A study by several researchers, including Health Canada monitoring specialist Ian Hoffman, reveals a sharp spike in radiation over southwest B.C. on March 20, 2011.
That was nine days after a devastating earthquake hit Japan, triggering a nuclear disaster at the Fukushima power plant.
Hoffman and the other researchers (Environment Canada's Alain Malo, Jean-Philippe Gauthier, and Gilles Mercier, and graduate student Réal D'Amours) relied on the Canadian Meteorological Centre's dispersion model to track the arrival of the radioactive plume in B.C.
With sampling conducted every 15 minutes, they concluded there are "small scale/sharp features in the plume even after several days of travel times".
A PowerPoint presentation declares that several studies already exist concerning the release of radiation from the crippled power-plant in Japan.
"The Fukushima plume provided nice opportunities to test radioactivity detection capabilities," The PowerPoint presentation states.
In 2011, investigative journalist Alex Roslin reported in the Georgia Straight that a Health Canada monitoring station in Sidney had detected radioactive iodine-131 levels up to 300 times normal background levels.
In 2011, Health Canada was declaring on its website that the quantities of radiation reaching Canada did not pose any health risk to Canadians.
"The very slight increases in radiation across the country have been smaller than the normal day-to-day fluctuations from background radiation," Health Canada said at the time.
Roslin maintained in his article that Health Canada's own data contradicted that assertion. Below, you can see more of what the researchers stated in the PowerPoint presentation about the radiation plume.