As uranium begins its cyclical decay chain in Canadian soil, homes on the surface act like a suction cup and draw in its deadly by-product: radon.
Odourless, colourless and tasteless, radon gas is just one domino in a radioactive cascade that enters structures new and old across the country, contributing to more than 3,300 lung cancer deaths per year.
“It’s the worst thing no one’s ever heard of,” said Anne-Marie Nicol, associate professor at Simon Fraser University’s Faculty of Health Sciences in Burnaby, BC.
As a public health researcher, much of Nicol’s work focuses on environmental carcinogens, specifically radon–the second leading cause of lung cancer in Canada.
“We’ve kind of shrugged this off as a smoker’s condition, but if fewer people are smoking we’re realizing there are other things that cause lung cancer as well,” said Nicol.
The latest technologies in radon remediation and mitigation offer a means to end the reign of this silent killer in homes and buildings.
Health Risks . . .
Canada is the world’s second largest producer of uranium–its soil so rich in the metal that there is always a measureable amount of radon in the air.
Outside, it dissipates and mixes with other gases, so concentrations drop to relatively harmless levels, ranging from 10 Becquerels–a measurement of radioactivity–per cubic metre (Bq/m³) to 30.
Inside, however, those levels can vary drastically from one structure to another.
Radon exists, on average, three to four days in an indoor environment before it decays, at which point it gives off radioactive alpha particles in addition to progeny, or “radon daughters.” The metal progeny “stick” to the sensitive lining of the lungs, further decaying and emitting radiation.
“People call radon radioactive, but it’s actually the decaying process that causes the problem,” Nicol said.
In 2007, Health Canada reduced its guideline for radon in indoor air from 800 Bq/m³ to 200. Comparably, the World Health Organization recommends a 100 Bq/m³ baseline, and the U.S. standard sits at 150.