Janet Whitehead has never smoked a cigarette. So when she was diagnosed with lung cancer in 2010, the news came as a shock.

After some research, Whitehead eventually learned that her former home had high levels of radon gas, an odourless, colourless substance that can rise from the ground and leach into basements, increasing homeowners’ risk of lung cancer.

“The levels were right off the charts -- 30 times the World Health Organization action guideline,” Alan Whitehead, Janet’s husband, told CTV News.

Radon is a radioactive gas that occurs when the uranium contained in rocks and soil breaks down. When released outdoors, the gas is diluted and doesn’t pose a threat. However, radon can become a health threat if it seeps into an enclosed space, like a house, school or basement.

If inhaled for long periods of time, doctors say the gas can increase the likelihood of developing lung cancer.

Since radon occurs naturally, it can be found across Canada.

Scientists suspect there are countless homes across the country with unsettling levels of radon gas. Despite those concerns, Health Canada says only about 6 per cent of Canadian homes have been tested for radon.

In an effort to better understand the extent of the problem, researchers from the University of Calgary are testing homes across Alberta.

Dr. Aaron Goodarzi, an assistant professor with the university, said one in eight homes in the study’s sample area tested positive for levels of radon above 200 becquerels, Health Canada’s maximum safe limit.

“One in two homes was actually over 100 (becquerels), and that’s where we start to see an increase in the relative lifetime risk of lung cancer,” said Dr. Goodarzi, who also serves as the Canada Research Chair for Radiation Exposure Disease.

The research is part of a program called Evict Radon, which encourages Canadians to test their homes for the gas.

Researchers in B.C. have also begun handing out free radon-testing kits to homeowners.

How to test your home for radon

Radon is impossible to detect by mere sight or smell. But there are several simple, cost-effective ways to effectively check radon levels in your house.

A small, puck-like device can be placed in a basement, where radon gas is known to gather. After about 90 days, the device can be sent into a lab for testing.

The Wave radon detector, a more costly solution at $249, syncs up with a user’s smartphone. Inventors say the device can deliver real-time radon levels within an hour of installment.

Alternatively, a professional tester can also be brought in to measure radon levels.

After learning of her diagnosis, Whitehead sought treatment for lung cancer, and is now doing well.

There is no definitive way to test whether or not radon caused a person with cancer to develop the disease. But Whitehead is convinced that breathing in the gas for years caused her to develop the disease.

She has since turned her efforts toward raising awareness of the deadly gas.

“I would urge anybody -- everybody -- to test their home,” she said.

Radon-testing kits can be purchased for as little as $25. Click your province below to learn where you can buy a kit.

British Columbia






New Brunswick

Newfoundland and Labrador

Nova Scotia

Prince Edward Island


With a report from CTV medical specialist Avis Favaro and producer Elizabeth St. Philip