Radon in rural homes linked to wells

Posted on March 14, 2024 by Ryan Dahlman

By Anna Smith
Southern Alberta Newspapers
Local Journalism Initiative Reporter

Researchers at the University of Calgary have found a connection between levels of radon gas within rural homes and their proximity to groundwater wells.

Radon is a radioactive noble gas that is colourless, odourless and tasteless. It is also a carcinogen, said principal investigator Dr. Aaron Goodarzi.

“Something that scientists across the world have become aware of over the past decade is that exposure to radioactive radon gas is the second leading cause of all lung cancers, and the leading cause of lung cancer in people who don’t smoke,” said Goodarzi.

Canada in general has a high level of radon gas present in the air inside of homes, and it’s been noted that homes in rural communities often have a much higher concentration of radon compared with homes in urban areas.

“The Evict Radon National Study, which is a citizen scientist based study, involving many tens of thousands of Canadian households who tested their properties for radon, and agreed to give the de-identified data on the radon levels and details about their houses, to ourselves to cancer researchers,” said Goodarzi.

The two major factors tend to come down to the architecture of rural homes, which tend to be large floor plan bungalows, “which are even better radon capture machines, if you will, compared to any other style of property,” said Goodarzi.

The other contributing factor is groundwater wells.

Dr. Cathy Ryan explained that initially, one of her partners in the study, Evangeline Eldridge, measured radon concentrations in groundwater because they thought water pumped into homes from wells was the source of higher radon. But they did not discover high enough radon levels for this to be true.

What they attributed to the higher radon in rural residences, instead, was gas within the earth that bubbles up in preferential pathways outside of well casings. Once these bubbles reach the soil above the water table, the radon gas migrates into any nearby basements.

“When bubbles below the ground intersect with wells, the annulus outside the well casing provides a nice pathway for them to move upwards under buoyancy. So, basically, we think that radon is bubbling up along water wells. And when that brings radon to the soil zone, it is more likely that radon will migrate into residences,” said Ryan.

While this issue is more prominent in rural communities, Goodarzi stressed that unless your residence doesn’t touch the ground, there is still a risk of radon exposure.

Ryan stressed that at this time, they can’t predict which houses will have higher concentrations of radon, and to get your home tested.

“Everybody should test because you can’t taste it, you can’t smell it. We’re all susceptible to it,” said Ryan.

“The good news is, it’s fixable,” said Goodarzi. “One or two days work in your typical Canadian house is enough to permanently fix radon issues for the lifetime of that house. Nobody needs to be exposed to radon.”