福島原発事故による要望書及び署名

Part 2 of Professor Tatsuhiko Kodama's testimony on July 27 to the Committee on Welfare and Labor in Japan's Lower House in the Diet.

Professor Kodama is the head of the Radioisotope Center at the University of Tokyo.

Professor Kodama's anger is now directed toward the government's non-action to protect people, especially children and young mothers, from internal radiation exposure. His specialty is internal medicine using radioisotope, so he says he has done the intense research on internal radiation:


I have been in charge of antibody drugs at the Cabinet Office since Mr. Obuchi was the prime minister [1998-]. We put radioisotopes to antibody drugs to treat cancer. In other words, my job is to inject radioisotopes into human bodies, so my utmost concern is the internal radiation exposure and that is what I have been studying intensely.

The biggest problem of internal radiation is cancer. How does cancer happen? Because radiation cuts DNA strands. As you know, DNA is in a double helix. When it is in a double helix it is extremely stable. However, when a cell divides, the double helix becomes single strands, doubles and becomes 4 strands. This stage is the most vulnerable.

Therefore, the fetuses and small children, with cells that rapidly divide, are most susceptible to radiation danger. Even for adults, there are cells that rapidly divide such as hair, blood cells and intestinal epitheria, and they can be damaged by radiation.

Let me give you an example of what we know about internal radiation.

One genetic mutation does not cause cancer. After the initial hit by radiation, it needs a different trigger for a cell to mutate into a cancer cell, which is called "driver mutation" or "passenger mutation". (For details please refer to the attached document about the cases in Chernobyl and cesium.)

Alpha radiation is most famous. I was startled when I learned of a professor at Tokyo University who said it was safe to drink plutonium.

Alpha radiation is the most dangerous radiation. It causes thorotrast liver damage, as we, liver specialists, know very well.

Internal radiation is referred to as such-and-such millisieverts, but it is utterly meaningless. Iodine-131 goes to thyroid gland, and thorotrast goes to liver, and cesium goes to urothelium and urinary bladder. Whole body scan is utterly meaningless unless you look at these parts in the body where radiation accumulates.

Thorotrast was a contrast medium used in Germany since 1890. It was used in Japan since 1930, but it was found that 25 to 30% of people developed liver cancer 20 to 30 years later.

Why does it take so long before cancer develops? Thorotrast is an alpha-radiation nuclide. Alpha radiation injures nearby cells, and the DNA that is harmed most is P53. We now know, thanks to genome science, the entire sequence of human DNA. However, there are 3 million locations on the DNA that are different from person to person. So today, it doesn't make sense at all to proceed as if all humans are the same. The basic principle should be the "personal life medicine" when we look at internal radiation - which DNA is damaged, and what kind of change is taking place.

In case of thorotrast, it is proven that P53 is damaged in the first stage, and it takes 20 to 30 years for the 2nd, 3rd mutations to occur, causing liver cancer and leukemia.

About iodine-131. As you know, iodine accumulates in thyroid gland, and that is most noticeable during the formative phase of thyroid gland, i.e. in small children.

However, when the first researcher in Ukraine was saying in 1991 "There are an increasing number of thyroid cancer", researchers in Japan and the US were publishing articles in Nature magazine saying "There is no causal relationship between the radiation and thyroid cancer." Why did they say that? Because there was no data prior to 1986, there was no statistical significance.

The statistical significance was finally noted 20 years later. Why? Because the peak that started in 1986 disappeared. So even without the data prior to 1986, the occurrence of thyroid cancer and radiation exposure from Chernobyl had the causal relationship. Epidemiological proof is very difficult. It is impossible to prove until all the cases are done.

Therefore, from the viewpoint of "protecting our children" a completely different approach is required.

Dr. Shoji Fukushima from a national institution called Japan Bioassay Research Center, which researches health effects of chemical compounds, has been studying diseases involving urinary tract since the Chernobyl accident.

Dr. Fukushima and doctors in Ukraine studied parts of bladders removed during more than 500 cases of prostatic hypertrophy surgery. They found out that in the highly contaminated area where 6Bq/liter was detected in urine, there was a high frequency of mutation of p53 though 6Bq may sound minuscule.

They also noticed many cases of proliferative precancerous conditions, which we assume was due to the activation of p38 MAP kinase and the signal called "NF-kappa B," leading inevitably to proliferative cystitis, with carcinoma in situ occurring with considerable frequency.

Knowing this, I was astounded to hear the report that 2 to 13Bq/liter [of radioactive cesium] was detected from the breast milk of seven mothers in Fukushima.

(to be continued in Part 3.)



When radioactive materials were detected from the breast milk, what did the government and government researchers say? "No need to worry. No immediate effect on health of the babies."

Professor Kodama is saying that by the time we have proof that there is a causal relationship between internal radiation exposure (however small) and cancer, it may be too late.


Thorotrast is a suspension containing the radioactive particles of thorium dioxide.

Again, here's the video (the same one as in Part 1).

http://ex-skf.blogspot.com/2011/07/part-2-professo...