Radon Gas is Deadly and it May be Lurking in Your Home


Carbon monoxide and radon are deadly gases that are colourless and odourless. However, we can detect carbon monoxide immediately if it's in our homes. Unfortunately, there is no immediate security system against radon gas, which allows it to accumulate in your home without you knowing. According to Health Canada, radon gas is the second leading cause of lung cancer, behind smoking. Long term radon gas exposure remains the leading cause of lung cancer in non-smokers. It also elevates a smoker's risk for developing lung cancer to 33 percent, a frightening 1 in 3 probability. Radon gas exposure kills 3,000 Canadians each year.

The statistics are scary, but don't stress. The harmful effects of radon gas depend on factors such as the concentration of radon in the air, and the duration of person's exposure to the gas. Moreover, radon gas affects our health only when we’ve been exposed to it for a long time, and not overnight.

Radon Gas in Canadian Homes

Radon gas is produced when the uranium present within the Earth's crust decomposes. It then seeps through groundwater and cracks in the bedrock. This seeping explains why radon is found in soil, rock, water, and air. As a matter of fact, trace amounts of radon gas are present everywhere in the outdoors! However, radon gas in the outdoors is non-threatening to our health. We should worry about our health when radon accumulates in our homes.

That's why Health Canada has set an acceptable radon concentration level of 200 Becquerels per cubic metre (Bq/m3). A concentration above 200 Bq/m3 in an enclosed space warrants investigation and mitigation.

A cross-Canada report released in 2012 on radon concentration in Canadian homes revealed that some provinces had more homes with radon concentration than other provinces. Homes in Manitoba, The Yukon, New Brunswick, and Saskatchewan displayed radon concentrations above Health Canada guidelines. Results from Prince Edward Island and Nunavut displayed homes having lower concentrations of radon. Despite these geographical findings, studies also reveal that radon concentrations in homes depend on the home's structure.

A study in 2014 found that 16% of homes in Thunder Bay, Ontario had above guideline radon gas concentrations, which varied significantly depending on regions throughout the city. Forty-three percent of homes in McIntyre ward had unsafe radon concentrations, while none of the homes in Westfort ward were found contaminated.

The study shows that Canadian homes within the same city or neighborhood may not have the same risk of contamination. Hence, it is important to check your home for radon gas even if you know about radon concentrations in your city, or province. For more information on radon concentrations across the country, check this interactive map on CBC.

How is my home at risk?

Now that we are aware about the basics of radon gas, and understand possible safety risks, it's time to learn how to prevent radon from accumulating in our homes.

The most important thing to know is that radon gas from the ground enters into our homes through cracks in the house's structure. Radon gas can enter through cracked concrete slabs, foundation, brickwork, floor-to-wall joints, holes, and even piping. Any crack that is not sealed tightly puts your home at risk. Rooms that have significant contact with the soil, like basements, are most commonly prone to radon gas concentration.

When am I most at risk for radon exposure?

Radon gas accumulation in the home is most serious during the winter time. Keeping windows and doors closed during the winter limits fresh air circulation in our homes, which allows radon gas to accumulate. Radon accumulation increases by 10 times during the winter months. So, if it's winter time, it's a great time to check your home for unsafe levels of radon gas.

How can I check for radon gas concentration in my home?

Checking to see if radon is collecting in your home is very easy.

You can purchase a radon gas test at a local hardware store, or you can have a professional test your home for you. There are 3-day short-term tests, and 91-day long-term tests. Radon levels can vary throughout the day, so long-term tests are highly recommended by professionals.

Place the test in an unused, low-lying room in the house, like a basement room. Doing so will provide you with the most accurate reading for radon concentration levels in your home. After sending the test for processing in a lab, you receive the results.

The radon gas test is useful because it shows you if dangerous levels of radon gas are present in your home. Knowing the radon concentration outlines whether mitigation is necessary. Remedial processes are most necessary if you have a radon concentration above 600 Bq/m3.

How to Eliminate or Reduce Radon Concentration

The radon mitigation procedure channels radon gas from the ground underneath your home to the outdoors. Experts will also ensure that the cracks in your home’s structure are filled and fixed. Fixing these cracks seals your basement, preventing radon from seeping into your home in the future. The cost of the mitigation procedure ranges from $1,500 to $2,000. Make sure you hire a certified professional who can assure the procedure’s efficacy and longevity.

I haven't heard of radon gas before and now I'm worried, what should I do?

Earlier on, we provided information that can help you understand radon concentrations based on your geographical location. Check out the interactive map on CBC to see if your region tends to have high radon concentrations. Additionally, you should consider these stepsafter finishing this article:

  1. Purchase a radon test as soon as you can before the spring. When the weather warms up, we tend to open our windows, and this can give you inaccurate test results. If you have a room that you hardly enter, like a cold cellar, place the test there. Try to find a long-term test and do it over the winter if you can.
  2. Relax. Radon gas is most harmful with long-term exposure, not overnight exposure. Moreover, radon concentrations may not even be an issue in your house.
  3. Consider your surrounding soil characteristics. Radon moves more quickly through sand than clay. This information can help you gauge how often to test for radon in your home.
  4. Seal up any known openings in your basement floor and walls. Drains, cracks, holes, and joints are opportunities for radon to seep into your home. Try your best to slow the process by closing these spaces with caulking, cement, and fillers.
  5. Consider a HRV or ERV ventilation system if mitigation isn't necessary. Proper ventilation in the home can help prevent radon gas from accumulating in dangerous amounts.
  6. Look into your home's structural history. Make note of any documented issues in the past, such as foundation cracks. Any known cracks in your foundation should prompt radon concentration testing sooner.
  7. Minimize certain appliance usage if you are doing a radon test, or are aware of high radon concentrations in your home. Some appliances such as fireplaces and exhaust fans can accelerate the speed at which radon enters the home. This happens because fireplaces and fans disrupt home air pressure. Reduce your use of such appliances until you have clear results from your radon gas test.
  8. Pay close attention to your test results:
    • If your results show a concentration below 200Bq/m3, retest every few years. Radon gas accumulation in your home can change annually.
    • If your results show a concentration between 200 and 600 Bq/m3, you may take mitigation action within the next 2 years.
    • If your results show a concentration above 600 Bq/m3, it's advised to take mitigation action within 1 year.
    • If you decide to mitigate, don't forget to post your project and review your skilled professional when the job's done at!

Posted by: Nicole Silver
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