the non-smoker's guide to lung cancer

The non-smoker’s guide to lung cancer: how to protect yourself from the invisible killer


If you don’t smoke, you’re not at risk of developing lung cancer. True or False?

If you said, “True”, think again.

About 16 per cent of lung cancer deaths, or 3,000 cases per year in Canada, occur in non-smokers. The leading cause of lung cancer in non-smokers is an invisible, tasteless, odourless gas called radon, which exists in harmful levels in almost 7 per cent of homes in Canada.

When radon is inhaled into the lungs, its radioactive particles damage cells which may then undergo malignant transformation. The risk of a non-smoker developing lung cancer after long term exposure to high concentrations of radon gas is 1 in 20, while for smokers, the risk is even higher at 1 in 3.

Where does radon gas come from?

Radon is a radioactive gas produced naturally when uranium in soil and rock breaks down. Outdoors it is very diluted and therefore not harmful, but when it enters your home the concentration increases, leading to toxic levels over time.
It can enter through any openings that have contact with soil, such as construction joints, foundation cracks, window casings and floor drains. These openings can be present in even new and well-built homes.

Who is at risk?

Radon content of soil and rock varies widely across Canada. The Cross-Canada Survey of Radon Concentrations in Homes, conducted by Health Canada between 2009 and 2011, found high levels of indoor radon in Manitoba, New Brunswick, Saskatchewan and the Yukon. In BC, radon levels are more likely to be elevated in homes in the interior of the province, near Castlegar and Kamloops.

Does that mean you can breathe a sigh of relief if you live outside of these regions? Unfortunately, no. There are no areas of the country that are radon-free and levels in the soil can vary from street to street and home to home. That is why Health Canada recommends that every home be tested for unhealthy levels of radon gas.

How can I have my home tested?

Testing for radon is simple and inexpensive. You can purchase a kit from most hardware stores or through the BC or Alberta Lung Association.

The small testing unit is placed in the lowest level of the house that is regularly occupied for at least 3 months, as radon levels will fluctuate. Testing should be done in the fall or winter months, when windows and doors are usually closed.

Health Canada has set the safe upper limit for indoor radon at 200 Bq/m3, but if your results are above this level, the issue can be corrected quite simply. There are a number of ways a contractor can vent your home to reduce radon. Look for a contractor certified by the Canadian National Radon Proficiency Program or C-NRPP.

If you are building a new home, you will be pleased to know that the 2010 National Building Code includes requirements that address radon. And don’t worry about that granite countertop; in February 2010 Health Canada studied 33 types of granite used for countertops in homes and none were found to give off worrisome levels of radon gas.

For more information, please visit the Health Canada website ( or the Canadian Lung Association (