A research report on Japanese use of chemical weapons during the Second World War

Abstract

This research report introduces the historical process of Japanese use of chemical weapons against the Chinese during the Second World War, which caused serious casualties and mass destruction. In addition, it also elaborates on the discarded chemical weapons' injuries to the Chinese people and their negative effects on environmental pollution. According to the Chemical Weapons Convention (CWC), which became effective in 1997, Japan should take responsibility for destroying all chemical weapons abandoned on Chinese territory.

Keywords:

• Second World War
• chemical warfare
• chemical weapons
• Japanese Army

Notes

1. The first Hague Peace Conference in 1899 passed three treaties and three declarations. Among them was the “Declaration on the Use of Projectiles the Object of which is the Diffusion of Asphyxiating or Deleterious Gases”; the second Hague Peace Conference in 1907 passed the “Laws of War: Laws and Customs of War on Land” (Hague IV), which reaffirmed the prohibition on using poisonous agents as a means of warfare.

2. The Geneva Protocol, also called the “Protocol for the Pacific Settlement of International Disputes”, prohibited the “use in war of asphyxiating, poisonous or other gases and of all analogous liquids, materials or devices”.

3. The Chemical Weapons Convention (CWC), formally called the “Convention on the Prohibition of the Development, Production, Stockpiling and Use of Chemical Weapons and on Their Destruction”, was signed in Paris on January 13, 1993. The first of its 24 articles states that signatories promise to destroy all chemical weapons production facilities and stockpiles, including chemical weapons abandoned on the territory of other State Parties.

4. Reports on the Japanese Army's use of chemical weapons. The majority of these reports are located in the Number Two Historical Archive in Nanjing.

5. Chinese Central Archives et al., Xijun zhan yu duqi zhan [Bacteriological and Gas Warfare] (Beijing: Zhonghua shuju, 1989).

6. Because the Japanese Army's chemical weapons research was top secret, very few wartime documents regarding its work have been made public. However, since the end of the war, a number of researchers who held important positions within the Japanese Army have testified publicly on their wartime research. Among them are the following: former Japanese Army Lieutenant General and Director of the Number Six Army Technology Research Centre, Koyanagitu Masao; former Japanese Army Major General and later also Director of the Number Six Army Technology Research Centre, Akiyama Kinsei; and former Japanese Army Lieutenant General and Director of the Army's Scientific Research Centre, Kumura Taneki. The American Occupation Headquarters received the majority of the testimony and materials provided by these individuals. As a result of their testimony and other relevant information, the basic organizational structure and history of the Japanese Army's chemical warfare research program can be reconstructed.

7. A substantial number of Japanese private businesses carried out production of chemical agents. The main producers were the Hototani Chemical Company and Japan Alkaloid.

8. After the war, former Japanese soldiers gave a relatively high estimation of the technological level achieved by Japan's chemical weapons program. The fact that the US sent a chemical warfare investigation team to Japan immediately after the war also suggests that the technological level of Japanese research was significant.

9. Among the official chemical weapons plans drawn up by the Japanese Ministry of the Army is a 1939 top secret document entitled “A Summary of Top‐secret Armaments”.

10. See, “A Technological History of Japanese Chemical Armaments”, (January 1957) – a document compiled by a Japanese soldier who helped carry out chemical attacks during the war.

11. Documents related to the Japanese Navy's chemical weapons are relatively few. In recent years, historical documents made public at the former factory site in Samukawa Machi include personal recollections related to chemical warfare.

12. Tatsimi Chiji, Kakusaretekita hiroshima [Hidden Hiroshima] (Tokyo: Nippon Hyoronsha Co. Ltd., 1993), 42.

13. Takeda Eiko, Chizukarakesareta sima [The Island Erased from Maps] (Tokyo: Domesu Publishers Inc., 1987), 1.

14. Yoshimi Yoshiaki, “Nihonngunha‐donogurai‐dokugasuwo‐seisansitaka” [The Quantity of Poison Gas Produced by the Japanese Army], Sansousekininkenkyu [War Responsibility Studies Quarterly], no. 5 (September 1994).

15. Chugoku Shinbun, “Dokugasu 746manpaton seizao” [The Production of 7,460,000 Poison Gas Shells], (Hiroshima, 7 June 1996).

16. Following the war, a group of former Okunojima factory workers suffering from ill health resulting from exposure to chemical agents raised the issue of compensation with the Japanese government. After repeated requests over several years, the Japanese government finally responded and offered to provide compensation to “official” workers of the wartime factory. The government also turned the Tadanoumi Machi Hospital into a healthcare centre specifically geared to their needs. In recent years, former workers from the Japanese Navy's Sagami Factory have also raised claims for compensation.

17. Over the last few years, major Japanese newspapers have published articles about the wartime chemical warfare program. These stories have gained a wide circulation throughout Japan – from Hokkaido in the north to eight different cities in Kyushu in the south.

18. In 1997 and 1998, the Japanese Ministry of Health and Welfare carried out an investigation into the extent of pollution resulting from chemical agents on Okunojima. At the site of the former underground warehouse where chemical agents were stored and in the surrounding waters, chemical pollutants are 2000 to 4000 times higher than the norm.

19. Compilation Committee of Army Narashino School History, Rikugun‐narashino‐gakkoushi [A History of the Army Narashino School] (Tokyo: Compilation Committee of Army Narashino School History, 1987).

20. Yoshimi Yoshiaki and Awaya Kentarou, eds., Dokugasusen kannkeishiryou [Materials on Poison Gas Warfare] (Tokyo: Fuji Shoppan, 1989).

21. Mainichi Shimbun, 5 April 1995.

22. Japanese High Command Order Number 64, in Collection of Army Orders and Army Directives of the Army Section Headquarters, vol. 2, ed. Morimatsu Toshio (Tokyo: EMOTEI, 1994).

23. Japanese High Command Army Directive Number 110, in Collection of Army Orders and Army Directives of the Army Section Headquarters, vol. 2, ed. Morimatsu Toshio.

24. According to statistics in Collection of Army Orders and Army Directives of the Army Section Headquarters, vol. 2, ed. Morimatsu Toshio.

25. Compilation Committee of Army Narashino School History, Rikugunn narashino gakkoushi.

26. Yoshimi Yoshiaki and Awaya Kentarou, eds., Dokugasusen kankeishiryou.

27. The recollections of former Japanese Army personnel include numerous references to the use of poison gas. Many Chinese materials are collected or edited by the aforementioned Chinese Central Archives et al., Xijun zhan yu duqi zhan. Materials from the Japanese side are found in some recollections of war criminals published by the Chinese Returnees Association.

28. A typical case of the use of gas against civilians occurred in Beituan Town, Dingzhou City, in Hebei Province, where there were over 800 civilian casualties.

29. Nationalist Government, Ministry of War (Jun zheng bu), “Kangzhan ba nian lai dijun yong du jingguo baogaoshu” [A Report on the Enemy Army's Use of Gas during the Last Eight Years of the War of Resistance], 1946.

30. Ji Xueren, Huaxuezhan shi [A History of Chemical Warfare] (Beijing: Junshi yiwen chubanshe, 1991), 273.

31. A document in the United States' National Archives details the disposal of chemical agents in Japan. It states that the disposal site was in the ocean 75–90 kilometres south of Muroto Zaki on Shikoku. The chemicals were loaded onto three transport ships which were sunk at the disposal site.

32. According to an investigation carried out by the Japanese Department of the Environment, eight chemical agent disposal sites have been located, and over 20 cases have been notified since the end of the war resulting in four deaths and 129 injuries. In addition, 18 sites have been identified that contain chemical weapons abandoned after the war.

33. In 1983, two former members of a Kwantung Army Chemical Unit (Unit 516), Takahasi Masaji and Wakao Jusaku, testified to the cover‐up of chemical weapons at Qiqihar in northeastern China where their unit was located. Their testimony states that a large quantity of chemical weapons was dumped into the Songhua River. In 1995, another former member of the unit, Kaneko Jiji, stated that he had once buried over 200 barrels of chemical agents.

34. Two members of the Japanese parliament, Kurihara Kimiko and Oowaki Ako, have requested that former members of the Japanese Army come forward to speak about and help to solve the issues surrounding the Japanese Army's use of and cover‐up of chemical weapons.

35. Some files on the Chinese clean‐up of chemical weapons abandoned by the Japanese.

36. Report submitted by the Chinese government at the 1992 Geneva Disarmament Conference.

37. Investigative reports and audio and video tapes held by the Heilongjiang Academy of Social Sciences.

38. An investigation of the pollution caused by chemical weapons buried in China has not yet been undertaken. However, at the Dunhua burial site the chemical weapons are buried on top of a reservoir and water source – an alarming situation, especially if this is a typical case.