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World War II-Japan
-In December 1941, Japan attacked American and British territories. -With near-simultaneous offensives against Southeast Asia and the Central Pacific including an attack on the US fleet at Pearl Harbor.
-The refusal of Japan to surrender on the United States terms, the United States dropped the first atomic bombs on the Japanese cities of Hiroshima, on 6 August 1945. -
Manhantten Project
-President Franklin D. Roosevelt authorized the formation of the Manhattan Project to bring together various scientists and military officials working on nuclear research.
-The Manhattan Project was the code name for the American-led effort to develop a functional atomic bomb during World War II.
-Much of the work in the Manhattan Project was performed in Los Alamos, New Mexico, under the direction of theoretical physicist J. Robert Oppenheimer, “father of the atomic bomb. -
Japan Prepares To Be Attacked
-To protect children from air raids, the government moved schoolchildren living in urban areas out to the countryside.
-Students in the third through sixth grades at national elementary schools were evacuated to seven counties in Hiroshima Prefecture: Futami, Yamagata, Asa, Takata, Saeki, Hiba and Sera.
-Evacuated children were forced to live in temples and inns away from their families.
-Many of these children would never be reunited with their families. -
U.S. Bomb Testing
-U.S. scientists worked on producing the key materials for nuclear fission—uranium-235 and plutonium (Pu-239).
-U.S. scientists working on the Manhattan Project successfully detonated the first-ever nuclear explosion in the ‘Trinity’ test at Alamogordo, New Mexico.
- A crater of fused soil, also known as “Trinite” radiates from ground zero.
-It created an enormous mushroom cloud some 40,000 feet high and ushered in the Atomic Age. -
Bomb dropped on Hiroshima
-8:15 AM the bomb, Little Boy was dropped at the Centre of Hiroshima.
-Forty-three seconds later, a huge explosion lit the morning sky detonated 9,700-pound uranium gun-type bomb detonated 1,900 feet above Hiroshima
-Extreme heat and pressure blast accompanied by a strong burst of gamma radiation and a more limited burst of neutrons.
-The explosion immediately killed an estimated 80,000 people; tens of thousands more would later die of radiation exposure,between 90,000 and 166,000. -
Immediate Aftermath
-Most of those located within 1.5 km of the hypocenter were killed.
-People experienced severe radiation burns, some so severe that they died soon after the bomb. Their skin was melted off, hanging off their bodies.
-Buildings that were mostly wood caught fire and burned for 3 days.
-Huge cloud of smoke and black rain hung over Hiroshima.
-Black rain containing radioactive materials lasted for days, causing health problems. -
Evacuation Post Bombing
-Families in Hiroshima were advised to leave.
-Many children without their families.
-Symptoms of radiation poisoning began
-These included hair loss, bleeding gums, loss of energy, purple spots, pain, and high fevers, often resulting in fatalities. -
Japan Surrenders
-In the early hours of August 15, a military coup was attempted by a faction led by Major Kenji Hatanaka, to keep Japan from surrendering.
-Aboard the USS Missouri in Tokyo Bay, Japan formally surrenders to the Allies, bringing an end to World War II.
-General Douglas MacArthur issued an occupation press code, restricting Japanese journalists from reporting on anything related to the bombings or the effects of radiation, and limiting foreign journalists. -
Survivor Cohorts
-Cohorts of survivors-those exposed in utero & children conceived after parental exposure were established to investigate late health effects of atomic bomb radiation & its transgenerational effects.
-Includes both a large proportion of survivors who were within 2.5 km & a similar-sized sample of survivors who were between 3 & 10 km from the hypocenters.
-Long follow-up period(1950–2000),includes both sexes & all ages at exposure,allowing a direct comparison of risks by these factors. -
The1996 Comprehensive Nuclear-Test-Ban Treaty
-Multilateral treaty that bans nuclear tests,for both civilian & military purposes,in all environments.
-It was adopted by the United Nations General Assembly on September 10,1996, but has not entered into force, as eight specific nations have not ratified the treaty.
-Geophysical & other technologies are used to monitor for compliance with the Treaty:forensic seismology, hydroacoustics, infrasound & radionuclide monitoring.
-3 countries have tested nuclear weapons:India, Pakistan & North Korea.
