Radon Gas


We now offer short-term radon detectors through Nova Scotia Public Libraries. For more information, click HERE

For the Mandatory RADON COURSE for real estate professionals, click HERE

If you are having issues registering for the mandatory course, please click HERE for commonly asked questions.


Radon is a radioactive gas produced naturally by the decay of uranium in the ground. It exists all over the world, although the amount of uranium and level of radon gas vary significantly, even from one house to the next. Radon is invisible, you can’t see it, smell or taste it and it can get into your home undetected.

The current Canadian Guideline for radon is 200 becquerels per cubic meter (Bq/m3). Becquerels per cubic meter is the unit of measurement for radon, the higher the number the greater the risk. Protecting your family’s health from the risk of radon exposure starts with learning more.

The only known risk from long-term exposure to radon is the development of lung cancer. Radon exposure is the 2nd leading cause of lung cancer after smoking. The level of risk depends on the concentration of radon as well as the number of years of exposure.  

Radon in your home?

Approximately 10-15% of Nova Scotians are living in homes with radon levels above the recommended Canadian guideline.1 Nova Scotia has some of the highest radon levels in Canada due to our geology. Radon is found in nearly all homes in Canada, new or old. The question is: how much is in your home? The gas can enter the home wherever it has contact with the ground. Radon tends to accumulate in the lower levels of the home, like the basement for example, where it can reach high concentrations.

The gas can seep into the house in a variety of places:

  • Foundation wall cracks;
  • Between floor tiles;
  • Packed earth floors;
  • Construction seams;
  • Gaps around pipes and support posts;
  • Crawl spaces, drains and sump holes.

The only way to know if you have a radon problem in your home is to measure its concentration with a simple test.


Protect your family's heath

Measure radon level
The only way to know the level in your home is to measure it using a radon detector. There are a number of measuring devices and services available. Testing is safe, simple and relatively inexpensive. Some radon detectors allow you to measure radon concentrations over short periods (days) while others do so over several months.

Health Canada recommends measuring radon in your home for at least three months, ideally in the fall and winter timeframe. Radon levels can vary significantly over time and therefore a long-term test is more accurate.

If the radon test results are above the Canadian Guideline of 200 becquerels per cubic meter (200Bq/m3), steps to reduce the level of radon in your home should be taken. The higher the level, the sooner corrective measures should be taken. Remember that you should not rely on your neighbors’ test result as results can vary significantly from one home to the next.

Test kits can usually be found at hardware stores. The Lung Association of Nova Scotia is also offering long-term radon test kits at a price of $46 (+$10 for S&H). Please phone (888) 566-5864 for more information.


Reduce radon levels

There are many ways to reduce the radon level in your home and, in most cases, these measures are simple and relatively inexpensive. For example:

  • Seal all cracks and holes in the foundation walls and floors, and gaps around pipes and drains;
  • Increase the mechanical ventilation, via an air exchanger or heat recovery ventilator (HRV), to allow an exchange of air;
  • Renovate existing basement floors, particularly earth floors;
  • Install a sub-slab depressurization system that will suck out and exhaust the radon outside – this is typically done by a contractor.

The effectiveness of these methods will depend on the level of radon in the home and characteristics of the home. As each house is unique, a qualified or certified contractor can assess your home and recommend one or several mitigation techniques.

The work should be done by a C-NRPP-certified contractor who has received proper training from a certified organization. Expect the work to cost anywhere from $500 to $3,000.


For new homes

When a new home is being built, it is not possible to predict the levels of radon it will contain. It is therefore simpler and less expensive to adopt preventive measures during construction than to take steps later on.

In December the 2010 National Building Code revisions were released and included in them were new codes to protect against radon entry.  These new codes apply to all new homes built in Canada, make sure that you builder is implementing them. The codes include:

  • A permeable layer (e.g., aggregate) under the slab
    • A vapor/air barrier between the permeable layer and slab
      • A sealed slab
        • A capped vent stub through the slab - a rough-in of a radon sub-slab depressurization system

        For more details on these codes you can visit the web at: http://www.nationalcodes.ca/

        Corrective and preventive measures are featured in Health Canada's brochure “Radon Reduction Guide for Canadians”.

        Additional resources for radon measurement and mitigation are:

        Guide for Radon Measurements in Residential Dwellings (Health Canada)
        Government of Canada Radon Guideline (Health Canada)

        Frequently Asked Questions

        Q: Where can I find radon test kits?
        A: There are two options for testing a house for radon: one is to purchase a do-it-yourself radon test kit and the other is to hire a radon measurement professional. If you choose to perform the test yourself radon detectors can be purchased over the phone, from the internet or from some home improvement retailers.. Health Canada encourages the use of long-term radon test kits. Long-term radon detectors commonly used are alpha track detectors and electronic chambers. 

        The Lung Association of Nova Scotia also sells long-term radon test kits for $46 (lab testing included) plus shipping for the delivery of the kit. Please click here to order your radon testing kit.


        Q: What areas in Nova Scotia are known to have the highest levels of radon?

        A. The Geological Services Division of the Nova Scotia Department of Natural Resources has produced an interactive map showing radon levels throughout the province. NS Radon Map


        Q: My radon test results came back and they are above Health Canada’s guideline of 200 Bq/m3. Now what?

        A: First, don’t panic. You have the highest risk of developing lung cancer when you are exposed to high levels of radon for a long period of time – years or decades.

        Next, consult the Canadian Mortgage & Homeowner’s Corporation’s booklet “Radon: a guide for Canadian homeowners”. Inside, you will find information about simple methods to reduce radon levels in your home. There is also information about dealing with contractors.

        If you would like to do more extensive work to lower radon levels, click HERE to find a certified radon professional. We do not endorse any of these companies.


        Q: How does radon gas cause lung cancer?

        A: Radon decays quickly, giving off tiny radioactive particles. When inhaled, these radioactive particles can damage the cells that line the lung. Long-term exposure to radon can lead to lung cancer.

        For more information on radon please contact the Lung Association of Nova Scotia toll-free (888) 566-5864


        1. https://www150.statcan.gc.ca/n1/pub/16-508-x/16-508-x2016002-eng.htm

        Page Last Updated: 14/10/2021