left the laboratory in late 1944 for another job. After the war, he read of a Japanese biological warfare attack on Chongqing using fleas, and he stated in the article that “the thought that I could have been involved in something related to that still troubles and worries me.” In the years intervening between the end of the war and his speaking to the Straits Times, he never spoke of his employment at Unit 9420.
In Japan, historian Matsumura Takao of Keio University credited the information from the former official with filling the gap between what had been strongly suspected about the Singapore operation and the lack of substantive proof. He also set about on his own search for information concerning the laboratory. He located the former head of the laboratory and got a story, albeit with credibility gaps. Phan of the Straits Times then followed up on his coverage in the newspaper’s November 11, 1991, issue with a second piece on the issue. In an article headlined “Germ lab’s head says work solely for research, vaccines … But Japanese professor skeptical about his claim,” Phan followed the progress of Professor Matsumura’s investigation into the issue, while also giving space to the former laboratory administrator’s rebuttal.
The story gave the Japanese government a problem, and it issued the predictable and well-worn denial. Concerning this response, Phan wrote that “the Japanese government responded, saying that it had no records of such a laboratory—a claim which contrasted with those in U.S. Army documents which mentioned its existence.” The documents of course are those which U.S. military authorities gathered from interviews with Unit 731 leaders forty-five years earlier, which made some passing mention of a Singapore unit.
The former head of the Singapore facility was “a retired doctor in his early eighties who refused to be identified.” According to the article, “he said he was transferred to Singapore a week after the island was occupied in February, 1942 from the main branch of … Unit 731 in Harbin, Manchuria. Singapore was the headquarters of the Japanese Southern Army and the base to supply material to the war front. To prevent the outbreak of diseases in the city, strict bacteriological checks on water supply and fresh food were carried out.” The retired doctor mentions soldiers catching rats in the city and conducting experiments with them, and comments, “Such behavior must have seemed odd to the people there and thus caused misunderstanding.”
Did the people misunderstand? Or did they, in fact, understand all too well? The former laboratory chief talks of the large scale on which his facility operated—it employed all of one thousand members—and the fact that it was had been set up by people brought into Singapore by Naito Ryoichi, a prominent Unit 731 officer who later played an important role in the outfit’s first negotiations with American occupation forces.
Matsumura’s counterargument concerning the benign role allegedly played by the Singapore unit was also carried in the same newspaper: “The other four branches of the unit at Harbin, Guangzhou, Beijing and Nanjing were involved in the manufacture of germ warfare weapons. It would seem strange if the branch in Singapore was not involved in similar activities.” More pointedly, he adds that it seemed odd to set up a laboratory for research on a disease in a place in which there was no epidemic. And he notes that the head of the lab, Naito, and other members had all come to Singapore after working in Harbin, where biological warfare weapons were manufactured.
In February 1995, a documentary on an Asahi Broadcasting Company program interviewed a former member, Takayama Yoshiaki, of the Singapore unit. His account of what he did in Singapore falls into the pattern of Japan’s methodology for creating plague as a weapon. He recalls, “We raised fleas in oil cans. Then, the infected rats were put into mesh enclosures, and lowered into the cans. The fleas would bite the rats, and the fleas became infected.”
The discovery of these facts regarding the Singapore unit throws light upon the geographical extent of Japan’s biological warfare ambitions.
Hiroshima
The charming island of Okunoshima lies just a few minutes by boat from the port city of Hiroshima. In 1929, a factory on the island started producing poison gas for chemical warfare. A small museum has been established near the remains of the factory to remind people of what went on here. The curator is a former worker in what was a highly secretive, dangerous operation. Photos show the scars and disfigurements suffered by the workers.
The island’s history as a center for chemical warfare production dates back to 1928, when the installation there engaged in production of mustard gas on an experimental basis. Equipment was imported from France, and workers were brought in from nearby rural communities on the Japanese mainland.
With the expansion of the war in the latter part of the 1930s, the Hiroshima plant increased production. Types of gases produced over the factory’s lifetime include yperite, lewisite, and cyanogen. So important—and confidential—was the work done at the island that it actually disappeared from Japanese maps as the army moved more aggressively into China.
The workers themselves were ordered to the same secrecy as Unit 731 personnel. And, as with Unit 731, the Japanese government has shown a deep reluctance to admit that anything untoward went on at Okunoshima. For a long time, the government refused to acknowledge responsibility for assisting former workers at the factory there. Finally, it granted some of them recognition as poison gas patients and allowed them compensation, if far from sufficient. For all the destitution and respiratory and other health problems these people have suffered, though, they are comparatively lucky: many of their colleagues died before the government moved to grant them any form of assistance at all.
The plant on Okunoshima supplied some of the gas used in the human experimentation in Manchuria. A reported two million canisters of poison gas abandoned in China by the Japanese army has been a constant bone of contention between the two countries. China has been asking for its removal, while the Japanese government has appeared to be waiting for it simply to go away on its own. Finally, some fifty years after the end of World War II, Japan is reacting to pressure, time, and perhaps the incentive of benefits perceived to be had from good relations with an economically booming China. At last, the abandoned gas weapons are scheduled for deactivation. Poison gas does not seem to fit in well with a booming, mercantilistic atmosphere.
Ties to the Civilian Sector
The massive scale of the new buildings and grounds was not the only major change concerning Ishii Shiro’s work when Unit 731 moved to Pingfang. The change in venue brought about a drastic revision in organization, as well. The first fortress/bacteria factory had been staffed only by military doctors and technicians. Now, however, Ishii aimed to move on from what had been a restricted exercise in military medicine, and involve the entire Japanese medical community. In order to attain this objective, Ishii once again needed to cash in on his talent for manipulation, this time to convince researchers to leave the security of their labs and join him in Manchuria. In the final analysis, Ishii’s talent as an organizer would be evaluated as being greater than his research ability, despite the knack for invention testified to by his water purification systems and biological warfare bombs.
He went back to his alma mater in Kyoto, to Tokyo Imperial University, and to other leading medical universities, and coaxed professors and researchers to come to Manchuria. Attracted by the lure of expanding their research possibilities, some researchers went themselves, while others sent their students. The students would write up their research, then send it back to their professors, who would then use the data to prepare their own reports and advance themselves in the medical community. In defense of some of the people recruited, it must be acknowledged that not all of them knew what they were getting into and were themselves used by Ishii and his henchmen. There were also students who were pressured by their professors to go work with Ishii’s organization. Defying a professor in Japan’s strict academic hierarchy was (and remains even today) equivalent to career suicide.
The degree of civilian involvement in the human-experimentation units has been a matter
