Japan History Lab

Unit 731: The Truth, the Experiments, the Significance.

By Gina Kwon

The Truth

Compared to the Nazi human experiments in their concentration camps, Japan’s history of human experimentation by Unit 731, is not well known. The history of Unit 731 is significant since many biological weaponry breakthroughs were discovered due to the experiments conducted under Doctor Shiro Ishii. This research paper will primarily focus on how the Shiro Ishii and his unit gathered information on biological weapons through experiments done on POWs, and the significance of the formation of Japan’s Unit 731. However, the life of a POW in Unit 731 was completely divorced from regular civilian daily life, which made writing this paper difficult due to the lack of information on the daily life of a POW. POWs who have survived do not know the exact aspects of the experiments done on them during their time in Unit 731, making it challenging to find solid evidence to what was afflicted on them. Therefore, while this paper will endeavor to describe the daily ordeals a POW faced during their period in Unit 731 and bring a tighter focus on the involvement of the U.S army, who covered up the atrocities of Unit 731, the exact details on the daily lives of POW are still unknown.

Shiro Ishii

Shiro Ishii

Shiro Ishii 1

Shiro Ishii was the mastermind of Unit 731, a military surgeon with connection among the right Japanese of high social ranking.2(pg2) Shiro Ishii was blessed with intellect and good physique, being unusually tall for a Japanese person. His childhood was detached as he received gifts of tribute among his fellow classmates, which was an effort on their part to gain the favour of his wealthy family. Put on a pedestal by his family and teachers, Ishii believed the world existed to serve him.2(pg6) According to Mark Felton, he “lacked empathy towards his fellow human beings.”3(pg13) However, Shiro Ishii was aware of his social standing; he understood the importance of social and career climbing. He was unashamed in begging for funds and prone to corruption and embezzlement.2(pg9) Initially, Shiro Ishii’s efforts to get funding from the government were largely ignored; the military wished to abide by the Geneva Protocol, although Japan signed the protocol, they did not ratify it.2(pg4) Despite the reluctance of the military, Ishii was convinced the role of biological weapons to be crucial to strategies and tactics. He reasoned that Japan should quickly develop biological weapons to give the nation an unbeatable lead over others. Ishii regarded biological weapons as the centerpiece of Japan’s strategies; it would give Japan a military edge over other nations, especially over the feared Soviets. With Ishii doggedly begging for funding, he finally persuaded the Kwantung Army to fund his research.3(pg11)

Unit 731

In 1932, the Kwantung Army provided Ishii enough funds to set up a biological weapons research facility- the Epidemic Prevention Unit, also known as Unit 731.2(pg22) Ishii’s first facility was located in Harbin, but the unit later expanded to other rural areas of Manchuria. Most facilities were located in strategic areas; Beiyinhe was chosen for the similarity of its climate to the areas near Soviet borders. In the article written by SStephens contains information on Unit 731, which expands on each division and their specific goal towards their experiments, such as developing biological weapons geared towards the Soviets. The Kwangtung Army saw the Soviet Union as their greatest enemy and wanted to push the Soviets back, expanding Japan’s boundaries.3(pg15) The Japanese developed small biological weaponry in the form of flea-infested mice from the natural plague area along the Manchurian-Soviet border.4(pg27) Specifically thinking of using the biological weapons against the Soviets, three prisoners were injected to test how effective the diseased fleas were. In efforts to understand the effects of the fleas the three prisoners were dissected while they were unconscious and delirious from their fevers.4(pg27)

Harbin Facility of Unit 731

Harbin facility of Unit 731 5

Living Conditions, Treatment and their Daily Life

After the construction of Unit 731’s facilities, human experimentation began in earnest. At first, the prisoners shipped to the unit were political prisoners, resistance members of anti-Japanese groups, or common criminals.4(pg28) Ishii was particular about his test subjects, therefore he wished for healthy men under the age forty, in order to have optimum control over the health variables in the experiment.2(pg28) However, as the facility became more engaged in their research, there was always a lack of human fodder. Civilians of all ages and sex living in the vicinity of the facility were lured into the facility, with promises of employment.6(pg35) Throughout the war, POWs were transported to the Mukden facility of Unit 731. The living conditions of the facility consisted of small cells, occupied by one or multiple prisoners, which included a flush toilet. 3(pg29) Cleanliness was essential to Ishii and his scientists since they needed their subjects to be uncontaminated and healthy. The building had central heating and cooling systems to maintain ample living conditions to subjects.3(pg29) The subjects had scheduled time to exercise in an exercise room.2(pg28) Prisoners were shackled and locked in their cells but the staff routinely checked the health of each prisoner.4(pg26) Physical health wise, a prisoner’s health was better than a regular civilian’s health in the surrounding areas of the facilities.

While the daily diet of the residents in the surrounding towns consisted of small steamed dumplings and a handful of pickled vegetables, 4(pg38) the POW’s diet consisted of well-balanced and nutritious meals.2(pg28) Major Peaty, a British POW in the Mukden facility, recorded what the scientists did to him and what he and his fellow POW were fed. He wrote, “treatment is fairly satisfactory” describing how each POWs were subjected to regular rectal examinations, which he believed to be health checks.3(pg80,84) Peaty records on 5 April 1943 “we estimate that we are receiving between 2,800 and 3,000 calories”,3(pg55) and on 14 Jun 1943 “Rations have improved. We are getting potatoes and fish in reasonable quantities, giving us about 3,000 calories.”3(pg56) It is noted, while Major Peaty was not a doctor, there were US doctors present, such as Major Kankins and Mark Herbst, who calculated the daily calorie intake.3(pg55) On 24 February 1943, Major Peaty meticulously recorded the funeral service for 186 American POWs who died within 105 days of arriving at the facility. 3(pg57)

Electric Shock Experiments

Unit 731 Scientists experimenting shock currents on a victim 7

The staff treated the POWs relatively humanely as they refrained from torture.8(pg76) However, almost all the victims of the experiments died in agony. The death tolls are contributed by the experiments the scientists of Unit 731 would inflict upon the POWs. Despite Major Peaty’s thoughts of the POWs’ treatment, the scientists treated victims as mere tools to satisfy their curiosity and to achieve their goals of developing biological weapons. While some POWs, such as Major Peaty would be ignorant to what is happening to other POWs and the civilians the unit had captured, the daily life of these prisoners were instilled with fear. Scientists injected prisoners with deadly diseases and observed the result. Unit 731’s experiments involving Chinese POWs and civilians have no known survivors of the experiments; those who survived the experiments were killed and studied.9(pg221) The experiments consisted of studies never done before, such as; injecting horse urine in the prisoners’ kidneys or blood transfusions with the horse urine,*2(pg40) taking large amounts of blood daily to see the effects of a progressive wasting disorder, and air pressure tests.2(pg29) There are also records of Iwanami Hiroshi, the Commanding Officer of Fourth Navel Hospital on Dublon Island, requesting eight American soldiers to experiment on. These experiments consisted of shock experiments and injection of streptococcus bacteria, which cased blood poisoning; among the eight, two survived. The two surviving soldiers were strangled to death and sent to be dissected; the hearts and organs were removed and placed in bottles. Iwanami also confessed to sending specimens of the soldiers to Tokyo by cutting of four of the soldiers’ heads and boiling them; however, there is no record of where and why the specimens were sent to Tokyo.10(pg37-38) Some more grotesque tests were the removal of organs with the victims still alive without anesthetics, or studies on methods of murder, such as striking the head with an axe and removing the brain, regardless of whether the victim was still alive, to observe the effects.10(pg30) There were also tests on how victims handle close range bomb detonations, either with or without pathogens, and afterwards dissect the victim to study the effects.*2(pg40) Women were not exempted from these tests, as there are records of prisoners of both sexes forced to have sex with each other, after one prisoner had been infected with syphilis.11(pg55) If the women, who were forced to engage in sexual intercourse, become pregnant the infant would be delivered by the doctors and then dissected and killed along with their mothers.11(pg56) In other tests the scientists used women as subjects for scientific education.11(pg33)

``We removed some of the organs and amputated legs and arms. Two of the victims were young women, 18 or 19 years old. I hesitate to say it but we opened up their wombs to show the younger soldiers. They knew little about women – it was sex education. `` 3(pg1)
[To get more information on the scientists of Unit 731, Sarah Stephens' article "Unit 731: The Side of the Scientist " contains information on the daily life of scientists in Unit 731.

After the discovery of Unit 731 in Beiyinhe, Shiro Ishii ordered the facilities there to be destroyed to ensure that his activities remained a secret and built another in Harbin. The facility was demolished through explosions and the remaining survivors were killed to prevent them from revealing the horrors they endured.4(pg30) Evidently, the life of a POW in Unit 731 was a short one. Despite vague information on the account of POWs of Unit 731, torture and cruelty was a certain feature of the daily life.


General Douglas MacArthur 12

The Significance

The significance of the formation of Unit 731 is an important factor to note. After the war ended Unit 731 seemingly vanished. There was no uproar compared to the reaction to the discovery of human experimentation in Nazi Germany. The Japanese government in 2001 only formerly recognized the reality of the things done in Unit 731.13 When the truth about Japan’s Unit 731 was revealed to the public, there was an outrage. However, it is hard to believe that American military intelligence knew nothing about the human experimentation. In 1945, the United States occupied Japan under General Douglas MacArthur. 3(pg127) When MacArthur had learned of the existence of the facilities, Lt. Colonel Murray Sanders, a highly qualified bacteriologist who served the US Chemical Warfare Service,6(pg121) was sent to investigate the Japanese biological warfare program. Although, MacArthur received manuscripts proving the truth of Japanese human experiments he did not understand the full extent of the experiments, MacArthur wanted to obtain the information concerning biological weaponry.3(pg128) The data was invaluable to whoever attained it. Researchers of the American biological weaponry division lacked information on how to deliver the diseases; the Japanese had information on how to make carriers so fleas and small animals can carry disease and plagues without killing the carriers.6(pg29) The American scientists also had limited field-testing experiments; the Japanese had ample results due to Unit 731’s raids in China.4(pg68) The field experiments done by the Japanese proved that plague fleas’ could disrupt Chinese lines of communication; they also had positive results in attempt to cause a small epidemic that claimed twenty-four lives by spraying plague fleas by

Operation Fugo was a large balloon that carried the biological agents from Unit 731 to Chinese fields as an experiment

Operation Fugo was a large balloon that carried the biological agents from Unit 731 to Chinese fields as an experiment14

aircraft.6(pg68) All the research material the Japanese scientists carried was essential for the American biological weapon development unit, while the American scientists were unable to experiment on humans; they were allowed to obtain data through other parties. Despite clear violations of human rights, MacArthur had to negotiate with the escaped Unit 731 doctors, granting them immunity from prosecution, in return of the data.3(pg128) The negotiations were the product of the belief that “ethics must be subordinate to the demands of war." 9(pg227) Not only was the immunity the result of lack of ethics in war, but the Japanese assurance that there were survivors of Unit 731 and the suggestion that the Soviets had also traded immunity for access to the data.9(pg226-227) The Americans and the Soviets were in the initial stages of the Cold War, understanding the Soviets also had information pertaining biological weapons made the Americans to prioritize national security over human rights, which includes moral blindness.9(pg228) Nonetheless, granting full immunity despite the death tolls of their countrymen, the Americans turned a blind eye to the Japanese experiments.

Through the understanding of Shiro Ishii’s motivation and desire for biological weapons, it is apparent how Unit 731 was his brainchild. As Shiro Ishii directed Unit 731 and his small empire of scientists, he succeeded in several breakthroughs concerning biological weaponry and their uses. Field experiments in China brought back positive results, which pleased high placed officials in Japan who also believed biological weapons to be the greatest secret weapon of Japan. The American cover-up displays how important the data on the biological weapons to the Americans, despite the thousand American POWs killed during the experiments. The significance of the negotiations brought American scientists data tested on humans, instead of animals.4(pg191) Despite the deaths of the POW, it’s undeniable that the American military saw value in the information obtained knowing that the investigation had “greatly supplemented and amplified previous aspects of [the biological weaponry] field.”4(pg206) By killing thousands of POWs and civilians, Shiro Ishii achieved great amounts of data on the human anatomy and on the development of biological weapons. Through successful negotiations with the U.S, Shiro Ishii and several doctors were released with no qualms. Justice was denied for the thousands of POWs and civilians who were experimented on without any consideration to their rights as human beings.