Unit 731... and you thought the Nazi was the worst...

Unit 731 (731 部隊, Nana-san-ichi butai?) was a covert biological and chemical warfare research and development unit of the Imperial Japanese Army that undertook lethal human experimentation during the Second Sino-Japanese War (1937–1945) and World War II. It was responsible for some of the most notorious war crimes carried out by Japanese personnel. Officially known by the Imperial Japanese Army as the Kempeitai Political Department and Epidemic Prevention Research Laboratory, it was initially set up under the Kempeitai military police of the Empire of Japan to develop weapons of mass destruction for potential use against Chinese, and possibly Soviet forces.

Unit 731 was based in the Pingfang district of the city of Harbin in the puppet state of Manchukuo.
Shiro Ishii, commander of Unit 731More than ten thousand people, from which around 600 every year were provided by the kempeitai, were subjects of the experimentation conducted by Unit 731. These were both civilian and military of Chinese, Korean, Mongolian, and Russian origin. Some American and European Allied prisoners of war also died at the hands of Unit 731. In addition, the use of biological weapons researched in Unit 731's bioweapons and chemical weapons programs resulted in tens of thousands of military and civilian deaths in China – possibly as many as 200,000 casualties by some estimates.
Unit 731 was the headquarters of many subsidiary units used by the Japanese to research biological warfare; other units included Unit 516 (Qiqihar), Unit 543 (Hailar), Unit 773 (Songo unit), Unit 100 (Changchun), Unit Ei 1644 (Nanjing), Unit 1855 (Beijing), Unit 8604 (Guangzhou), Unit 200 (Manchuria) and Unit 9420 (Singapore).
Many of the scientists involved in Unit 731 went on to prominent careers in post-war politics, academia, business, and medicine. Some were arrested by Soviet forces and tried at the Khabarovsk War Crime Trials; others, who surrendered to the Americans, were granted amnesty in exchange for access to the data collected by them.
Because of their brutality, Unit 731's actions have now been declared by the United Nations to have been crimes against humanity.

A special project code-named Maruta used human beings for experiments. Test subjects were gathered from the surrounding population and were sometimes referred to euphemistically as "logs" (丸太, maruta?). This term originated as a joke on the part of the staff due to the fact that the official cover story for the facility given to the local authorities was that it was a lumber mill. The test subjects were selected to give a wide cross section of the population, and included common criminals, captured bandits and anti-Japanese partisans, political prisoners, and also people rounded up by the secret police for alleged "suspicious activities" and included infants, the elderly, and pregnant women.

Vivisection

Prisoners of war were subjected to vivisection without anesthesia. Vivisections were performed on prisoners after infecting them with various diseases. Scientists performed invasive surgery on prisoners, removing organs to study the effects of disease on the human body. These were conducted while the patients were alive because it was feared that the decomposition process would affect the results. The infected and vivisected prisoners included men, women, children, and infants.Vivisections were also performed on pregnant women, sometimes impregnated by doctors, and the fetus removed. Prisoners had limbs amputated in order to study blood loss. Those limbs that were removed were sometimes re-attached to the opposite sides of the body. Some prisoners' limbs were frozen and amputated, while others had limbs frozen then thawed to study the effects of the resultant untreated gangrene and rotting. Some prisoners had their stomachs surgically removed and the esophagus reattached to the intestines. Parts of the brain, lungs, liver, etc. were removed from some prisoners. In 2007, Doctor Ken Yuasa testified to the Japan Times that "I was afraid during my first vivisection, but the second time around, it was much easier. By the third time, I was willing to do it." He believes at least 1,000 persons, including surgeons, were involved in vivisections over mainland China.

Weapons testing

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  Human targets were used to test grenades positioned at various distances and in different positions.


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  Flame throwers were tested on humans.


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  Humans were tied to stakes and used as targets to test germ-releasing bombs, chemical weapons and explosive bombs.

Germ warfare attacks

Prisoners were injected with inoculations of disease, disguised as vaccinations, to study their effects. To study the effects of untreated venereal diseases, male and female prisoners were deliberately infected with syphilis and gonorrhea, then studied. Prisoners were infested with fleas in order to acquire large quantities of disease-carrying fleas for the purposes of studying the viability of germ warfare. Plague fleas, infected clothing, and infected supplies encased in bombs were dropped on various targets. The resulting cholera, anthrax, and plague were estimated to have killed around 200,000 Chinese civilians.Tularemia was tested on Chinese civilians. Unit 731 and its affiliated units (Unit 1644, Unit 100, et cetera) were actively involved not only in research and development, but also in experimental deployment of epidemic-creating biowarfare weapons in assaults against the Chinese populace (both civilian and military) throughout World War II. Plague-infested fleas, bred in the laboratories of Unit 731 and Unit 1644, were spread by low-flying airplanes upon Chinese cities, coastal Ningbo in 1940, and Changde, Hunan Province, in 1941. This military aerial spraying killed thousands of people with bubonic plague epidemics.

Other experiments

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  Prisoners were subjected to other experiments such as:
  being hung upside down to see how long it would take for them to choke to death.


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  having air injected into their arteries to determine the time until the onset of embolism.


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  having horse urine injected into their kidneys.


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  being deprived of food and water to determine the length of time until death.


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  being placed into high-pressure chambers until death. being exposed to extreme temperatures and developed frostbite to determine how long humans could survive with such an affliction, and to determine the effects of rotting and gangrene on human flesh.


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  having experiments performed upon prisoners to determine the relationship between temperature, burns, and human survival.


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  being placed into centrifuges and spun until dead.


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  having animal blood injected and the effects studied.


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  being exposed to lethal doses of x-ray radiation.


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  having various chemical weapons tested on prisoners inside gas chambers.


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  being injected with sea water to determine if it could be a substitute for saline.