One in eight Calgary homes has excessive radon: study
Author pushes for public awareness
An invisible killer is lurking inside one in every eight Calgary homes, an alarming University of Calgary study has found.
The research, published in Wednesday’s CMAJ Open journal, tested radon levels in 2,382 homes in Calgary and its surrounding communities, finding the radioactive gas — the second leading cause of lung cancer in Canada — to be above acceptable levels in 12.4 per cent of the homes monitored.
Aaron Goodarzi, an assistant professor at U of C’s Arnie Charbonneau Cancer Institute and the study’s lead author, said the numbers were higher than he expected.
And yet, despite the dangers from the potentially deadly gas — exposure to which claims some 3,200 Canadian lives a year — according to Lung Cancer Canada, many Calgarians seem generally unaware of risky radon.
“I think we’re looking at less than five per cent who actually even know what it is,” said Goodarzi, who led the three-year study that wrapped up late last year.
“One of our goals with this study was to advance public awareness, and we’re gearing up to do that in a more widespread manner.”
Key findings in the sweeping study included the fact that newer homes, those built within the past 25 years, had 31.5 per cent higher radon levels compared with those built before 1992.
But Goodarzi warned there are no safe zones from the naturally occurring gas — which is odourless, colourless and tasteless — produced through the radioactive decay of uranium in rocks and soil. Though common throughout Canada, it’s especially prevalent in the Prairies, having been deposited by glaciers.
“It’s not to say homes older than 25 years are free of risk, but newer homes definitely have a higher risk factor,” he said.
“The homes being built today are roughly twice as large as those being built in the ’70s, and those homes are also taller, which is another factor.”
Radon seeps through the soil into homes via cracks in foundations, through windows or through floor drains and sumps, building up in the basement before moving up into living areas in a chimney effect. Calgarian Bob McCauley, one of the homeowners who participated in the study, discovered his twoyear-old home in West Springs had a radon concentration of nearly double the acceptable Health Canada limit of 200 becquerels per cubic metre (200 Bq/m3). The World Health Organization has set the acceptable limit at 100 Bq/m3.
“I didn’t know quite what to expect when the numbers came back but we saw the hazard was pretty serious,” said the father of an 18-month-old with another baby on the way this summer, whose own home showed a concentration of 357 Bq/m3.
“When we learned we could reduce it down to pretty much zero we thought that would be a good investment.”
The cost to modify a home to reduce radon levels is anywhere from $2,000 to $2,500, a number McAuley said was far from a burden given the potential consequences.
The study found the average indoor radon level was 126 Bq/m3, with the highest average levels shown in the town of Cochrane and Okotoks, both of which have experienced a boom in new home growth. The highest concentration of radon measured in the study was 3,441 Bq/m3 in Cochrane.
Goodarzi said the numbers represent a legitimate public health concern, and he’s already been in touch with Alberta Health in hopes of putting together some sort of strategy. He’s also planning to continue with the study in hopes of mapping concentrations of radon in the area and looking at the genetic and environmental risk factors of radon-induced cancer.
He said anyone who thinks they have nothing to worry about should think again.
“If you look across the whole spectrum, we’re all in the danger zone,” he said.
To participate in the ongoing radon study visit DNAscience. ca/radon