Thawing permafrost can expose northerners to cancer-causing gas, study says
Radon is a risk to people's health when it accumulates in enclosed spaces
Thawing permafrost might be exposing people in northern Canada to higher levels of a naturally-occurring gas that causes lung cancer, says a new study out of the U.K.
Paul Glover, the study's lead researcher, said permafrost has been acting as a "hidden guardian" by keeping radon locked in the ground in the circumpolar Arctic and preventing it from travelling to the Earth's surface and accumulating in buildings.
Radon is an odourless, tasteless radioactive gas that is created from the decay of uranium in minerals found in rock, soil and water, according to Lung Cancer Canada. It is the leading cause of cancer in non-smokers, and the second-leading cause of cancer in smokers.
"With climate change, of course, that barrier of permafrost is actually degrading," said Glover, who is the chair of petrophysics at the University of Leeds. He studies the physical properties of rocks, and how things like fluids and gas can flow through them.
In his peer-reviewed study published in the journal Earth's Future last week, Glover said 42 per cent of permafrost is expected to be lost in the Arctic circumpolar permafrost region by 2050.
"We're losing [permafrost] at a very large rate, and therefore there would be the potential for a plume of radon perhaps to be released and affect the health of people living in those zones."
Though his study is based on modelling, Glover said he would be "very surprised" if this was not already affecting parts of the Arctic, given how quickly permafrost is thawing.
When it's a problem
When radon is released into the outdoor air it's not a concern, according to Health Canada. But it becomes a risk to people's health when it accumulates in enclosed spaces.
Buildings that are built on piles are not affected because they have natural ventilation, said Glover. But homes with basements and homes that are either built on the ground or into the ground should be tested, he said.
Lung Cancer Canada says radon can enter a home through an opening where the house contacts the ground — including cracks in the foundation floor or walls, construction joints, gaps around service pipes and floor drains.
It can take several years for the gas to peak and dissipate from a building, the study said.
"It's potentially a very big problem for health," said Glover, who also pointed to an increased risk to people who smoke. The study says smoking exacerbates radon-acquired lung cancer by 26 times, and the prevalence of smoking in northern Canada and Greenland is about three times the global average.
But the issue of radon does not require a "medical intervention," said Glover. In fact, the solutions are relatively simple.
Test kits available
Courtney Howard, an emergency room physician in Yellowknife and past president of Canadian Association of Physicians for the Environment said radon is one type of climate change impact that "we'll be able to manage" so long as "we're on top of it."
In Yukon, residents can purchase radon test kits from the Home Hardware in Whitehorse or from the Yukon Housing Corporation community offices.
Carleen Kerr, a communications director for Yukon's health and social services department, said in an email that Yukon has "some of the highest levels of radon in Canada" and that people may have had more exposure to it because they're spending more time at home during the pandemic.
The territory ran an awareness campaign in November where it sent information to households and offered a rebate for buying a test kit, she said. Mitigation efforts can cost between $2,000 and $5,000, said Kerr, and the Yukon Housing Corporation offers loans to help eligible homeowners cover the bill.
Kerr said that all the corporation's community housing units were tested for radon in 2018.
The N.W.T. government does not monitor buildings for radon, but people who own or live in buildings can hire professionals or purchase a kit online to carry out the testing, said Jeremy Bird, a communications manager for the territory's Department of Health and Social Services in an email.
There are suggestions for where to buy a kit on the website for Take Action on Radon, an awareness initiative funded by Health Canada. They range in price from $30 to $65.
"Every Canadian is exposed to some degree of radon from the natural environment," wrote Bird. "The potential radon exposure in N.W.T. is similar to other jurisdictions in Canada."
He also noted that exposure is "very dependent" on the characteristics of a building.
"We will be preparing a FAQ on this subject to inform the public about how they can take steps to address this issue, including doing a radon test in their homes or buildings in the context of permafrost thawing due to climate change," he said.
Howard would like to see testing kits made more accessible in the N.W.T. She'd also like to see home repairs associated with radon qualify for rebates — like they do in the Yukon.
Glover said one of the simple solutions is bring a ventilator into the room that is prone to radon buildup. Lung Cancer Canada also suggests radon mitigation systems, hiring a contractor to install a pump that'll draw radon outside instead of into a home, and sealing cracks and openings in foundation walls, floors, pipes and drains.
One of Glover's concerns, however, is that people aren't going to realize they have a problem.
"People at the surface will say 'well we know we don't have a radon problem' but they haven't been aware that in some ways they've had this hidden guardian that's been keeping the radon away from their houses," he said. "They very well may have it and they very well may not know they have it."
Howard agreed that awareness is "way lower" than it should be, and she didn't learn about herself until after graduating from medical school.
"Lung cancer is a life threatening diagnosis, so now is really the time that we ought to be increasing awareness."