Japanese radiation detected on East Coast of Canada

"The detection equipment is so sensitive that isotopes have been identified that are indicative of those being released in Japan. Isotopes such as Iodine-131 are products of the process that takes place inside nuclear reactors and are not normally seen in our environment," Duguay said. "The levels detected do not pose a health risk to our employees or to the public."

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So this is starting to hit close to home as I'm not that far from Lepreau. My concern is the limited information on the detection equipment being used (which I am trying to find info about). They have detected "low levels" of Iodine-131. Is this the only isotope they have found? Is this the only one they can detect?

People will be used to hearing that you get more radiation during a chest x-ray. Well that's fine, but that's an isolated incident. If this radioactive material is present in the environment, wouldn't you be getting prolonged exposure? Prolonged exposure to iodine causes thyroid cancers, and this is what potassium iodide protects against.

131I decays with a half-life of 8.02 days with beta and gamma emissions.

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So did this make it from Japan to the east coast of Canada in under 8 days? This is where my knowledge falls off, when talking half-life, does the rate of decay refer to total? So any amount of Iodine-131 would decay in around 8 days from release? Can someone explain that?

half life means that it will be half as strong as what it previously was. so if it has a half life of 8 days then that means every 8 days the streantgh of radiation is cut in half.