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Dr. Kodama on Fukushima/Japan 衆院厚労委員会 児玉龍彦参考人

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The next witness is Prof. Kodama. I'm a head of the Tokyo University Radioisotope Center and I was totally astonished on March 15. At the University of Tokyo, we have 27 isotope centers. We are responsible for protection from radiation and decontamination of radioactive materials. I am a doctor of internal medicine myself, and I've been involved in the works such as decontamination at the radiation facilities at Tokyo University Hospital for a few decades. On March 15, as you can see in this picture here, at around 9 AM, we detected 5μSv dose at Tokai-Mura. So we immediately reported it to the ministry of ECSST following the Article 10. Then in Tokyo the doses in excess of 0,5 μSv were detected. This came down soon. But then in Tokyo on March 21, when it rained radiation of 0,2 μSv was measured. And we believe that was causing the high doses until this day. At this time the Chief Cabinet Secretary Edano mentioned, "For now there is no immediate health problems". But I thought that this would be something extremely serious. And Why? The current Radiation Hazard Prevention Act has been set assuming that you handle the highly radioactive materials but in small quantity. In those cases, the total amount of doses are not a big issue but concentration of each radioactive material would be. However the Fukushima nuclear accident case is totally different because, the measurement marks 5μSv in the area of 100 km radius, 0,5 μSv in 200 km radius. It also extends to tea leafs from Shizuoka Ashigara which is beyond 200 km radius. Today, everyone knows this fact quite well. When we face this kind of Radiation Hazard, we consider the total amount of radioactive materials. Regarding the total amount of radioactive materials, either TEPCO or the government hasn't so far reported the exact figures at all. Therefore we have calculated some figures based on the knowledge of our Isotopes Center. In our estimate, based on the amount of heat, the equivalent of 29,6 of the Hiroshima atomic bomb is leaking. Based on the amount of uranium, it is equivalent to 20 pieces. What we know from the previous findings is more formidable. When you compare the residual amount of radioactivity between a nuclear bomb and this accident... After 1 year, the nuclear bomb's radioactivity residue will be reduced to about 1/1000, but ones from this accident will be reduced to only about 1/10. This means that the problem of Fukushima is similar to the Chernobyl. It is important to argue based on the following estimate; it released radioactivity equivalent to dozens of atomic bombs and contaminated far more than that created by the atomic bomb. We analyze the hazard from the view of Systems Biology in which we approach the problems in systematic theory way. When the total amount is low then we need to consider only the density of radiation to a patient. However the amount of radioactive materials is huge which means we have to see them as particles. Diffusion of particles need to be analyzed in the science of Nonlinear. That is most difficult calculation in the field of fluid mechanics. A nuclear fuel is something like "fine sand grains embedded in synthetic resin". When they released at a melt down there will be a lot of fine particles released. The release of fine particles could cause a problem we recently encountered, namely the contamination of hay. For example in Fujisawa-cho , Iwate pref., they measured 57 000 Bq / kg in straw. 17000 Bq / kg at OSaki, Miyagi pref. 106000 Bq / kg Minamisoma, Shirakawa, 960000 Bq / kg, Iwate (Ibaraki Takahagi?) 64 000 Bq / kg were detected. Those figures never follow on concentric circles. How much and where the particles fall is depend on the weather conditions, or if the particle absorbed water or not. Every weekend I travel 700km to Minamisoma-city, Our center has done decontamination there seven times. When we visited for the first time, they only had one NaI radiation counter. When the Ministry of Agriculture, Forestry and Fisheries issued a notice of feeding instruction to cows on March 19, their food, water and gasoline were diminishing. So a wistful appeal of the mayor of Minamisoma was uploaded to the web which is a widely known fact. No one could read or know the notice as one sheet of paper under such a circumstances. No farmers knew that their hay were dangerously contaminated. Since they knew about it the farmers have been paying a large sum to buy imported feed, and given the spring water to cows, that is drinking water for themselves. In this circumstance, what we need to do is... to make sure that complete measurements can be performed in the contaminated area. We mentioned that there was only one Geiger counter when we visited Minamisoma at the end of May. Yet the US military had dispatched 20 personal Geiger counters there. But no one from the City Board of Education could understand the English manual. Only after we visited and explained how they work, they could use those 20 counters. This is what actually going on there. There have been discussions about food inspection here but we shouldn't bother with germanium counters. Many imaging-based instruments using semiconductors have been developed and available. Why not the government spend our budget to utilize and spread those to the entire country? 3 months have gone by with no such actions taken and I cannot hold my anger anymore. Second, since the time of Prime Minister Obuchi, I've been a head of the antibody drug project of the Cabinet. This is a cutting-edge research area, so the government spend 30 billion yen for the cancer treatment using isotope labels on antibody drugs. Since my job is to inject radioisotopes to the human body, I'm seriously studying problems of internal radiation exposure. So I'd like to explain how internal exposure happens. The biggest problem of internal radiation exposure is cancer. Radiation cuts DNA then the cancer occurs. As you may know DNA is double helix and it's very stable in this form. When cell division happens, double helix temporarily unfastened and it is duplicated. at this process, the DNA becomes very sensitive to radiation. Therefore for fetuses in pregnant women, juveniles, and highly-proliferative cells of people of growing ages, radiation hazard is very critical. Even in adults, for active cell growth, such as hairs, bloods, and intestinal epithelium cells, are sensitive to radiation. These are ABC of Radiation Hazard. I'll give the known cases of when those cells are affected, i.e internal exposure. Just a single mutation cannot cause cancer. After radiations hit DNA for first time, then a second event happened, a cancer would be generated. We call these changes driver mutations or passenger mutations. It's a bit technical but you can see the references on the appendix of my document. including cases for Chernobyl and cesium. The most infamous is the α-ray. I was shocked when I heard about a professor of Tokyo Uni who said "it is safe to drink Plutonium." but the α-ray cause the most risk. It is well known as thorotrast injury to us hepatologists. In short, what the internal exposure means... From earlier discussion, we talk of mSv but for the internal exposure mSv means nothing. Iodine -131 accumulates at thyroid gland. Thorotrast accumulates in the liver. And cesium accumulates at the urothelium and bladder. Without examining each accumulation point, there is no use to perform whole body scanning. In the cases of thorotrast, please take a look the larger ones later. Thorotrast is a contrast medium. Since 1890, it had been used in Germany and, since 1930, it had been used in Japan. Our research shows that it causes liver cancer in 25 to 30 % of the patients after 20 to 30 years of application. I'll tell you why it takes 20 years to cause the first cancer. Thorotrast generates α-ray and damages cells around it. The first gene to be hit is p53. We know all the DNA sequence of the human genome. The differences between one person to the another are about three million bases. So it's no point of treating everyone in a same way. So-called personalized medicine is important in those cases. Its important to check which genes are damaged and what changes are generated in person to person. In the case of thorotrast, it's proved that the p53 gene disrupted in the first step, and the second and the third mutations occur next 20 to 30 years, and finally the liver cancer and leukemia will show. Next is iodine 131. As you know, iodine is concentrated in the thyroid gland. Its accumulation is most evident in growing ages, especially in infants. The Ukrainian researchers reported that the thyroid cancer occurred frequently in 1991, Japanese and the American researchers argued on a journal Nature that they could not find any causality in their report. The reason for that was there was no data before 1986, it was claimed that there is no statistical significance. However, it turned out to be statistically significant. This was confirmed 20 years later as Dr Nagataki mentioned earlier. Because the peak observed in 1986 disappeared 20 years later, Therefore the causality became evident without the past data. Thus, the epidemiological proof is very difficult and generally you cannot prove it until all cases are over. So right now we have to take a totally different approach to protect our children. Here is one example. Dr. Shoji Fukushima in the National Bioassay Research Center is working to find a chemical substance which is concentrated in the urinary tract system of people around Chernobyl. Dr. Fukushima collected, in cooperation with Ukrainian doctors, more than 500 cases from the operation for prostate hypertrophy together with samples of the bladders. By inspecting samples from the highly contaminated site, although radioactivity in the urine was not so high, 6Bq per liter, mutations in the p53 gene were frequently found. Besides it's in a state of proliferative precancerosis, in which p38MAP kinase and NF kappa B were activated, and proliferative cystitis were always associated. Thus, it's reported that cancer in the epithelium has been seen at a considerable high rate. I also was surprised very much by the figures that 2-13 Bq were detected in milk from seven mothers in Fukushima. this sounds alarming. Next page please. Our Radioisotope Center are sending four staff members to Minami-Soma every week and working to help decontamination. The problem in Minami-Soma is also alarming. There's no point making a concentric circle whose radius is 20 km or 30 km. It's necessary to measure the radioactivity in every kindergarten. Right now 1,700 children are going to schools in the 30 km zone from the 20 km zone by bus. However, in Minami-Soma, the radioactivity is high in the sea-side, and 70% of schools show relatively low radioactivity. Yet the children are moved by bus to schools in the 30km zone near Iidate village. Every day one million yen is spent to forcibly send children to more contaminated area. Please stop such an absurdity at once. The worst obstacle is a compensation issue. The money only goes to forced refuge. In a Committee of the House of Councilors, Ex-President of TEPCO, Mr. Shimizu, and the Minister of Economy, Mr. Kaieda, gave such a speech. Please do not mix these. Please separate the compensation issue from the issue of the children’s health immediately. I plead you to make every possible effort to protect our children. I ask you another request which I leaned from my experience in Fukushima. I want you to separate urgent decontamination from lasting decontamination clearly. We have done urgent decontamination by ourselves in great extent. For example, a bottom of the slide, as you can see on a chart, is the place where a small child always touches. Every time rainwater washes down the slide, the radioactive materials concentrate here. When there is a tilt between the right and left sides, it can be more than 10 micro Sv in certain area where the environmental radioactivity is around 1 micro Sv . We must decontaminate such places urgently and vigorously. And places like under a rain gutter where moss is growing... this is also where a kid often touches. If I clean such a place with a high pressure jet wash and remove the moss, the level decreases, for example, from 2 micro Sv to 0.5 micro Sv. But, it's very hard to make the radioactivity less than 0.5 micro Sv. This is because all of the buildings, the trees, and areas have been contaminated. It is very difficult to lower the radioactivity as the whole just by washing small parts. So, for starting decontamination, we need to think about the scale of the problem and how much it will cost us. In the case of the Itai-Itai disease, the total area polluted with cadmium was about 3,000 hectares. By now, the government has spent 800 billion yen to decontaminate the area of 1,500 hectares. How much cost will be needed if the area is 1,000 times larger? Therefore I'd like to present the four urgent proposals. First, as a national policy, you should measure the radiation of food, the soil, and water. You should use the latest imaging machines which are available in Japan. Imaging with the semiconductor has become simple. By making an assembly-line system to check the radiation on products using the latest equipment. improve the situation radically please. This is totally possible with the present Japanese technology. Second, please urgently establish a new law to decrease the radiation exposure of children. All of what I am doing now are illegal. The current Radiation Hazard Prevention Act restricts the amount of radiation and nuclear species that can be handled in the radioisotope facilities. I currently mobilize all of 27 radioisotope centers of Tokyo Uni and support decontamination at Minami-Soma, but most facilities aren't allowed to use cesium. It's also illegal to carry radioactive materials by car. However, since I can not leave them to mothers and teachers, our team puts all contaminated materials in drum cans and takes them to Tokyo with us. Carrying them into Tokyo Uni is illegal. Everything we do is illegal. It is the Diet’s responsibility that caused such a situation. The isotope centers of National Universities in Japan have many newest machines including germanium detectors. If they are tied hand and foot by the law, how can they work to protect our children with all their might? This is due to a complete negligence by the Diet. Third, as a national policy, gather powers from the private sector to develop technologies for the soil decontamination. Various chemical companies for example, Toray, Kurita, and radiation decontamination companies, Chiyoda technol, atox and Takenaka and other companies have various know-how for decontamination of radioactive materials. The government should establish a decontamination research center by mobilizing those companies. Since this will cost tens of trillions of yen from public money, I really worry that it may become an inappropriate public work involving the right and money. There is no such margin if we consider the financial state of this country. The proper decontamination is an urgent matter... When 70,000 evacuees still live away from their homes, what is the Diet actually doing? That is all I want to say.

Video Details

Duration: 16 minutes and 25 seconds
Country: Japan
Language: Japanese
Views: 1,864
Posted by: lichiebonbon on Jul 31, 2011

The base souce of the English subtitles is here :http://d.hatena.ne.jp/sivad/20110730/p1#c

2011年7月27日 (水)におこなわれた衆議院厚生労働委員会より、児玉龍彦氏(東京大学先端科学技術研究センター教授 東京大学アイソトープ総合センター長)の発言部分



At the Committee of Health, Labor and Welfare, the House of Representatives.

An unsworn witness: Dr. Tatsuhiko Kodama

Professor at Research Center for Advanced Science and Technology and Director, Radioisotope Center, The University of Tokyo

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