The book is scheduled for publication in Japan this spring. The origins of Unit 731 go back to 1930 and the Tokyo laboratory of an ultranationalist surgeon and microbiologist, Shiro Ishii, who was later made a general. Within two years, after Japanese troops overran Manchuria in northeast China, Ishii, using the cover of a sanitation unit, set up the first of several large biological warfare and human research centers in Ping Fan and other areas around Harbin, a heavily Russian city near the Soviet border. Over the next decade, scholars and researchers say, the Japanese attacked hundreds of heavily populated communities and remote regions with germ bombs. Evidence of the attacks continues to emerge.
Many questions remain unanswered.
It is still not established, for example, whether American prisoners of war were among those experimented on. Some Americans have said they were sickened by contaminated feathers in their food, and Japanese accounts tell of jars containing body parts labeled American among other nationalities. He said one of his jobs at Mukden was to retrieve for dissection frozen corpses that he was certain were American. The light pink icicles in the stomach weren't thawed. But records of their debriefings by American officials remain unavailable.