Medical Survey of Rongelap People Eight Years After Exposure to Fallout

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AUSTIN LOWREY, COL (MC) USA, A. HICKING, PRACTITIONER, AND EZRA RIKLON, PRACTITIONER

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MEDICAL SURVEY OF RONGELAP PEOPLE EIGHT YEARS AFTER EXPOSURE TO FALLOUT AND EZRA RIKLON, PRACTITIONER With the technical assistance of ‘ Brookhaven National Laboratory, Upton, New York ‘ South Nassau Communities Hospital, Rockville Centre, New York 3M.D. Anderson Hospital, University of Texas, Houston, Texas 4 Boston City Hospital, Boston, Massachusetts 5Walter Reed Army Medical Center, Washington, D.C. ‘ Department of Public Health, Trust Territory of the Pacific Islands BROOK HAVEN NATIONAL LABORATORY UPTON, NEW YORK

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TMs report was prepared as an account of Government sponsored work. Neither the United States, nor the Commission, nor any person acting on behalf of the commission: 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 fmm the use of any information, apparatus, method, or proces disclosed 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 Commission, or hls employment with such contractor. PRINTED IN USA Available from the Office of Technical Services Department of Commerce

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Summary of Past Findings ................................................................................ Beta Irradiation of the Skin .................................................................... Difficulties Associated With the Examinations ...................................... History and Physical Examinations ...................................................... Cancer Detection Survey ........................................................................ Growth and Development Studies in Children ...................................... Results and Discussion ...................................................................................... Growth and Development Studies .................................................... Cancer Detection, Leukemia Survey ...................................................... Residual Beta Burns .............................................................................. Studies of Aging Criteria, Dental Survey ................................................ Other Laboratory Studies ...................................................................... Estimation of Body Burden of Sr’o .................................................................... Appendix 1. Rongelap Group and Control Mean Blood Counts at Various Times After Exposure .......................... Appendix 2. Ailingnae Group and Control Mean Blood Counts at Various Times After Exposure ............................ Appendix 3. Individual Hematological Findings, 1962 .................................. Appendix 4. Individual WBC, Basophil, and Alkaline Phosphatase Determinations, 1962 ........................ Appendix 5. Individual Physical Examination Findings, 1962 ........................ Appendix 6. Pathologic-Anatomical Diagnoses on

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MEDICAL SURVEY OF RONGELAP PEOPLE EIGHT YEARS AFTER EXPOSURETO FALLOUT The results of a medical survey of the people of Rongelap in the Marshall Islands, carried out in March 1962 at 8 years after the accident, are presented in this report. These people had been accidentally exposed to fallout radiation following a detonation of a high yield thermonuclear device during experiments at Bikini in the Pacitic Proving Grounds in March 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 ) 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 Yeceived the largest fallout exposure: an 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 ( Adingnae ), where less fallout occurred, received only an 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 Allingnae. Lastly, 157 Marshallese on Utirik Island, about 200 miles further 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 peopIe were evacuated from these islands by plane and ship about two days after the accident and taken to Kwajalein Naval Base about 150 miles to the south, where they received extensive examinations for the following three months. In view of the generally negative findings on the American servicemen, they were later returned to their duty stations. The Utirik people were ako allowed to return to their home island, where radioactive contamination was slight enough to allow safe habhation. Because Rongelap Atoll was considered to be too highly contaminated, a tempeople on Majuro Atoll several hundred miles to the south, where they lived for the foilowing 3% years and were examined at yearly intervals by a special medical team. In July 1957, after carefd evaluation of the radioactive contamination situatiom Rongcdap Island was considered safe for habitation. A new village was constncted, and the Rongelap people were moved thereby Navy ship. The annual medical surveys have since been carried out on Rongelap Island. A group of more than 100 Rongdap peopIe, who were relatives of the exposed people but had been away 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. This number has since increased to about 200. Following the initial survey of the Utirik peopIe on 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 Kwajalein and Majuro Atolls for examination of a number of Rongelap people, now residing at these atolls, and also groups of children who represent Figure 1. Map of !allout area (Mmi+I 1, 1954), Mar-

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part of the control &oup used for the growth and development studies of the exposed children. The accumulation of data from these surveys is becoming increasingly voluminous. Since conditions have not been favorable for performance of extensive statistical anal yses or use of electronic 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. Summary of Past Findings Reports have been published on the findings of surveys made at the following times after expoyears.’ The following is a brief summary of the findings previously reported. During the first 24 to 48 hr after exposure, about ?4 of the Rongelap people experienced anorexia and nausea. A few vomited and had dhrrhea. 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 and 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 and that significant doses of radiation had probably been received. In addition to the whole-body 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 accormg to the mode of exposure: penetrating irradiation, skin irradiation, and internal irradiation. One of the earliest tirt~ indicative of signi& cant exposure in these people was lowering of levels of leukocytes and pfutefets of the fXTipherid blood. This was most marked in the 64 people on RongeIap who had received 175 r, and was less marked in the other groups receiving less exposure. The hemopoietic depression was roughly proportional to the dose of radiation received. Even in the 157 Utirik people who received only an estimated 14 r, it was possible to distinguish s!ight platelet depression in the group as a whole. The smaller goup on Ailingnae and Rongerik showed peripherrd blood levels between those of the high and low exposure groups. The chronological records of blood findings in the Rongelap and Ailingnae groups are presented in Table 10 and in Appendices 1 and 2. Lymphopenia of about half the level of the comparison Marshallese population was evident when the Rongelap people were first examined on their arrival at Kwajalein 3 days after exposure. This depressed level was maintained steadily with only slight increase noted by one year. In the following year, mean counts approached the levels of the comparison population but have since generally remained slightly below. Neutrophil levels fluctuated considerably during the first month; possibly this was related to the prevalence of beta burns of the skin during that period. Neutrophil depression became evident by 5 and 6 weeks post exposure with levels reaching about half that of the comparison population. This degree of neutropenia was insufficient to result in any apparent increased infectious processes, and indeed it was noted that neutrophilic leukocytosis was possible in people showing casual infections at this time. Neutrophil levels recovered more rapidly than lymphocyte levels and reached near control levels by one year. Subsequent annual surveys have revealed that recovery does not appear to be complete, particularly in younger and older Platelet counts showed less fluctuation than other blood counts and fairly consistently showed increasing &pression, reaching levels of about 3090 that of the comparison population by the 4th week. A spurt of recovery to about 75’ZO of comparison levels occurred during the following few weeks, which was followed by slower recovery but with mean levels never reaching higher than 85 to 90?40 that of the comparison population during the 7 years post exposure. Erythropoz”etic depression has not been a consistent tinding as with the leukocytes and thrombocytes. Slight depression of red blood counts, hematocrits, and hemoglobin have been noted at times.

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No gross abnormalities of bone marrow smears were reported at 6 months post exposure. Depression of peripheral blood elements in the Ailingnae and Rongerik groups was not so pronounced as in the Rongelap group. However, a slight lag in complete recovery in the Ail@nae peripheral blood count has also been noted. The persistent depression of peripheral blood elements in the exposed people makes it appear likely that there is slight residual bone marrow A general” anemic tendency has been evident in both exposed and unexposed Marshallese. PriceJones curves, on the average, showed a slight microeytic tendency. Serum iron levels have generally been normal, and the cause of this anemic tendency has been undetermined. Reticulocyte counts have been about the same in the exposed as in the unexposed people. Except for radiation-induced lesions of the skin, patchy epilation, and early gastrointestinal symptoms, clinical examinations have revealed no disease processes or symptoms which could be related directly to radiation effects. No prophylactic or specific therapy of radiation effects was ever considered necessary or given. Epidemics of chicken pox and measles that occurred showed no greater incidence or severity in the exposed than in the unexposed Marshallese people. During the first months post exposure about half of the exposed group exhibited loss of weight of several pounds. This may possibly have been related to their radiation exposure, although it is difficult to rule out effects possibly due to change of At 3 years post exposure the immune response to primary and secondary tetanus antitoxin was tested and found not to be significantly different in the exposed compared to the unexposed popuFour persons in the exposed population died of disease: ( 1 ) a 46-year-old man with a hypertensive heart disease which had been present at the time of exposure, who died 2 years after the accident; (2) a 78-year+ld man who died, 3 years after exposure, of coronary heart disease complicating diabetes; (3) a 35-year-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; and (4) a 60-year~ld woman who died of a cancer of the ovary at 5 years after exposure. There was no apparent relationship between any of these deaths and radiation exposure. Four deaths have occurred in the comparison population. The four deaths that have occurred in the exposed people since exposure represent a mortality rate of 7.1 per 1000 population, compared with 8.3 for the Marshall Islands as a whole. Growth and development studies on the chilments, radiographic studies for bone age) have revealed that slight retardation in growth and development has occurred in the exposed boys who were under 12 years of age at the time of exposure, particularly those 12 to 18 months of age at exposure. Only slight immaturity was noted in the exposed female children. It was also noted that children born of exposed parents were slightly retarded and that they had slightly lower levels of neutrophils, lymphocytes, and platelets, compared with male children of unexposed parents. It was diiiicult to evaluate the effects on fertility. However, a review of the birth rare of the exposed group over the past 7 years seems to indicate no noticeable effect of their exposure on fertility. The 31 births represent a rate of 54 per 1000 population, compared with 37.3 for the Marshall Islands ( 1957). The 21 births over a 4-year period for the comparison population represent a rate of 72 per 1000 population. A somewhat greater incidence of posed women during the first several years after exposure, but because of the paucity of vital statistics on the Marshallese and the small number of people involved, the data are not readily amenable to statistical analysis. A cardiovascular survey of the adults (1959 )‘ showed no outstanding differences between the exposed and unexposed groupa. The people appeared to have less hypertension on the whole than is noted in people in the continental United States. An arthritis survey ( 1959) r showed no great differences between the exposed and the unexposed ~le, and about the same incicknce as is seen in Ophthahnofogical surveys showed no remarkable differences between the exposed and muxpoaed of cases of pterygia pinguecuk, and corned scars intheexposed group. Itisnot known whether thia 6nding is of any sigdkanee in relation to their radiation exposure. Slit-lamp obsemationa showed no opacities of the lens chmwkmtus“ “ of radiation exposure. As a whole, visual and amommdation

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levels in the Marshallese appeared to be above the average in the U.S. population. in caries rate between exposed and unexposed groups. However, the incidence and severity of periodontaldisease was slightly greater in the exPOSEXJPUP. It is not known whether or not this finding is related to radiation effects. The poor oral hygiene generally observed in the Marshalkse had its usual results; namely, high cacies rate in teen- ~ children, severe peridontaI lesions in adults (heavy cdculua and 10SSof alveolar bone), and edentulous rhouths in the aged. Radiation exposure did not appear to have afkcted developing dentition in the exposed children. Late e&cts of radiarwn. Various parameters usually associated with a~”ng were measured or ticity, and senile changes; greying of the hair and …