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A news story has done the rounds on social media this year claiming that salmon in Canada had been found contaminated with radioactive isotopes from the damaged nuclear power plant at Fukushima in Japan.
Is it true? And, if so, is there anything to worry about? The answer to the first question is “yes, sort of”, but the answer to the second is “definitely not”!
The story grew from the fact that, in 2015, a single salmon caught in Osoyoos Lake in British Columbia was found to contain very low levels of a radioactive isotope called caesium-134. |
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The isotope is produced during nuclear fission – the process that drives both atomic power stations and atomic bombs. Because it has a half-life of about two years, any caesium-134 that was released into the atmosphere by previous bomb tests or reactor disasters (such as Chernobyl) has long since decayed away.
Therefore, any caesium-134 found in anything at the moment can only have come from Fukushima.
So, yes, a radioactive nasty from Japan did end up in a fish in Canada. However, there is much more to the story than that.
First off, scientists have always predicted that radioactive stuff from the damaged reactor would spread around the world, through the oceans and the air. |
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