2015 and 2018 confirm that the public and the environment around the Elliot Lake historical mine sites are protected and that there are no expected health or environmental impacts.


Elliot Lake historical mine sites


Results Table

1 The < symbol indicates that a result is below the provided laboratory analytical detection limit.

2 N/A – not available


Under the Nuclear Safety and Control Act, licensees of nuclear facilities are required to implement an environmental monitoring program (EMP) to demonstrate that the public and the environment are protected from emissions related to the facility's nuclear activities. The results of these monitoring programs are submitted to the CNSC to ensure compliance with the  applicable guidelines and limits, as set out in the regulations that govern Canada's nuclear industry.

The CNSC has implemented its IEMP to verify that the public and the environment around licensed nuclear facilities are protected. The IEMP is separate from, but complementary to, the CNSC's ongoing compliance verification program. The IEMP involves taking samples from public areas around the facilities, and measuring and analyzing the level of radioactive and hazardous substances in those samples. CNSC staff collect the samples and send them to the CNSC's state-of-the-art laboratory for testing and analysis. Since the IEMP was implemented, areas outside the perimeter of the Elliot Lake historical sites were sampled in 2015 and 2018.

2015 and 2018 results

The 2015 and 2018 IEMP sampling plans for the Elliot Lake historical mine sites focused on both radioactive and hazardous substances. A site-specific sampling plan was developed based on the licensee’s approved environmental monitoring program, CSA Group standards and the CNSC’s regulatory experience with the sites. In 2015 and 2018, samples were collected in publicly accessible areas outside the perimeter of the Elliot Lake historical mine sites, including samples of water and sediment. View detailed sampling data.

The concentrations of radioactive and hazardous contaminants in the water samples were all below guidelines. At two sediment sampling locations, heavy metal concentrations exceeded the sediment quality guideline issued by the Canadian Council of Ministers of the Environment (CCME), but remained below the CCME’s probable effect level and below the severe effect level established in Ontario’s Provincial Sediment Quality Guidelines. Although finding elevated heavy metal concentrations in sediment is common near sites of historical industrial activities, CNSC staff will continue to ensure these locations are monitored.  The levels of heavy metals in the water samples taken at these locations were below those set out in the water quality guidelines, indicating that the public and the environment remain protected.

Focus on health

The CNSC also conducts studies and reviews third-party research to assess the health of the public near nuclear facilities. For example, the CNSC funded a study conducted by Cancer Care Ontario to examine the risk of lung cancer mortality among miners who worked at the Elliot Lake, Bancroft and Agnew historical mine sites from 1954 to 1996. The study concluded that in general, for all causes of death, male mine workers were healthier than the general male population, and their health was similar to that of the general male population, considering all causes of cancer death. However, uranium miners did have an excess lung cancer than the general male population, due to working in conditions prior to radon protection measures. As radon exposure increases, the likelihood of developing lung cancer increases. Ontario miners also had higher rates of silicosis, from exposure to ore with high silica content.

Find out more about the health of past miners, including those from Elliot Lake mines, in the Ontario Uranium Miners Cohort Study Report.

CNSC staff have also reviewed the Algoma Public Health Unit’s community health profile which includes the Elliot Lake region and found that disease rates were comparable to those in other regions of northeastern Ontario where there are no nuclear facilities. 

CNSC staff collecting water samples near an Elliot Lake historical mine site in 2018.


The IEMP results from 2015 and 2018 indicate that the public and the environment in the vicinity of the Elliot Lake historical mine sites are protected and that there are no expected health impacts. These results are consistent with the results submitted by Rio Algom Limited, demonstrating that the licensee's EMP protects the health and safety of people and the environment.

To obtain the full technical IEMP report, contact us at or call 613-995-5894 or 1-800-668-5284 (in Canada). Please provide the name of the facility and the report year.

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