A new report out of the University of Calgary shows an alarming increase in the presence of radon gas in homes across Canada.
In 2012, about seven per cent of homes were found to have dangerous quantities of the gas.
Now that figure is 17.8 per cent, meaning that an estimated 10 million Canadians are living in homes with dangerous amounts of radon.
This is of concern because radon exposure is the second leading cause of lung cancer, after cigarette smoking. Around 21,000 Canadians die of lung cancer each year, and perhaps as many as a sixth of those deaths are due to radon exposure.
Radon is formed when the radioactive element radium decays, and being seven times heavier than air, is usually found in basements.
It is colourless, odourless and deadly. When breathed in, it decays into radioactive lead that has a half-life of 22 years — much longer than radon itself. That means it remains in the lungs long enough to cause cancer.
The gas is measured in Becquerels per square metre (Bq/m3), with 200 units of Bq/m3 being the upper safe limit.
Quantities vary widely across the country. The highest levels are found in the B.C. Interior, Atlantic Canada and Yukon, where one in three homes have radon levels at or above the safe level.
By comparison, in the Pacific Coastal region as a whole, only one in 75 homes have that level.
In Victoria, homes average around 22 Bq/m3, with only one in 200 at or exceeding the safe limit. In Vancouver, the average radon count per home is 18 Bq/m3, and only one in 113 exceeds the safe limit.
The easiest way to measure the amount of radon in your home is through the Evict Radon agency, a national research organization that carries out periodic home-based tests. It can be found at evictradon.org.
Test kits can be ordered at a cost of $54. They arrive by mail, and are about the size of a hockey puck.
The kit must be left in the basement, or lowest floor, for three months.
It is then mailed back to the agency with a prepaid return envelope, and a reading is provided within six to eight weeks.
Radon detectors can also be purchased online. These, too, must be left in place for at least three months, since the quantities of radon seeping into basements varies greatly from day to day.
Unfortunately, clearing a home of the gas may not be cheap.
The most common method is to vent air out of the basement through a pipeline under the foundation. The average cost countrywide is around $1,200, but prices can go as high as $2,000 to $2,500, depending on the home layout.
It’s not known exactly why radon quantities have increased in recent years. Part of the explanation may be that new homes tend to be more airtight, and that allows the gas to concentrate.
It is also a reality that as the dangers of radon exposure become better known, more people are testing than before.
Unfortunately, there has been little work done in testing high-rise apartment buildings — the numbers given here are for detached, semi-detached or row houses.
This is a serious deficiency that should be corrected at the earliest opportunity.
All the more so because lung cancer is one of the deadliest cancers. Across the country, the five-year survival rate is only 22 per cent.
Clearly, radon is a threat that all of us should take seriously.
• Thanks to professor Aaron Goodarzi, the lead author in the Calgary study, for his help with this editorial.
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