Page 71 - MaterialsTrial-JapaneseArmy-1950

Interpreter TSVIROV

EXCERPT FROM RECORD OF INTERROGATION
OF KAJITSUKA RYUJI

October 23, 1949 City of Khabarovsk

Question: What, concretely, was done by Detachment 731 in preparing to conduct
bacteriological warfare?

Answer: In February 1941, the Chief of Detachment 731, Colonel of the Medical Service
Ishii, in my office in Changchun, while reporting to me on the detachment's work, with the
permission of Commander-in-Chief of the Kwantung Army Umezu, told me what the
detachment had done in preparing to conduct bacteriological warfare, thereby fulfilling the
promise he had given me when I visited Detachment 731 in 1940.

According to what Ishii said, researches carried out by the detachment had shown that the
dropping of bacteria contained in aerial bombs was of little effect because, as a consequence
of strong air pressure and excessively high temperature, the germs of dysentery, typhoid,
paratyphoid, cholera, and plague, being frail, perish almost 100 per cent. Ishii said that great
hopes had been reposed in these researches, but these hopes had been disappointed, as the
bombs and also shells containing these bacteria did not spread infection on as wide an area as
had been anticipated.

As regards the hardiest bacteria, such as the germs of anthrax, Ishii said that it was possible
to use them in this way, and that further research was proceeding.

Research had also shown that the dropping of bacteria from aircraft, in the same way as
was done with poisonous substances, had relatively large effect.

Ishii told me that bacteria could not be dropped from high altitudes, because the bacteria
perished; they could be dropped from an altitude not exceeding 500 metres, but when
dropped from a low altitude, the area over which the bacteria scatter is too small. . . .

I learned from Ishii that dropping cholera germs on enemy territory was of little effect and
difficult to carry out, firstly, because they had to be dropped from a low altitude, which
enables the enemy easily to fire at the aircraft, and secondly, because an excessively large
quantity of germs is needed for this purpose.

Ishii told me further that it was much more effective to drop bacteria not in their "bare"
shape, but in conjunction with an insect medium, fleas in particular. Fleas, being the most
tenacious insects, were infected with plague and dropped from aircraft, and the plague germs,
remaining in the fleas, successfully reached the ground with them. This method reduced the
vulnerability of aircraft to enemy antiaircraft artillery.

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