Should Canada do more to curb the health threat of radon gas?

In 2009, Donna Schmidt died of lung cancer. By the time she noticed symptoms and was diagnosed, the cancer had spread from her lung to her spine, liver, breast, bone and brain. She wrote a blog chronicling her last few months in treatment, signing her last post off with, “Thanks to all for everything you have given me.”

Schmidt had smoked earlier in her life, but had quit 20 years before her diagnosis. Trying to make sense of the tragedy, her husband, Dana, delved into research and news articles about lung cancer. “The word radon came up with Castlegar [British Columbia], where we lived for 15 years,” he remembers. When he tested his former house, the results revealed the concentration of radon gas in the house averaged around 400 becquerels per cubic metre (Bq/m3). Health Canada recommends that people who live in homes that test above 200 Bq/m3 take action to reduce the levels of radon gas entering the home. Venting systems can effectively bring radon gas to very low levels if installed properly.

Jing Chen, of the Radiation Protection Bureau of Health Canada, recently estimated that radon gas is responsible for 16% of lung cancer deaths in Canada, making it the second-biggest cause of lung cancer next to smoking. According to her analysis, radon gas kills 3,261 people in this country a year.

For several years now, groups like the Cancer Society, the national and provincial Lung Associations and the Radiation Safety Institute of Canada (RSIC) have been raising awareness of the harms of radon gas through media interviews and public outreach. Their efforts increase in November, which is Radon Action Month. The groups are supported by Health Canada, which has a radon outreach budget of $550,000 a year.

Still, most Canadians don’t know they should test for radon gas. A survey commissioned by the Canadian Cancer Society in late 2014 found that 96% of Canadian respondents hadn’t tested their homes for radon. Only one in three of those surveyed were aware that radon gas can cause lung cancer.

Some radon experts think raising awareness isn’t enough and are calling for more legislation that would require testing. After all, there are ways to bring the level of radon down if it’s high. Currently, “it’s like the Wild West,” says Bob Wood, president of the Canadian Association of Radon Scientists and Technologists (CARST), with little legislation to protect Canadians from radon gas exposure.

What is radon gas and what does the evidence say about who’s at risk?

Radon gas is invisible and odorless, so the only way people know the concentration of gas in their home is by testing. A product of the breakdown of uranium, radon gas comes from the soil and enters a home through cracks or openings in the foundation, floor drains and pipes.

Most people exposed to radon gas in homes aren’t harmed by it. In rare cases, however, particles from radon gas damage cells in the lung and lead to cancer. There is currently no evidence linking radon exposure with any other health issues aside from lung cancer.

A review of 13 controlled studies in Europe found that the lifetime risk of developing lung cancer would be 0.4%, supposing no exposure to radon gas. For smokers, taking radon gas out of the equation, the lifetime risk of lung cancer is 10%.

For people exposed to indoor radon gas concentrations at 100 Bq/m3, the lifetime exposure risk of lung cancer increases to 0.5% and 12%, for non-smokers and smokers respectively. And for those exposed to radon gas at concentrations of 800 Bq/m3, the lifetime risk jumps to 1% for non-smokers and 22% for smokers.

Most people in Canada live in homes that have radon gas concentrations below 200 Bq/m3, according to a Health Canada survey of approximately 14,000 homes conducted over 2009 to 2011. But 7% of the randomly tested homes were found to have radon gas exposures above this level. With the exception of Nunavut, homes with radon gas levels above 200 Bq/m3 were found in every province and territory. New Brunswick had the highest proportion of homes testing above the cut-off, with 25% of homes found to have high radon, followed by Manitoba. This is due to higher average concentrations of underground uranium in these provinces, but “there are pockets” of high uranium concentration throughout the country, explains Steven Mahoney, president and CEO of the Radiation Safety Institute of Canada.

Even in areas low in underground uranium, the type of soil beneath a home, as well as the number of cracks or openings in a home’s foundation, all impact a home’s radon gas levels. “Even if your neighbor has low levels you might have high levels,” explains Robert Nuttall, assistant director of the cancer control policy at the Canadian Cancer Society.

Those who live in basement apartments or spend most of their time in basements are especially at risk because radon gas is heavy and is found in the highest concentrations in basements. For this reason, the U.S. Environmental Protection Agency recommends testing only for all homes below the third floor.

Regulations need to better protect Canadians from radon gas

Currently, it’s up to individuals to learn about radon and decide if they want to buy a testing kit. Health Canada doesn’t require home owners to make radon tests a condition of selling a home. According to Andre Gagnon, media relations officer for Health Canada, that’s because “radon testing during a real estate transaction…would typically not allow for a long-term three-month test.” (While short term tests are available, and can be requested by individual buyers, they don’t always provide a representative reading because radon levels in a house fluctuate – the concentration tends to be higher in winter, for instance, when windows are closed.)  Wood says his organization is currently researching to see if a short-term test could be used to provide a reasonable picture of radon concentration in a home.

In the meantime, CARST, along with RSIC, are calling on the Ontario government to require owners of basement apartments to do long term radon testing. “We looked at what the government could do that would have the biggest bang with low cost to the government,” says Wood, noting that long-term testing devices cost around $30. (The cost of mitigating a house found to be high in radon is estimated between $1,500 and $3,000.) No provincial government or territory currently requires the testing of basement apartments.

In addition to targeting basement apartments, other regulations being pursued involve provincial buildings and workplaces. To protect employees, most provinces have adopted the Canadian Guidelines for the Management of Naturally Occurring Radioactive Materials, which state that full-time workers should not be exposed to radon levels above 200 Bq/m3. However, testing of workplaces is not enforced, explains Wood. In Ontario, for instance, it’s up to employees to request a radon test result, and if the employer refuses, a work refusal may be the only solution. “The Ministry of Labour gets involved in the case of a work refusal and could make an order to get the workplace checked,” says Wood.

Bill 11, which is currently sitting in Committee in Ontario Legislature, would mandate testing of workplaces and public buildings, and also require the government to educate Ontarians on the importance of testing. But Mahoney doesn’t have high hopes for the bill. “It’s gone through first and second reading three times in the past and it’s currently waiting a slow and painful death,” he says. He believes the bill isn’t getting high priority because it’s a private member’s bill, rather than a government bill, and because testing of provincial buildings alone could cost $20 million.

The cost is not insurmountable, however. Quebec requires all public schools to test radon levels. In that province, at least 10% of schools have had at least one classroom test high in radon, says Wood, with mitigation efforts completed or underway to divert the radon gas out of the building.

Barb MacKinnon, president and CEO of the New Brunswick Lung Association, says her organization is also calling for mandatory testing requirements for provincially owned buildings and workplaces, in addition to changes in the federal income tax law that would make renovating homes high in radon tax deductible.

Are changes in building codes the answer?

Here’s the complicated part. According to research by Health Canada, even if testing and mitigation regulations ensured that no Canadian was exposed to radon gas concentrations above 200 Bq/m3, that would only prevent 927 of the 3,261 deaths caused by radon gas annually.

That’s because more than 93% of Canadians are being exposed to levels of radon gas below 200 Bq/m3, and spread across a big population, even that low-level exposure is causing lung cancer deaths. “There’s no level of exposure that is without any risk,” explains Ray Copes, chief of environmental and occupational health at Public Health Ontario.

For this reason, Copes recommends changing building codes such that radon gas levels in homes would be closer to the outside concentration, of around five to 15 Bq/m3.

BC recently amended its building code to require homes in most of the province to install such a venting system. Ontario’s building code requires one town and two townships in the province to build in radon-reducing piping and fans. Alberta’s code, meanwhile, mandates that homes have a “rough in” that would make it simple and cost-effective to install a radon-venting system in the future, if radon was found to be high.

Schmidt argues, however, that simply making it easier to address radon gas exposure in the future isn’t good enough. He thinks building codes should follow BC’s example and require all new homes to have a system that draws radon gas from below the home to the outside.  Without a venting system, new homes can have even higher levels of radon compared to old homes, because they are sealed tightly, says Schmidt, based on results from the hundreds of homes tested for free by the Memorial Society.

Schmidt argues governments’ slow movement on building codes and provincial legislation to reduce radon gas exposure is reminiscent of the time it took to mandate seat belts.

“More people die from radon gas than from car accidents,” Schmidt says. “It wasn’t until seat belts were required by law that companies started putting them in cars.”

The comments section is closed.

  • Roxana Tudor says:

    I am doing my masters in lung cancer and although it is not directly focusing on radon as a major risk factor of lung cancer development, it is a hot topic that often gets discussed between labs and conferences. Since radon causes more of a “silent” death (especially since more than 50% of lung cancer diagnoses are made in advanced stages), and since the number of individuals who are never-smokers is increasing, I think the provincial government (especially since lung cancer is a postal code disease) should mandate a health-care policy requiring radon-testing in at least all public-health service buildings. Yes, it is mentioned above that this would cost the government around $20 million, however the cost of lung cancer treatment is around $50,000/case (*keep in mind that in Canada, every 1 hour 3 people are diagnosed with lung cancer) and this is not including new targeted therapies and/-or the indirect costs (ie taking time off, driving between hospitals, parking at hospitals especially in Toronto downtown) that family-members have to burden when taking care of a family member with such nasty disease. The minister of health should definitely be more hands-on when it comes to this topic, especially since lung cancer is often stigmatized. We have to face the reality however and spread more awareness that lung cancer is not a smoker’s debilitating disease anymore!

  • Ina Chomyshyn says:

    Radon concentrations are not higher in basements because it is a
    “heavy” gas.

    Other “facts” were also off the mark.

    Please check your facts and get help from a professional if you need help understanding. There is enough radon misinformation out there.

  • Ray Buncic says:

    How does one go about arranging a long termn radon test in one’s home?

  • Rola Priatel says:

    Good to see an article on Radon published. I used to think this is crazy talk until it hit me personally. In a span of 10 years, on one street of 30 houses, 7 people under the age of 55 were diagnosed with metastatic solid tumours , my father was one of them. This street is in Vancouver and is only 30 years old. chiselled from rocks on rocks and a new school was built in the back of the street where a forest used to be. This street is in an area which is also new and the only three women I know who died of cancer in their 30’s also lived in that area, a few blocks down from this one street I mention. I looked up the cancer rates and rates on that street were much higher than the national average ! I did call health Canada to enquire and they confirmed that they are investigating some areas but are focusing on Ontario for now (back in 2010) . The solid tumours were colon, prostate, breast and anal, not lung, but could there still be a link to radon? The gas emissions, the seepage into the water lines? Wish that street was not one of Canada’s most expensive real estate. I can only imagine the financial and political impact should news of cause/effect of radon is established in that area.

    • Kira says:

      agree! It’s 4 years later and nothing special happened. The knowledge about Radon is still less than statistical error, and it should be especialy publicized in the mining areas, where this radiation is higher than anywhere. Another thing is what you’re writing about, it’s good to know from where building materials were taken, becuase in some components concentration of this gas is out of limits. If you do not believe me, read this book about cancer risk factors –


Wendy Glauser


Wendy is a freelance health and science journalist and a former staff reporter with Healthy Debate.

Sacha Bhatia


Dr. Sacha Bhatia is the director of the Institute of Health Systems Solutions and Virtual Care and a Staff Cardiologist at Women’s College and University Health Network.

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