Hematogical Effe STATE OF HEMATOLOGICAL EFFECTS ON HEAVILY IRRADIATED JAPANESE FISHERMEN TToSHIYUKI _KUMATORI Division of Radiation Health, National Institute of Radiological Sciences Chiba, Japan The fishermen were 1 From the radioac Externally from 1 the deck etc. (3) Internally from t The diameters of the (1) (2) reef fragments, ranged fri According to the 1954). March, rare-earth elemen! activity and uranium cont INTRODUCTION On | March in 1954, a thermonuclear test explosion was performed by the United States Authorities at Bikini Lagoon in the Pacific Ocean. At that time one Japanese fishing boat “the 5th Fukuryu-maru” was located at about 90 miles east from explosion center. The boat was nearly 100 tons and 23 fishermen aged from 18 to 39 were on board. At about 3:40a.m., while they were occupied in fishing tuna theysaw a huge red light in the west and heard a detonation several minutes later. specific activity of the mat of these data, a value of 1 a.m. on 1 March. However, radiation lesions. External radiatic exposure dose for 14 days cent of these doses was Tr on the results of the e decay curves of many } At about 7:00 a.m. white material began to fall, which continued for ap- Table t proximately 5 hours, They gave up fishing and returned to their mother port on 14 March 1954. After landing, all the fishermen were found to have been injured by the radioactive materials. Seven of them were hospitalized to the Tokyo Univer- sity Hospital and the other 16 were received by the First National Hospital of Tokyo by 28 March. They were discharged from both hospitals in May 1955, except For one fatal case who died on 23 September 1954. After being discharged we continued the follow-up studies so far as possible on annual basis. However, mainly because of the varied status of their occupations and widely distributed addresses, it was not always possible to get them all together fur medical examination. Medical data of the fishermen have been reported several times (M1yosnt and Kumatort, 1955; Korama et al., 1955; Mixamo et al., 1956; Miyvosui and Kumatori, 1962; Kumatror: and Mrrosui, 1963; MrvosHr and Kumatoat, 1964; Kumatoar et al., 1965). - FALLING OF RADIOACTIVE MATERIALS Nuring the falling of the white materials, when its intensity was greatest, these persons were unable to keep their mouths and eyes open. Their footprints were clearly marked on the deck covered by fallout. The internally deposited radic Es Subject No. T-1 T-2 T-3 T-5 T-6 T-7 T-8 K-1 K-2 K-3 K-4 K-5 K-6 K-T K-8 K-9 K-10 K-l1 K-12 K-13 K-14 K-15 K-16 OU * T-3 put the fall-out added in total.