A simple test can determine whether a cancer-causing gas is in your home, but many Nova Scotians still aren't aware of radon's danger — and they're not testing for it.

"The threat of radon gas exposure is very real, especially as the cold weather arrives and Canadians spend more time indoors with the windows closed," said Steve Horvath, president of the Radiation Safety Institute of Canada.

The institute is a registered charity dedicated to promoting and advancing radiation safety in the workplace, in the environment and in the community.

"Radon awareness is still not as high as it should be in Nova Scotia and that's been our goal to make people aware of it," said Robert MacDonald, spokesman for the Lung Association of Nova Scotia.

"It's the second leading cause of lung cancer," he said.

"If you do the statistics on that, it's around 120 Nova Scotians each year that pass away from lung cancer due to radon."

Last year his organization gave away 200 test kits in Tantallon, N.S., a community outside Halifax that has extremely high levels of radon. Of those kits, 110 were sent for testing. Sixty per cent of those showed radon levels above acceptable limits.

Nova Scotia Radon Risk Map

The government of Nova Scotia keeps a map of the potential risk for radon in indoor air. The darker the colour, the greater the risk. (Government of Nova Scotia)

The Radiation Safety Institute provided CBC Nova Scotia with five radon test kits to distribute to our audience as a way of encouraging others in the province to test for it.

Halifax resident Carly Brake participated in the CBC News testing. She has an 18-month-old son and wanted to make sure her home is safe from radon gas.

"I was thinking to myself just the other day about the irony," she said.

"I do all these things to keep him safe: I have baby gates, I have a car seat, I make sure I try to install it properly.  All these things we do to make sure he's safe and I'm not checking out something that could cause him respiratory issues."

If you spend time downstairs, you need to test

It's recommended people test for radon in the lowest level room in the house. While Brake and her family don't spend a lot of time in their basement, it's a different story across the harbour in Eastern Passage where Marilyn and Denis Martineau live. Their basement includes a finished family room where Denis spends a lot of time watching sports.

"We've talked about [testing] but if you don't smell it, taste it and are not aware of it, you just put it out of your mind," Marilyn said.

Home of Marilyn and Denis Martineau

Marilyn and Denis Martineau are having their home tested for radon. (CBC)

Radon is a radioactive gas formed naturally by the breakdown of uranium.

Health Canada says it can enter a home any place it finds an opening "where the house contacts the soil: cracks in foundation walls and in floor slabs, construction joints, gaps around service pipes, support posts, window casements, floor drains, sumps or cavities inside walls."

Home owners can buy the kits at some hardware stores or through the Lung Association, which charges $40, including testing.

Kits are available for long-term and short-term testing. Long-term tests take three months, while short-term tests take a matter of days. Health Canada recommends homeowners use the long-term kits.

CBC

One of the radon test kits used by CBC participants to test for the deadly gas. (CBC)

This year, the Lung Association gave away 500 radon test kits to people across the province.

"When it comes to your health and avoiding lung cancer, a simple $40 test is something we recommend you should do," MacDonald said.

In addition to Halifax and Eastern Passage, CBC News distributed kits to people in Chester Basin, Fall River and Tantallon.

CBC News will be reporting on those results, as well as the Lung Association's testing, when the testing is completed in three months and the results are available.