A Calgary-area woman who runs a business that tests for radon gas says most people in the west are unaware of the problem.

Radon is the second leading cause of lung cancer in Canada after smoking. It's a radioactive gas naturally emitted from the earth through the breakdown of uranium in soil. It enters your home by seeping in through cracks, pipes, windows and the foundation of your house.

It's estimated that radon kills 3,000 Canadians a year. 

A CBC News investigation into radon gas levels in neighbourhoods across the country is based on never-before released Health Canada test results.

The information shows Manitoba, New Brunswick, Saskatchewan and Yukon had the highest levels. Health Canada recommends no more than 200 becquerels per cubic metre (Bq/m³) of radon in homes. A becquerel is the unit scientists use to measure radioactivity.

'It actually really bothered me'

Renata MacQueen got into the testing business after she got a reading of 2,500 Bq/m³ in her home.

“What I was upset about is I was really careful as a mom to feed my kids vegetables, we exercise, you know I'm very careful — life jackets, you name it, you know, car seats proper. And when I found the home was unsafe it actually really bothered me,” said MacQueen, who runs Radon West in Cochrane, Alta.

“When we first started talking about radon I felt like we were selling snake oil. People think you're trying to sell something. Basically, my message is you can test yourself, it can be fixed and it's one of the few things you can fix.”

CBC News also discovered Health Canada considered making radon testing mandatory in real estate transactions but abandoned the idea because of concerns from industry groups.

There are several ways to reduce the levels of radon in a home: 

  • Installing a radon reduction system, sealing cracks around foundation walls, floors pipes and drains or increasing ventilation.
  • In 2010, national building codes were added for the protection against radon entry. New homeowners should ensure that builders are following these codes.
 Radon gas levels high across Canada

Radon gas levels high across Canada. (CBC)