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

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”.

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/