Reduce the risk of the #1 cause of lung cancer in non-smokers.

Being exposed long-term to high levels of radon is the number one cause of lung cancer in non-smokers. Radon is present in almost every home and building. To find out the level of radon in your home, or any indoor space, you have to test for it.

How do you test your home for radon?

Testing your home for radon is easy.

  • Purchase a long-term radon test kit (average $30 – $50), install it on the lowest occupied level of your home during fall and winter, and leave it there for at least three months. Or, hire a certified radon professional to help you test.
  • At the end of three months, send the radon test kit to the laboratory address included with the kit. The laboratory will send a report back to you with your radon levels.

What can you do if your radon levels are above the guideline?

If your levels are above the Health Canada guideline of 200 bequerels per cubic metre of air (a bequerel is a measure of radioactive decay), you should take action to reduce the amount of radon in your home. A radon professional can offer options for what to do next, such as the following:

  • Hire a certified radon contractor to install an Active Sub-Slab Depressurization system, which is a small exhaust fan that draws the radon from below the concrete floor slab and vents it through a pipe to the outdoors. This is the solution that is likely to be most effective in reducing radon to acceptable levels.
  • Increase the ventilation in your home by hiring a contractor to install a heat recovery ventilator (HRV) or by optimizing the use of an existing ventilation system.
  • Seal all cracks and openings in foundation walls and floors.

The higher the level of radon, the sooner you should take action.

What else can you do?

Do not allow anyone to smoke inside your home. Exposure to cigarette smoke combined with high radon levels significantly increases the risk of developing lung cancer. A person who has had long-term exposure to high radon levels has a 1 in 20 chance of developing lung cancer. When combined with exposure to cigarette smoke, the risk of developing lung cancer increases to 1 in 3.

Need more information?


Home Safety for your Kids’ Sake mini-poster – Valentine’s Day version

Radon Testing for your Kids’ Sake
March 2015

Home Safety for your KIDS’ sake mini-poster
February 12, 2014

Reduce Radon
February 2013
Tip card

Health Canada Publications

  • Radon: Is it in Your Home? Information for Health Professionals. A guide to help health professionals answer their patients questions about radon.

Frequently Asked Questions (FAQ)

Q: How much does a do-it-yourself radon test kit cost?
A: A long-term (three-month) radon test kit costs approximately $35-75.
Q: I saw a 4-day radon test kit at my local home improvement store. Can I use that instead of a long-term test?
A: Conducting a short-term test is better than not testing at all, but because the levels of radon in your home vary over time, a longer-term test will give you a more accurate result. A test conducted over at least three months is recommended, and preferably between September and April when the windows are mostly closed.
Q: Are children more at risk from radon than adults?
A: Research shows that children are at greater risk than adults from exposure to certain types of radiation, but it is not known if a child’s risk from radon (a radioactive gas) is also greater than that of an adult. The lungs continue to develop throughout childhood and adolescence, which may contribute to a greater vulnerability.
Q: We’ve recently done a renovation. Could that affect the radon levels in our home?
A: Yes, renovations and energy efficiency measures may affect radon levels in your home. Energy retrofits and some home renovation work will seal a home more tightly to reduce energy loss, which can mean that radon will build up more readily in indoor air. Also, some energy efficiency work, such as installing ventilation fans, may create negative pressure in a home and can draw radon into the home from the surrounding soil. A renovation that results in a more tightly sealed foundation, however, may reduce radon levels. Even if you have already checked your home for radon, it is a good idea to conduct another radon test after the energy retrofit work or renovation has been completed.
Q: We conducted a radon test and found that the apartment we are renting has a high radon level. What can we do?
A: Talk to your landlord or building manager about your concerns and provide him/her with a copy of your radon test result. If he/she is not familiar with radon, show him/her Health Canada’s information on radon health risks and related guidance on how to reduce radon levels. At present, there is no legal requirement for a landlord to take action on radon, even if the levels are above the Health Canada guideline of 200 bq/m3. Nevertheless, you should request that action be taken. In the meantime, there are some things you can do that may help reduce exposures and risks, such as reducing the amount of time that you and your children spend in basement rooms, opening windows more frequently and ensuring that no one smokes inside your apartment.
Q: If I find that my home has high levels of radon, how much will it cost to fix it?
A: The cost of installing an Active Sub-Slab Depressurization system generally ranges from $2,000 to $3,000. This system is what most homes require to reduce the radon levels to an acceptable level. However, other lower-cost measures can help, such as sealing gaps and cracks in your basement and improving the ventilation in your home.