Medical Survey of Rongelap People Five and Six Years After Exposure to Fallout (with an Addendum on Vegetation)

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(With an Addendum on Vegetation) l BROOK HAVEN NATIONAL LABORATORY Associated Universities, Inc. under contract with the ., LJn’i ted States Atomic Energy Commission

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MEDICAL SURVEY OF RONGELAP PEOPLE FtiE AND SIX YEARS AFTER EXPOSURE TO FALLOUT (With an Addendum on Vegetation) JOHN IAMAN, PRACTITIONER,2 AND JACK HELKENA, PRACTITIONER with the technical assistance of ‘Brookhaven Notic - al Loborotory, Upton, New York ~Deportment of Public Hec!th, Trust Territory of the Pocific lslonds ‘South Nossau Communities Hospital, Rockville Centre, New York 5M. D. Anderson Hospital, University of Texos, Houston, Texas 6National Institutes of Health, Bethesda, Maryland 7Atomic Bomb Casualty Commission, Hiroshima, Japan 8Naval Medical Research Institute, Bethesda, Maryland ‘Memorial Hospital for Cancer and Allied Diseases, New York, New York BROOK HAVEN NATIONAL LABORATORY

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This report was prepared as an account of Go\,ernmcnt spon.wred woA. Neither the United Statea, nor the Commission, nor any person acting on behalf of the Commission: A hfakcs an)- warranr> or repr~nlation, expressed or implied, with respect to the accuracy, comp]ctehcs, or uscfulncs of the information contained in this repo% or that the use of any information. apparatus, method, or pmces discbscd in d-ii rqmrt B. Assumes any liabilities with respect to the usc of. or for damagm resulting frons the use of an; information, apparatus, method, or proms disclosed in this report- .+s used in the above, “pm-son acting on behalfof the Commission” iocludcs any elOployee or contractor of the Commission. or employee of such contractor, to the extent that such employee or contractor of lhe Commission, or employee of such contractor prepares. disseminates. or provides access to. any information pursuant to his employment or contract with the Commission, or his emplo>mcnt with such contractor. Office of Technical Semi~ Department of Commerce

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Suhmomy OF PAST FINDINGS...................................................................................... Beta Irradiation of the Skin .................................................................................. History and Physical Examinations.. .............................................................

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Review of Data on h40rta1ity and Pregnancy Terminations Over the Past Six Years ..... ...................................... 17 Growth and Development Studies .................................................................. 20 Studies of Aging Criteria ...................................................................................... 28 Sodium and Potassium Levels, 1959 ............ .................................................... 38 Studies of Genetically Inherited Trai~ ............................................................ 41

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Estimation of the Internal Radiation Hazard .................................................... Results and Discuxion .......................................................................................... Radiochemical Analysis of Urine .................................................................... APPENDIX 1. Rongelap Blood Coun~ ...................................................................... 61 APPENDIX 4. Hematological Findings, 1960 ............................................................ 68 APPENDIX 6. Blood Groupings and Hap(oglobins, 1958–1959, and BIT and Cholesterol Levels, 1959 ..................................................... 74 A Note on the Vegetation of the !forthern Islets of Rongelap ,4toll, hlarshall Islands, Nlarch 1959 ... ........................ 85

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MEDICAL SURVEY OF RONGELAP b FIVE AND SIX YEARS AFTER EXPOSURE The results of medical surveys of the people of Rongelap i~ the Marshall Islands, carried out in March 1959 and in March 1960 at 5 and 6 years after the accident, are presented in this report. These people had been accidentally exposed to fallout radiation following a detonation ofa high yield thermonuclear device during experiments at Bikini in the Pacific Proving Grounds in hfarch 1954. An unpredicted shift in winds caused a deposition of significant amounts of fallout on four inhabited hflarshall Islands to the east of Bikini (see Figure 1) and also on 23 Japanese fishermen aboard their fishing vessel, the Lucky Dragon. Of the inhabitants of the island of Rongelap, 105 nautical miles away from the detonation, 64 recei~ed the largest fallout exposure: an estimated dose of 175 r of whole-body gamma radiation, contamination of the skin sufficient to result in beta bl]rns, and slight internal absorption of radioactivc materials through inhalation and ingestion. .4nother 18 Rongelap people a~vay on a nearby island (Ailingnae), where less fallout occurred, recei~ed only an external gamma dose of about 69 r. There were 28 .4merican servicemen on the island of Rongerik further to the east \sho received about the same amount of radiation as did the Rc)ngelap people on .4ilingnae. Lastly, 157 Nfarshallese on ~tirik Island, about 200 miles fu~her east, received about an estimated 14 r of whole-body radiation. The fallout was not visible on this island and no skin effects developed. The exposed people I, ere evacuated from these islands by plane and ship about t}~o days afier the accident and taken to K\vajalein Naval Base about 150 miles to the south, \vhere they recei~ed extensive examinations for the follo~ving three months. In ~’iew of the generall;- negative findings on the American servicemen, they \\ere later returned to their duty stations. The Utirik people were also allowed to return to their home is]and, where radioactive contamination \vas considered to be ofa slight enough extent to allo~v safe habitation. Because Rongelap Atoll was considered to lx too highly contaminated, a temporary village was constructed for the Rongelap people on” Majuro Atoll se~’eral hundred miles to the south, where they lived for the following 3% years and were examined at yearly intervals by a special medical team. In July 1957, after careful evaluation of the radioactive contamination situation, Rongelap Island was considered safe for habitation. A new village was constructed, and (he Rongelap people were moved there by h’a~y ship. The annual medical sun-eys have since been carried out on RongeA group of more than 100 Rongelap people, who were relatives of the exposed people but had been aivay from the island at the time of the accident, moved back with the Rongelap people to their home island and have served as an ideal comparison population for the studies. Following the initial survey of the Utirik people on Kw-ajalein in 1954, a repeat survey i{as carried out in March 1957. In addition, during the past survey, as in the pre~’ious surveys, a visit \sas made to “hfajuro .4to11 to examine a group of children who represent part of the control group used for the Figure 1. hlap of fallout area

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The accumulation of data from these surveys is becoming increasingly voluminous. Since conditions have not been favorable for pcrforlnance of extensive statistical analyses or use ofclcc:ronic computing procedures to store and manipulate the data, the annual survey reports published by this Laboratory are made as complete as possible. This report, therefore, includes a considerable amount of raw data, much of it in appendices, so that others may have an opportunity to make further calculations if desired. This report also contains a brief addendum on the vegetation of Rongelap Island. Summary of Past Findings Reports have been published on the findings of surveys made at the following times after expoyears,’ 3 years, s and 4 years. s The following is a brief summary of the findings previously reported. During the first 24 to 48 hr after exposurr, about ‘X+of the Rongelap people experienced anorexia and nausea. .4 few vomited and had diarrhea. Many also experienced itching and burning of the skin, and a few complained oflachrymation and burning of the eyes. Follo\ving this, the people remained asymptornatic until about 2 ~seeks after the accident, \shen cutaneous lesions and loss of hair developed, due largely to beta irradiation of the skin. It was apparent when the people were first examined, a fe~v days after exposure, that the lymphocytes \rere considerably depressed and that significant doses of radiation had probably been recei~’ed. In addition to the \vholebody dose of radiation and the beta irradiation of the skin, radiochemical analyses of the urine material had also been absorbed internally. The effects of the radiation can best be summarized under three headings according to the mode ofexposure: penetrating irradiation, skin irradiation, and internal irradiation. Ailingnac and l_~lirik groups were similar hut less marked. Certain unrxplaincd fluctuations biive occurred from year to year in tbc peripheral blood levels of the comparison populations as well as of the exposed groups. Depression of the peripheral blood elements as represented by mean population levels occurred as follows. Lymphocytes fell promptly and by [he third day were about 557( of the control values in adults, and slightly lower in children. There was only slight recovery after six months. At 2 years, although further recovery \vas e~’ident, the mean values of these cells were still found to be below the comparison population levels (75 to 8070). At 3 years the mean lymphoc~~e counts were slightly below those of the comparison population. At 4 years the mean level appeared to be about the same as that of the comparison population, but many counts remained lower. ing the fimt few weeks but fell gradually to a low of about 5(-)’%0of comparison population levels by the 6th week after exposure. Slow recovery ensued, but at 6 months they \sere still slightly below the unexposed levels. However, by 1 year post exposure they had returned to the level of the comparison population and have remained so, \vith the possible exception of those of children <12 years old, \{hich generally have been lower (ban those of the unexposed children ofcornparable Platelets fell to about 30% of the unexpmed values by the 4th \veek. By 6 months they had reached 70T0 of the controls; at 1 year the nlean platelet count w-as still below that of the control population but higher than at the 6-month survey. .41though further increases ~vere apparent at the 2-, 3-, and 4-year examinations, the levels t\’ere still below those of the comparison population. Changes in hematocnt were not remarkable in any of the groups. cesses or symptoms which could be attributed to radiation effects, aside from skin lesions, loss of hair, and early symptoms. Epidemics of chicken pox and measles occurred. The diseases encountered were no more severe or frequent in the irradiated group than in the unexposed group, even eral blood elements.. Three ~rsons in the exposed population died of disease: (1) a 46-year-old man w-ith a hypeflensive heafi disease which had been The changes in the peripheral blood of the more heavily exposed Rongelap people who received 175 r will be re~-ielved in the section on hematological examinations (see Figures 33, 35, and 38, and Appendices 1 and 2). The changes in the~

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present at [he time ofcxposure, W}]Odied 2 years died, 3 years after exposure, of coronary heart disease complicating diabetes; and (3) a 36-~ear-old man who died of acute varicella, 4 years after exposure, who had received only 69 r, having been on Ailingnae at the time of the fallout. There was no apparent relationship between any of these deaths and radiation exposure, and mortality in the exposed group did not appear to be greater than in the unexposed population. It was diffi~ult to evaluate the effects on fertility. However, a number of apparently normal babies were born during the 4-year period, and there has been no discernible fall in birth rate. A slightly higher number of miscarriages occurred in the exposed women than in the unexposed group; this will be further evaluated in the present report. No opacities of the lens or other eye changes have been found that could be related to radiation. Studies on height, weight, and bone age seemed to show a slight degree of retardation in growth and development in the exposed children. However, the small number of children involved, and a later finding that exact ages of some of the children were in doubt, has resulted in are-evaluation of these data based on more reliable age deterBETA IRRADIATION OF THE SKIN It was ‘impossible to get an accurate estimate of the radiation dose to the skin. Beta burns of the skin and epilation appeared about 2 weeks after exposure, largely on parts of the body not co~ered by clothing, About 90% of the people had these burns, and a smaller number developed spotty epilation of the scalp. hfos( of the lesions were superficial; they exhibited pigmentation and dry, scaly desquamation, and were associated with little pain. Rapid healing and repigmentation followed. Some lesions were deeper, showed wet desquamation, and were more painful. A few burns became secondarily infected and had to be treated with antibiotics. Repigmentation of the lesions gradually took place in most instances, and the skin appeared normal within a few weeks. However, in about 15% of the people, deeper lesions, particularly noted on the dorsum of the feet, continued to show lack ofrepigmentation with varying degrees of scarring and atrophy of the skin. At 4 yearn the only residual effects of beta radiation of [hc skin were s~.rn in ]2 cases which showed varying degrees of pigment aberrations, scarring, and atrophy at the site of the former burns. hTumerous histopathological studies have been made,’” and the changes found have been consistent with radiation damage. At no time have changes been observed either grossly or microscop ically indicative of malignant or premalignant change. Spotty epilation on the heads was short lived, regrowth of hair occurring about 3 months after exposure and complete regrowth of normal hair by six months. N’o further evidence ofepilation has been seen. An interesting observation was the appearance of a bluish-brown pigmentation of the semilunar areas of the fingernails and toenails in about 9W0 of the people, beginning about 3 weeks afier exposure. By 6 months, this pigmentation had largely grown out with the nail and had disappeared in most cases. The cause of this Phenomenon has not been explained. DOE AaRCHNES Radiochemical analyses of numerous urine samples of the exposed population showtd internal absorption of radioactive materials, probably brought about largely through eating and drinking contaminated food and water and to a lesser extent through inhalation. During the first few days ~hen the body levels were at their highest, the maximum permissible concentrations were approached or slightly exceeded only in the case of strontium-89 and the isotopes of iodine. The concentrations were believed to be too low to result in any serious effects. Body levels fell rapidly, so that by 2 and 3 years post exposure, they \vere far below the accepted maximum permissible level; by 6 months acti~’ity in the urine was barely detectable. The return of the Rongelapese to their home island (which after careful survey was considered safe for habitation, despite a persisting low level of radioactive contamination) lsas reflected in a rise in their body burdens and increased urina~ excretion of certain radionuclides. Beginning in 1957, gamma spectroscopy by use of a Io\v-level counting chamber u-as added to the techniques of radiochemical analysis. This, along with radiochemieal analysis of urine samples, shelved an increase in body burdens ofcesium-137 by factom of up to 100 and of swontium-90 by a factor of 10 to 20; and some increase also in zinc-65, since the re-

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turn of the pcop]c to RoIlgclap. The body ltnrls of the unexposed people who returned to the island also increased, becoming indistinguishable from those of the originally exposed group. However,b’ the levels remain well below the maximum permissible limits. Analyses of bene sampl= on one of the men who died showed 3.7 strontium-90 units/g . Other studies have been carried out on the Rongelap people which are not direcdy related to radiation effects. An intensive intestinal parasite survey showed that the people were infected Mith many types of protozoa and helminths. This finding did not entirely account for the generally high incidence ofeosinophilia. Other findings that need further explanation are …