Unit 731

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.

Unit 731 was the code name (tsūshōgō) of an Imperial Japanese Army unit officially known 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.

Description

Unit 731 was based at the Pingfang district of Harbin, the largest city in the Japanese puppet state of Manchukuo (now Northeast China).

Shiro Ishii, commander of Unit 731

More than ten thousand people, from which around 600 every year were provided by the Kempeitai, were subjects of the experimentation conducted by Unit 731.

More than 95 percent of the victims who died in the camp based in Pingfang were Chinese and Korean, including both civilian and military. The remaining 5 percent were South East Asians and Pacific Islanders, at the time colonies of the Empire of Japan, and a small number of the prisoners of war from the Allies of World War II.

According to the 2002 International Symposium on the Crimes of Bacteriological Warfare, the number of people killed by the Imperial Japanese Army germ warfare and human experiments is around 580,000. According to other sources, the use of biological weapons researched in Unit 731's bioweapons and chemical weapons programs resulted in possibly as many as 200,000 deaths of military personnel and civilians in China.

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 surrendered to the American Forces.

On 6 May 1947, Douglas MacArthur, as Supreme Commander of the Allied Forces, wrote to Washington that "additional data, possibly some statements from Ishii probably can be obtained by informing Japanese involved that information will be retained in intelligence channels and will not be employed as 'War Crimes' evidence." The deal was concluded in 1948.

Because of their brutality, Unit 731's actions have since been declared by the United Nations to have been crimes against humanity.

Formation

In 1932, General Shiro Ishii (石井四郎 Ishii Shirō), chief medical officer of the Japanese Army and protégé of Army Minister Sadao Araki was placed in command of the Army Epidemic Prevention Research Laboratory. He and his men built the Zhong Ma Prison Camp (whose main building was known locally as the Zhongma Fortress), a prison/experimentation camp in Beiyinhe, a village 100 kilometers south of Harbin on the South Manchurian Railway.

Ishii organized a secret research group, the "Togo Unit", for the conduct of various chemical and biological investigations. A jailbreak and later explosion (believed to be an attack) in 1935 led Ishii to shut down Zhongma Fortress. He moved to Pingfang, approximately 24 kilometers south of Harbin, to set up a new and much larger facility.

In 1936, Hirohito authorized, by imperial decree, the expansion of this unit and its integration into the Kwantung Army as the Epidemic Prevention Department. It was divided at the same time into the "Ishii Unit" and "Wakamatsu Unit" with a base in Hsinking. From August 1940, all these units were known collectively as the "Epidemic Prevention and Water Purification Department of the Kwantung Army (関東軍防疫給水部本部)" or "Unit 731" (満州第731部隊) for short.

Activities

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". They 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 people, including surgeons, were involved in vivisections over mainland China.

Weapons testing

• Human targets were used to test grenades positioned at various distances and in different positions.
• Flame throwers were tested on humans.
• 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 400,000 Chinese civilians.
• Tularemia was tested on Chinese civilians.
• Unit 731 and its affiliated units (Unit 1644, Unit 100, et cetera) were involved in research, development, and 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

Prisoners were subjected to other torturous experiments such as:

• being hung upside down to see how long it would take for them to choke to death.
• having air injected into their arteries to determine the time until the onset of embolism.
• having horse urine injected into their kidneys.
• being deprived of food and water to determine the length of time until death.
• being placed into high-pressure chambers until death.
• being exposed to extreme temperatures and developing frostbite to determine how long humans could survive with such an affliction, and to determine the effects of rotting and gangrene on human flesh.
• having experiments performed upon prisoners to determine the relationship between temperature, burns, and human survival.
• being placed into centrifuges and spun until dead.
• having animal blood injected and the effects studied.
• being exposed to lethal doses of x-rays.
• having various chemical weapons tested on prisoners inside gas chambers.
• being injected with sea water to determine if it could be a substitute for saline.
• being buried alive.

Biological warfare

Japanese scientists performed tests on prisoners with plague, cholera, smallpox, botulism, and other diseases. This research led to the development of the defoliation bacilli bomb and the flea bomb used to spread the bubonic plague. Some of these bombs were designed with ceramic (porcelain) shells, an idea proposed by Ishii in 1938.

These bombs enabled Japanese soldiers to launch biological attacks, infecting agriculture, reservoirs, wells, and other areas with anthrax, plague-carrier fleas, typhoid, dysentery, cholera, and other deadly pathogens. During biological bomb experiments, scientists dressed in protective suits would examine the dying victims. Infected food supplies and clothing were dropped by airplane into areas of China not occupied by Japanese forces. In addition, poisoned food and candies were given out to unsuspecting victims and children, and the results examined.

Known Unit members

• Lieutenant General Shiro Ishii
• Lieutenant Colonel Ryoichi Naito
• Dr. Masaji Kitano
• Yoshio Shinozuka
• Yasuji Kaneko

Divisions

Unit 731 was divided into eight divisions:

• Division 1: Research on bubonic plague, cholera, anthrax, typhoid and tuberculosis using live human subjects. For this purpose, a prison was constructed to contain around three to four hundred people.
• Division 2: Research for biological weapons used in the field, in particular the production of devices to spread germs and parasites.
• Division 3: Production of shells containing biological agents. Stationed in Harbin.
• Division 4: Production of other miscellaneous agents.
• Division 5: Training of personnel.
• Divisions 6–8: Equipment, medical and administrative units.

Facilities

One of the buildings is open to visitors

The Unit 731 complex covered six square kilometers and consisted of more than 150 buildings. The design of the facilities made them hard to destroy by bombing. The complex contained various factories. It had around 4,500 containers to be used to raise fleas, 6 cauldrons to produce various chemicals, and around 1,800 containers to produce biological agents. Approximately 30 kg of bubonic plague bacteria could be produced in several days.

Some of Unit 731's satellite facilities are in use by various Chinese industrial concerns. A portion has been preserved and is open to visitors as a War Crimes Museum.

Tons of biological weapons (and some chemicals) were stored in various places in northeastern China throughout the war. The Japanese attempted to destroy evidence of the facilities after disbanding. 29 people were hospitalized in August, 2003 after a construction crew in Heilongjiang inadvertently dug up chemical shells that had been buried deep in the soil more than 50 years before.

Anta testing site

This site was an open air testing area about 120 km from the Pingfang facility.

Hsinking (Changchun) HQ

Headquarters of "Wakamatsu Unit" (Unit 100), under command of veterinarian Wakamatsu Yujiro. This facility dedicated itself to both the study of animal vaccines to protect Japanese resources, and, especially, veterinary biological-warfare. Diseases were tested for use against the Soviet and Chinese horses and other livestock. In addition to these tests, Unit 100 ran a bacteria factory to produce the pathogens needed by other units. Biological sabotage testing was also handled at this facility: everything from poisons to chemical crop destruction.

Peking (Peiping) HQ

This HQ served as the headquarters of Unit 1855. It was also an experimental branch unit based at Tsinan, Shantung. Pandemic diseases were extensively studied at this facility.

Nanking HQ

This section was the headquarters of the "Tama Unit" (Unit Ei 1644) and conducted extensive joint projects and operations with Unit 731.

Kwangtung (Canton) HQ

The headquarters of the "Nami Unit" (Unit 8604). This installation conducted human experimentation in food and water deprivation as well as water-borne typhus. In addition, this facility served as the main rat-farm for the medical units to provide them with bubonic plague vectors for experiments.

Syonan (Singapore) HQ

Formed in 1942, by Ryoichi Naito, Unit 9420 had approximately 1000 personnel based at the Raffles Medical University. The unit was commanded by Major General Kitagawa Masataka and supported by the Japanese Southern Army Headquarters.

There were two main sub units: the "Kono Unit," which specialized in malaria, and "Umeoka Unit," which dealt with the plague. In addition to disease experiments, this facility served as one of the main rat catching and processing centers. Evidence points towards this facility supplying a medical sub-unit operating in Thailand, with diseases for unknown operations and or experiments.

Hiroshima HQ

A top secret factory in Ōkunoshima produced chemical weapons for the Japanese military and medical units. Starting with mustard gas production in 1928, the factory moved on to such poisons as Lewisite, and Cyanogen. During the 1930s, as the war in China grew worse, the island the factory sat on was removed from most maps to strengthen secrecy and security.

Manchuria HQ (Unit 200)

This unit was associated directly with Unit 731, and worked mainly in plague research.

Manchuria HQ (Unit 571)

This section, with unknown headquarters, was another unit that worked directly and extensively with Unit 731.

Special Mobile Teams

Special units led by Ishii Shiro's elder brother and only staffed with members from Ishii's home town operated separately from the regular medical organizations as roving researchers and trouble shooters.

Special Operations units

Units with special and unknown assignments in Manchuria and the Asian mainland. It has been suggested that nuclear weapons research was conducted in Manchuria towards the end of the war by this branch.

Disbanding and the end of World War II

Information sign at the site today.

Operations and experiments continued until the end of the war. Ishii had wanted to use biological weapons in the Pacific conflict since May 1944, but his attempts were repeatedly foiled by poor planning and Allied intervention.

With the Russian invasion of Manchukuo and Mengjiang in August 1945, the unit had to abandon their work in haste. The members and their families fled to Japan.

Ishii ordered every member of the group "to take the secret to the grave", threatening to find them if they failed, and prohibiting any of them from going into public work back in Japan. Potassium cyanide vials were issued for use in the event that the remaining personnel were captured.

Skeleton crews of Ishii's Japanese troops blew the compound up in the final days of the war to destroy evidence of their activities, but most were so well constructed that they survived somewhat intact as a testimony to what had happened there.

After Imperial Japan surrendered to the Allies in 1945, Douglas MacArthur became the Supreme Commander of the Allied Powers, rebuilding Japan during the Allied occupation. MacArthur secretly granted immunity to the physicians of Unit 731 in exchange for providing America with their research on biological warfare. American occupation authorities monitored the activities of former unit members, including reading and censoring their mail.

The United States believed that the research data was valuable. They had conducted small-scale human experimentation on their citizens but not on such a large scale, and not with prisoners of war. The U.S. did not want other nations, particularly the Soviet Union, to acquire data on biological weapons.

The Tokyo War Crimes Tribunal heard only one reference to Japanese experiments with "poisonous serums" on Chinese civilians. This took place in August 1946 and was instigated by David Sutton, assistant to the Chinese prosecutor. The Japanese defense counselor argued that the claim was vague and uncorroborated and it was dismissed by the tribunal president, Sir William Webb, for lack of evidence. The subject was not pursued further by Sutton, who was likely aware of Unit 731's activities. His reference to it at the trial is believed to have been accidental.

Although publicly silent on the issue at the Tokyo trials, the Soviet Union pursued the case and prosecuted twelve top military leaders and scientists from Unit 731 and its affiliated biological-war prisons Unit 1644 in Nanjing, and Unit 100 in Changchun, in the Khabarovsk War Crime Trials. Included among the prosecuted for war crimes including germ warfare was General Otozo Yamada, the commander-in-chief of the million-man Kwantung Army occupying Manchuria.

Many Russian civilians, including women and children, and Soviet POWs held by Japan were killed in chemical and biological warfare experiments by Unit 731, along with the Chinese people, American POWs, Russian and other nationalities. The trial of those captured Japanese perpetrators was held in Khabarovsk in December 1949.

A lengthy partial transcript of the trial proceedings was published in different languages the following year by a Moscow foreign languages press, including an English language edition: Materials on the Trial of Former Servicemen of the Japanese Army Charged with Manufacturing and Employing Bacteriological Weapons (Moscow: Foreign Languages Publishing House, 1950). (French language: Documents relatifs au procès des anciens Militaires de l'Armée Japonaise accusés d'avoir préparé et employé l'Arme Bactériologique / Japanese language: 細菌戦用兵器ノ準備及ビ使用ノ廉デ起訴サレタ元日本軍軍人ノ事件ニ関スル公判書類 / Chinese language: 前日本陸軍軍人因準備和使用細菌武器被控案審判材料)

This book remains an invaluable resource for historians on the organization and activities of the Japanese biological warfare "death factory" lab-prisons. The lead prosecuting attorney at the Khabarovsk trial was Lev Smirnov, who had been one of the top Soviet prosecutors at the Nuremberg Trials.

After World War II, the Soviet Union built a biological weapons facility in Sverdlovsk using documentation captured from Unit 731 in Manchuria.

The Japanese doctors and army commanders who had perpetrated the Unit 731 atrocities and germ warfare experiments received sentences from the Khabarovsk court ranging from two to 25 years in a Siberian labor camp.

Some former members of Unit 731 became part of the Japanese medical establishment. Dr. Masaji Kitano led Japan's largest pharmaceutical company, the Green Cross. Others headed U.S.-backed medical schools or worked for the Japanese health ministry. Shiro Ishii in particular moved to Maryland to work on bio-weapons research.

In popular culture

• Japanese author Morimura Seiichi published the book The Devil's Gluttony (悪魔の飽食) in 1981, followed by The Devil's Gluttony: A Sequel in 1983, which were the first Japanese language publications to reveal the history of Unit 731 in Japan.
• The Chinese movie "Hei tai yang 731" Men Behind the Sun, directed by Tun Fei Mou (1988), is a graphic film about the atrocities committed by Unit 731, as is the Russian film Philosophy of a Knife, directed by Andrey Iskanov and released in 2008.
• Japanese director Minoru Matsui's 2001 documentary Japanese Devils was composed largely of interviews with 14 members of Unit 731 who had been taken as prisoners by China and later released.
• Japanese author Shusaku Endo published the book The Sea and Poison (1958): Set largely in a Fukuoka hospital, during World War II, this novel is concerned with lethal vivisections carried out on downed American airmen. It is told from the first-person point of view of one of the doctors and the third-person perspective of his colleagues who cut open, experiment on, and kill the six crew members. This is based on a true incident.
• The television show The X-Files weaves Unit 731 into its complex government conspiracy mythology. In the episodes "Nisei" and "731", Japanese scientists given amnesty in the U.S. after World War II are said to be continuing their work in secret, experimenting with alien-human hybrids, possibly to be immune to biological weapons. The name of the character in charge of the former Unit 731 doctors, Takeo Ishimaru, and his alias, Shiro Zama, are based on Dr. Shiro Ishii and Camp Zama (a U.S. Army base in Sagamihara, Japan).
• The book The Zombie Survival Guide by Max Brooks claims that Unit 731 was involved in the creation of zombies to use against Chinese resistance fighters, but all attempts ended either in disaster or the elimination of the zombies by Chinese Communist guerillas.
• American Thrash Metal band Slayer released a song on their 2009 album World Painted Blood by the name of Unit 731. The song depicts the acts performed by the Japanese in Unit 731.

See also

• War crime

Pacific War (World War II)

• Japanese human experimentations
• Changde chemical weapon attack
• Japanese war crimes
• Kaimingye germ weapon attack
• Second Sino-Japanese War
• Shiro Ishii

Nazi Germany

• Nazi human experimentation
• Josef Mengele

In Asia

• North Korean human experimentation

Further reading

• Barenblatt, Daniel. A Plague Upon Humanity: The Secret Genocide of Axis Japan's Germ Warfare Operation, HarperCollins, 2004. ISBN 0-06-018625-9.
• Barnaby, Wendy. The Plague Makers: The Secret World of Biological Warfare, Frog Ltd, 1999. ISBN 1-883319-85-4, ISBN 0-7567-5698-7, ISBN 0-8264-1258-0, ISBN 0-8264-1415-X.
• Endicott, Stephen and Hagerman, Edward. The United States and Biological Warfare: Secrets from the Early Cold War and Korea, Indiana University Press, 1999. ISBN 0-253-33472-1.
• Gold, Hal. Unit 731 Testimony, Charles E Tuttle Co., 1996. ISBN 4-900737-39-9.
• Handelman, Stephen and Alibek, Ken. Biohazard: The Chilling True Story of the Largest Covert Biological Weapons Program in the World—Told from Inside by the Man Who Ran It, Random House, 1999. ISBN 0-375-50231-9, ISBN 0-385-33496-6.
• Harris, Robert and Paxman, Jeremy. A Higher Form of Killing: The Secret History of Chemical and Biological Warfare, Random House, 2002. ISBN 0-8129-6653-8.
• Harris, Sheldon H. Factories of Death: Japanese Biological Warfare 1932–45 and the American Cover-Up, Routledge, 1994. ISBN 0-415-09105-5, ISBN 0-415-93214-9.
• Moreno, Jonathan D. Undue Risk: Secret State Experiments on Humans, Routledge, 2001. ISBN 0-415-92835-4.
• Williams, Peter. Unit 731: Japan's Secret Biological Warfare in World War II, Free Press, 1989. ISBN 0-02-935301-7.

External links

• The Nazi War Crimes and Japanese Imperial Government Records Interagency Working Group (IWG) — The U.S. National Archives and Records Administration (NARA).
• History of Japan's biological weapons program — The Federation of American Scientists (FAS).
• History of United States' biological weapons program — The Federation of American Scientists (FAS).
• Dan Barenblatt's A Plague Upon Humanity: The Continuing Story — an internet gathering place for news and emerging information about Japan's human experiment and biological warfare program of the 1930s and '40s, commonly known in shorthand as "Unit 731".
• UNIT 731: Japanese Experimentation Camp (1937-1945) — information site.
• Unit 731, Nightmare in Manchuria, a World Justice documentary, [1]
• The forgotten victims of biological warfare — online slideshow from the Sunshine Project.
• Unit 731: Auschwitz of the East — AII POW-MIA images.
• Army Doctor — a firsthand account by Yuasa Ken.
• Theodicy - through the Case of “Unit 731” — by Eun Park (2003).
• Why the past still separates China and Japan — by Robert Marquand (2001), Christian Science Monitor.
• China recalls germ warfare experiments — Agencies (2005), China Daily.
• Ex-Japanese Soldier Deemed War Criminal — by Michael Zielenziger (1998), Houston Chronicle.
• US paid for Japanese human germ warfare data — Australian Broadcasting Corporation News Online.
• Japan's sins of the past — by Justin McCurry (2004), The Guardian.
• The Asian Auschwitz of Unit 731 — by Shane Green (2002), The Age.
• Doctors of Depravity - by Christopher Hudson (2007), the Daily Mail.
• War Crimes: Never Forget - review of the book Unit 731 by Peter Williams and David Wallace