Summary of Medical Survey of Rongelap People Five and Six Years After Exposure to Fallout

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FIVE Am SIX YEARS Aarrtral medtcal surveys of the Marshsllese Islanders wre carried out in March 1959 and MBTch 1960, 5 and 6 gems after their accidental mm t o the fallout f’roa~the weapn exploded a t Bikini March 1, 1954. hurine the 1959 survey 76 exposed persons, including their children, and 166 uneqpoeed Rongelap people, who semed M a canparison population, were Kwajalein Atolls were -ned at! costrole for the growth and 8web-t studies on the exposed Rongelap children, only the exposed people beimg examined. As a reeult of their exposure in 1954, many of the bngetap people had experienced early sgnptorns related t o the gastrointestinal tract and beta burns of the skin along with spotty epilation. Later they showed deprsssion of their peripheral blood elements cwn8urate with the calculated doses of gmma radiation (175r t o 64 pqle and 69r t o 18 people). ~naddition, radioclaearical analyses of urine samples indicated that they had aeqpired fractional boQy burdens of certain radionuclides. Despite these evidences of crrposure, acute radiaCion sickness did not develop in the people and there were no deaths then (or 6ubsegImitv) that could be SssignSa t o their radiation exp~mxre. Bo specific therapy 4mpbc)rteS and platelets, proceeded gradually over the e n a n g JnarS. The beta burns, which appeared about two wecb after utposurc, were, for the most part, superficial in nature and haled in several weeks; only a few lesions persisted and there were not dissbliag i n any way. Thc &air regrew mnmlly, begimdng about three m n t b after -sure. The internally absorbed radionucllder caused no lhBowg acute cffects aad -re rapidly excreted so that bare btactaible 8t2tidty was i d a par o r two later, excepk mg the 3 0 aait cs137 isotopes present in tlie Tire 5- and 6-year post--sure surveys were ainad primariu a t evaluating the general medical status of the people in conparison with N e unexgosed control papulation, particularly aa to slowly developing Medical histories of the -le during 199 t o 1960 were eeeentially uneventfUl; no speaialdiseme occurred and there were no significant differences in mortality ratee. Faur deaths havc occurred in the exposed people since erpostlre givlng a mortality rate of 8.1 per lo00 populafioa, campared with 8.3 per lo00 for the control popuhtion and 6.8 for the the past six gears indicates no noticeable change i n fertility. The 24 births repraeent a rate of 48 per lo00 population, cumpared with 62 per 1000 f o r the control population and 37.3 for the Marshall Islands (1957). In addition, grotrpr of children atWt i rik, B&jum, and The 1960 survey WSB brief, Recovery of the peripheral blood clcsents, particularly the The birth rate in the exposed group m r

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Physical examinations showed both the generally i n a hitate of good health. exposd and unexposed people to be No conditions were seen that could be directly rebtd to radiation effects. minor disorders i n both adults and children was about the same i n the exposed and unexposed groups. Tbs ineiitance of various I n connection with growth and developpsnt sttldies in the six-year chronological age group, three boys and one.&rl out of five boys snd two girls In the exposed group exhibited significautly retarded skeletal maturation as Judged by x-ray examination; but tbe over-all group size8 are too small t o warrant interpretation. Lcardiovaasculrrr mmey of the adults showed 110 outstanding differences between the ewosed and uneqosed groups. An arthritis survey showed no real differences beheen the exposed end the uneuqosed people; the incidence i s about the sane as that seen i n An opthslmologioal survey demonstrated no differences between the exposed and unexposed groups except possibly a sU@tly greater Incidence of corneal hypertrophy and scam i n the emsed group. A dental survey showed no significant differences i n either caries rate or incidence of peridonterl disease between erposed & unexposed groups. FWiation exposure appears not t o have af'fected dentition in the &e b t e effects of radiation are difficult t o ~18scssaa they are those associated w%thnormal. weing (skin looseness, elasticity, and senile changes; peytng of the herfr enod balding; loss of acemodation, reduced visual. acuity, and arcus esenflisj reduced hearing; cardiovascular changes including blood pressure and degrees of peripheral and retinal arteriosclerosis; retrogmsdsfon of neurcmtnasrrlar *&ion and hand strength were measured or estiasfed on a o t o 4 + scale). th@semeasurements in exposed and ungxposed indiv3duals of the 88138 age groups revealed LIO elear differences. One case of' cancer developed i n the exposdl group five ~resre&ter exgosure, but thfs is too soon, It is believed, t o be related t o radiation exposure. Uukemia surveys including physical findings, studies of white cell counts and typesp alkaline phosphatase staining, and basophil counts ebowed no evidence of leukemia o r leukenrLc tendenw. Genetic effects ham! not been specifically studied beeause of the erndll number of people involved. genetfc changes have been detected on routine pbysical examination i n the first-generation children of exposed parents. However, no apparent radiation-induced

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heanatological slxrrrcgs continue to show conslt3erable fluctuation gear-to-year mean levels of leukocytes in both the exposed and me&sed gr&s. The man leugoqte level of tb me ed shod a decrease at the 1960 survq compared t o 1959 (no unexposed psople were examined). !i%ereasons for these fluctuations are not apparent. A t five pars post-exposure (1959), the exposed people a t i l l had meran platelet levels 10 to 154 below those of the unerposed groqp, but in 1960 the lsnaphowe levels for the first time equsled those of the unexposed group. The mean erythrocyte levels =re slightly lower i n the eqmsed people but a general anemic teh n cy exists in all Marshallese, both -sed and un w sed. The fact that some of the bwod elements i n the exposed group have not yet returned t o the lpels of' the unexposed group raises the possibility thata residual radiation effect on the bone marrow persists, but other, not irmnedi8tSl.y apparent, factors nmy be involved. Radionuclide body burdens of Csl-37, zP65 and Sr9O were evaluated by measurement in a whole-body counter or by estimation from r8dio cWO al malyses of the urine. and Srgo continue to r i s e but at docrewing rates, whereas the level for Cslx appears t o have reached equilibrium and now t o be di8linishing. Llttle or none of the body burdens of the -sed group appear t o be due t o the initial exposure, since a t present them is little difference between the levels of the exposed and unexposed populations Uvfng on Rongelap Island. llbis nay be elrplained by the fuet that additional weapon tests held in the area have deposited additional fission products into the eDviroment, and the fact that certain staples of diet are imported and, hence, the people are not living i n a "closed envimnmunt." Consequently, it may never be possible t o equate body burdens with snvironmental contaminations. burdens are now and will be of small significance in terms of Mati on The body burdens of Zn65 In a q case, the body Judging f'mm the Japanese populstions beiag sfudied by the A t d c Bomb Casualty Cds sion at Hiroshima and Ragamki, the next five years will be the critical pextod for the development of lsukctmia in the MarsUese. Sines animal eqmiments indicate that still othcr late effects may occur i n man such as premature ageing, shortsning of life span, increme i n degenerative diseases, genetic change8, et&, continued careful WtamiHlation of these populations is in order; all effects should be doclaaented and therapeutic procerdures in8tItuted wherever possible, should such effects develop. In addition, the relation of the envirOrnncnW contamination on Rongclap to the b w burdens of radionuclides of the people living there, Imperfect tm it is, warrants close study. The United &tione, Scientific Committee on the Effects of Atornic Radiations now reviews these yearly surveys.