Health Physics Pergamon Press 1972. Vol. 22 (March), pp. 245-250. Printed in Northern Ireland IRON-55 IN RONGELAP PEOPLE, FISH AND SOILS T. M. BEASLEY,* E. E. HELD Laboratory of Radiation Ecology, College of Fisheries, University of Washington, Seattle, Washington 407871 and R. M. CONARD Medical Department, Brookhaven National Laboratory, Upton, L.I., New York (Received 5 February 1971; in revisedform 12 April 1971) ve Abstract—The **Fe body burdens for 60 residents of Rongelap Atoll are reported. The measured burdens are approximately 3 times higher than those ofa similar numberofresidents from ‘Vokai-mura, Japan. Since previous measurements in 1966 revealed substantial *°Fe body burdens in Japanese residents, the current Rongclapese **Fe body burdens pose interesting questions. INTRODUCTION SINCE 1965, the distribution of *5Fe in the biosphere has been studied both in the United States and in the Scandinavian countries, Initially, ®*le concentrations: were determined in Alaskan Eskimos, residents of Richland, Washington, and in representative foodstuffs of both.@ Subsequently, ®*ie concentrations in environmental samples and in residents of Finland™ and Swedenwere reported which generally confirmed the findings of the earlier study. Additional research shows that (i) marine organisms and people whose diet is largely scafood contain the highest concen- trations in 1966 and continue to decrease.'%7) JAAKKOLA'! has recently presented an excellent summary of the measurements of 55Fe in includes a We determined the **Fe body burdens of * Present address: Environmental Sciences Branch, Division of Biology and Medicine, U.S. Atomic Energy Commission, Washington D.C. 20545. the dicts of males or females. Thus, the deter- mination of °5Fe 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 1954.00 We considered it probable that retention of ®5Fe ai the atoll from that event, coupled with input from world wide fallout from large-scale METHODS AND ‘TECHNIQUES valuable natives at Rongelap Atoll in the Marshall Islands. Onur interest in this particular population derives from two important considerations. First, the Rongelapese are a maritime culture, and they derive a large portion of their dict from the sea.Prominent in this diet are the ‘There are no apparent qualitative differences in to elevated concentrations of 5*Fe in marine species in the Rongelapese diet and therefore unusual body burdens of this radionuclide in Rongelap residents. the **Fe levels in people reached peak concen- which Estimates of fish consumption vary, but daily intakes between 75-150 g appear reasonable. nuclear device testing in 1961-1962 might lead trations of **Fe;“) (ii) residents of the northern hemisphere have higher *5Fe body burdens than those of the southern hemisphere;") and (iii) Finnish Lapps bibliography. reef fishes; goatfish (Mudloidicthys, sp.), mullet ( Neomyxus, sp.) and surgeon-fish (Acanthurus, sp.). ‘The method of separation of 95Fe wasidentical to that previously described.“ The counting technique was changed slightly; a gas filled (Xe) proportional counter operating in anticoincidence with an umbrella of nine Geiger— Miller tubes was used to detect the 5.9-keV A-ray emitted in the clectron capture decay of *°Ie. Pulses from the proportional counter 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 the **I'e photopeak was 1.7. counts/min7, 24 5 ye ge