Hematogical Effects on Heavily Irradiated Japanese Fishermen 65 STATE OF IRRADIATION AND ESTIMATED RADIATION DOSE N HEAVILY SHERMEN The fishermen were irradiated in the following 3 ways: (1) From the radioactive materials adhering to the bodysurface. (2) Externally from the radioactive materials deposited in the cabins, on (3) the deck ete. Internally from the radioactive materials entering various organs. The diameters of the fallout materials, which were the powders of coral- reef fragments, ranged from 19 to 460 4, mainly 100 to 4Uu 4 (Kixucui et al, 1934). 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). osion was performed by : Pacific Ocean. At that iu” was located at about s nearly 100 tons and 23 in fishing tuna they saw on several minutes later. -hich continued for ap- internally deposited radioactive materials was difficult. However, radiation from bedy 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 eturned to their mother Table 1 Subject No. wave been injured by the ‘d to the Tokyo Univer- First National Hospital 1 both hospitals in May ‘mber 1954. After being was possible on annual of their occupations and ible to get them all to‘d several times (Mivosut ERIALS 's intensity was greatest, Their foot- * Estimated dose of whole body gamma radiation. First Day Total T-1 T-2 T-3 T-5 T-6 T-7 T-3 240~290 R 210~260 150~200 400-~430 130~180 140~190 310~360 450~500 R 390~440 260~310* (360-410) 660 ~699 200 ~250 220~270 520~570 k-2 K-3 K-4 K-5 K-6 K-7 K-8 K-9 K-10 K-11 K-12 K-13 K-14 K-15 K-16 130~180 140~190 120~170 140~190 180~230 230~280 220-~ 270 310~360 140~190 120~170 1900~150 256~ 300 420~500 140~190 120~170 200~250 230~250 190~240 220~270 300~350 340~390 380~430 550~600 230~280 170 ~~220 170~220 370 ~ 420 510~590 210~260 190~240 K-l t al, 1956; Mryosur and ‘At and Kumatonrr, 1964. eyes open. allout. The specific activity of the material was 0.37 mCi/g on 23 Apnl. By extrapolation of these data. a value of 1, 4Ci/g was obtained as the specific activity at 7:00 a.m. on 1 March. The estimation of radiation dose, especially that from 190~220 310~340 . , T-3 put the fall-out material close to his bed. added in total. Therefore about 100R shouldbe