Medical Examination of Rongelap People Six Months After Exposure to Fallout (Operation Castle-Addendum Report Project 4.1A)

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Report to the Scientific Director MEDICAL EXAMINATION OF RONGELAP PEOPLE SIX MONTHS AFTER EXPOSURE TO FALLOUT Naval Medical Research Institute U.S. Naval Radiological Defense Laboratory San Francisco, California The Medical Research ~cmtcr

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Follow-up medical examinations were made of the Marshallese inhabitants of Rongelap Atoll 6 months after they had been exposed to atomic bomb fallout radiation during the Operation CASTLE test series in March, 1954. During the early acute period following exposure, these people had shown systemic effects and marked hematological changes resulting from penetrating gamma radiation; extensive superficial skin lesions and epilation associated principally with beta and soft gamma radiation from fallout material deposited on uncovered skin areas; and minimal internal contamination with fission products, resulting principally from ingestion of fallout material. At the time of the 6-month resurvey the individuals, in general, appeared healthy and normally active, and no deaths had occurred in the interim period. Three babies had been born since exposure, none of whom displayed detectable abnormalities. One miscarriage at 3 months occurred during the interim period. No specimen was available for study. The skin lesions previously prominent had healed completely, and only occasional hy - perpigmentation of depigmented scars was seen in a few individuals who had severe early skin damage. Regrowth of hair had commenced during the third month following exposure and was essentially complete at the 6-month examination. Residual of the fingernail discoloration previously noted was found in three individuals. No additional findings on physical examination could be ascribed to radiation exposure, and most had gained weight during the interim period. A measles epidemic was in progress during the examinations. The severity of the disease in the Rongelap people was no greater than in a control unexposed population, and the incidence was no higher. Chest X-rays of all individuals revealed no abnormalities ascribable to the fallout radiation. Analysis of hematological data obtained failed to demonstrate a significant , effect of measles on the peripheral blood count. Neutrophile, lymphocyte, and platelet counts were not significantly dtiferent from counts tiken on the 74th post-exposure day, and none of these values had returned to control levels. Studies of bone marrow specimens obtained on 20 adult individuals revealed no significant abnormalities. Minimal amounts of residual radioactivity were detectable in the urine of approxj mately one-third of the exposed individuals.

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The authors are indebted to a number of individuals at a number of administrative levels for their extensive aid and willing cooperation, so necessary for the success of a field mission of this type. Drs. JohII Bugher and Charles Dunham of the Division of Biology and Medicine, Atomic Energy Commission, coordinated and expedited all necessary arrangements among the State Department, the Department of the Interior, the Navy Department, and the Trust Territories. The Chief of Naval Operations arranged all necessary transportation. Commander Harry Etter of the Bureau of Medicine and Surgery was instrumental in completing arrangements so that the resurvey team could proceed on schedule. CAPT R. A. Hinners, .Director, Officer, Naval Medical Research Lnstitute (NMRI), p~aced all necessary facilities of the two laboratories involved at the disposal of the medical team, as did CAPT A. R. Behnke, RadioTompkins and E. P. Cooper, Scientific and Associate Scientific Director, respectively, of the NRDL. The authors are particularly indebted to CDR. E. P. Cronkite, NMRI, in charge of the original observations on the e~sed people, for his extensive efforts in organizing the resurvey and for his support throughout all phases of the endeavor. Maynard Ness, District Administrator, and Dr. Dunham Kirkham, Medical Officer at the Trust Territory Headquarters, Majuo, Mrshall Islands, furnished all necessary facilities at Majuro, and the entire resurvey team is grateful for the cooperation and hospitality extended by all Trust Territory representatives. The efforts of LCDR L. J. Smith, advance administrative representative for the resurvey team, materially expedited the accomplishment of the work. The authors are indebted to all members of the team for their cooperation and extensive efforts, particularity to Chief p. K. Schork, and to H. H. Hechter for performing the necessary analyses of data. The authors are indebted for histopathological consultation provided by Dr. David Wood of ings and to Dr. N. L. Petrakis for performing the differential counts.

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1.3 General Methods; Control Population . CHAPTER 3 SKIN LESIONS, EPI.LATION, AND NAIL PIGMENTATION CHAPTER 5 INTERNAL RADIOACTIVE CONTAMINATION

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APPENDIx A EXPOSED POPULATION: COMPARISON WITH INITIAL FINDINGS OF INDIVIDUAL WEIGHTS AND HEMATOLOGICAL VALUES . . CHAPTER 3 SKIN LESIONS, EPILATION, AND NAIL PIGMENTATION Color plates 1 to 12 .... 4.1 Serial Post-exposure Changes in the Neutrophile, and Lymphocyte Counts 4.2 Serial Post-exposure Changes in the Mean Total Leukocyte, for the Rongelap Group . Mean Platelet Counts 4.3 Cumulative Neutrophile Counts for the Rongelap Group at the Time of Maximum Depression and 6 Months After Exposure . 4.4 Cumulative Platelet Counts for the Rongelap Group at the Time of Maximum Depression and 6 Months After Exposure . CHAPTER 2 CLINICAL EXAMINATION 2.1 Positive Findings on Physical Examination of the Exposed and 4.1 Hematological Data for Control Populations by Age and by Sex . 4.2 Mean Values for Peripheral Blood Determmations on the Rongelap 4.3 Mean Values for Peripheral Blood Determinations on the Ailinginae 4.4 Mean Blood Counts for the Exposed and Control Populations, with and 4.5 Bone Marrow Differential Counts on Exposed and Control Marshallese

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The present medical resurvey was organized as the first of a contemplated series designed to provide long-term medical examinations of the Marshallese people exposed to radiation from fallout during Operation CASTLE. Following the detomtion of a thermonuclear device on Bikini Atoll on 1 March, 1954, 28 Americans on Rongerik Atoll and 239 Marshallese (64 on Rongelap, 18 on Ailinginae, and 15? on Utirik) were exposed to significant amounts of radiation from fallout. These individuals were evacuated to Kwajalein, where they were cared for during the acute period following exposure by a special medical team composed of individuals from the Naval Medical Research Institute (NMR.1) in Bethesda and in the U.S. Naval Radiological Defense Laboratory (NRDL) in San Francisco. A report of medical findings has been issued as an Operation CASTLE report. * The present report is concerned with the medical status 6 months later of the Marshallese people who received the highest estimated dose of gamma radiation, the Rongelap and Ailinginae’ The Rongelap group was exposed to an estimated 175 r of gamma radiation, calculated from dose rates measured free in air, over a period of approximately 46 hr. The Ailinginae group received an estimated 69 r of gamma radiation over approximately 54 hr. Both groups received additional beta radiation to exposed skin areas. All findings were more severe in the Rongelap than in the Ailinginae grcup. These iindings are reviewed later in the report. Because of the continuing hazard from radiation on their home atolls, thk Rongelap and Ailinginae people were not returned to their homes after observation at Kwajalein. Instead, they were moved to Majuro Atoll, the Trust Territory Headquarters for the Marshall Islands. Housing was furnished them on Ijij Island (pronounced “edgit”), 10 minutes by boat from the Trust Territory Headquarters, where they were residing at the time of the present examinal The Utirik people, who received comparatively slight exposure, were returned to their home atoll following observation at Kwajalein and were not examined during the present resurvey. The exposed Americans had been returned to their duty stations in the United States.

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1.3 GENERAL METHODS; CONTROL POPULATION— The facilities of the Marshall Island Memorial HospItal in the Trust Territory Headquarters were made available for the clinical and laboratory examinations. The resurvey included the establishment of a control group of unexposed Marshallese, in addition to obtaining interval histories, complete physical examinations, hematological studies, and radioactivity y excretion studies on all the exposed individuals. Similar examinations were conducted on this control group for immediate comparison of findings and to serve as a base line for comparing growth and other future changes in the two groups. The control patients were obtained principally from among the residents of the village of Rita, located about 2 miles from the hospital. This population was chosen on the basis of its similarity with respect to the living conditions of the exposed people, its relative permanence, and its acceasibllity to the Memorial Hospital. The individuals were selected on the basis of age and sex to be paired with the members of the exposed group. Thus, each individual of the exposed group was assigned a control individual of the same sex and approximately the same age. The age distribution of the exposed and control populations is given with the hematological results in Chap. 4. The age distribution of the exposed and control groups was the same, except that suitable controls were not found for two women of reported ages 60 and 100, nor were controls established for the three babies born to members of the exposed group since March, 1954. Numbers were assigned to the controls by adding 1000 to the number of the corresponding member of the exposed group. For example, Labnir, number 1011, was the control for 1. E. P. CronMte et al., Study of Response of Human Beings Accidentally Exposed to Significant Fallout Radiation, Operation Castle final report of Project 4.1.

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Within hours of exposure to radiation, approximately two-thirds of the Rongelap people felt nauseated and one-tenth of the group had vomiting and diarrhea. One Ailinginae individual reported nausea. Itching and burning of the skin and eyes during this period occurred in over one-quarter of the Rongelap residents and in a smaller number of the Ailinginae population. With the exception of skin lesions and epilation reported in Chap. 3, there were no further symptoms nor findings on physical examination that could be attributed with certainty to radiation exposure. AH individuals were normally active throughout the period of observation. The various clinical conditions encountered in the highest exposed Rongelap and Aili.nginae groups were not remarkably different in type or extent from those seen in the least exposed Utirik group. Although a number of individuals were markedly neutropenic, no infections attributable to neutropenia @r se were observed. No external evidence of hemorrhage was observed, although platelet counts in 20 per cent of the Rongelap group fell to 90,000/mmS or lower at the time of maximum depression. Antibiotics were used in a few individuals where indicated for incidental infections. However, no prophylactic or therapeutic drugs were necessary or given because of whole-body radiation exposure alone. The following procedures were carried out routinely on both exposed and control groups: (1) brief past history, l (2) complete interval history, (3) skin examination (including biopsies and photographs in selected cases), (4) complete physical examination (including ophthalmoscopic, rectal, and pelvic examinations), (5) chest X-ray, and (6) hematological studies (including bone marrow aspirations in selected cases). Serology was done on some of the exposed individuals. Special measurements were taken on children to provide a base line for future growth and development studies. Past histories revealed little of note, with the exception of a high incidence of yaws (exposed group, 23; control group, 17) and gonorrhea (exposed group, 21; control group, 19). One * Interval and past histories were taken by Dr. John Iaman, a Gilbertese physician who spoke excellent English as well as Marshallese. English-speaking Marshallese nurses aided in the physical examinations.

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control patient gave a history of syphilis for which she had been treated twice. Interval histories were essentially negative. No deaths had occurred in the exposed population, and three apparently healthy infants had been born in the interim period. Their Zn utero ages at the time of exposure were approximately 3, 6, and 7 months. Three other pregnancies were noted during the present examinations, in one cf which conception had occurred at about the time of eXpOsure and in the remaining two, 2 to 4 months after exposure. TABLE 2.1—Positive Findings on Physical Examination of Exposed and Control Populations No. of J No. of Rita Diagnosis group group with heart disease with heart disease Luetic heart disease (?) Heart disease, etiology unknown Fibromyoma of uterus (?) Furuncle of Iabium Tuberculosis, pulmonary, arrested Hernia, inguinal, direct Table 2.1 summarizes the principal findings from history and physical examinations, and additional data on individuals are given in Appendices A and B. Dermatological findings are reported in detail in Chap. 3. There appeared to be no significant difference m disease incidence between exposed and control populations, and no findings, with the exception of those reported in Chap. 3, could be ascribed to radiation effects. A measles epidemic, in progress in both populations during the examinations, had begun to decline in the control group but was still at its peak in the exposed group at the completion of this study. The time interval between the peak incidence of measles in the two populations was probably due to the relative isolation of the exposed group. Body weights of the exposed patients were compared with their weights in March, 1954. Although there were a few instances of significant weight loss in individuals, the over-all popu -

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lation showed an increase. This was probabiy because of relative inactivity inadditlon to having ample supplies of food. Weight changes are shown in Appendices A and B. The special measurements taken on children age 19 or less showed no significant abnormalities. Chest X-ray examinations revealed only long-standing changes ascribable to previous disease. * Estimates of bone age from wrist X-raysi were in keeping with the stated hge. Xrays of long bones showed no abnormalities ascribable to radiation effects. Of 40 Kahn teSt5 given to exposed individuals, three were 3+. Two of these gave a history of, or had physical findings consistent with, late syphilis. Previous yaws per se did not result in a positive Kahn 1. John Caffey, Pediatric X-ray Diagnosis, Year Book Publishers, 1950.

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SKIN LESIONS, EPILATION, AND NAIL PIGMENTATION The Rongelap and Ailinginae groups observed the fallout as a powdery material that fell for several hours and clung to their skin and hair. Thorough decontamination was not accomplished until evacuation occurred one to two days later. The dosage to the skin, resulting from soft bem and soft gamma radiation, could not be calculated due to the complex make-up of the fallout material. Initial symptomatology related to the skin consisted of burning and itching in a large number of people, and irritation of the eyes with lacrimation in a small number, the first two days after exposure. The early s ymptoms were followed by pronounced lesions of the skin and epilation of the head, which first appeared about the 12th to the 14th day pst-exposure in the Rongelap group and after the 20th day in the less-exposed Ailinginae group; the lesions occurred primarily on the exposed parts of the body which were not protected by clothing. Those persons who remained under shelter in their homes developed less severe lesions or no lesions, Also, there was some protection to those who bathed or remained in their homes during the fallout. The development of the skin lesions did not conform in all respects to beta skin lesions described in the literature. No …