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

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MEDICAL SURVEY OF RONGELAP ‘PEOPLE HVE AND SIX YEARS AFTER EXPOSURE TO FALLOUT (With an Addendum on Vegetation) BEST COPY AVAILABLE BROOK HAVE NN AT IONAL LABORATORY United States Atomic Energy Commission under contract with the

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MZ ICAL SURVEY OF RONGELAP PEOPLE FIVE AND SIX YEARS AFTER EXPOSURE TO FALLOUT (With an Addendum on Vegetation) with the technical assistance of ‘Brookhaven National Laboratory, Upton, N e w York ?Department of Public Health, Trust Territory of the Pacific Islands 3Walter Reed Army Medical Center, Washington, D.C. ‘South Nassau Communities Hospital, Rockville Centre, N e w York 5M.D. Anderson Hospital, University of Texas, Houston, Texas *National Institutes of Health, Bethesda, Maryland ’Atomic Bomb Casualty Commission, Hiroshima, Japan 8Naval Medical Researqh Institute, Bethesda, Maryland 9Memorial Hospital for Can;& and Allied Diseases, N e w York, New York BROOKHAVEN NATIONAL LABORATORY

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This report was prepared as an account of Government sponsored work. Neither the United States, nor the Commission, nor any person acting on behalf of theCommiGion: A. Makes any warranty or representation, expressed or implied, with respect to the accuracy, completeness, or usefulness of the information contained in this report, or that the use of any information, apparatus, method, or process disclosed in this report may not infringe privately owned rights; or B. Assumes any liabilities with respect to the use of, or for damages resulting from the use of any information, apparams, method, or process diwlosed in this report. As used in the above, “person acting on behalf of the Commission’’ includes any employee or contractor of the Commission, or employee of such contractor, to the extent that such employee or contractor of the Commission, or employee of such contractor prepares, disseminates, or provides access to, any information pursuant to his employment or contract with the &rnmihion, or his employment with such contractor. Available from the Office of Technical Services, Department of Commerce

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Beta Irradiation of the Skin ................................................. .................................. Attitudes of Rongelap People. ........................................................................ Studies of Aging Crlterla ................................................................................. Studies of Genetically Inherited Characteristics............................................ Radionuclide Body Burden Evaluation ..........................................................

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Review of Data on Mortality and Pregnancy Terminations Over the Past Six Years ........... . ............................. Growth and Development Studies .................................................................. Sodium and Potassium Levels, 1959............................................................ ....

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Estimation of the Internal Radiation Hazard ...................................................... 45 Whole-Body Counting With the Gamma Spectrometer _..._............._..._._....... APPENDIX5. Individual WBC, Basophil, and Alkaline Phosphatase, 1959-1 960.. APPENDIX6. Blood Groupings and Haptoglobins, 1958-1959, and BFT and Cholesterol Levels, 1959................................................... .... 74 ADDENDUM.A Note on the Vegetation octhe Northern Islets of Rongelap Atoll, Ma6ha.U Islands, March 1959 85

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MEDICAL SURVEY OF RONGELAP PEOPLE FIVE AND SIX YEARS AFTER EXPOSURE TO FALLOUT T h e results of medical surveys of the people of Rongelap in the Marshall Islands, carried out in March 1959 and in hlarch 1960 at 5 and 6 years after the accident, are presented in this report. These people h a d been accidentally exposed to fallout radiation following a detonation of a high yield thermonuclear device during experiments at Bikini in the Pacific Proving Grounds in hlarch 1954. An unpredicted shift in winds caused a deposition of significant amounts of fallout on four inhabited Marshall Islands to the east of Bikini (see Figure 1 ) a n d also on@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 received the largest fallout exposure: a n estimated dose of 175 r of whole-body gamma radiation, contamination of the skin sufficient to result in beta burns, and slight internal absorption of radioactive materials through inhalation and ingestion. Another 18 Rongelap people away on a nearby island (Ailingnae), where less fallout occurred, received only a n external gamma dose of about 69 r. There were 28 American servicemen on the island of Rongerik further to the east who received about the same amount of radiation as did the Rongelap people on Ailingnae. Lastly, 157 Rilarshallese on Utirik Island, about 200 miles further east, received about a n estimated 14 r of whole-body radiation. T h e fallout was not visible on this island and no skin effects developed. T h e exposed people were evacuated from these islands by plane and ship about two days after the accident a n d taken to Kwajalein Naval Base about 130 miles to the south, where they received extensive examinations fo,r the following three months. In view of the generally negative findings on the American servicemen, they were later returned to their duty stations. T h e Utirik people were also allowed to return to their home island, where radioactive contamination was considered to be of a slight enough extent to allow safe habitation. Because Rongelap Atoll was considered to be too highly contaminated, a temporary vil1,age was constructed for the Rongelap people o n hlajuro Atoll several hundred miles to the south, where they lived for the following 3 ' i 2 years and were examined at yearly intervals by a special medical team, In July 1937, after careful evaluation of the radioactive contamination situation, Rongelap Island was considered safe for habitation. A new village was constructed, and the Rongelap people were moved there by Navy ship. The annual medical surveys have since been carried out on RongeA group of more than 100 Rongelap people, who were relatives of the exposed people but had been away from the island at the time of the acc4 dent, moved back with the Rongelap people to their home island and have served as a n ideal comparison population for the studies. Following the initial survey of the Utirik people o n Kwajalein in 1954, a repeat survey was carried'out in March 1957. In addition, during the past survey, as in the previous surveys, a visit was made to Majuro Atoll to examine a group ofchildren who represent part of the control group used for the growth a n d development studies of the exposed Figure 1 M a p of fallout area

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T h e accumu%i’n of data from these surveys is tions have not been favorable for performance of extensive statistical analyses or use of electronic computing procedures to store and manipulate the data, the annual survey reports published by this Labpratory are made as complete as possible. This report, therefore, includes a considerable amount of rhrv data, much of i t in appendices, so that others may have a n 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 expobrief summary of the findings previously reported. During the first 24 to 48 hr after exposure, about % of the Rongelap people experienced anorexia and nausea. A few vomited and had diarrhea. Many also experienced itching and burning of the skin, and a few complained of Iachrymation and burning of the eyes. Following this, the people remained asymptomatic until about 2 weeks after the accident, when cutaneous lesions a n d loss of hair developed, due largely to beta irradiation of the skin. It was apparent when the people were first examined, a few days after exposure, that the lymphocytes were considerably depressed a n d that significant doses of radiation had probably been received. In addition to the wholebody dose of radiation and the beta irradiation of the skin, radiochemical analyses of the urine showed that measurable amounts of radioactive material had also been absorbed internally. The effects of the radiation can best be summarized under three headings according to the mode of exposure: penetrating irradiation, skin irradiation, and internal irradiation. 4 T h e changes in the peripheral blood of the more heavily exposed Rongelap people who received 175 r will be reviewed in the section on hematological examinations (see Figures 33, 35, and 38, and Appendices 1and 2). The changes in the Ailingnae and Utirik groups were similar but less mar ked. Cer t ai n u nex pi ai ned fl uc tua tio ns have occurred from year to year in the peripheral blood levels of the comparison populations as well as of the exposed groups. Depression of the peripheral blood elements as rkpresented by mean population levels occurred as follows. Lymphocytes fell promptly and by the third dav were about 55% of the control values in adults, a n d slightly lower in children. There was only slight recovery after six months. At 2 years, although further recovery was evident, the mean values of these cells were still found to be below the comparison population levels ( 7 5 to 80%). At 3 years the mean lymphodyte 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 first few weeks but fell gradually to a low 3’‘ of about 50% of comparison population levels by the 6th week after exposure. Slow recovert en- ,sued, but at 6 months they were still slightly $elow .f the unexposed levels. However, by 1 year pdst ex- ’ posure they had returned to the level of the comparison population a n d have remained so, with the possible exception of those ofchildren < 1 2 years old, which generally have been lower than those of the unexposed children of comparable Platelets fell to about 30% of the unexposed values by the 4th week. By 6 months they had reached 70% of the controls; at 1 year the mean platelet count was still below that of the control population but higher than-at the 6-month survey. Although further increases were apparent a t the 2 - , 3-, a n d 4-year examinations, the levels were still below those of the comparison population. Changes in hematocrit were not remarkable in any of the groups. Clinical examinations revealed no disease processes or symptoms which could be attributed to radiation effects, aside from skin lesions, loss of hair, a n d early symptoms. Epidemics of chicken pox and measles occurred. The diseases encountered were no more severe or fiequent in the irradiated group t h a n in the unexposed group, even during the period of greatest depression of peripheral blood elements. Three persons in the exposed population died of disease: ( 1 ) a 46-year-old man with a hypertensive heart disease which had been

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present at the tim?%?e%posure, who died 2 years died, 3 years after exposure, of coronary heart disease complicating diabetes; and (3) a 36-yeear-old man who died of acute varicella, 4 years after exposure, who had received only 69 r. having been on Ailiggnae at the time of the fallout. There was no apparent relationship between any of these deaths a n d radiation exposure, and mortality in the exposed group did not appear to be greater than in the unexposed population. It was difficult 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 o n height, weight, and bone age seemed to show a slight degree of retardation in growth a n d 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 a re-evaluation of these d a t a based on more reliable age deterBETA IRRADIATION OF THE SKIN Y t was impossible to get a n accurate estimate of the radiation dose to the skin. Beta burns of the skin a n d epilation appeared about 2 weeks after exposure, largely on parts of the body not covered by clothing, About 90% of the people had these burns, anda smaller number developed spotty epilation of t h e scalp. Most of the lesions were superficial; they exhibited pigmentation and dry, scaly desquamation, a n d were associated with little pain. Rapid healing a n d repigmentation followed. Some lesions were deeper, showed wet desquamation, and were more painful. A 'few burns became secondarily infected and had to be trealed with antibiotics. Repigmentation of the ( ( lesions gradually took place in most instances, and' 2% the skin appeared normal within a few weeks. However, in about 15% of the people, deeper lesions, particularly noted o n the dorsum of the feet, continued to show lack of repigmentation with varying degrees of scarring and atrophy of the skin. At 4 years the only residual eRe'ects of beta radiation of the skin were seen in 12 cases which showed varying degrees of pigment aberrations, scarring, a n d atrophy at the site of the former burns. Xumerous.histopathological studies have been and the changes found have been consistent with radiatioli damage. At no time have changes been observed either grossly or microscopically indicative of maliznant or premalignant change. Spottv epilation on the heads was short lived, regrowth of hair occurring about 3 months after exposure a n d 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 90% of the people, besjnning about 3 weeks after exposure. By 6 months, this pigmentation had largely grown out with the nail and had disappeared in most cases. T h e cause of this phenomenon has not Radiochemical analyses of numerous urine samples of the exposed populaeion showed internal absorption of radioactive materials, probably brought about largely through eating a n d drinking contaminated food and water and to a lesser extent through inhalation. During the first few days when 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. T h e 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 were far below the accepted maximum permissible level; by 6 months activity in the urine was barely detectable. The return of the Rongehpesc to their home island (which after careful survey was considered safe for habitation, despite a persisting low Ievd of radioactive contamination) was reflected in a rise in their body burdens a n d increased urinary excretion of certain radionuclides. Beginning in 1957, gamma spectroscopy by use of a low-level counting chamber was added to the techniques of radiochemical analysis. This, along with radiochemical analysis of urine samples, showed an increase in body burdens of cesium- 139 by factors of u p …