My name is (Dr. Tatsuhiko) Kodama and I am chairman of the Radioisotope Center at the University of Tokyo. I would like to express my deepest shock surrounding events occuring on the day of March 15.
We at the University of Tokyo have 27 radioisotope centers and are responsible for measures of nuclear safety and decontamination.
As a doctor of internal medicine I have been involved in the operation of decontamination facilities at the hospital in the University of Tokyo for many decades.
On March 15, (referring to this diagram here) at around 9:00am we detected 5 microsieverts (μSv/h) of radiation in Tokai Village and reported it in accordance with the law (Article 10) to MEXT (the Ministry of Education, Culture, Sports, Science and Technology).
Later on, we measured radioactivity measuring over 0.5 μSv in Tokyo.The radioactivity levels in Tokyo were transient measuring 0.2 μSv after it rained on March 21. We believe that this is one of the causes of high levels of radiation existing to the present day.
When I heard Chief Cabinet Secretary Edano announce that at the present time there were few health risks, I began to fear that we would really be in serious trouble. The reason is because current law regarding nuclear safety assumes that only small amounts of highly radioactive material are handled.
In this case, it is not the amount of radioactivity but the levels of concentration emitting from each individual piece.
However, as I am sure you all aware by now that radioactivity has been detected measuring 5 μSv/h within a range of 100 km and 0.5 μSv within a range of 200 km. High levels of radioactivity have even been detected beyond these ranges even in tea grown in areas from Ashigara (Kanagawa Prefecture) to Shizuoka.
When measuring amounts of radioactive contamination, we aim to know the total amount. But even up till now, TEPCO and the government have not made any reports regarding specific total amounts of radioactivity at all!
Therefore, my team at the Radioisotope Center took it upon ourselves to measure and calculate the total amount of radioactive contamination using all of our expertise on the subject and found the total amount of leakage to be about 29.6 times the amount of contamination caused by the nuclear bomb dropped on Hiroshima. Assuming the source material to be uranium, we think the total amount of leakage is about 20 times the contamination caused by the Hiroshima bomb.
To make matters worse, if we compare the residual radiation of material from the Hiroshima bomb with the residual radiation of material from the Fukushima plant, the residual radiation from the bomb was found to descrease at a rate of 1 / 1000 per year while residual radiation in Fukushima decrease by only 1 / 10 per year.
In other words, we must now assume that the Fukushima accident is equivalent to the Chernobyl disaster, that the amount of radiation leaked is in the tens of times the radiation leaked by the Hiroshima nuclear bomb, and that the high levels of residual radiation leaked is even worse than that of the Hiroshima bomb.
When assessing the situation using methods from systems biology (where we look at biologicalorganisms as part of a system) in cases where total amounts of radioactivity are small, we can just look at the levels of concentration for each individual organism.
However, for cases where total amounts of radioactivity are extremely large… this is a molecular particle.I would like to talk about the spread of radioactive particles in more detail but this usually involves non-linear science and extremely complicated calculations using fluid dynamics. So for our purposes I will say that the fuel used in nuclear plants resemble sand pebbles of radioactive particles buried within a composite resin.
When a meltdown occurs, large numbers of these small particles are released and problems like the contamination of livestock feed straw occur.
For example, 57 kilobecquerels per kg of straw was measured in Fujiwara, Iwate Prefecture, 17 kBq per kg in Ozaki, Miyagi Prefecture, 10.6 kBq per kg in Minami Souma, 9.7 kBq per kg in Shirakawa City, Fukushima, and 6.4 kBq per kg in Iwate. All of these values will never be distributed over the affected area in concentric circles.
Where these particles may fall depends on a variety of factors like the weather at the time, and whether it may have for example, absorbed water etc. In order to gather more decisive data, our teams have travelled every week from the Radioisotope Center in Tokyo to and from Minami Souma 700km away to conduct tests and decontamination. We have made 7 trips to Minami Souma so far. The first time we went we had only one sodium iodide based geiger counter with us.
The situation at the time of March 19th had events like MAFF (the Ministry of Agriculture, Forestry and Fisheries) issuing its directive (to use only feed straw that had been harvested prior to the accident) and the mayor of Minami Souma pleading for help over the Internet as his city was running out of food, water and gasolline.
Simply sending out government directives in this sort of situation where communications and lifelines were slowed greatly or severed were highly ineffective. The people who needed to know couldn’t know. There was no way farmers could know just how dangerous the condition of their feed straw became.
From that day on, farmers were to start spending tens of thousands of yen on imported feed and share the same limited amounts of ground water that they use themselves.
In light of all this, what we believe needs to happen is we need to ensure that we are able to measure the levels of radiation in a comprehensive and detailed manner.
As I was talking about earlier when we started going to Minami Souma in late May, we had only one sodium iodide based counter with us. There were actually 20 personal geiger counters supplied by the US military available for our use. However, the City’s Board of Education couldn’t understand the papers explaining the equipment because they were all in English. It was only when our team arrived that we found the equipment and were able to explain it to them.This is the sort of situation the disaster area is in.
Regarding the testing of food products I was talking about earlier, we need to use more advanced equipment capable of graphic imaging and using many semiconductors that have already been developed, not just simple germanium based counters.
Why won’t the government commit the money to buy the equipment to perform these necessary measurements?! I am filled with anger that three months have passed and yet absolutely nothing has
The second point I would like to make: My specialization is in cutting-edge research of antibody drugs. This research was endorsed by the government from when Keizo Obuchi was still prime minister. Working with a budget of 3 billion yen, this research involved attaching radioisotopes to antibodies for use in the treatment of cancer. This means that I am quite familiar with the problem of internal exposure to radioactive materials as studying the effects of radioactive materials on the body is part of the research I am diligently conducting.
Therefore, I would like to take this opportunity to explain what problems will occur from internal exposure to radioactivity. The biggest problem from internal exposure to radioactivity is cancer.
Cancer occurs during DNA replications. As you may all know, DNA is in the form of a double helix. In this state, DNA is extremely stable.
During cell reproduction, the two strands merge into one, split into two, and then split again to form four strands. It is during this process where dangerous problems can occur.
Therefore, radioactivity becomes extremely dangerous for fetuses of pregnant women, young children, and any type of cells that are frequently produced.
Furthermore, radioactive damage to cells which are frequently produced for example, hair, anemia, and the outer skin of the intestines etc. can affect adults as well.
Allow me to share an actual case of the specific effects of internal exposure to radioactivity. In this case, cancer will not occur from one bad mutation of a gene.
Even after applying the first hit of radiation, there is a another, seperate reason for cancer occuring which manifests as “driver mutations” or “passenger mutations” which I will refrain from explaining in detail at this time. You may find their descriptions in reference documentation I have listed at the end of my report. I will also refer back to them later when I talk about Chernobyl, cesium etc. But first, I would like to say that the most well-known cause of cancer are alpha (α) rays.
I was shocked to learn about a professor from the University of Tokyo who said that there were no health risks in ingesting plutonium. I want to emphasize that alpha rays are the most dangerous of substances.
From studying the effects of thorotrast on the liver, my team is very familiar with the destructive effects of alpha rays. First off, I would like to say that it is completely meaningless to talk about the effects of internal exposure to radioactivity using current discussion methods involving microsieverts etc.
Iodine-131 gathers in the thyroid gland. Thorotrast accumulates in the liver. Cesium will gather in the outer skin of the brain stem and bladder. There is no point in doing full body scans when radioactivity must be measured from the specific areas of the body where these radioactive materials gather.
In the case of thorotrast… the numbers reported here are a bit on the small side and I would have liked to show an example with larger numbers… in any case, thorotrast was used as a contrast medium in Germany in 1890 and was brought into use in Japan in the 1930s. We now know that 20
to 30 years after ingesting thorotrast the liver incurs a 25% to 30% increased risk of developing cancer.
Why does it take 20 years for cancer to develop? The alpha ray nuclides emitted from the thorotrast damages nearby cells. The gene which receives the most damage from this is the P53 gene.
From genomic studies, we now know that 3 million segments of the human genome sequences between any two individuals differ from each other. Because of this, applying the same treatments to all affected individuals is completely meaningless.
In what is known as “personalized medicine”, instead of just looking at the damage caused by radioactivity, the most important principle is seeing which specific genes have been damaged and how they have changed.
In the case of thorotrast, the P53 gene is affected in the first stage with second and third stage mutations occuring after 20 to 30 years. It has been proven that development of liver cancer and leukemia in these later stages.
Next, I would like to talk about iodine-131. I131 gathers in the thyroid gland but the greatest chance for damage occurs in small infants where their thyroid gland is still developing.
In 1991 when Ukranian researchers discovered numerous cases of thyroid cancer occuring, Japanese and American scientists could not prove that iodine-131 was the direct cause of thyroid cancer in a report they submitted to the science magazine “Nature”.
The reason they could not prove statistically the relation between I131 and thyroid cancer over a 20 to 30 year period was because there was no data existing on the subject before 1986. However, what they were able to determine statistically is that it would take 20 years as Prof. Nagataki was talking about earlier.
The fact that a peak occuring from 1986 disappeared was evidence enough to show that effects would occur in 20 years without the need for prior data.
In other words, to show epidemiological proof is extremely difficult as the entire process over time has to end before arriving at concrete proof.
In light of this, completely different methods are demanded of us if we are to tackle the problem from the perspective of protecting our children.
One hint at an answer comes from Prof. Shoji Fukushima who has dedicated himself to researching substances which gather in the urinary tract of Chernobyl victims at the National Bioassay Research Center where they conduct research on the effects of chemical substances.
Prof. Fukushima’s team has worked on over 500 cases in consultation with doctors from the Ukraine. These cases involve surgery on prostate glands so enlarged that the bladder would also get removed when operated on. Further investigations into these cases show that even trace amounts such as 6 becquerels per litre of urine gathered would cause a very large increase in the number of P53 gene mutations from patients in areas with a high concentration of contamination. Reports also show that this pre-cancerous state is made worse with the high chance of developing cancer on the outer walls of the bladder as a result of malignant bladder inflammation that is sure to develop through the activation of P38 MAP kinases and NF kappa B signal genes (by the alpha rays).
After knowing these facts, we were appalled to discover reports showing 7 mothers from Fukushima having breast milk with radioactivity measuring 2 to 13 becquerels. (Please turn to the next page.)
We at the Radioisotope Center have been continuing sending teams of about 4 people every week to assist with decontamination efforts 700km away in Minami Souma.
Needless to say, radioactive damage is occuring in Minami Souma. I would like to say that it is completely meaningless to seperate afflicted areas by 20 kilometres or 30 kilometres etc. We must perform detailed measurements of radioactivity at each individual kindergarten.
Minami Souma’s central district is near the ocean and 70% of its school have relatively low levels of radioactivity. There are buses that pick up 1,700 children living in the areas at the 20 to 30 km range and bring them to school.
The schools are located in areas beyond the 30 km range but have been found to have high levels of radioactivity. We are in effect spending one million yen every day in the forced transport of children into areas with high radioactivity.
I urge you to stop these sorts of initiatives as soon as possible!
Next, the biggest problem we see currently is are rules stating that without a forced evacuation being issued victims are not eligible to receive compensation that were being discussed by then- president Shimizu of TEPCO and Mr. Kaieda, Minister of the Economy, Trade and Industry. I urge you all to please seperate these issues!
Please seperate the issues of compensation from the protection of our children as soon as possible. I urge you all to please focus all of your efforts on protecting our children.
Another point I would like you all to consider the clear differences between emergency decontamination and long-term, permanent decontamination measures.
Our team has been duly conducting emergency decontamination efforts in the disaster areas.An example of our findings that I would like to show is illustrated in this diagram regarding the bottom of a playground slide. The hands of small children may come in contact with the ground below after sliding to the bottom. Our findings show that rainwater that has flowed through the slide acts to increase concentration of radioactive materials in the ground at the bottom of the slide.
Areas to the left and right of the slide show different levels of radioactivity with a noticeable concentration of radioactivity on one side. Although the average radioactivity level for the area is 1μSv the highest concentration measured over 10μSv. We must work quickly to decontaminate these kinds of areas.
We must also pay attention to other areas such as moss growing under drain pipes of gutters. These are areas where children may come in contact with. If we could, for example, apply high pressure water washing to clear the moss away, an initial reading of 2μSv could be reduced to 0.5μSv.
Even so, it is extremely difficult to reduce the radioactivity of an area below 0.5μSv. To clear radioactivity from one particular spot could be achieved but to decontaminate buildings and trees for an entire area is extremely difficult.
Therefore if you really want to decontaminate a given area, one must figure out just how big of a problem it is and how much it will cost. For example, the cost of decontaminating 1500 hectares of the approximately 3000 hectares contaminated by cadmium in Toyama Prefecture has cost Japan about 8 trillion yen.
If we were to attempt to decontaminate an area 1000 times that, just how much money will be necessary?
With that in mind, I would like to propose four emergency contingency plans.
The first plan is to drastically improve the measurement of radioactivity in food products, water and soil by introducing the latest equipment that allows imaging using semi-conductors and the creation of efficient workflows as a matter of national policy.
It is entirely possible to implement tihs plan given the technology we possess in Japan.
The second plan is to enact new emergency legislation to minimize internal exposure of radioactivity to our children.
For instance, everything I have been working on so far is in violation of current law. Current nuclear safety laws have defined the quantity and types of radioactive material each facility is permitted to handle. Although all 27 radioisotope centers at the University of Tokyo have been mobilized to support communities like Minami Souma, many of the centers do not have legal permission to handle cesium.
Transportation of radioactive materials using automobiles is also illegal under current law. However, we could not just leave highly radioactive material with mothers or school teachers etc. Currently we pack the contaminated material into large metal drums and transport them back to the University for decontamination.
Accepting radioactive material in this fashion is a violation of current law. Everything we have been doing is a violation of current law.
This sordid situation is due to the neglect of the government. There are many places like radioisotope centers in national universities who possess the latest equipment from germanium counters and better all over the country.
With all of these facilities being unable to act due to current law, how can we expect our citizens to pool our resources to protect our children?
This situation is the result of complete and utter negligence by the government!!
The third plan I would like to propose is to procure equipment for soil decontamination from the private sector as a matter of national policy. For example, any of these chemical manufacturers like Toray and Kurita, manufacturers of decontamination equipment like Chiyoda TechnoAce, Atox and Takenaka Corporation possess the equipment and knowledge to deal with radioactive contamination.
With the equipment and manpower from the private sector procured, a decontamination center should be established immediately in the disaster area. Because this decontamination effort will cost Japan tens of trillions of yen and the existence of many competing interests, I truly fear that this needed public works project will never get off the ground.
Given the state of our country’s finance, they cannot spare any money for the decontamination effort.
Just how will we be able to decontaminate the disaster areas? Just what the hell has the government doing when 70,000 people have been left to fend for themselves after being forced from their homes?!
That is all I have to say.