Page 48 - Unit 731

epidemic anaemia (see Fig. 29). 2
Army surgeon Hojo Enryo, a supporter and assistant of Ishii, was a core member in the research epidemic prevention centre established by the School
of Army Surgeons (Tokyo) in 1932. He was a member of the Japanese Medical Office and studied bacteriology at the Robert Koch Institute in Berlin,
Germany. On 10 April 1947, Hojo was interrogated by the US Army and submitted his 1941 report ‘About Bacteriological Warfare’ in which he explained:

The following bacteria can be used in bacteriological warfare. First is bacteria for human beings, including vibrio cholera, dysentery Bacillus, paratyphoid Bacillus, brucellosis, plague Bacillus, rabbit
fever bacteria, salmonella, typhoid and yellow fever. The second type is for animals including anthrax, glanders, CBPP and foot and mouth disease. The third type is for plants, such as wheat Puccinia,
Mycovellosiella, Erwinia and Cercospora for potatoes and other plants. 3
Concluding Reports from the US Army
‘Thompson’s Report’ recorded the narratives of Shirō Ishii and Masaji Kitano about the types of bacteria Unit 731 researched:
… typhoid and paratyphoid, dysentery, cholera, plague, pertussis, meningococcal meningitis vaccine and gonococcal. Toxin research was done to prevent gas gangrene, tetanus, diphtheria and scarlet
fever. In order to prevent gas gangrene, tetanus, diphtheria, scarlet fever, erysipelas, dysentery, Streptococcus, Staphylococcus, pneumonia, meningococcal meningitis and plague serum therapy was
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improved. Also, [Unit 731] conducted research on typhus, epidemic haemorrhagic fever, forest tick encephalitis, rabies, smallpox vaccine and bacteria vaccine. [See Fig. 28.]
‘Fell’s Report’ recorded nine types of bacteria used in human experimentation: anthrax, plague, typhoid, paratyphoid fever, paratyphoid ‘B’, dysentery,
cholera, glanders, and epidemic haemorrhagic fever. The experiments included direct infection experiments, immunisation experiments, bomb tests,
stability tests, and spray tests.
Hill interrogated twenty-two former members of Unit 731 and put his conclusions in ‘Hill’s Report’. In total, twenty-nine kinds of agents were
researched by Unit 731.
Chart 2: Bacterial agents recorded in ‘Hill’s Report’ 5
Serial Type of Bacterial Agent Interrogated Individuals
1 Typhoid Kozo Akamoto, Seiwa Tanabe
2 Paratyphoid ‘A’ and ‘B’ Unrecorded
3 Dysentery Ueda Masaaki, Tomoshisa Masuda, Saburo Kojima, Seiwa Tanabe
4 Cholera Tachiomaru Ishikawa, Kozo Okamoto
5 Plague Shirō Ishii, Masahiro Takahashi, Kozo Okamoto, Tachiomaru Ishikawa
6 Anthrax Masumi Ota
7 Glanders Shirō Ishii,
Tachiomaru Ishikawa
8 Tetanus Shirō Ishii and more
9 Anaerobes Unrecorded
10 B Hystolyticus Unrecorded
11 B Welchii Unrecorded
12 B Vovgii Unrecorded
13 Undulant fever Shirō Ishii, Yujiro Yamauchi, Kozo Yamamoto, Kiyoshi Hayakawa
14 Tuberculosis Hideo Futatsugi, Shirō Ishii
15 Tularaemia Shirō Ishii
16 Typhus Shiro Kasahara, Den Masayoshi, Masaji Kitano, Tachiomaru Ishikawa
17 Songo Shiro Kasahara, Masaji Kitano, Tachiomaru Ishikawa
18 Gas Gangrene Shirō Ishii
19 Smallpox Shirō Ishii, Tachiomaru Ishikawa
20 Aerosols Masahiro Takahashi, Junichi Kaneko
21 Botulism Shirō Ishii
22 Fugu Toxin Tomohisa Masuda
23 Influenza Shirō Ishii
24 Meningococcus Shirō Ishii, Tachiomaru Ishikawa
25 Mucin Ueda Masaaki, Uchino Snji
26 Plant Disease Yukimasa Yagisawa
27 Salmonella Kiyoshi Hayakawa, Seiwa Tanabe, Saburo Kojima
28 Tick encephalitis Shiro Kasahara, Masaji Kitano
29 Tsutsugamushi Shiro Kasahara
Production of Bacterial Agents
Unit 731 established divisions of bacterial research and experimentation to produce the bacterial agents of plague and cholera. Bacterial agents were the
essential element. Unit 731 was concerned with keeping costs low and with producing powerful toxins with strong resistance to external forces and low
traceability. Its staff utilised the latest technology and facilities to produce such agents.
From research and production to storage and transportation, the system was closely supervised. It conducted research on methods of attack with
bacteriological warfare including hand-thrown or gun-delivered bombs, spray, aerial bombs, and bacteria-infected modes of delivery.
During the trial in Khabarovsk, the head of the Unit 731 bacteria production division, Kawashima Kiyoshi, claimed: ‘Unit 731 could produce 800 to
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900 kilograms of salmonella typhoid, 600 kilograms of anthrax, 1000 kilograms of cholera, paratyphoid and dysentery each month’. As to quantity of
production, Kawashima continued: ‘… the following are the amounts produced in one month: 100 kilograms of Yersinia pastis, anthrax 200 kilograms, 300
kilograms typhoid bacteria, 300 kilograms paratyphoid A, 330 kilograms cholera and 300 kilograms dysentery bacteria’. 7
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In 1942, during bacteriological warfare in Zhejiang-Jiangxi, Kawashima’s division produced 130 kilograms of typhoid and anthrax for use in war. In
addition to Unit 731, other bacteria production divisions were involved in production and research, including Changchun Unit 100, Beijing Unit 1855,
Nanjing Unit 1644, and Guangzhou Unit 860. Vast quantities of bacterial agents were produced by Unit 731 alone, and if the entire amount was used, there
would be another worldwide disaster similar to the Black Death in Europe during the fourteenth century.
Battles of Khalkhin Gol
From May to September 1939, battles at the Soviet–Japanese border took place involving Japan, Manchukou, the Soviet Union, and Mongolia. Japan