Radon in Canada 

The majority of cities and towns in Canada have been built on high radon potential soils. This includes the BC interior, the Yukon, the Prairies, the Greater Toronto Area, much of Quebec and the Atlantic province region.

1. Canada is a very large country with many areas of VERY HIGH RADON POTENTIAL (meaning >300 Bq/kg of surficial geology – see Monograph #7 for details).
2. Canada also has STRONG SEASONAL FLUCTUATIONS in weather and temperature – meaning our winters are often very cold, and our summers are very hot. Collectively, this environment causes Canadians to spend a great deal of time inside either artificially warmed or cooled indoor air environments. Such environments have the potential for highly concentrated radon levels.
3. Without knowing it, Canadians have settled and built our villages, towns and cities on soils with very high radon potential, and we have designed and build houses that are very ‘good’ radon capture and contain devices. Thus, Canadians are among the MORE RADON-EXPOSED POPULATIONS on Earth.
4. It is important to recognize that this problem is preventable but, by and large, is no-one’s

What the science says:

There have been several recent studies on Canadian radon exposure including:

1. Cross Canada Radon Survey from Health Canada 
2. Canadian geologic radon potential mapping 

Publications comparing Canadian radon to countries all over the globe (Gaskin et al., 2018 and Stanley et al., 2019 (LINK) ).

Radon Across Western Prairies 

The North American Prairies is a region of exceptionally high geologic radon potential. On average, 1 in 6 Prairie homes are >200 Bq/m3. Residents of this area are amongst the most radon-exposed people on Earth.

1. The surficial geology of North American Prairies is comprised of a lot of soils left behind as glaciers retreated during the last ice-age. This is called “GLACIAL TILL”, and contains a great deal of radon-generating minerals such as radium, thorium and uranium.
   1. 1. There is so much radium in areas of Western Canada, they’ve named towns after it! Who amongst us have enjoyed the hot springs in the town of Radium, BC?
      2. Canada has a lot of uranium, and is amongst the most prolific miners and exporters of this mineral in the world. These mines are predominantly in Northern Saskatchewan and Manitoba.
2. We have mapped radon levels in the indoor air across the provinces of Alberta and Saskatchewan, finding that 1 in 6 HOMES EXCEED 200 Bq/m3 – the maximum tolerated dose exposure limit that is indicated by Health Canada. Thus, it is not surprising we have as many radon-induced cancers as we do.

What the science says: 

Evict Radon Canadian university researchers have found that W. Prairie residences contained an average (geometric mean) of 108 Bq/m3, with 17.8% being ≥200 Bq/m3. The highest observed so far is 7,199 Bq/m3.

Reference: Stanley et al. Radon exposure is rising steadily within the modern North American residential environment, and is increasingly uniform across seasons. In Press, 2019.

Urban vs. Rural Radon 

Both urban and rural Canadian homes can have high radon. However, in more isolated, rural areas of North America there are additional considerations such as radon exposure via well water, proximity to fracking and/or access to radon mitigation services. 

1. There are big differences between properties in highly urbanized, large population centres vs. the rural, low population density areas of any country. Rural regions tend to have fewer high rise apartments and more larger detached homes – both of which mean higher radon. 
2. In cities, any radon dissolved in water is ‘scrubbed out’ at treatment plants. In rural homes relying on well water, however, radon can de-gas from the water into the home unless precautions are taken.
3. A recent study found that homes closer to fracking operations (injecting liquid at high pressure into subterranean rocks to force open fissures) showed statistically higher radon. The reason is still unclear. 
4. If a radon mitigation is required, remote locations means that a professional may incur logistical issues (long distance) to complete the jb. As a result, it is possible that rural radon mitigation may be more costly compared to urban areas. 

What the science says:

In a recent survey in Ohio, scientists measured the amount of radon in homes as a function of the area population density and distance from 1,162 known fracking operations. Rural homes and/or those closest to the fracking wells showed higher radon vs. urban area homes.

Reference: Xu et al. Impactof the Hydraulic Fracturing on Indoor Radon Concentrations in Ohio: A Multilevel Modeling Approach. Front Public Health. 2019 Apr 10;7:76.