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Fukushima No. 1 worker’s leukemia officially deemed a work accident

KYODO

The health ministry Tuesday certified a man with leukemia as having suffered an industrial accident and being entitled to benefits after he was exposed to radiation as a construction worker at the Fukushima No. 1 nuclear plant, though it did not confirm there was a link between the radiation and the cancer.

The man, now in his early 40s, is the first person involved with working at stricken facility to receive the certification for developing leukemia.

He installed covers for the damaged reactor buildings at the plant between October 2012 and December 2013 before being diagnosed with leukemia, according to the ministry. He developed the disease while in his 30s.

“While the causal link between his exposure to radiation and his illness is unclear, we certified him from the standpoint of worker compensation,” an official of the Health, Labor and Welfare Ministry said.

Workers who are injured or become ill due to work or commuting can receive benefits under Industrial Accident Compensation Insurance. To receive compensation, they must submit claims to a labor standards inspection office, which will examine and pass judgment on them.

For leukemia to be certified as an industrial accident caused by radiation exposure, a claimant must meet certain requirements, such as being exposed to radiation of at least 5 millisieverts in a year, and having developed the illness more than a year after they were first exposed to radiation.

In the aftermath of the nuclear disaster, Tokyo Electric Power Co. installed covers over the damaged reactor buildings to prevent the further dispersal of radioactive material.

  • Starviking

    These are the key points, which will be ignored in favour of the headline:

    “While the causal link between his exposure to radiation and his illness is unclear, we certified him from the standpoint of worker compensation,” an official of the Health, Labor and Welfare Ministry said.

    No confirmed radiogenic link.

    For leukemia to be certified as an industrial accident caused by radiation exposure, a claimant must meet certain requirements, such as being exposed to radiation of at least 5 millisieverts in a year, and having developed the illness more than a year after they were first exposed to radiation.

    To be certified a link between the illness and radiation exposure does not seem to be required.

    • Charlotte Morgner

      Of course as leukemia is a naturally occuring disease one can only speak about likability when looking at the single case. So it’s a good thing they decide the status of work disease in favor of the patient in such a case even so causation cannot be proven entirely. Otherwise it would be unjust.
      However I agree to you that the headline is missleading.

    • Sam Gilman

      You should look at Greenpeace’s coverage: “His condition is a direct result of him working at Fukushima. ”

      Sigh. I used to give them money.

  • Starviking

    These are the key points, which will be ignored in favour of the headline:

    “While the causal link between his exposure to radiation and his illness is unclear, we certified him from the standpoint of worker compensation,” an official of the Health, Labor and Welfare Ministry said.

    No confirmed radiogenic link.

    For leukemia to be certified as an industrial accident caused by radiation exposure, a claimant must meet certain requirements, such as being exposed to radiation of at least 5 millisieverts in a year, and having developed the illness more than a year after they were first exposed to radiation.

    To be certified a link between the illness and radiation exposure does not seem to be required.

  • Sam Gilman

    I posted this on the AP site. I might as well C&P here.

    Others have already commented that this case is not a medical judgement in any meaningful sense and that it’s wrong to read from the compensation decision a scientific truth about Fukushima. Let me put some numbers to these comments to show how these comments are justified.

    The dose the man received was 11 millisieverts. Average annual dose from all sources ranges from 3mSv-6mSv depending on where you live, but some places from natural exposure can provide a much higher rate. So we’re looking at an exposure that’s not that much above background.

    It is generally agreed that the lowest known level of short-term exposure where an increase in cancer of any kind has been clearly detected has been detected is 100mSv. At this level, there is a 0.5% increase in the chance of developing a cancer – from say 40% to 40.2%. We really are talking low levels. Below that it becomes difficult to detect increases within the noise of the data. So at 11mSv we’re looking at possibly no increase, or one so small it’s undetectable.

    Or, we could look at a recent study that found a Excess Relative Risk of Acute Myeloid Leukaemia (AML) of 2.96 per Gray. (Gray is absorbed dose, Sievert is exposed dose; I’ll assume here for calculations they’re interchangeable). That means a virtually threefold increase per Sievert. This study is controversial in that it purported to show effects from radiation at very low levels, and according to an accompanying note probably overestimates, but I’ll use it anyway.

    5 British men (as an example) in 1000 develop AML leukaemia. Thus 1000 men exposed to a 1 sievert dose would therefore probably produce 15 cases – an extra 10 cases that could be said are probably the result of radiation, although precisely which of the 15 cases were radiogenic we could not tell (as far as I understand there are no clearly distinct markers of radiogenic leukaemia identified). On the other hand, one could say any case of leukaemia following this exposure would more likely than not be the result of radiation. Using the linear model the paper supports, 100 mSv would produce (2.96/10) * 5 =1.48 extra cases, ie between one and two extra cases per 1000 over a lifetime. Here most cases of leukaemia (5 out of 6) are not the result of leukaemia. Because of the yearly variation in leukaemia, it would ordinarily be difficult to establish statistically below this level that any rise in leukaemia had occurred. The study I’m using uses massive numbers to show an effect below this level, and it’s been disputed.

    But let’s assume the leukaemia study is right. What about 11 mSv? At that dose, the ERR is 0.0326, leading to 5.16 cases: 0.16 extra cases per 1000. There would be only a 3% rise in AML leukaemia cases in a population of men exposed to an extra 11 mSv between now and when they die.

    Of course, for this individual it’s happened early, whereas the majority of leukaemias are found later in life. However, given potentially long latency periods for AML leukaemia, including radiation induced (it has a wide range) it could easily have been there before the accident. (This condition wasn’t picked up in screening, he had already become symptomatic.) He’s actually at the age where AML incidence (ie detection) starts to pick up. We just don’t know. In any case, it is just highly unlikely that this leukaemia is caused by radiation given the level of exposure. The body of literature on dose-response in leukaemia doesn’t support a different conclusion.

    Why then has this compensation been granted? This can and must be a political decision, as the science cannot get you far enough. The man has leukaemia. I’m glad he is getting compensation.

    However, this means that people who use this compensation decision as if it were a scientific judgement of health issues in their political battles over Fukushima would be wrong to do so. Alas, Greenpeace of course are doing just that (“There’s terriblefantastic news from Japan today” – FTFY Greenpeace), but they have a very poor track record on this topic, having been the sponsors of monumentally awful work in the past.

    (If anyone sees errors in my calculations, please feel free to point them out.)