The real fallout from Fukushima

‘You can go ahead and eat the fish.’ Colby Cosh on the actual impact of the spread of radioactive seawater from Japan


 
  12
DigitalGlobe/Getty Images

DigitalGlobe/Getty Images

On the verge of the new year, scientists from the federal Department of Fisheries and Oceans issued the first systematic report of measurements on the spread of radioactive seawater from Japan’s damaged Fukushima nuclear reactor to the coast of British Columbia. The bad news, if you want to call it that, is that Japanese-originated radioactivity has in fact reached detectable levels on Canada’s continental shelf. The menace from the Land of the Rising Sun is officially here—and is, for now, growing.

The good news is that, as responsible scientists almost universally predicted, the amount of radioactivity involved is infinitesimal and completely harmless. You can go ahead and eat the fish.

Accurate measurements of the Fukushima plume are possible because humans wisely stopped testing nuclear weapons in the atmosphere in 1980. There is still a “fallout background” of radiation lingering in the world’s oceans from these nuclear tests—and, of course, from those two nuclear explosions that did not quite have the character of tests. But every kind of radioactive isotope has a different rate of decay, usually expressed as a “half-life,” and the short-lived ones from nuclear testing are all gone.

This means that the 2011 Fukushima disaster left a distinctive “fingerprint” of fast-decaying radioactives that cannot be attributed to any other source. So that’s what the scientists measuring the plume look for—fanning out between Vancouver Island and Japan on Canadian Coast Guard oceanographic vessels, gathering up seawater from various depths, and pumping it through ion exchangers to extract the telltale radioactive cesium that spewed out of the damaged reactor.

In 2011, the measurements along the B.C.-Japan line looked just like usual. But the levels of cesium-134, which can only have come from Fukushima, suddenly increased about 1,500 km off the continental shelf when samples were taken in 2012. In 2013 the “fingerprint” of Fukushima seems to have reached the shelf itself.

Cesium-134 degrades fast. What physicists and doctors have been concerned about is the equal amount of cesium-137 spilled at Fukushima: that isotope has a half-life of 30 years, so most of whatever reaches B.C. now will be around for a while. The radiation emitted by the fallout background—the cesium-137 presently left in the ocean by past nuclear testing—works out to about one becquerel per cubic metre of seawater. That figure has now doubled. The total peak level of ocean radioactivity off Canada’s Pacific Coast is expected to reach somewhere between three to five becquerels per cubic metre before beginning to drop back down.

Sounds fairly alarming, doesn’t it? The sea is going to become maybe five times as radioactive! But a becquerel is such a small amount of radiation—literally just one atomic nucleus splitting apart per second—that the naturally occurring isotopes of potassium and other elements in your body are generating kilo­becquerels of radiation right now. As the paper by federal oceanographers notes, drinking water in Canada is allowed by law to emit up to 10,000 Bq/m³ of radioactivity.

The “fallout background” itself was greater not so long ago, as you’ve already figured out if you caught that the half-life of cesium-137 is 30 years. (The implication: 30 years ago, there was twice as much.) Overall, the authors of the paper expect the Fukushima plume to make B.C. ocean water as radioactive as it was in the 1980s—a pretty modest rewind of the planet’s radiological history. And if you really are worried about the fish, they’re known to accumulate only about as much radioactive cesium as the seawater they swim in has. That’s a fraction of what they, like us humans, would otherwise emit just from the natural radioisotopes in their bodies. In turn, you get only a fraction of that excess radiation from eating them.

This is, broadly speaking, the story that experts expected to hear about the Fukushima plume. Really all you needed was some physics literacy. In 2011, people lacking that produced plenty of scary colourful maps of Fukushima death juice creeping across the Pacific. And of course David Suzuki could not resist weighing in a year ago with a bizarre Fukushima scare scenario, one which physicists promptly denounced as “insane” and “ridiculous.”

The consequences to Japan of the Fukushima accident are still being added up, and the sum is not altogether final until decades of decommissioning work is completed. But so far, when it comes to human mortality, the nuclear energy industry still has a lot less to apologize for than dams, coal or even oil.


 

The real fallout from Fukushima

  1. You are so full of it Maclean’s.
    One type of radiation, in one format, and one of the least concerning.
    Radiation is cumulative.
    Cesium is not the only type being produced. The other types are also being deposited and they have half lives of tens of thousands of years. And they are raining and in the ocean and accumulating over the course of a life time.
    They are also cumulative in your body from consuming things which concentrate their ingestion / accumulation of radiation.

    You get the radiation from the fish. And the half life accumulation of long lived radiation from the cow that ate the grass that had radiation accumulating in it. And its milk. And the fish. And the water. And if adds up in your body, and it deposits more over time into that ecosystem.

    That’s not hysteria. That’s logic. Something you are not using you pandering mouth pieces.

    • Absolutely everything you wrote was wrong.

      Radiation is not “cumulative”. Radionuclides are removed from the environment at a rate called the “ecological half-life”. Depending on the radionuclide and the environment, this can range from a few days to a few decades. Cs-137 in the surface ocean, for example, the ecological half-life is about 12 years.

      Cesium is not being produced. It is released in large quantities in the initial stage and is leaking comparatively much smaller amounts today. No new radiocesium has been “produced” since the reactors were shutdown. Radiocesium escaped in large quantities because it became gaseous at the temperatures experienced in the meltdowns. Very little of the other fission products and activation products escaped because they have very high melting and boiling points.

      Radiation does not accumulate in the body. It is removed at a rate called the “biological half-life”. Some radionuclides, like plutonium, have such long biological half-lives they might as well be considered to be accumulative but very little plutonium escaped from Fukushima. Chernobyl released 13,000 times as much plutonium as Fukushima did.

  2. The greatest risk to human life that’s resulted from Fukushima is even-stronger resistance to the only scalable and remotely affordable source of baseload energy that does not put carbon dioxide in the atmosphere. Even those of us who are strongly skeptical of the equilibrium climate sensitivity numbers produced in reports like those published by the IPCC can figure out the relative risks of nuclear power versus global warming; why can’t the “greens” who treat those reports as gospel?

  3. This is an amazing story! The Pacific is only 5 times more loaded with radiation and its getting worse and saying this like its no big deal! Well it is a big deal! The FDA announced that pregnant women should not eat any tuna at all now! Thats BAD and for anyone eating Pacific fish should think about doing a radiation and heavy metal detox with the natural mineral called Zeolite.

    • The reason that pregnant women should avoid tuna has nothing to do with radiation and everything to do with mercury. Also, that zeolite you advise everyone to ingest is many times more radioactive than an entire cubic metre, that is 1000 litres, of sea water.

  4. The author Colby Cosh is confusing normal background radiation & MAN MADE radiation, whereby eating one hot particle of man made radiation will cause infinitesimal more damage (higher chance of cancer & other ailments) than eating a banana, for example (which causes NO damage).
    You know this to be true – because BEFORE all the nuke ‘testing’ by the ‘leadership’ (psychopaths) – cancer rates were generally few to unknown.

  5. Anyone who chooses to search the ‘net for news about Fukushima quickly learns that at least three reactor cores have melted through to the soil. Containment has been lost. This is an unprecedented event. Far worse than Chernobyl. The coriums will likely never be retrieved, resulting in higher and high levels of long-lived isotopes accumulating in the Pacific Ocean. Not mentioned in this story is the generation of strontium 90 and its implications to health and welfare. Leakage is ongoing, 24/7. Millions of people on both sides of the Pacific depend on food grown and caught in these waters. Their livelihoods and safety are now at risk. For obvious reasons, the mainstream media dares not report the out-of-control nuke plants in Japan. Think, people. The reality of Fukushima is far different than reported by Colby Cosh.

  6. I think it’s irresponsible to say that based on one event, that “the nuclear energy industry still has a lot less to apologize for than dams, coal or even oil.”
    How many thousands of people have died as a direct or indirect result of nuclear energy? Think of how many people will be affected by the nuclear waste produced alone. As a society, we have no long term waste disposal plan for the nuclear by-products that emit radioactivity for thousands if not millions of years. Just saying…

    • The number of people who have died from the direct or indirect results of nuclear energy is vastly fewer than the number for coal. Black lung, mine disasters, air pollution . . . you can count everyone killed by nuclear weapons (both directly and by fallout) against nuclear power, and in both total deaths and per kilowatt, nuclear power is still better than coal . . . before even considering any climate change effects of carbon emissions, which is a much bigger deal than small quantities of easily-confined nuclear waste.

  7. URGENT: People need to know this fact if in a nuclear event! If you have already been radiated Potassium Iodide or Iodine is totally worthless and this will most likely be the real situation! The best and most safe way to remove radiation from your body after being radiated is with the natural ingestible mineral called Zeolite which is proven to safely remove both radiation and heavy metals from your body! If you have already been radiated you need to detox with natural zeolite! If you live close to a nuclear power plant or if your are preparing for a nuclear release or event you need to prepare and have a stock of clean powdered micronized medical grade zeolite for human consumption! Not industrial or Agricultural Grade zeolite! For more information on how to remove toxic radiation from the body do a search on the website at http://www.removeradiation.com

Sign in to comment.