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Masao Tomonaga’s Interview

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Masao Tomonaga is the honorary director of the Japanese Red Cross Nagasaki Atomic Bomb Hospital and a hibakusha, an atomic bomb survivor. He studied internal medicine and hematology at the Nagasaki University Medical School. Currently, he runs a retirement home for older hibakusha. In this interview, Dr. Tomonaga discusses his experience surviving the bombing of Nagasaki. He outlines the immediate physical impacts the bomb had on people’s bodies, the long-term physical impacts, such as cancer, and the psychological harm. He also discusses the simulation Japan’s Ministry of Foreign Affairs conducted to see what a one-megaton nuclear detonation would look like in a modern city today.

Date of Interview:
February 19, 2019
Location of the Interview:


 [Note: This interview contains graphic descriptions of the injuries suffered by atomic bomb victims.]

 Cindy Kelly: It is February 19, 2019, and I am in Nagasaki. [I am] Cindy Kelly, Atomic Heritage Foundation. I would like to have my guest say his full name and spell it.

Masao Tomonaga: My name is Masao Tomonaga, honorary director of the Japanese Red Cross Nagasaki Atom Bomb Hospital. I am one of the young A-bomb survivors, two years old at the time of the bombing. Later, I will explain how I was exposed to the atomic bombing. Shall I start my talk?

Kelly: Yes, please.

Tomonaga: The title of my talk is “The Long-Term Consequence of Atomic Bombings in Hiroshima and Nagasaki: Evidence of the Antihumanitarian Aspect of Nuclear Weapons.” Maybe you know very well about the details of the bombs – that is Little Boy and Fat Man – and the casualties for Hiroshima and Nagasaki. Maybe you know very well, so I don’t explain anymore.

Usually, I would explain in this way. Only 64 kilograms of uranium detonated, but actually 850 to 900 grams detonated, to destroy the whole of Hiroshima. That is equivalent to 16 kilotons of uranium. And in the case of the Nagasaki bombing, 21 kilotons, plutonium was used. That is the equivalent of 10 kilograms in plutonium, pure plutonium, and actually, 1 kilogram detonated. Such a small amount of detonation expelled [misspoke: destroyed] the cities of Nagasaki and Hiroshima.

This is a photograph taken by the U.S. Air Force a few days before the atomic bombing. That was August 9. The original target was here. My home was located about one kilometer from the original target, but the actual target changed to this point, about two kilometers north of the original. The next photographs explain how this northern part of Nagasaki was destroyed completely.

You can see here Ground Zero. My house was about 2.5 kilometers from Ground Zero. This point, okay. This area is where [there were] actually military arsenals, Mitsubishi arsenals. And also Mitsubishi shipyards are located here. They were completely destroyed. My alma mater medical school was located inside the one-kilometer range from Ground Zero. This is the old buildings of Nagasaki Medical University Hospital, totally destroyed. Later, I’ll talk in more detail. This area was surrounded by about 300-meter hills and mountains. Inside this area, almost all buildings, except for this gigantic hospital – destroyed, more than 90 percent. You can see over there are the ruins of the arsenals.

This rate according to the distance from Ground Zero was calculated within three months of suffering the bombing by surviving professors and medical students at Nagasaki University Hospital. They calculated based on 6,000 interviews. They found, amazingly, this rate was very low. Only the University Hospital [survived]. That was due to heavy shielding by thick concrete buildings. 

The blast reached over three kilometers. The red area shows the 100 percent complete destruction of buildings. Of course, our University Hospital was inside the one-kilometer range. This was the hypocenter, Ground Zero. My house was located about 2.5 [kilometers away], about this area. Military arsenals located along this big river.

This is a real site where I was exposed to the atomic bombing. Here, you see a Catholic church, the second largest church in Nagasaki city. This was almost completely destroyed. My house was a wooden house. All areas are full of Japanese wooden houses. They were crushed completely or partially. Then within ten to fifteen minutes, a huge firestorm came to my house also. 

I was sleeping on the second floor of this wooden house. My mother was preparing lunch on the first floor. She quickly came up to my room on the second floor. She said I was sleeping on the bed because I was ill. The day before the atomic bombing day, August 9, I suffered from tonsillitis and a high fever. So she took me to the University Hospital on August 8. That was August 8, one day before. At night, almost seven o’clock [to] around eleven. I was sleeping in the bed. She took me out of the broken house. The firestorm had not reached yet. She could take me out of the broken house and she escaped from this area to a nearby shrine and spent one night. We were completely safe at the time of the bombing. We were a lucky family, okay. You have some question?

Kelly: Where was your father?

Tomonaga: My father was not in Nagasaki. He was serving for the Japanese Army Air Force in Taiwan. His troops were stationed in Taiwan, the south of Taiwan.

Kelly: I see.

Tomonaga: He was an army doctor belonging to the Army Air Force in Taiwan. There he heard about the news, the complete destruction of Nagasaki city. He said to us he once thought his family all perished, but later, maybe within one month, my mother’s letter safely reached him. He got the news that we were alive. 

He was ordered by Chiang Kai-shek’s Army government in Taiwan to stay in Taiwan more and to serve the Taiwanese people for medical care. So he stayed there one and a half years. Then he came back to Nagasaki. So we met in Nagasaki in 1947 – two years [later]. He left Nagasaki in 1942, after graduation from this medical school.

Okay, so within a one-kilometer distance from Ground Zero, the situation was terrible. Many, many carbonized bodies were seen. Also, white bones were seen. Carbonization occurred by the strong direct heat rays from the detonation. Those people walking on the street were directly exposed to heat rays. Later, the bodies were burned again by the firestorms. Then, become white ones. Some docs wrote the atomic bomb energy evaporated human bodies directly to white ones. This might not be correct in terms of the physical power of heat rays. Heat rays have not such a huge energy to make the human body evaporate, okay. You understand, yeah. Evaporation is instantaneous destruction of all organs, all deep organs, but this was not true. Maybe I suspect, that black boy, inside his body still organs are existing, but later if he was burned by fire, firestorms, his body became only white bones.

Kelly: His body would become ashes?

Tomonaga: Ashes. Sometimes ash, yeah.

Kelly: Destroyed.

Tomonaga: Almost within 500 meters, the bones became ashes. You can just take the ashes.

Kelly: But that’s different from evaporation.

Tomonaga: Dr. [Takashi] Nagai wrote this scene, when he found his wife’s bones in the ruin of his previous house. He said that he couldn’t take the bones, just ash on his hand. So he wrote, “My wife escaped from my fingers. Escaped from my fingers.”

The right upper side photograph shows the most severe total skin burns. Maybe he was facing the explosion, directly, and exposed to the heat rays. Heat rays destroy our very thick skin, maybe three centimeters, four centimeters, thick – all over their bodies. Directly. Deep, these skin layers. So the skin began peeling off and bleeding and the pain. This is a terrible situation. Even the skin of [their] arms [was] hanging down. Almost all of them walked like this if they were still alive. Most of them died sooner or later, okay.

Those two bodies, babies and mothers. This is also instantaneous death. Left side, you see also black, carbonized bodies, probably the mother. She found – daughter found her mother. So again, the black boy. On the right side, upper side, shows dead and agonizing survivors or fairly well-looking survivors, a mixture of such people. This is a photograph taken on the second day by Mr. [Yosuke] Yamahata. There are no photographs showing the first day scenes of the Nagasaki bombing. In Hiroshima, there are two or three photographs, only three photographs. Later, I will show you.

This red-back boy, famous boy, was 16 years old. He was riding on a bicycle to deliver letters. He was a postman, a 16-year-old, and burned directly from the back. He was [half] naked, unfortunately. He was [half] naked at the time because of the summertime, too hot. He was [half] naked, only with pants. Then, his skin was all destroyed and peeled off. Later, he could survive. Age 80, he became very famous atom-bomb-eradication activist, Mr. [Sumiteru] Taniguchi. Maybe you heard his name once or twice.

Kelly: Yes.

Tomonaga: His skin recovered after two years. As you see here, there is shining skin, but this not real skin. This is scar tissues. He could not sweat. He could not have soft skin with oily texture. He was always suffering from dry skin, especially in the summertime. It was a terrible time for him, because his entire back could not sweat. Could not sweat. So he was always sitting in front of the fan or air conditioners.

Within two weeks, people who were exposed to atomic bomb radiation began to show hair falling [out]. This is called in medical terms “epilation.” This girl had complete epilation. That means their bodies were deeply irradiated by atomic bomb rays. That is consistent of gamma rays and neutron rays, two major radioactive rays. That radiation reached almost 2.5 kilometers. You remember my house was located about 2.5. I might have been exposed to the smallest amount of radiation.

During the early pregnancy, the fetus was exposed also to radiation and those boys showed microcephaly, small head. Boys and girls. Maybe around 100 such babies were born from direct survivors, mothers who were pregnant.

This is the second showing. You may see on the second day no rescue teams arrived at this point. Medical rescue teams, I mean. Almost all medical facilities – especially the largest medical facilities were Nagasaki University Hospital – were destroyed. Although 45 percent of doctors and students survived, medical facilities, including our drugs and blood transfusions, all gone. So there was no rescue on the second day.

There was no hospital in the atomic field. A nearby elementary school half destroyed by the blast wind began to be used for ambulant places for medical care. But there was no meaningful medical care at that point. Only supplying water, foods, and so on. Many people died in this ambulant elementary school. There was no burning system of dead bodies. This playground of the elementary school was used for burning dead bodies. The situation was terrible. 

This is a boy agonizing and died within a few days after this photograph, showing some extraneous skin bleeding. This was a typical sign of bone marrow destruction. You know bone marrow. This is normal bone marrow. This is such a heavily irradiated people’s bone marrow autopsy tissue photograph. There were no blood cells being made. So platelets, that prevent bleeding, became almost zero. Then, their capillaries and small vessels began to bleed spontaneously. So they die. Also, those photographs, again, show hair falling [out].

Deep inside a body, bone marrow, and this is intestine, large intestine. All mucosal membranes were destroyed by the heavy radiation. The death rate curves were later calculated, showing H—Hiroshima and N-Nagasaki, two curves. A little bit different at this range, almost overlapped like this.

At my point, 2.5 kilometers, the death rate was below five percent. Mostly, they died in broken Japanese houses. They could not escape from the broken houses and were burned by the firestorm. But within 1 kilometer, the death rate goes up from 80 percent to over 95 percent. Very high.

This is a normal colon. You can see many folds. The surface of the colon mucosa is very wide and can absorb enough water and nutrients, but a severely burned colon shows no folds and all mucosal cells were destroyed. Bone marrow also destroyed like this. The agonizing period ended within three months. After three months, survivors became fairly well in early 1946. But in 1947 to ‘48, survivors faced the very surprising phenomenon of [an] increasing number of acute leukemia, especially among small children and later adults. Within 1.5 kilometers, the curves rapidly elevated, maybe ten times or more compared to the normal population, nonexposed population.

Leukemia is a disease which occurs very rarely among healthy people. That is the control rate. Middle areas, middle distance areas show a little bit lower, but within 1.5 kilometers, that means heavy radiation. It shows very rapid increase of incidence per 100,000 per year – a very high rate, consistent almost for 15 years, and then declined gradually. But this was not the disappearance of atomic bomb radiation. 

This is the total results until the present time, 2018. The first risk of leukemia appeared like this and the decline. But later, the throat cancer phase began and continues until now, 73 years after the bombing. Most of the survivors who are suffering from cancers at this time – over age 73 – they were very young at the time of bombing, less than ten years old. Now [they are] getting older and older, but still suffering from throat cancer and also another type of leukemia called MDS [Myelodysplastic Syndromes].

This figure clearly proves that the atomic bomb radiation’s effect on human bodies is a real lifelong effect. This is very scientific data. About 80,000 survivors were calculated for their exposure dose based on the U.S. Army data. They have individual dosimetry – those individual doses. The leukemia excess cases appear like this depends on the dose they were exposed [to]. This is not a linear curve, but we call it “carotid curve.”

This is a curve for whole throat cancers, different from leukemia. This curve is linear. We don’t know yet why the leukemia curve and the cancer curve are different. Maybe some difference in the mechanism of cancer induction at the molecular level, at the gene level.

Recently, we are facing a very dangerous situation. It is a multi-cancer occurrence among short distance survivors. This is almost three times higher among 1.5-kilometer, shorter [distance] survivors. In my hospital, Atom Bomb Hospital, this is the present situation still in 2018.

This is a second type of leukemia called myelodysplasia syndrome. This is basically showing linear response curves. So quite different from the first leukemia data. Maybe some difference in leukemogenesis after almost 70 years, more than half a century. So there are still unsolved problems to understand how radiation induced leukemia and cancers in human bodies.

We specialists must explain why the atomic bomb radiation’s effect is such a long-lasting one. We are now trying to explain. There are stem cells in our organs. Stem cells can continue to live whole human lives and produce mature functioning organ cells. Please consider bone marrow. Bone marrow has stem cells. They are providing mature red cells, white cells, and platelets. Those stem cells might be irradiated in 1945 and recovered once for almost an entire life of a survivor, but still they are carrying damage induced by radiation. Someday, this induces stem cell changes into cancer stem cells. This is our hypothesis now. I believe this may be true.

Actually, we can sometimes observe chromosome damage in the white cells and the red cells. The same chromosome abnormalities between two different cells, but this means the stem cells common to these white cells and red cells might have been directly hit by atomic bomb radiation. These chromosome aberrations go up linearly. Cancer and leukemia radiation dose is higher. The cytogenetic abnormalities, chromosome abnormalities, right, go up. Here, see atomic bomb survivors have white cells and red cells carrying chromosome abnormalities, even now, even now, after 70 years.

In addition to body effect, we have long seen psychological damage to survivors. This young lady who was one of seven brothers and sisters. Only she survived. Her keloid formation, her face, and the skin look fairly well now, but these are not real, normal skin, scars. By using the WHO [World Health Organization] General Health Questionnaire, we found dose-dependent increase of depression and PTSD [Post-Traumatic Stress Disorder], posttraumatic stress disease. The rate increases, like this.

In conclusion, the atomic bombs are gene-targeting weapons. The radiation immediately causes DNA damage that causes immediate deaths and also later  induces leukemia, cancers during survivors’ entire lives. The psychological effect is also long-lasting and profound.

My next part of [my] talk is if a 16-kiloton, Hiroshima-sized bomb were detonated on the modern city at the present time, how many deaths and cancers, leukemia, we would observe. This is a simulation study recently done by Hiroshima and Nagasaki specialists. This was a study planned by the Japanese Ministry of Foreign Affairs three years ago.

Copyright 2019 The Atomic Heritage Foundation. This transcript may not be quoted, reproduced, or redistributed in whole or in part by any means except with the written permission of the Atomic Heritage Foundation.