What’s happened to 80,000 people who have worked in Canada’s mines and processing facilities?
The Canadian Nuclear Safety Commission (CNSC) is leading a national study examining incidences of lung cancer in uranium workers from across the country.
The Canadian Uranium Workers Study (CANUWS) will examine health data from 80,000 past and present employees at Canada’s uranium mines, mills and processing and fabrication facilities. The study, which is now underway and set to end in 2023, is the largest examination of lung cancer in Canadian uranium workers to date.
Rachel Lane, one of the lead researchers on the new study, told Canada’s National Observer she believes it will reassure workers they face less risk than before from lung cancer arising from exposure to radon, an odorless, colorless, radioactive gas. Lane is a radiation and health scientist specialist at the CNSC in Ottawa and holds a PhD in epidemiology.
The new study will build on the results of two historical studies: the Eldorado study and the Ontario Uranium Mine Workers Study, both of which found elevated risks of lung cancer in uranium workers. During numerous follow-ups ending in 2015, both studies found lung cancer among miners was still more prevalent than in the general population.
Those findings were a wake-up call that prompted uranium mine safety improvements, including mechanical ventilation in mines, greater monitoring of workers, and automation of some of the workers’ tasks. Researchers believe this next health study will show the risks have been addressed.
Higher Rates of Lung Cancer in Uranium Workers
Historically, uranium mining has proven a risky occupation. Past studies have found that overall, uranium workers are generally as healthy as other Canadians. However, deaths from lung cancer associated with radiation were historically higher for uranium workers than the general male population.
The most recent follow-up to the Eldorado study assessed radon exposure and incidences of death or cancer in 17,660 uranium workers employed at Eldorado mines from 1932 to 1980. The follow-up was done in 2010. It found a “statistically significant” increased risk of lung cancer with radon exposure but “no evidence of an increase in any other cancers or other causes of death.”
The authors noted evidence from the Eldorado study on the effects of low radon exposures and exposure rates helped them understand the long-term health effects experienced by current workers. As well, the study will advance researchers’ knowledge of, and help them address the health risks to people who have naturally occurring radon within their homes.
In 2015, a follow-up to the 2007 Ontario Uranium Miner Cohort study was done. It examined approximately 28,546 male and 413 female uranium miners who had worked at least one week in the Elliot Lake and Bancroft regions or at the Agnew Lake Mine between 1954 and 1996.
The conclusion: “Significant elevations in lung cancer mortality and incidence, as well as silicosis and injury mortality were observed in comparison with the general Canadian population.”
The study now underway involves a team of health researchers led by Lane and Kristi Randhawa, a radiation and health sciences officer with the CNSC.
Anne Leis, the department head of Community Health and Epidemiology at the University of Saskatchewan, will administer the project and analyze the data. Her colleague, Punam Pahwa, a professor of biostatistics, will lead the statistical analysis of the health data.
The CNSC says radon gas produced during mining and milling is constantly monitored, controlled, and safely ventilated away from the workers. “Presently, worker exposures to radon in the uranium mining and processing industry are as low as, or only slightly greater than, public exposure from natural radon,” the agency maintains.
Concerns Over Possible Bias
Kneen contends that for years, the CNSC has served both as a regulator and promoter of the nuclear industry. “Their tendency has been to extend license periods and to give operators, whether it’s in the uranium industry or the nuclear power industry, more space, more time in terms of licensing and more leeway rather than the kind of tight supervision and oversight that the public probably would expect.”
Therefore, it’s a question of scrutinizing who’s doing the work and reviewing the study to ensure that it really is independent, according to Kneen. He notes that’s a difficult task given that the methodology around radiation is intricate and that not many people can decipher the technical details.
Dewar, a longtime general physician in northern Saskatchewan, recently told Canada’s National Observer: “They want to show that it doesn’t cause cancer. I think they want to find that result.”
Dewar expressed surprise that the CNSC has opted for a focused study when northerners have been asking for decades for a baseline health study to determine such things as whether or not there have been increases in autoimmune diseases or cancers that couldn’t be explained by diet, for example.
“I think not only is it virtually a sin that they’ve never done this, but I think it’s a really huge missed opportunity because if they had a study done like this, they would have researchers around the world trying to get information out of it.”
Compensation for Uranium Workers
Another, less discussed issue is compensation for uranium miners. In the United States, the Radiation Exposure Compensation Act (RECA) administered by the Department of Justice has awarded over US$2.4 billion in benefits to more than 37,000 claimants since its introduction in 1990.
In Canada, no such compensation program exists.
Asked whether the current CNSC study might help open the way to compensation for uranium miners, Lane said that wasn’t anything she could address. “Right now our workers are healthy and the current knowledge of the health effects of radiation and the radiation protection measures are in place to adequately protect the workers.”