Hematogical Effects on Heavily Irradiated Japanese Fishermen STATE OF IRRADIATION AND ESTIMATED RADIATION DOSE N HEAVILY ‘SSHERMEN The fishermen were irradiated in the following 3 ways: (1) From the radioactive materials adhering to the body surface. (2) Externally from the radioactive materials deposited in the cabins, on the decketc. . (3) Internally from the radioactive materials entering various organs. The diameters of the fallout materials, which were the powdersof coral- reef fragments, ranged from 19 to 4604, mainly 100 to 400 4 (Krxvucni et al., 1954). According to the results of radiochemical analysis of fallout on 26 March, rare-earth elements contributed about 50 per cent of the total radioactivity and uranium contributed about 20 per cent (Kimura et al., 1956). The specific activity of the material was 0.37 mCi/g on 23 April. osion was performed by ¢ Pacific Ocean. At that aru” was located at about $ nearly 100 tons and 23 in fishing tuna they saw ion several minutes later. vbich continued for apreturned to their mother have been injured by the ed to the Tokyo Univer> First National Hospital n both hospitals in May ember 1954. After being ar as possible on annual i Of their occupations an d sible to get them all to-d several times (Miyos ut t al, 1956; Mryosyr and SHI and Kumatorr, 1964; ERIALS ts intensity was Sreate st, eyes open. Their foo tallout. By extrapolation of these data, a value of 1.4 Ci/g was obtained as the specific activity at 7:00 a.m. on 1 March. The estimation of radiation dose, especially that from internally deposited radioactive materials was difficult. However, radiation from body surface was large enough to cause skin lesions. External radiation dose was estimated as shown in Table 1. The exposure dose for 14 days ranged from about 170 to 690 R, and nearly 60 per cent of these doses was received on the first day. This estimation was based on the results of the experimental reproduction of ash-fall, extrapolation of decay curves of many places of the boat, and on detailed investigation of Table 1 Estimated dose of whole body gamma radiation. Subject No. T-1 T-2 First Day Total 240~290 R 210~-260 450~500 R 390~440 T-3 T-5 T-6 T-7 T-3 150~200 400~430 130~180 140~190 310~360 K-2 130~180 K-5 K-68 140~190 180~230 K-8 220~270 380~430 K-10 K-li K-12 140~190 120~170 100~150 230~2&0 170~220 170~220 K-} K-3 K+4 K-7 K-9 K-13 K-14 K-15 K-16 260~310* (360~410) 660~690 200 ~250 '220~270 520~570 190~220 310~340 200~250 140~190 120~170 230~280 310~360 250~300 420~500 140~190 120~170 230~280 190~240 ‘ 220~—270 300~350 340~390 550~600 370~420 510~590 210~260 190~240 * T-3 put the fall-out material close to his bed. Therefore about 100R should be added in total.