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 odourless, colourless, radioactive gas. Lane is a radiation and health scientist specialist at the CNSC in Ottawa and holds a PhD in epidemiology.
“The more we know about the health effects of uranium workers, especially now at the low levels of exposure they are having, the better we are able to ensure they’re healthy and (able) to protect them.”
The $800-million mining and milling uranium industry employs over 2,000 people — of whom more than half are residents of northern Saskatchewan — at mine sites. The researchers plan to examine causes of death in uranium workers from 1950 on and chart their cancer data from 1970 onwards, using research from previous studies.
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 followups 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.
Are #uranium workers still at increased risk of dying from lung cancer? @CNSC_CCSN has launched a health study to find out. #cancer #nuclear
The most recent followup 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 followup 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.
Lane was one of the lead researchers on the study, which was carried out by the CNSC.
In 2015, a followup 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.”
While the CNSC funded the study, researchers from the Occupational Cancer Research Centre in Toronto carried out the investigation.
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.
Uranium mining companies Cameco, Orano and BWXT are co-funding the study, contributing $60,000. The CNSC is providing $125,000, while the Saskatchewan government is kicking in $60,000, and the University of Saskatchewan is contributing $90,000 of in-kind funding.
The CNSC says a working group of radiation specialists, workers, unions, Indigenous community representatives and others will look for ways to “keep the process and results relevant and meaningful.” As well, the final report will be peer-reviewed.
Lane notes past studies of uranium miners have contributed to the scientific understanding of the effects of radon, and radiation protection measures that “significantly reduce” workplace exposures to workers.
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.
Continuing to study the workers’ health allows researchers to examine particular issues in more detail, find answers to questions left from previous studies and conduct further followup with miners throughout their lifespan.
The new study will address, among other things, the risk of low radon exposure among workers since radiation protection measures were put in place. Lane says researchers hope to see fewer incidences of lung cancer.
Uranium processing and fabrication workers will also be included in a study for the first time. “Their exposures are considerably lower, but they’re still an important group to study,” Lane said.
Concerns over possible bias
While former employees and industry watchers applaud efforts to study the health of uranium workers, some are skeptical about the ability of CNSC to produce an unbiased report.
Jamie Kneen, communications and outreach co-ordinator at Mining Watch Canada, says it’s important to understand the longer-term impacts of radon on the miners. But he cautions that the peer review and oversight of the study must be carefully examined because it is being led by CNSC.
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 licence 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.
“So there’s a lot of potential for not necessarily deliberate manipulation, but for error to creep in and biases to creep in.”
Rod Gardiner, a former general foreman at the now defunct Cluff Lake Mine in Saskatchewan, expresses his own concerns about the industry. Gardiner was at the mine for 33 years, working his way up to general foreman and acting mine manager.
He alleges management at Cluff Lake, which was owned by the multinational mining corporation Orano Group, consistently boasted that working in the mine was as safe as working in a supermarket and putting prices on soup cans. “That’s what they used to say, the company.”
He hopes a new study might answer questions about workers’ health.
But others aren’t sure whether results will be trustworthy, primarily because the CNSC is partially funding and leading the study.
The CNSC’s work has been subject to just those kinds of complaints in the past.
Writing in the journal Canadian Family Physician in 2013, Dale Dewar and two other authors expressed concern over the CNSC’s ability to act independently of government and industry. The authors noted the former Conservative federal government fired the commission’s CEO when she applied safety guidelines to shut down the Chalk River reactor in Ontario.
The authors observed: “It is concerning that health standards are set by physicists and industries, based on financial and technological convenience, rather than by those educated in and committed to public health and safety.”
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.”
Lane dismisses the notion the CNSC study is too narrowly focused, arguing that all causes of death are examined. Firstly, she says researchers compare workers to the general population of Canada to see if they have any increased rate of diseases. Previously, the only radiation-related disease that showed an increase was lung cancer, Lane says.
“All other cancers and all other causes of death were not in excess compared to the general population.”
Lane notes in the last 20 years, researchers have looked for correlations between radon and leukemia, heart disease and other illnesses, but haven’t seen any strong relationships. “We really only have seen strong evidence of a relationship between radon and lung cancer at high doses.”
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.
Among those qualifying for the benefits are uranium miners, millers and ore transporters who worked between 1942 and 1971, and who developed one of the types of diseases specified in the statute. Those include lung cancer and a number of respiratory diseases. The qualifying miners receive $100,000 each.
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.”
Candyce Paul, a spokesperson for the Committee for Future Generations, an anti-nuclear group in northern Saskatchewan, believes uranium workers who got cancer should receive compensation.
Paul lives on the English River First Nation in northern Saskatchewan and protested the proposal for a nuclear waste repository in the region. “Most of them (uranium miners) get exposed to this or that.
“And there’s never been any compensation for anybody.”