The After-Effects of The Atomic Bombs on Hiroshima & Nagasaki
December 29, 2011 92 Comments
On August 6, 1945, an American B-29 bomber named the Enola Gay left the island of Tinian for Hiroshima, Japan. This section recounts the first atomic bombing.
Hiroshima was chosen as the primary target since it had remained largely untouched by bombing raids, and the bomb’s effects could be clearly measured. While President Truman had hoped for a purely military target, some advisers believed that bombing an urban area might break the fighting will of the Japanese people. Hiroshima was a major port and a military headquarters, and therefore a strategic target. Also, visual bombing, rather than radar, would be used so that photographs of the damage could be taken. Since Hiroshima had not been seriously harmed by bombing raids, these photographs could present a fairly clear picture of the bomb’s damage.
A T-shaped bridge at the junction of the Honkawa and Motoyasu rivers near downtown Hiroshima was the target. At 8:15 a.m., Little Boy exploded, instantly killing 80,000 to 140,000 people and seriously injuring 100,000 more. The bomb exploded some 1,900 feet above the center of the city, over Shima Surgical Hospital, some 70 yards southeast of the Industrial Promotional Hall (now known as the Atomic Bomb Dome). Crewmembers of the Enola Gay saw a column of smoke rising fast and intense fires springing up. The burst temperature was estimated to reach over a million degrees Celsius, which ignited the surrounding air, forming a fireball some 840 feet in diameter. Eyewitnesses more than 5 miles away said its brightness exceeded the sun tenfold.
In less than one second, the fireball had expanded to 900 feet. The blast wave shattered windows for a distance of ten miles and was felt as far away as 37 miles. Over two-thirds of Hiroshima’s buildings were demolished. The hundreds of fires, ignited by the thermal pulse, combined to produce a firestorm that had incinerated everything within about 4.4 miles of ground zero.
To the crew of the Enola Gay, Hiroshima had disappeared under a thick, churning foam of flames and smoke. The co-pilot, Captain Robert Lewis, commented, “My God, what have we done?”
About 30 minutes after the explosion, a heavy rain began falling in areas to the northwest of the city. This “black rain” was full of dirt, dust, soot and highly radioactive particles that were sucked up into the air at the time of the explosion and during the fire. It caused contamination even in areas that were remote from the explosion.
Radio stations went off the air, and the main line telegraph had stopped working just north of Hiroshima. Chaotic reports of a horrific explosion came from several railway stops close to the city and were transmitted to the Headquarters of the Japanese General Staff. Military headquarters personnel tried to contact the Army Control Station in Hiroshima and were met with complete silence. The Japanese were puzzled. They knew that no large enemy raid could have occurred, and no sizeable store of explosives was in Hiroshima at that time, yet terrible rumors were starting.
A young officer of the Japanese General Staff was instructed to fly immediately to Hiroshima, to land, survey the damage and return to Tokyo with reliable information for the staff. Headquarters doubted that anything serious had occurred, but the rumors were building. When the staff officer in his plane was nearly 100 miles (160 km) from Hiroshima, he and his pilot noticed a huge cloud of smoke from the bomb. In the bright afternoon, the remains of Hiroshima were burning.
The plane soon reached the city and circled it. A great scar on the land was still burning, covered by a heavy cloud of smoke. They landed south of Hiroshima, and the staff officer immediately began to organize relief measures, after reporting to Tokyo.
On August 9, 1945, another American B-29 bomber, Bock’s Car, left Tinian carrying Fat Man, a plutonium implosion-type bomb. The primary target was the Kokura Arsenal, but upon reaching the target, they found that it was covered by a heavy ground haze and smoke. This section recounts the atomic bombing of Nagasaki, Japan.
Like Hiroshima, the immediate aftermath in Nagasaki was a nightmare. More than forty percent of the city was destroyed. Major hospitals had been utterly flattened and care for the injured was impossible. Schools, churches, and homes had simply disappeared. Transportation was impossible.
Many of the survivors—Hibakusha—have recorded their memories of those days.
Fujie Urata Matsumoto, relates this scene: “The pumpkin field in front of the house was blown clean. Nothing was left of the whole thick crop, except that in place of the pumpkins there was a woman’s head. I looked at the face to see if I knew her. It was a woman of about forty. She must have been from another part of town – I had never seen her around here. A gold tooth gleamed in the wide-open mouth. A handful of singed hair hung down from the left temple over her cheek, dangling in her mouth. Her eyelids were drawn up, showing black holes where the eyes had been burned out…She had probably looked square into the flash and gotten her eyeballs burned.”
Kayano Nagai remembers “I saw the atom bomb. I was four then. I remember the cicadas chirping. The atom bomb was the last thing that happened in the war and no more bad things have happened since then, but I don’t have my Mummy any more. So even if it isn’t bad any more, I’m not happy.”
Two years after the bombing plants growing at ground zero presaged the frightening genetic aberrations in humans that were to come: sesame stalks produced 33 percent more seeds but 90 percent of them were sterile. For decades abnormally high amounts of cancer, birth defects, and tumors haunted victims.
Both Hiroshima and Nagasaki have memorialized the events of August, 1945 with museums, sculpture, peace ceremonies, and parks. They want no one to forget.
The Nagasaki Atomic Bomb Museum states, “The question of how to inform young people about the horror of war, the threat of nuclear weapons and the importance of the peace is therefore a matter of passing concern. The citizens of Nagasaki pray that this miserable experience will never be repeated on Earth. We also consider it our duty to ensure that the experience is not forgotten but passed on intact to future generations.
It is imperative that we join hands with all peace-loving people around the world and strive together for the realization of lasting world peace.”
Today, Nagasaki is a busy, industrial city with a population of almost 500,000. The Mitsubishi plant, so complete
Hiroshima was in ruins. The T-bridge’s barriers had been knocked awry; utility poles stood at odd angles, and familiar landmarks were gone or unrecognizable. Buildings—even strong modern structures—had suffered significant damage, some pushed off their foundations, some gutted by fire, others utterly destroyed. Many steel and concrete buildings appeared intact at first glance, but their outer walls hid internal damage due to the downward pressure of the air burst. Cemeteries were uprooted, and churches had become rubble.
In the late 1950’s, psychologists in Hiroshima and Nagasaki reported increased complaints among survivors of neurotic symptoms, including general fatigue, amnesia, and lack of concentration…After surveys were given to survivors. Additional symptoms included, “…recalling the occurrence and becoming upset, experiencing an increased sense of unresponsiveness and immobility, and feeling guilt and discouragement”
PTSD (Post Traumatic Stress Disorder) symptoms include: nightmares, flashbacks, intense anxiety, feeling numb, anger and irritability, insomnia, having trouble concentrating, depression, suicidal thoughts
The survivors, known as hibakusha, sought relief from their injuries. However, 90 percent of all medical personnel were killed or disabled, and the remaining medical supplies quickly ran out. Many survivors began to notice the effects of exposure to the bomb’s radiation. Their symptoms ranged from nausea, bleeding and loss of hair, to death. Flash burns, a susceptibility to leukemia, cataracts and malignant tumors were some of the other effects.
-Cancer, especially leukemia and lymphoma
–Small brain size
–Also, NOT in babies (ie. those already alive when the bomb was dropped): Horrible scarring; increase in breast cancer in women and men; thyroid problems; hair loss; diarrhea.
Hair loss caused by exposure to radiation.
- Radiation exposure might have caused 421 excess cancers. Of the 17 types of cancers considered, survivors suffered excesses in 16
- Studies on 1600 children who were irradiated while they were in their mother’s womb during the atomic bomb explosions in the two cities revealed that 30 of them suffered clinically severe mental retardation.
- Studies of children born to mothers who received whole-body radiation doses of between 50 and 100 rad following the Japanese atomic bombing showed that the children had an increased risk for small brain size and mental retardation. This was especially true for those women who were eight to 15 weeks pregnant at the time of exposure. Compared with non-exposed children, children exposed to whole-body radiation doses during this period before birth had lower intelligence test scores and performed less well in school.
- Some estimates state up to 200,000 had died by 1950, due to cancer and other long-term effects. From 1950 to 1990, roughly 9% of the cancer and leukemia deaths among bomb survivors was due to radiation from the bomb.
Meet the bombs:
1. Little Boy:
In essence, the Little Boy design consisted of a gun that fired one mass of uranium 235 at another mass of uranium 235, thus creating a supercritical mass. A crucial requirement was that the pieces be brought together in a time shorter than the time between spontaneous fissions. Once the two pieces of uranium are brought together, the initiator introduces a burst of neutrons and the chain reaction begins, continuing until the energy released becomes so great that the bomb simply blows itself apart.
2. Fat Man:
The rapid spontaneous fission rate of plutonium 239 necessitated that a different type of bomb be designed. A gun-type bomb would not be fast enough to work. Before the bomb could be assembled, a few stray neutrons would have been emitted, and these would start a premature chain reactionleading to a great reduction in the energy released.
Seth Neddermeyer, a scientist at Los Alamos, developed the idea of using explosive charges to compress a sphere of plutonium very rapidly to a density sufficient to make it go critical and produce a nuclear explosion.
|Length:||128.375 inches (10 feet 8 inches / 3.25 meters)|
|Diameter:||60.25 inches (5 feet / 1.5 meters)|
|Weight:||10,265 lbs (4,656 kg)|
|Yield:||21 kilotons (+/- 10%)|