Scientists don’t know how much radon is actually emanating from areas with melting permafrost today, says Nicholas Hasson, a geoscientist and PhD student at the University of Alaska Fairbanks: “I would call this a blank spot.” He notes that, in real life, permafrost layers are complex and irregular, and agrees with Glover that field measurements are essential to validate the model. Instead of
a uniform sheet of ice underground, imagine permafrost as more of a higgledy- piggledy Swiss cheese of ice, with some areas much thicker than others and places where groundwater courses through it, exacerbating the thaw.
Hasson and colleagues have studied locations where permafrost is thawing unusually quickly and emitting methane, a greenhouse gas many times more potent than carbon dioxide. Similar “chimneys” could be spewing out elevated amounts of radon gas in some places, he suggests.
For human health, what really matters is the amount of radon that gets into people’s homes. Scientists and even homeowners themselves can use radio- activity detectors to assess this. A study published online in February 2022, which is yet to be peer-reviewed, measured levels of radon over the course of a year in more than 250 homes in three towns in Greenland. Out of 59 homes in Narsaq, for instance, 17 were found to have radiation levels above 200 Bq/m3.
Lead author Violeta Hansen, a radioecologist at Aarhus University in Denmark, stresses that these are early results based on a small number of homes. It would take much more research, she says, before she could evaluate the health risks associated with radon in properties like these across Greenland. She is now leading an international project that will run field experiments and gather
radon measurements from homes in various countries, including Canada and Greenland. “We need to come back to the public with low-cost and effective, validated mitigation measures,” Hansen says.
It is important to avoid panicking people without solid data and solutions on hand, says Aaron Goodarzi, a radiobiologist at the University of Calgary in Canada. The good news is that there are tried-and-tested methods of lowering levels of radon inside a house once the homeowner knows it is there. Goodarzi points, for example, to a technique called sub slab depressurization, in which a sealed pipe is inserted below the house and connected to a fan. This sucks any radon out from below the building before blowing it away into the atmosphere. “Think of it simply like a bypass,” he says.
The type of building matters. Glover’s model found that homes built on piles or stilts, and thus separated from the ground, did not experience a boost in radon levels. Fortunately, many homes in the Arctic and sub-Arctic are constructed in this fashion. But for those that aren’t, the cost of mitigating radon could be prohibitive for low-income communities in these regions. “That’s an equity
issue that has to be considered, certainly,” says Goodarzi, who notes that the onus might be on social housing administrators in some areas to ensure that
the housing they provide is healthy.
A spokesperson for Health Canada says that the government agency currently recommends that homeowners test radon levels in their properties and use certified suppliers to install mitigation technologies if such are required.
Many people may not think about radon very much, given the fact that it is invisible. Glover says that getting informed now, before the permafrost thaw worsens, could save lives.
“We know that people die from it,” he says. “But at the same time, there’s so much that we can do to protect ourselves.”
10.1146/knowable-051122-1
... continued from page 51.
Continued on next page ...
52