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20msv/yr: What Does The Rest Of The World Think?

ByStephanie Nakajima

Sep 22, 2011

July 19th, 2011
Fukushima City

“It is correct, is it not, that Fukushima citizens have the same and equal right as other Japanese citizens to spend their life without receiving unnecessary radiation doses. That is correct, is it not?”
– Fukushima citizen

“I dont know whether or not they have that right”
– Akira Sato, Director of the government’s Nuclear Emergency Response Headquarters

Before the March 11th earthquake, Japan’s standard for radiation exposure for the general public was, uniformly, 1 millisievert (mSv) per year. While this standard remains in place for the rest of the country, a provisional standard raising the limit to 20 millisieverts per year was enacted for Fukushima prefecture; this “adjustment” has been greatly contested by Japanese citizens as well as the global community, as this figure is also used to determine the evacuation zone. For context, 20 millisieverts per year is also the limit for nuclear workers. Though repeatedly implored to justify the change, government officials have yet to account for why this standard is suddenly acceptable.

How was the provisional standard decided?

On April 19th, the Ministry of Education, Culture, Sports, Science and Technology (MEXT) issued a notification to Fukushima Prefecture. The notification stated the maximum allowable permitted value for use of school grounds shall be 3.8 microsieverts per hour of radiation; this calculates to 20 millisieverts per year.

Fukushima Citizens Groups

After discovering high levels of radiation on school grounds, concerned residents formed The Fukushima Conference for Recovery from the Nuclear Earthquake Disaster, and called for a study to be done. Fukushima prefecture cooperated, and the study revealed that 76% of Fukushima prefecture schools had levels of contamination exceeding the designation of a workplace as “radiation-controlled” (0.6 microsievert per hour). Such areas are off-limits to individuals under 18. Even higher radiation levels were recorded at over 20% of the schools, levels warranting “individual exposure control” if occurring in a workplace – which, according to NSC documents, requires that individuals be monitored with dosemeters.

Concerned teachers and parents collaborated on various efforts to reduce radiation exposure to children, and citizen’s group demanded that the schools be promptly decontaminated and closed until safe.

The government responded not with measures to aide such efforts, but by distributing pamphlets that include questionable claims. MEXT published a controversial booklet and distributed it to all Fukushima schools. Titled, “To Correctly Understand Radiation”, the pamphlet offered justifications of the 20mSv/year standard claiming, among things, that

– ‘for “definitive impact” there is a “threshold” below which there is absolutely no damage found. For example, temporary decline in white blood cells will be seen [only] above the threshold level of 250mSv.’
– ‘no clear correlation has been seen between radiation and an increase in the probability of cancer.’

According to the Fukushima Conference, this greatly shifted the tone of the debate; many felt their concerns were largely assuaged by the agency’s confident declarations of safety. This development created an atmosphere where it became more difficult to voice concerns – those in opposition to MEXT’s stance found themselves criticized for “over-reacting”.

Many international groups have come out to criticize the 20 millisievert standard, and, inadvertently, to counter points made in MEXT’s booklet; all have pointed out that children are particularly vulnerable to the long-term effects of radiation.

L’Institut de Radioprotection et de Sûreté Nucléaire (IRSN)

On May 27th, France’s Institute for Radiological Protection and Nuclear Safety (IRSN) highlighted an area northwest of the plant that lies beyond the 20-km (12 mile) zone whose inhabitants have already been evacuated. This report was created to “provide insight” on evacuation measures “to minimize the medium and long-term risks of developing leukaemia or other radiation-induced cancers”. The drafters inform the reader that “it is of the utmost importance” to remember that “these dose estimates only refer to external exposure due to deposits, and do not take into account the additional dose that could be received as a consequence of consumption of contaminated foodstuffs produced locally. It is estimated that the effective dose from ingestion may be significantly higher than the external dose according to the deposit conditions and depending on the effectiveness of implemented food restrictions”.

France starts evacuating at 10 millisieverts; the IRSN, in its study, has recommended that an additional 70,000 Fukushima citizens be evacuated.

Japan Medical Association

On May 12th, the association issued the following statement:

“The scientific basis for choosing the maximum amount of 20 mSv in the band of 1 to 20 mSv is not clear. The government’s action should be more carefully deliberated considering the fact that growing children are more sensitive to radiation exposure compared to adults. We as a nation should make the utmost effort to reduce the exposure to radiation of children, as well as adults. We are responsible for the children’s health and life.” The statement continues, “We urgently request that the Japanese National government strive to reduce children’s exposure to radiation in the fastest and most effective way possible.”

Physicians for Social Responsibility

The U.S. affiliate of International Physicians for the Prevention of Nuclear War in late April issued a statement criticizing the Japanese government’s provisional standard, citing research on the link between low-level radiation and cancer. The statement reads:

“It is the consensus of the medical and scientific community, summarized in the US National Academies’ National Research Council report Biological Effects of Ionizing Radiation VII (BEIR VII report), that there is no safe level of radiation. Any exposure, including exposure to naturally occurring background radiation, creates an increased risk of cancer. Moreover, not all people exposed to radiation are affected equally. Children are much more vulnerable than adults to the effects of radiation, and fetuses are even more vulnerable. It is unconscionable to increase the allowable dose for children to 20 millisieverts (mSv). Twenty mSv exposes an adult to a one in 500 risk of getting cancer; this dose for children exposes them to a 1 in 200 risk of getting cancer. And if they are exposed to this dose for two years, the risk is 1 in 100. There is no way that this level of exposure can be considered ‘safe’ for children.”

Japan Federation of Bar Associations

Even the attorneys had to chime in! Utilizing their legal skills, the association analyzed the ordinance on the “Prevention of Ionizing Radiation Hazards”, pointing out that “the maximum dose permitted by the new guideline, however, far exceeds (the ordinance’s) limit. Moreover, the Ordinance was enacted to regulate activities involving radiation work and therefore assumes that some degree of control over the degree of radiation exposure is possible. The current situation, however, involves an ongoing crisis, and exposure due to changing weather conditions is entirely possible. The guideline must take full account of such unforeseen factors.” The association goes on to call for the establishment of a “considerably lower radiation limit for children”.

illustration by Mari Kurisato

The government has responded with its usual incompetence. In fact, no government agency (MEXT included, but also NSC, and the Ministry of Health, Labour and Welfare) has actually taken responsibility for this standard. While MEXT established the 3.8 microsieverts/hr provision for school grounds, when the agency faces questions on the resulting 20 msv/hr standard, the bumbling equivocations begin. MEXT’s statement, “we do not believe that there is danger at 20 millisieverts…however, we do not believe that it is fine at 20 millisieverts” seems like a modern zen riddle, requiring multiple re-reads that garner little elucidation. And while the ministry of education did, according to the Fukushima group, rescind the 20 millisieverts standard at a press conference, there have been no concrete actions taken to suggest that it has indeed been rescinded.

The conference, when asked if they had experienced any resistance from the government for their actions, say that though the government has not directly harassed, when they tried to sell a flyer to a newspaper they were told that “nothing that mentions radiation can be distributed in the newspapers.”

It seems that many residents feel that they have already been exposed to the worst of it; conference members expressed concerns that none of the exposure from March 11 to April was counted when the government was setting the provisional standard, of course the interval in which the greatest amount of radiation was most likely released.

More work by Mari Kurisato, who does the wonderful illustrations for our blog, can be found here: http://marikurisato.com/

Stephanie Nakajima

Contrarian philosopher, half-woman, half-Japanese, all dolphin.

19 thoughts on “20msv/yr: What Does The Rest Of The World Think?”
  1. That’s because there IS NO DANGER at 20 MsV per year. People love to scaremonger and grab headlines with “OMG! RADIATION! RUN!” and declare that radiation will cause babies to grow 3 heads if it’s higher than 0, but in reality, that isn’t the case. Will it increase the risk of cancer? Sure, but by fractions of fractions of a percent which will are statistically insignificant. Heck, taking a trip to some parts of Italy will cause your risk of cancer to increase tenfold due to background radiation, so why aren’t we evacuating Italy?

    Now could the Japanese Government have handled things better? Absolutely!

  2. I’ve read various accounts of this situation in Japanese and English and this is the most interestingly written. Japan’s government is subjecting its children to a level of radiation 4 times higher than the Soviet Union’s mandatory evacuation level for adults after Chernobyl. This is unconscionable. The government has offered no assistance in reducing the radiation levels. They are leaving it to teachers and parents who sometimes scrape up contaminated school grounds with children right beside them. Why parents are not protesting more vigourously is beyond me. This policy is criminal. By the way, it has been speculated that the governor of Fukushima was actually the one behind the absurdly high limit. Rather than the bureaucrats forcing it on him, he requested it from them. Do you have any information on this claim?

    1. Thanks for writing. Stephanie did an amazing job on that article. The governor of Fukushima is a total tool. His predecessor was opposed to TEPCO and framed for bribery. He is an admirable man.

  3. I watched the whole thing at the time, and I don’t think you’re representing the government’s position fairly. I’m not surprised these frightened, angry parents didn’t follow it and that guy’s explanation wasn’t very good, but here’s how I’m understanding it:

    – The science on how much danger there is below 20mSv isn’t really clear – if there’s an effect, it’s too small to detect, unless you’re willing to expose people to radiation on purpose. But extrapolating from higher levels where you can detect an effect, there might be one.

    – …hence they don’t think it’s safe, but they don’t think it’s dangerous.

    – Normally you want to keep radiation away from kids, so take whatever you think is very, very safe, add a big buffer, pick a nice round number, and you get 1mSv.

    – The plant just blew up, so they’ve now got to make other trade-offs – like the health effects from making everyone evacuate. So you lift the 1mSv limit. But replace it with what? They weren’t sure, so they stayed vague and played for time. What what they did need in the meantime was a short-term hourly limit, so they set one of those.

    – They did NOT set a yearly 20mSv limit. They set a temporary hourly limit that, if exposed all the time (or maybe it was 16 hours) for a year, would hit 20mSv. I drive at up to 70 mph, which by the same measure would be over 400,000 miles per year. But I didn’t drive 400,000 miles last year, because 70 mph is my peak speed, not my average speed.

  4. It seems incredible to me that, as yet, no one has looked to the Chernobyl Children’s Project in Ireland and the work that they have done:


    I also believe that it will take a number of years before the true medical cost of Fukushima will be seen but it is inevitable that the people of that region will pay a heavy price. As with DDT, asbestos, thalidomide, Bhopal and, of course, Hiroshima and Nagasaki, history will not be kind.

  5. From the above mentioned website:

    “Twenty-five years after the nuclear meltdown in Chernobyl, the aftermath continues to affect more than a million children in and around the contaminated area. There has been a 250 percent increase in congenital birth deformities since the explosion, a 100 percent increase in the incidence of cancer and leukemia and a staggering 2,400 percent increase in the incidence of thyroid cancer. Other disorders, including congenital heart diseases, have also increased significantly. ”


    Japan — you have failed your children.

  6. The MEXT data is based on information from exposure studies performed at the end of World War II on Hiroshima and Nagasaki. There has been enormous advancement in medical research since then. Please go to:
    Then click the “Purchasing Information” for April 2010: Committee publishes new Recommendations. ECRR 2010: The Health Effects of Ionising Radiation Exposure at Low Doses and Low Dose Rates for Radiation Protection Purposes: Regulators’ Edition (Purchasing information)
    Then click on free download.
    It is very important that you read this ECRR2010 document. Then you will see why all prior studies are woefully out of date. Woefully out of date.

  7. great to see this stuff written up into one article!

    Here is a debate between British expert Dr. Chris Busby and the former scientific secretary of the ICRP, Dr. Jack Valentin. Very interesting. Busby is polemical, but his points are good.

    Most importantly, in the exchanges after the two presentations, Valentin admits that the ICRP model is useless for internal exposure. Despite this, most reports you see on exposure risks continue to either mix up the two or ignore internal contamination.


    and here is a recent press conference given by Dr Busby in Japan. Rather long winded given the overly lengthy translations (the translations often expand into explanations, but I feel for the guy!), but worth a listen. Not for the faint-hearted:

    Part 1


    the original broadcast was about an hour. split up on Utube, but the links to latter parts seem to be there.

    here is some footage of young Japanese citizens determined to exercise their rights to peaceful protest. posted by someone who views them as a bunch of ultra-leftist nutters. interesting in itself!


  8. Hey Jobe!

    Thanks for writing in 😀

    Very interesting gossip about the Fukushima governor! I will have to look into that. It wouldn’t surprise me.

  9. Oh wow. Props to those brave Fukushima residents standing up to the government officials. Thanks for writing about this/posting that video.

  10. wow. Great stuff everyone. I’m gonna take a look at all these links, and maybe incorporate them into Part II of this article..

  11. This is just the beginning. Cleanup squads are being paid to basically shut up and shovel contaminated dirt and sludge into bags for delivery to what amounts to a secret nuclear waste dumping site in the mountains.


    From what I’ve seen online and scouring images, it appears they’re hastily pouring concrete with teflon covering and dumping the bags into there.

    Similar hijinks in the past in my home state of Washington has led to billions of dollars in waste cleanup, and guess who gets holding the invoice for such cleanup!

    The issue here is not so much the cost but the long term environmental impact. Those bags are nothing but burlap, and in a highly seismic zone like basically all of Japan, can anyone reasonably deduce that these sites will be monitored for leaks, radioactive water runoff, and be maintained?

    I’d bet you dollars to dinars that officials will sweep this under the rug and in 30 years when they find that animals and people are drinking radioactive runoff, the government will bleat useless propaganda as usual. Hell it may be longer than 30 years. Feral hogs in the forests of Germany are still considered too contaminated for food from the disaster at Chernobyl, and that is just from indirect effects of radioactive fallout. Who knows what the wastewater runoff will do.

  12. Thank you Johan. I also lived in Washington State for a bit- I went to ultimate frisbee tournaments in Hanford (we had radioactive symbols painted on our discs). 😀

    some of you commented that there is no evidence linking low levels of radiation to increased cancer risk- but this is why I posted links to all the various studies, so that you could see for yourselves that this is not true.

    Even more disturbing is the Chernobyl research done in the past few years, which I am sifting through now.

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