Hematogical Effe STATE OF HEMATOLOGICAL EFFECTS ON HEAVILY IRRADIATED JAPANESE FISHERMEN The fishermen were it (1) TosHiyuxk1 KuMATORI (2) (3) Division of Radiation Health, National Institute of Radiological Sciences Chiba, Japan 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 they saw a huge red light in the west and heard a detonation several minutes later. At about 7:00a.m. white material began to fall, which continued for approximately 5 hours. They gave up fishing and returned to their mother Externally from t the deck etc. Internally from t The diameters of the _ reef fragments, ranged fre 1954). According to the March, rare-earth element activity and uranium conti specific activity of the mat of these data, a value of 1 a.m. on 1 March. The internally deposited radic However, radiation lesions. External radiati: exposure dose for 14 days cent of these doses was © on the results of the e decay curves of many| Table t Es Subject No. port on 14 March 1954. T-1 T-2 T-3 T-5 T-6 T-7 T-8 K-l K~-2 K-3 K-4 K-5 K-6 K-7 K-83 K-9 K-10 K-11 K-12 K-13 K-14 K-15 K-18 After landing, all the fishermen were found to have been injured by the radioactive materials. Seven of them were hospitalized to the Tokyo University 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 (Mryosut and Kuwatort, 1955; Koyama et al., 1955; Mrxamo et al., 1956; Miyosu1 and Kumatort, 1962; Kustatort and MryosHi, 1963; Mivosnt and Kumatoat, 1964; Kumatonr et al., 1965). - FALLING OF RADIOACTIVE MATERIALS During 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 cleariy marked on the deck covered by fallout. From the radioac * 77-3 put the fall-out addedin total.