Thursday, July 21, 2011 Radiation in Japan: 100 Millisieverts in Lifetime to Be Set as New Radiation Standard in Japan

Thursday, July 21, 2011



#Radiation in Japan: 100 Millisieverts in Lifetime to Be Set as New Radiation Standard in Japan



How much more meaningless can it get?



The Japanese government is about to set 100 millisieverts as lifetime, cumulative acceptable radiation exposure standard, counting both internal and external radiation exposure, and this is on top of the average 1.5 millisievert/year natural radiation exposure.



Up till now, the acceptable radiation exposure has been 1 millisievert per year, in addition to the natural radiation exposure in Japan which is about 1.5 millisievert per year. There has been no standard for lifetime cumulative radiation exposure.



I read the following Asahi Shinbun article, translated it, and realized how utterly meaningless the whole exercise was. No one knows how much extra radiation that the Japanese (and the rest of the northern hemisphere) have gotten thanks to the broken reactors and spent fuel pools at Fukushima I Nuke Plant. In parts of Fukushima Prefecture, the cumulative air radiation level already exceeded 100 millisieverts.



And how many people, other than the nuke plant workers, have been tested with the whole body counters? Answer: not many. Reasons often cited are: background radiation too high in Fukushima for proper testing; there are not many whole body counters in Japan, 100 at most. Then, I read that a man from Iitate-mura in Fukushima demanded he be tested for radiation using the whole body counter. He finally got his wish several months after the start of the accident, and they refused to tell him the number. He still doesn't know how much radiation he's received.



So, my conclusion is that this new so-called standard or the article like Asahi that discusses the standard is to imprint the number in people's mind: "100 millisieverts, 100 millisieverts, it's safe up to that number." Yes, they'll also tell you it's the lifetime cumulative number, but that doesn't mean a thing when you don't know how much of it you have had to spend already since March.



Soon, as Dr. Yamashita already said in a slip of a tongue, it will be safe up to 100 millisieverts per year.



From Asahi Shinbun (1:25AM JST 7/22/2011):





放射性物質が人体に与える影響を検討していた食品安全委員会の作業部会で２１日、「発がん影響が明らかになるのは、生涯の累積線量で１００ミリシー ベルト以上」とする事務局案が示された。食品だけでなく、外部環境からの被曝（ひばく）を含む。平時から浴びている自然由来の放射線量は除いた。この案を 軸に来週にも最終結論を出し、厚生労働省に答申する。ただ厚労省からは「基準づくりは難航しそうだ」と、戸惑いの声があがっている。



The working group of the Food Safety Commission that has been considering the effect of radioactive materials on humans disclosed the plan of the secretariat that would say "The cancer-causing effect of radiation becomes only noticeable at and above 100 millisieverts of lifetime cumulative radiation." The number includes not just the internal radiation from food but also external radiation exposure from the environment. It does not count the natural radiation exposure. Based on this secretariat's plan the Commission will come up with its final plan and submit it to the Ministry of Health, Labor and Welfare next week. However, there are those at the Ministry who worry that it won't be easy to create a new standard.





　東京電力福島第一原発事故を受け、厚労省は３月１７日に食品衛生法に基づき、放射性物質に汚染された食品の流通を規制する暫定基準を設定。この基準の科学的根拠を得るため、食品からの被曝による健康影響評価を同委に諮問していた。





In response to the Fukushima I Nuke Plant accident, the Ministry of Health, Labor and Welfare set the provisional safety standards on March 17 to regulate the sale of food items contaminated with radioactive materials. Then, it asked the Commission to evaluate the effect of internal radiation exposure from food on human health, in order to scientifically justify the provisional safety standards.





　同委は当初、食品だけからの被曝レベルを検討。国際放射線防護委員会（ＩＣＲＰ）勧告の元になった論文を含め、様々な国際的な研究を精査した。だが食品 とその他の被曝を分けて論じた論文は少なく、「健康影響を内部と外部の被曝に分けては示せない」と判断。外部被曝も含め、生涯受ける放射線の総量を示す方 向を打ち出した。宇宙からの放射線など平時から浴びている自然放射線量（日本で平均、年間約１．５ミリシーベルト）は除く。





The Commission at first tried to come up with the radiation limit from food only, and carefully studied various international research papers including the paper which became the basis for the ICRP recommendation. However, there were few papers that discussed the radiation from food separately from all the other radiation, and the Commission decided it was not possible to show the effect of radiation on health by separating internal and external exposures. Instead, the Commission will set the lifetime cumulative amount of radiation allowable, which includes external radiation exposure. It will exclude the natural radiation exposure from cosmic rays, etc., which is about 1.5 millisievert per year average in Japan.





　生涯の累積線量を目安に考えるということは、例えば、緊急時に一時的に２０ミリシーベルトを浴びたら、残りの生涯で被曝を８０ミリシーベルト以下に抑えるのが望ましいとするものだ。





In considering the lifetime cumulative radiation, if one is exposed to 20 millisieverts of radiation in a short time in an emergency, then it will be desirable if the radiation exposure is under 80 millisieverts for the rest of one's life.





　また、子どもや胎児については成人より影響を受けやすいという研究があり、事務局案では「留意が必要」としている。





There are studies that show children and fetuses are more susceptible to radiation exposure, and the secretariat's plan calls for "an attention".





　ＩＣＲＰの考え方では「１００ミリシーベルトを浴びると、発がんリスクが０．５％上がる」とされる。





According to the ICRP, "The cancer risk goes up by 0.5% with 100 millisieverts exposure."





　外部被曝も含めた形で結論を出すことに委員の一人は「本来は原子力安全委員会など他の政府機関でやるべきだが、他がやっていないので仕方ない」と話す。





As to deciding on a new standard that includes external exposure, one commissioner said "It should be done by other government organization like the Nuclear Safety Commission, but no one is doing it. So we have to do it."





　緊急時を想定した現行の暫定基準は、食品からの年間被曝量をヨウ素やセシウムなど核種ごとに割り当て、全体で年１７ミリシーベルトを超えないように設定されている。





The current provisional safety standards for foods is for an emergency situation. A safety limit is decided per different nuclide (iodine, cesium, etc) so that and the combined total radiation exposure from food does not exceed 17 millisieverts per year.







　食品安全委の答申が出れば、厚労省は食品ごとの基準を改めて検討することになる。担当者は「年間被曝量で答申されると想定していた。生涯累積線量だと、若者から高齢者まで年代ごとに摂取量を考えなければならず、作業に時間がかかりそうだ」と話した。



Once the conclusion by the Food Safety Commission is submitted, then the Ministry of Health, Labor and Welfare will have to reconsider the safety limit per food. The person in charge of the process said, "We thought they would give us the number as annual radiation exposure limit. If it is going to be the lifetime cumulative radiation exposure limit, it may take a long time as we will have to consider different food intake amount for different age groups, from young to old."

The government-funded researchers and scholars are already busy imprinting this number "100 millisieverts" in the minds of the populace. The reference to X-rays and CT-scans are back. No need to worry up till 100 millisieverts!



Now, does anyone know how much radiation that the residents in Fukushima, Tohoku or Kanto have gotten since March 11? No one does. Are all vegetables in the market tested? No. They only sample one item from one plot from one farm in one city, and if that passes the test the entire crop from the entire city is considered safe.



Radioactive beef? What radioactive beef? The government will buy the meat and burn it, satisfied? Schoolyards with radiation exceeding 1 microsieverts/hour? So? Don't come complaining unless it's above 3.6 microsieverts/hour. All our experts say there's no danger below 100 millisieverts! If you are exposed to 20 millisieverts this year, well you will have 80 millisieverts for the rest of your life (we don't know how long) to spend, so don't worry.