1 in 5 Canadians exposed to high levels of radon inside their homes

A radon level test is pictured. (Dylan Dyson/CTV News Ottawa)

A new report says a silent killer is invading more homes in Canada than ever before.

Radon, an invisible, odorless and tasteless gas, is being found at dangerously high levels inside homes, affecting 17.8 per cent or approximately one in every five Canadians.

The report, promoted by Health Canada, was conducted by researchers at the University of Calgary.

"Radon is a gas that comes from the ground," said Alex Budd, owner of Budd Radon Services. "It's released from the uranium contained inside of rock."

"It's released underneath your home, leaks up into your home and it can accumulate in your home and cause lung cancer."

Radon is the second leading cause of lung cancer, behind smoking, Budd says.

He says the gas often finds its way inside homes through foundation cracks and sump pumps, seeping up through soil via the path of least resistance.

Experts say radon levels inside homes can be higher in the winter, due to the ground being frozen. The lack of ventilation within homes because of closed windows is also a contributing factor.

Budd recommends all homeowners test their properties as there is no way of knowing if your home is exposed to high levels of radon without one.

Health Canada's radon action guideline is 200 becquerels per meter cubed (Bq/m³). In the United States, it's 150 Bq/m³, and the World Health Organization recommends nothing over 100 Bq/m³.

Budd says Health Canada advises mitigation within a year if levels are over 200 Bq/m³ to avoid adverse health effects, although impacts vary based on individuals.

"It's like smoking, right? Some people smoke their whole lives, they never get lung cancer. Some people get it fairly young. It's the same thing with radon," he said.

Radon tests are available at a range of price points at local hardware store retailers.

Budd says the average cost for a mitigating system could cost a homeowner approximately $2,500, and involves installing a ventilation system that draws radon out from under a home and expels it into the atmosphere.

"It takes all the air from underneath the concrete, brings it to the fan, and then exhausts it outside, making sure that it doesn't have a chance to leak up into the home," he said.

"It's pushing it away from the home. It hits the ground and disperses into outdoor air."

Kinburn homeowner Doug McClenahan recently installed a radon mitigation system in his home after learning his home was in a higher risk area.

"I measured in the basement and I was flabbergasted at the value that I got, over a thousand. It was 1240 Bq/m³," he told CTV News.

McClenahan and his family spend extended time throughout the year in British Columbia, leaving their home sealed without ventilation.

He says he feels much more comfortable now after taking action to lower the levels in his home.

"We have levels now as low as 30 or even 25 Bq/m³."

Budd notes that generally, radon levels can fluctuate greatly in small areas, even from home to home within neighbourhoods.

Health Canada has a map available to show which regions across the country are at great risk.