Hematogical Effect STATE OF } -HEMATOLOGICAL EFFECTS ON HEAVILY IRRADIATED JAPANESE FISHERMEN The fishermen were in (1) From the radioact (2) Externally from th the deck etc. TosHlyuKI KuMATORI (3) Internally from tt The diameters. of the Division of Radiation Health, National Institute _ reef fragments, ranged fro 1934). According to the of Radiological Sciences March, rare-earth element activity and uranium contr specific activity of the mat of these data, a value of 1 a.m. on 1 March. The internally deposited radio However, radiation | Chiba, Japan INTRODUCTION On 1 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” waslocated 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. Jesions. exposure dose for 14 days cent of these doses was r on the results of the e> decay curves of many ] At about 7:00a.m. white material began to fall, which continued for ap- Table 1 proximately 5 hours. They gave up fishing and returned to their mother and Kumatort, 1955; Koyvama et al., 1955; Mixamo et al., 1956; Mryvosu1 and Kumatoat, 1962; Kumator1 and Miyvosu1, 1963; Mryosn1 and Kumatont, 1964; Kumatoanl et al., 19635). - FALLING OF RADIOACTIVE MATERIALS During the falling of the white materials, whenits 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. Es Subject No. duit 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 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 for medical examination. Medical data of the fishermen have been reported several times (Mtyosnt External radiatic 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-T K-8 K-9 K-10 K-11 K-12 K-13 K-14 K-15 K-16 eeeneer * T-3 put the fall-oul added in total.