Unit 731 conducted “Field Tests” using planes in the experimental use of massive biological weapons on Chinese cities that induced epidemics of plague, cholera, and typhoid on a large scale, infecting an estimated 200,000 Chinese, Korean, Mongolians, and Allied civilians. In 1942, Japan carried out massive biological weapons attacks dropping pathogens from airplanes in a large scale combat operation that backfired: the operation resulted in 10,000 casualties many of who were Japanese soldiers. In 1944, Ishii developed a bomb using plague infected fleas to spread the disease in targeted populations.

The use of these weapons on urban populations was a direct violation of the 1925 Geneva Protocol, which outlawed the use of biological and chemical weapons in war. (Read In-depth critical analysis by Tsuneishi Keiichi, Japan’s leading specialist on biological warfare and Unit 731 in Asia-Pacific Journal: Japan Focus) Fears of another outbreak still haunt the Chinese cities.

In 2003, expert witnesses testified in a Tokyo court about the continued threat posed by the biological weapons dropped on Chinese cities by the Japanese Imperial Army. Qiu Ming-xuan, a Chinese survivor of a bacterial attack and a doctor, testified:

“The incubation period of plague is normally seven to ten days, but the fleas had been infected with a more toxic form of plague. Only Unit 731 was capable of making such an intensified bacterium,”

“Quzhou had never experienced bubonic plague in its history, yet around 50,000 people died from the disease in the years following the attack… After 60 years, we are still finding positive antibodies of bubonic plague in rats, dogs, cats and other animals…And not only animals.  Every year a certain number of healthy people develop typhoid. Japan’s Germ Warfare has left behind problems that still threaten our lives. ”

Huang, a bacteriologist testified: “Environmental pollution and damage to the ecosystem are very serious. The issue is still threatening people in China.” (China is Still Plagued by Diseases from Japan, New Scientist, Feb. 2001; posted at: World Health)

Daniel Barenblatt, author of new book A Plague Upon Humanity: The Secret Genocide of Axis Japan’s Germ Warfare Operation (2004), said in a recent interview,

“There could be over 700,000 or even 1,000,000 lives lost to Japan’s Bio-Warfare programme…. The plague bacteria released then still lingers on in some animal populations today. It is still there…. rodents still test positive for antibodies to the bubonic plague …. What the US did in making the deal with top doctors is unconscionable. As far as we know, no one in the US government raised any more objection to it.”   

Like the Nazi doctors, Shiro Ishii did not act alone.  His was not a renegade operation.

“He was aided by many thousands of skilled physicians, scientists, veterinarians, dentists, and others with some scientific or medical technical expertise.  Many of Japan’s premier doctors and scientists volunteered to serve in the various Units that ultimately would engage in the practices outlined above.  Few in Japan refused to serve, rejecting either the blandishments or threats should they decline the call to duty.” (Sheldon Harris. Japanese Medical Atrocities in WWII: Unit 731 Was Not An Isolated Aberration)

The deadly experiments conducted by Unit 731 researchers were part of the medical atrocities committed by Imperial Japan. Professor Takashi Tsuchiya points out that according to a large body of testimony, murderous experiments were also performed in other so-called “Epidemic Prevention and Water Supply Department” such as Units 1644 and 1855 in New Guinea, where American, Australian, and New Zealander POWs were subjected to experiments by Surgeon Captain Einosuke Hirano where eight U.S. airmen were killed in surgical experiments.

As a leader of army surgeons, Ishii controlled army hospitals in occupied cities in China, and involved many Japanese universities to collaborate in biowarfare research. Surgeons at army hospitals were trained in surgical skills by performed surgeries on Chinese captives with anesthesia. Hundreds of these surgeons have confessed to having exercised suturing of blood vessels and nerves, thoracotomy, celiotomy, craniotomy, blood transfusion, appendectomy, serially on six bodies of “prepared materials.”

“In the summer of 1989, human bones from more than 100 bodies were found in the ground where the Army Medical College had been located in Tolyo from 1929 to 1945. Eleven skull and most long bones were heavily sawed or drilled. One skull was shot and another one was stabbed. Judging from the condition and technique, they must have been subjects of test surgeries, preserved as specimens in the Army Medical College, and finally buried when Japan surrendered. They may be the remains of vivisected Chinese prisoners.” (Takashi Tsuchiya.”The Imperial Japanese Experiments” in Oxford Textbook of Clinical Research Ethics, Ed. By Ezekiel Emanuel, 2008)

According to Daniel Barenblatt, the Japanese also carried out experiments on other Japanese in the home islands akin to Nazi efforts on the mentally handicapped. The victims were Japanese soldiers who had been prisoners of the Soviets. After their release, they returned to Japan where they were despised. It was the gravest shame to have been captured by the inferior Russians – who were further stigmatized as communists. Their ordeal ended in their death as Japanese subjects of inhumane experiments.

Estimates about the scope of Japan’s killing laboratories in China vary from 10 to 26. Professor Harris estimated somewhere between ten and twelve thousand men, women and children were “sacrificed” in laboratory experiments conducted at Ping Fan… Perhaps as many as two hundred fifty thousand others were killed in the field tests, and in post-war outbreaks of epidemics that can be attributed directly to the biological human experiments.  These figures exceed greatly the number of victims of the Nazi doctors experiments with their hapless victims.

Five years later, after polling opinions of scholars at a conference in Hunan province in 2002, Daniel Barenblatt, author of A Plague Upon Humanity: The Secret Genocide of Axis Japan’s Germ Warfare Operation, 2004, estimated a far higher number of casualties, 580,000. In an interview he indicated that the number of lives lost to biological warfare has been difficult to determine because the victims and their families, many of whom lived in remote villages in China, did not know why they became ill after being exposed to biological weapons unleashed by the Japanese army. The death toll, he stated “could be over 700,000 or even 1,000,000.” (Japan’s Biowarfare Exposed, Taipei Times, 2004)

As Japan’s defeat became imminent, Ishii took steps to destroy evidence of the atrocities: he ordered the remaining 150 “logs” killed and the facilities burned. He instructed his Unit 731 doctors and assistants to “take the secret of its activities to the grave.” The physicians were evacuated to Japan where they resumed their careers as eminent figures in the postwar medical and scientific establishment. The secret was maintained for four decades—as Unit 731 was not part of the Tokyo War Crimes Tribunal or any US tribunal.

According to Barenblatt, the Japanese military considered targeting the US with bioweapons at the end of World War II. He cites a plan in which a plane from a specially equipped submarine would spray San Diego and saboteurs were to land secretly to poison California’s water supply. (Japan’s Biowarfare Exposed, Taipei Times, March 2004)