Concerns over Decontamination

An Unsworn Testimony on Health Influences of Radiation, given by witness Tatsuhiko Kodama (professor of Research Center for Advanced Science and Technology, head of Radioisotope Center, of Tokyo University)

given at Welfare and Labour Committee of the House of Commons that met on 2011-07-27 Wednesday (starting at 09:00)

[Chairman: Next, Mr. Kodama. Please begin.]

I am Kodama, the head of Radioisotope Center in Tokyo University. I was very surprised on March 15th.

Tokyo University has 27 radioisotope centers that are committed to radiation protection and decontamination. I myself am a doctor of internal medicine. I have been doing decontamination works at radiation facilities for the last few dacades.

On March 15th, as this panel shows, we first detected a 5 μ Sievert dose around 9 AM in Tokai-mura Village, which we immediately reported to MEXT in compliance with the Article 10 (of Act on Special Measures Concerning Nuclear Emergency Preparedness). Later, they detected a dosage over 0.5 μSv in Tokyo. Then there was a transient decrease. Next, there was a rainfall in Tokyo on March 22rd. Fallouts scored 0.2 μSv and so on. This was the cause of the high radiation that remains till today.

At that time, Mr. Edano, the chief cabinet secretary, made a public announcement to the effect that it was not an immediate health problem, but I knew this was going to be disastrous.

I'll state the reason. The current "Laws Concerning the Prevention from Radiation Hazards due to Radioisotopes and Others" pertain to disposing small amounts of radioactive matter with high dosage. The problem it deals with is not the gross amount but the density of individual doses. The current Fukushima I accident is very different. It discharged radioactivity as strong as 5 μSv in the 100-kilometre radius, 0.5 μSv in the 200-kilometre radius. Further than these areas, it has contaminated tea-leaves grown in Ashigara and Shizuoka. I expect everyone knows about these today.

Experts of radiation damage, myself included, are interested in the gross amount.Then if TEPCO and the Government have made a detailed report on the gross amount of radioactive material discharged in this Fukushima I incident? No.

Our Radioisotope Center have made calculations based on expertise. In terms of heat quantity, the discharge is as 29.6 times as large as that of Hiroshima Atom Bomb. In terms of uranium equivalence, the discharge is as large as 20 Hiroshima Bombs.

Even horrifying still is the slowness of decrease. Today we know that radioactive discharge from power plants only gets to one tenth within a year while that from an atom bomb decreases to the one thousandth.

Everything should be based on the fact that this accident, like Chernobyl, has discharged radiation equalling to tens of bombs and the residual radiation is much worse than contamination by bombs.

From the viewpoint of systematic biology, an application of system theories, in case of small discharges, the density of individual contaminations matters most. In case of huge discharges, the key is particles. The proliferation of particles is dealt in a non-linear way, one of the most difficult calculations in fluid dynamics. Quite simply, nuclear fuels are like sand grains embedded in synthetic resin. When the reactor melts down and there is a discharge, a lot of fine grains are emitted.

When they are emitted, they cause problems such as the current issue with rice straws. [Caesium-contaminated rice straws from Miyagi was fed to meat cows. Not all beef samples exceeded the legal 500 bq/Kg but some of the meat has been consumed. Contaminated straws were from very far places distant-wise. The contaminant was a rain cloud in March that travelled in the wind as southwards as Kanto and then to the north. This is the same cloud that made Iidate an extra evacuation zone.]

Contaminations found in rice straws are for instance, 57000 bq/Kg in Fujisawa-chō Town, Iwate, 17000 bq/Kg in Ōsaki, Miyagi, 106000 bq/Kg in Minami-Sōma, 97000 bq/Kg in Shirakawa-shi, 64000 bq/Kg in Iwate-shi. As theses figures tell, dosage levels cannot be mapped on concentric circles. Strength of dosage depends on the weather as well as if the material has absorbed water.

Every week I travel for 700 kilometres to Minami-Sōma with the Radioisotope Center team from Tokyo University. We have done decontamination works for seven times up to present. When we first got there, there was only one dosimeter available. Ministry of Agriculture say that they have passed on the notice not to feed rice straws to cattle on March 19th. On the same day, the mayor of Minami-Sōma made a well-known announcement on the Web, including a heart-felt request for food, water and petrol.

While a crisis like this was unfolding, no one can be expected to read or know about the notice written on a piece of paper. No farmers knew that their rice straws are so dangerous. They, however, started buying feedstuff for extra few hundreds of thousand yen. On that day on, they have been giving the same groundwater that they themselves drink.


The first thing we should do is to make a thorough measurement possible in contaminated areas. Like I said, Minami-Sōma had only one dosimeter when we first went there. But in fact they already had got 20 personal meters from the US military. They at the education committee in the city hall, however, couldn't read the English instruction manual. These 20 meters had not been used until we read them the document and showed how to use dosimeters. A glimpse of how things were there.

Food inspection has hitherto been discussed in this committee. Why use germanium counters? Nowadays, a lot of imaging-based measuring devices have been developed on semiconductors.

Why do the Government not make extensive application of them and invest money across the nation?

There has not been no such attempts after three months, which I resent from the bottom of my heart.


My second point is internal exposure.
Prime Minister Obuchi has appointed me as the head of antigen medicine development at Cabinet Office. This research field now gets 3 billion yen from Funding Program for the World-Leading Innovative R&D on Science and Technology. Radioactive isotopes are used to mark antigen drugs so we can check how they treat cancer. Otherwise said, my job is injecting isotope into human body. This is how internal exposure is the top-most priority in my researches.

So, let me explain how internal exposure happens.
The biggest issue with internal exposure is cancer. Cancers are born from dissected DNAs. DNAs are usually put together in double helix, which is very stable. When a cell divides, the double helix separates into single helices, then doubles into 4 helices. The danger is in this process.

Radiation damage poses a tremendous danger for the foetus in a expecting mother, small children as well as for cells with active division in growing phase. Even in adults, actively dividing cells are dangerous; causing loss of hair, anaemia. Cells in intestinal epithelia are affected too. These are a few basics about radiation damage.

I shall cite reported examples of internal exposure.

Mutation on a single gene does not cause cancer.
After the first radiation hit, there is another factor, and then there is a cancerous mutation. These are called driver mutation or passenger mutation by experts. For them, please refer to the literature listed in the last pages. We will now look at examples of Chernobyl and caesium.

The most famous cause is alpha particles. I was alerted by a Tokyo Univ. professor that he thinks it is okay to drink plutonium solution.

Alpha particles are one of the most dangerous matters.
Liver specialists like myself know this from liver damage by thorotrast.
This committee has been discussing internal exposure in a generic so and so mili Sievert but that's senseless.

I-131 concentrates in the thyroid gland. Thorotrast concentrates in the liver. Caesium concentrates on the urinary tract epithelium and the bladder. Unless you look at these places of concentration, no whole-body scan is meaningless.

Details of Thorotrast can be found in the reference materials. Thorotrast is a contrast agent, first used in Germany in 1890 and in Japan around 1930. After 20 to 30 years of use, it was found to cause liver cancer by 25 to 30%.

Cancers take 20 years to develop in this way. First, thorotrast, being an alpha radiation nuclide, damages adjacent cells with alpha particles. The likeliest victim is a gene called P53. According to genome science today, knowledge of exhaustive patterns of human genes, one human is different from another in about three million genes.

Nowadays, it is totally meaningless to treat a patient on the assumption that all humans are the same.

Applying the so-called personal life medicine, internal exposure to radiation should be diagnosed basically by looking at which genes have been damaged with what effects.

Thorotrast, in the first step, destroyed P53 gene. Second and third mutations take 20 to 30 years. This is the proven steps for liver cancer and leukaemia.

Next, iodine 131.
As you know, iodine concentrates in the thyroid gland. Concentration in the thyroid gland is most typical to the thyroid growth period, that is, for small children.

Despite this, when researchers in Ukraine first reported a frequent occurrence of thyroid cancer in 1991, some researchers in Japan and USA criticised the report on Nature. Their ground for reasoning was that the report was not statistically significant due to the absence of data prior to 1986.

Like Professor Nagataki mentioned just now, statistical significance was proven 20 years later. After 20 years, disappearance of the peak started in 1986 was taken as the evidence despite the absence of previous data. Proving something epidemically is very difficult; it usually takes until all cases are over.

Saving children, which is the perspective now incumbent upon us, requires a very different approach. An example of this approach is by Doctor Shōji Fukushima at the national Japan Bioassay Research Center. This is a research institute for analysing effects of chemical compounds. He has been studying samples found in urinary system from Chernobyl. Fukushima and Ukraininan doctors collected over 500 bladders taken out while operating on enlarged prostates. They have found that high-level contamination zones, where radiation can be found in urines however small around 6 bq/L, have steep rise of mutations in P53. This is accompanied by proliferative precarcinomatous state, inferred from activation of P38, an MAP kinase and a signal called NF-κB. This necessarily leads of proliferative bladder infection. High probability of intraepithelial cancer is also reported.

With this, I have been appalled to hear the report of radiation between 2 and 13 Becquerels found in milk from seven Fukushima mothers.

Please turn to the next page.

We at Radioisotope Center sends four personnels every week, travelling 700 kilometres to help Minami-Sōma city decontaminate. For problems in Minami-Sōma as elsewhere, telling 20-kilometre radius from 30-kilometre radius does not make sense at all. Unless we measure different parts of each kindergarten, everything is meaningless. Presently, they hire buses to send 1700 Minami-Sōma children from the 20km-zone to the 30km-zone. In fact, Minami-Sōma's radiation concentrates on the cost line. Dosage is relatively low at about 70% of schools.

Despite this, they send school buses into the 30km-zone, and this is closer to Iidate. They spend one million yen per day to forcibly send children there. This must be stopped as soon as possible.

The single biggest obstacle for children's safety is the policy of not compensating losses for evacuation other than by forced evacuation; such was the statement by TEPCO'S then-president Mr. Shimizu and Mr. Kaieda, the Minister of Economy, Trade and Industry at the previous committee in the Upper House. Still, they must be discussed separately.

Please set problems of compensation, or where to limit compensation, apart from the issue with children.

I beg you to apply all of your strength to protect children.

Another request.
Please devise plans for permanent decontamination, not just impromptu one.

We do impromptu decontamination on a frequent basis. This diagram lists "under the slide." Little children touch the place under the slide. Despite this, every time rain water flows down on the slide, it gets condensed dosage. If the two sides of the slide are uneven, one slide gets them all. In a place where the average dosage is 1 μ, 10 μ or above can be detected under the slide. Places like this can use immediate, impromptu decontamination a lot.

Children also touch places under the drip moulding, where various moss species grow. Using pressure washer to blow mosss growths off, the dosage drops from 2 μ to 0.5 μ.

Still, getting radiation below the 0.5 μ level is very difficult.

If the whole building or the whole tree growth or the whole community is contaminated, washing radiation down in one place does not really contribute to lowering the air dose rate of a area. I draw on the case of itai-itai disease (softening of bones and kidney failure in Toyama Prefecture identified as cadmium poisoning in the 1950s) for tasks and costs of serious decontamination works. Cadmium-contaminated area is about 3000 hectares, out of which 1500 hectares have been decontaminated so far for 800 billion yen, at government expense. If the current contamination is spread to 1000 times as large areas, I cannot even begin to contemplate how much the Government should spend.

Having said all this, I should like to make four urgent proposals.

First, radiological exams needs a fundamental improvement with Japan's most advanced imaging devices. Imaging is now very easy with semiconductor instruments. With advanced imaging machines, exams will be a quick automatic process. Please commit to this as a national policy. This is well within the scientific, technological means of Japan today.

Second, immediately pass a new law to reduce exposure of children.
Everything that I do now is against the law.
The current Prevention from Radiation Hazards Law decrees facilities need authorisation for dosage levels and types of nuclides. I am mobilising all 27 isotope centers at TU to help Minami-Sōma, but many facilities haven't got authorisation to handle caesium. It's against the law to use cars to transport radioactive materials. Still, I cannot give high-dose decontamination waste to those mothers and teachers and let them dispose of it, so we pack it in drums and bring them back to TU.
Accepting them into our facilities is against the law.
Everything is against the law.

The Parliament is responsible for this negligence. Many facilities all over Japan, such as radioisotope centers in national universities, are equipped with the most advance devices such as germanium detectors. Why are they tied hand and foot while we have to mobilize the full potential of the people to protect children?
The Parliament has been completely negligent in its duties.

Third, please make it a national policy to bring together the expertise in the private sector for soil decontamination. They have a lot of know-how for radiation removal; chemical manufacturers such as TORAY and Kurita, manufacturers of radiation removal devices such as Chiyoda Technol and ATOX, as well as Takenaka the construction company. Please make use of their power to make a research center for decontamination in Fukushima.

This is going to cost tens of trillion yen from the national treasure. I am worried that, if this goes on, the work is reduced to just another public work projects, marred with right hunting.

Considering the tough fiscal situation, you cannot afford that even for one moment. You should be thinking how to do the real work of decontamination. What have you been doing in the Parliament while 70 thousand people are driving out of their homes?

[I haven't gotten around to translate what Prof. Kodama said in the following Q&A session.]

Kodama was invited to speak before the committee by MP Tomoko Abe (Social Democratic Party).