The Medical ResearchCenter *: Brookhaven NationalLaboratory. 401816 Upton, L. 1, New York wr Hezlth Physics PergamonPress 1972. v Q S Oe we ( in t}oy SL 9 Jy r=} YX Q 6.x ET _ —=—hCoD 8 8 C byt me Si, 22 (March), pp. 245-250, Printed in Northern Ireland (7 G IRON-55 IN RONGELAP PEOPLE, FISH AND SOILS FF /632 - 17/3 ISLANDS wv FOLDER REPOSITORY- BNL RECORDS mb a T. M. BEASLEY,* E. E. HELD of! A Laboratory of Radiation Ecology, College of Fisheries, University of Washington, Seattle, Washington and R. M. CONARD . Medical Department, Brookhaven National Laboratory, Upton, L.I., New York (Received 5 Februcry 1971; in revisedform 12 April 1971) Abstract—The “Fe body burdens for 60 residents of Rongelap Atoll are reported. The measured burdens are approximately 3 times higher than those of'a similar numberofresidents from Tokai-mura, Japan. Since previous measurements in 1966 revealed substantial Fe bedy . burdens in Japanese residents, the current Rongelapese *°Fe body burdens pose interesting questions. INTRODUCTION Srxcz 1965, the distribution of §5Fe in the biosphere has been studied both in the United States and in the Scandinavian countries. Initially, 55Fe concentrations were determined in Alaskan Eskimos, residents of Richland, Washington, and in representative foodstuffs of both.” Subsequently, 55Fe concentrations in environmental samples and in residents of Finland™and Sweden) were reported which generally confirmed the findings of the earlier study. Additional research shows that (i) marine organisms and people whose diet is largely seafood contain the highest concen- trations of 55Fe;‘) (ii) residents of the northern hemisphere have higher 55Fe body burdens than those of the southern hemisphere;and (iii) the *5Fe levels in people reached peak concen- trations in 1966 and continue to decrease.'®? Jaaxkora®®) has recently presented an excellent reef fishes; goatfish (MMullozdicthys, sp.), mullet (Neomyxus, sp.) and surgeon-fish (dcantiurscs, 14.5. Estimates of fish consumption vary, bur diily intakes between 75-150 g appear reascnz3!e. There are no apparentqualitative differences ia the dicts of males or females. Thus, the cezermination of ®5F¢ in this population is of interest for comparison with other maritime cultures. Second, Rongelap Atoll received high-level fallout following the detonation of a thermonuclear device at Bikini Atoll in 1954.90 We considered it probable that retention of **Fe at the atoll from that event, coupled with insut from world wide fallout from !arge-scale nuclear device testing in 1961-1962 might lead to elevated concentrations of 55Fe in marine species in the Rongelapese diet and theredcre unusual body burdens of this radionucEde in Rongelap residents. METHODS AND TECHNIQUES The methodofseparation of55Fe was ideatical summary of the measurements of Fe in Yinnish Lapps which includes a valuable bibiiegraphy. We determined the ®5Fe body burdens of natives at Rongelap Atoll in the Marshall islands. Ourinterest in this particular population derives from tio important considerations. Vist, the Rongelapese are a maritime culture, and they derive a large portion of their diet froin the sea." Prominent in this diet are the * Present address: Environmental Sciences Branch, Division of Biology and Medicine, U.S. Atomic Energy Commission, Washington D.C, 20545. to that previously described. The counting technique was changed slightly; a gas fled (2se) proportional counter operating in anzicoincidence with an umbrella of nine Geiger— Miller tubes was used to detect the 5.o-heV “-ray emitted in the clectron capture decay of S5Fe, YPulses from the proportional cowater were recorded in a 512-channel multichannel analyzer. The detection system was surrounded by 4in. of lead shielding and the resultant background counting rate under ihe S5fe 245 photopeak was 1.7 counts/min-!,