Unit 731

by Hal Gold

  These successful air attacks showed that disease could be delivered by air, and so the army doctors redoubled their efforts to produce and accumulate rats and fleas. Still, imperfections remained in the system. The early attacks had all been carried out by slow, low-flying planes that were effective against peaceful, unarmed villages or cities. Battlefield conditions would be far more demanding. Ishii wanted to have the ability to deliver pathogens from higher altitudes, and started developing a series of bombs that could deliver rodents and insects from greater heights.

  The test ground at Anda started seeing drops from higher altitudes using different prototypes of biological warfare bombs. Early attempts had proven that explosives were not practical for releasing the bombs' contents since the detonations killed the insects. Glass bombs were experimented with, and then Ishii remembered Japan's ceramic heritage. He went into villages where traditional kilns had turned out ceramic wares, and ordered bombs made to his specifications.

  It was not the first use of ceramics for war. The secret poison gas factory at Okunoshima had ordered ceramic gas bombs from the centuries-old pottery makers in the Kyoto region. Japan had also made ceramic land mines, avoiding use of precious metals in anticipation of a possible Allied invasion of the home islands. Only the sensors on top were metal.

  The artisans making Ishii's bombs reportedly had no idea what they were making. Their orders were to follow the plans and produce the "objects" he designed. About sixty-five centimeters in length, each had a screw-top in the nose that could be removed so that pathogens could be loaded in.

  New light on the pathogenic air attacks on the Chinese population centers was shed by Okijima, the former Unit 731 member who, at seventy-eight years of age, broke a half-century of silence and gave his observations on the civilian makeup of Unit 731. In 1939, Okijima became a civilian employee of the army and was sent to Unit 731. He was assigned to work with bacteria in the laboratory of the unit's air wing. On the morning of the attack on Ningbo, Okijima dressed in an anti-contamination protective suit, and pumped liquid pathogens from oil drums into two tanks fixed to the belly of the plane that would be used in the attack. The combination of this liquid and the wheat flour described by the resident of Ningbo might account for the smoky appearance of the plane's payload.

  Okijima also explained one of several preliminary tests that was conducted beforehand.

  We used the airfield inside the Unit 731 complex. A truck filled with eggs drove into the airport. Several hundred eggs were broken into a drum and mixed, then loaded onto a plane. The meteorological team was checking wind direction and velocity. We placed square boards, fifty centimeters to a side, on the ground at regular intervals and had the eggs sprayed from the air. Then, we studied the boards to see what kind of dispersal and coverage we got.

  Once we used the inside of a huge mausoleum-type structure and a stopwatch to measure the rate of fall of rice husks in a windless environment. We poured dyes into the Songhua [Sungari] River to see how far they travel and what concentrations remain at various distances from the source. This was to determine the effectiveness of an attack by pathogens added to rivers.

  Liquid would have done away with the problem of handling living animals, such as the insects and rats discussed earlier, in battle conditions. Other factors, however, apparently prevented its proving a suitable vehicle. Okijima said that the Ningbo attack was the only time he handled liquid pathogens.

  Frostbite

  Professor Tsuneishi has conducted nearly two decades of research into the activities of Unit 731, and his knowledge of its history and activities is encyclopedic. Of everything that went on in the prison cells, on the dissection tables, and in the research labs, he has expressed his opinion that the cruelest experiments of all were those which concerned frostbite research.

  These tests were directed by Dr. Yoshimura Hisato, a physiologist from the same school, Kyoto Imperial University, as Ishii. According to Yoshimura's memoirs, Ishii came to recruit him for the experiments in Manchuria, and Yoshimura asked what a physiologist could do in a bacteriological research unit. He said he could understand his being used in submarine research, for example, or in high-altitude research for pilots. But what, he asked, could he do for the Ishii unit?

  Japanese military leaders were always looking at the possibility of having to fight the Soviets. In 1905, after sacrifices and feats called superhuman by foreign observers, Japan had crushed Russia's sea and land forces and established herself solidly in Manchuria. Since then, Russo-Japanese relations had remained icy, and Moscow remained on Tokyo's list of potential adversaries. Now, Japan's incursion into China was again putting her eye-ball-to-eyeball with Moscow. If another clash came, it was sure to be in cold weather.

  In fact, cold-weather combat had already established itself as a problem. At the time of the Manchurian Incident that began Japan's occupation of parts of China in 1931, army medics treated large numbers of Japanese soldiers who suffered from frostbite. Usually, fingers and toes would be affected. Frostbitten and normal parts of limbs were marked with blue or green dividing lines. Treatment of the problem normally involved application of ointment to affected areas and amputating where necessary (without anesthetic). This experience made it clearer than ever that cold-weather fighting demanded prior knowledge of frostbite prevention and treatment.

  Training for the Russo-Japanese War had included winter maneuvers by Japanese troops in the mountains of northern Japan. Preparation for the next round of potential winter warfare would be supervised by physiologist Yoshimura. Yoshimura was called to Manchuria to conduct cold-weather tests on human subjects, and one of the standard methods that he employed in his research was deliberate induction of frostbite.

  A member of the Yoshimura team, Nishi Toshihide, was captured by the Soviets, and he testified at the Khabarovsk trials as to how some of the experiments were carried out. He also stated that 16-mm movies had been made as a visual record of the experiments. Reports from other Unit 731 members corroborate his statements.

  People were taken from prison into below-freezing temperatures. They were tied up, with their arms bared and soaked with water. Water was poured over the arms regularly; sometimes the ice that formed on them would be chipped away and water again poured over. The researcher would strike the limbs regularly with a club. When an arm made a sound like a wooden board's being hit, this indicated that the limb was frozen through, and from there different methods of treatments were tested. Legs and feet were exposed to similar treatment.

  Temperatures in Manchuria can reach as low as minus twenty to thirty degrees Celsius. Some of the tests were conducted outdoors in these winter conditions. At times, electric fans were used to speed the freezing. At Pingfang, Yoshimura had his own large refrigerator lab that allowed him to freeze subjects all year round and reach even lower temperatures than out in the open—temperatures that reached as low as minus seventy degrees Celsius.

  Some experiments resulted in the flesh and muscle falling from the bones. Others left the bones so brittle that they were shattered by the blows from the clubs. Either way, the eventual result was the same: gangrene and the rotting away of extremities. Several former Unit 731 members have commented on seeing victims of the experiments. They reported that the victims "had no hands ... no feet."

  A miniature model of a frostbite experiment was displayed at the Unit 731 exhibitions: It depicts an experiment being performed on a Russian prisoner. Chinese were also used as fodder for the freezing experiments, and some of the victims were women. Yoshimura conducted his frostbite experiments right up until the end of the war. One of the discoveries for which Yoshimura subsequently became famous was that the previously standard treatment of rubbing frozen limbs until they thawed was not the most efficient way of restoring them. Through trial and error, he showed that the best treatment was placing the affected parts in warm water between thirty-seven degrees (normal human body temperature) and forty degrees Celsius. There is no way to count the number
of people and human limbs he consumed in arriving at this finding.

  After the war, Yoshimura became an eminent authority on polar human biology. He held university posts and later became president of the Kyoto Prefectural University of Medicine. Newspaper articles later came out accusing him of conducting human experimentation, but he denied the accusations. Then, in 1982, a Japanese newspaper carried an article on a paper which Yoshimura presented at a meeting of the Japan Physiology Society. Interestingly, the article identified him only as "A." However, the article's mention of his age, a description of the school of which he was president, the fact of his residence in Kyoto, and other clues made "A's" identity quite clear.

  The article was headlined "Human Experimentation Blatantly Presented in Lecture." It announced that "a former member of Unit 731 presented the results of his human experimentation on frostbite in Manchuria at a meeting of the Japan Physiology Society. The results of his wartime research were printed in the society's journal, and the medical community directed heavy criticism against the group and its behavior.

  "Last year, at the fifty-eighth meeting of the Japan Physiology Society in the city of Tokushima, this member presented a lecture on the 'History of My Research.' His talk included a description of ethnic comparisons of adaptability to cold."

  Yoshimura was reported as commenting with pride that "the English-language Japan Journal of Physiology carried the report completed by me and my late assistant in three issues between August 1950 and February 1952." The printed report covered tests on more than five hundred males from the ages of eight through forty-eight. Test subjects included Mongols, Chinese, Siberian tribesmen, and others. The tests were conducted by placing coils on the subjects' fingers and immersing them in ice water. Changes were measured in skin surface, and data analyzed according to age and ethnic stock to determine a correlation between cold resistance and race.

  This experiment does not seem especially cruel, and Yoshimura has criticized the press on numerous occasions for exaggerating the callousness of his research. What has not been brought to public view, however, are the frostbite tests which destroyed the limbs and then the lives of their subjects. Eyewitness testimonies about having seen such tests and their victims with blackened extremities provide evidence that he was engaged in destructive work.

  The journal of the Japan Physiology Society was even criticized by its own members for publishing Yoshimura's report without censuring his methods. Former students of Yoshimura have commented on his attitude at class lectures, about how very cavalier he was about using and discarding human beings for research. Students were constantly amazed that he never seemed to consider anything he did to be wrong, and associates frequently advised him to be more prudent about describing his methods. Apparently, he never saw a need to heed their advice.

  In celebration of his seventy-seventh birthday, considered auspicious by Japanese, Yoshimura Hisato wrote a book of his reminiscences which was published in 1984. In its pages, he mentions his association with Unit 731 several times, yet defends himself against accusations that his experiments were cruel. He shows one photograph of a young Chinese in a laboratory undergoing an apparently painless test, with hands placed in cold water to record heat loss. "This person is obviously undergoing very little stress," he comments. His other tests get no mention.

  Yoshimura's human experimentation led to his removal from the chairmanship of an academic organization in Japan. Student protests about issues including his human experimentation also led to his stepping down from the presidency of Kyoto Prefectural University of Medicine.

  In 1981, reporters from the Mainichi newspaper searched out former members of Unit 731 for interviews. (Three of these appear in Part 2 of this book.) They approached a "former army technician who became president of a public medical university after the war" and asked him about human experimentation. His answer, given in his office at the Kyoto Prefectural University of Medicine, was simultaneously evasive and unabashed: "Human experimentation? Maybe my subordinates did that, but I never did. But you people are thinking wrong. Even that did happen, it was war. The orders came from the country. All the responsibility lies with the country. The individual is not responsible."

  Yoshimura's special, two-story tall "refrigerator laboratory" still stands at the Pingfang ruins.

  4

  End and Aftermath

  Attempted Biological Warfare Against the Americans

  Only six months after Pearl Harbor, the battle of Midway in June 1942 marked the end of Japan's string of victories in the Pacific. From that point on, the territory under her control continued to ebb away. As the situation grew darker, Tokyo began considering measures as desperate as the position in which it found itself. Ishii looked to biological warfare, which had had devastating effect against the Chinese, as a weapon that could help Japan make a comeback against Allied forces.

  In 1944, the United States attacked Saipan, an island in the western Pacific. For the Japanese, it was vital that the island remain out of American hands, for it would make a perfect staging ground for large-scale bombing raids against Japan itself. Ishii dispatched a special team of about twenty men equipped with biological weapons, under the command of two army medical officers from his alma mater of Kyoto Imperial University, to launch an attack of plague and perhaps other diseases against the enemy. Their ship was sunk en route, however, and the pathogens never reached the battlefield.

  As 1945 arrived, the Japanese waited for an American landing on Okinawa. Not all the defense preparations were taking place near the prospective battlefield, however; in far-off China, the Ishii organization was making plans to meet the invaders with plague bacteria. Ironically, Okinawans themselves never heard anything about these plans until January 1994, when the Unit 731 Exhibition opened there.

  While the touring exhibition spread shock among Japanese wherever it opened, it hit home especially hard and deep for Okinawans. Fifty years after they were educated to sacrifice every man, woman, and child to repel the invaders, in a place where civilians armed with bamboo spears and indoctrinated into dying for the emperor charged into guns, news of yet another Japanese betrayal broke. A seventy-one-year-old former member of Unit 1855 in Beijing gave testimony that appeared in the (Japanese-language) Okinawa Times.

  Ito Kageaki, now living in Yokohama, was assigned to the Beijing unit toward the end of 1943. His work there entailed raising fleas for spreading plague. He told of the education he and his comrades received at the unit, and how an officer advised them that "this kind of tactic was not permitted until now, but if we employ it, it will be against the American landing at Okinawa."

  Ito recalled how his detachment had first consisted of only five or six men. Then, from around 1944, personnel and facilities were expanded. "Plague germs were brought in from other units," he recounted, "and Chinese prisoners were experimented upon." Ito himself was never required to carry out human experimentation, but as a member of the unit he was a witness to it.

  After the war, Ito never spoke to his parents or family about his experiences in the unit. He worked for the Japanese National Railways, and was afraid of losing his job if he brought up the subject. Then, in 1988, he made a trip to China, met with citizens there, and gained a completely different perspective.

  "There was no reason for Japan to make China an enemy," he commented, "and I should not carry my experiences to the grave. I want our past to be an education for the next generation."

  After returning to Japan from his China trip, he started telling his story. The Unit 731 Exhibition's arrival in Okinawa gave him an opportunity to tell Okinawans of the real position they occupied in the minds of the Japanese military: "Tokyo was under air attack, Japanese were making suicide stands in the Pacific, and there were other setbacks for Japan. The situation grew progressively worse. Okinawa could be thrown away if Japan could gain some military advantage." He added, "I question whether the military would have planned for BW [biological warfare] if the landing had been pr
ojected for Kyushu instead of Okinawa. I believe that behind the military's thinking was the fact that this is the former Kingdom of the Ryukyus [as distinct from Japan proper], and this shows the racial disdain the Japanese military had for the Okinawans."

  One of the local organizing committee members for Okinawa's Unit 731 exhibition, a high school teacher, gave his impression of Ito's recollections: "If this is true, it sends a shiver down the spine. This makes the sacrifices in the Okinawa battle even more pitiful."

  In the end, the attack never came together in time for execution. A merciful coincidence of timing thus spared the people of Japan's southernmost prefecture from further suffering at the hands of their Imperial Japanese Army "protectors."

  Even this was not the most shocking idea conceived by Japan's military planners, however. Recent evidence points to a plan to carry Japan's biological warfare program to the United States itself.

  The top navy leaders who looked to biological warfare as a last-ditch effort to turn the tide of the war set their sights no lower than the American mainland itself. They targeted it for an attack that would combine elements of previous attacks on Chinese cities and villages with a kamikaze delivery system. A former officer of the Imperial Japanese Navy who had been involved with the plan let the world hear about it for the first time in an interview carried by the Sankei newspaper on August 14, 1977. Former captain Eno Yoshio, seventy-three years old and living in Hiroshima at the time he talked to the paper, was closely involved in the operation from the beginning. The Sankei article quoted Eno as admitting that "this is the first time I have said anything about Operation PX, because it involved the rules of war and international law. The plan was not put into actual operation, but I felt that just the fact that it was formulated would cause international misunderstanding. I never even leaked anything to the staff of the war history archives at the Japan Defense Agency, and I don't feel comfortable talking about it even now. But, at the time, Japan was losing badly, and any means to win would have been all right."