RESPONSE OF HUMAN BEINGS ACCIDENTALLY EXPOSED TO FALL-OUT RADIATION SIGNIFIC: Commander Eugene P. Cronk (MC), U. S. N., Victor P. Bond, M.D., San Francisco, Commander Robert A. Conard, Lie a . N. Raphael Shulman, Lieut. Richard §. Farr, (MC), U.S. N., Stanton H. Cohn, Ph.D., San ancisco, Charles L. Dunham, M.D., Washington, D. C. and Lieut, Col.L. Eugene Browning (MC), U.S. Army After detonation of a nuclear device in Islands during the spring of 1954, radioa Hj and sifted into the lightly constructed thatched-roof the Marshall material houses. The material whitened the hair and clung to the skin. During the night following the explosion and for the next two days, about two-thirds of the population developed nausea and 10% vomited and had diarrhea. During this period also, many developed itching and fell upon several neighboring inhabited atolls The fall- out material consisted of pulverized and incinerated coral (calcium oxide) coated withradioactive fission products, forced high into the atmosphere by the violence of the explosion. The particulate matter was then'distributed over a wide area by the wind structure. The field of radiation resulting from the deposition of this'radioactive material on the islands was sufficiently intense to result burning of the skin and some reported burning of the eyes with lacrimation. Supervised decontamination and medical care was not possible until the exposed individuals were evacuated to the nearby naval base at Kwaja- in significant whole-body irradiation of theinhabitants. kein. By this time, initial symptoms had completely In addition, the skin was contaminated with the material, whole-body dose of radiation in roentgens asimeasured in subsided. An emergency medical team, composed largely of naval personne! from the Naval Medical Research In- island groups is shown below. The ex ratory, was organized and sentto the area, arriving on and someofit was inhaled and ingested. The calculated stitute and the U. S. Naval Radiological Defense Labo- ‘air and the amountof fall-out observed foreach of the American the ninth day after exposure. Complete initial histories and physical examinations and frequent follow-up examinations and treatment for medical conditions were cartied out on all personnel. In addition, hematological studies to assay the degree of radiation damage and uri- Calculated Whole Body Dose of Radiatibn Island Group Rongelap Allinginss Rongerik , Utirik Populatica & Marshallese 18 Marehatiess Whole-Body Does in r 3136 a servicemen 187 Marshallese 1s 23 American i) ? i, Observed Heavy (qnow-like) M (mist-Iike) ‘a (mist-Ike) nary excretion studies for radioactive materials were performed. It was apparent from initial blood studies that significant radiation had been received, and by 12 to None servicemen were returned to duty after extensi 14 days further evidence of radiation injury was appar- examinations at Kwajalein and at the Tripler General Hospital, Honolulu, T. H. The Utirik ent in the form of skin lesions and epilation. With the exception of the development of skin lesions and epila- tion, physical examinations at no time revealed findings le were re- turned to their native atoll after the initial period of ob- servation. The Rongelap and Ailinginae re: in any group that could be attributed with certainty to radiation, moved to Majuro Atoll for temporary otcupation of dwellings built for them. These gamma raydoses were calculated from field instrument readings faken at the time of evacuation and decay schemes appropriate for the estimated times of exposure. For the of brevity, CLINICAL OBSERVATIONS, THERAPY, AND HEMATOLOGICAL FINDINGS Since the degree of depression of peripheral blood details will be presented only on the more) severely exposed Rongelap group and ferred to only for comparative purposes. . The detonation of the device was observed in the early morning, and hours later the exposed individuals noticed a snow-like ‘material falling from the sky; this continued for several hours. The material was visible on the ground From the Naval Medical Research Institute, Bethesda, Md., and U. S. Naval Radiological Defense Laboratory, San Francixco, Commander Cronkite is Dow atBrookhaven National Laboratory, Upton, N. Y. Lieut. afr is now Mediel St at7" nlyersity ofChicago, School of , Biological and ‘ore Section on Military Medicine at the 104th Annual Meeting of the American Medical Association, Atlantic City, June 8, 1955. Drs. David A. Wood, University of California Hospital, San Francisco, and Edward L. Alpen, U. 8. Naval Radiological Defense Laboratory, San Francisco, made the hixopathological evaiuation of the skin The discussion of this paper was opened by Dr. Lee EB. Parr, Upton, N. ¥., and Major Carl Hanson, Washington, D, C, : 1. Effects of High-Yield Nuclear cistempet by Lewis L. Strauss, chalrman, and report by Usited States eat Boergy Com mission, Atomic Energy Commission, Feb. 1955. . _ elements is believed to be the best index of severity of radiation injury, systematic serial determinations were carried out. These determinations consisted of total leukocyte, neutrophil, lymphocyte, and platelet counts and hematocrit determinations. Control groups, as com- parableas possible to the exposure groups in respect to age, race, sex, and background, were selected. Findings are expressed in terms of percentage of control values. Significant age and sex difference in blood cell counts were noted in the control groups, and the data are pre- sentedin accordance with the differences noted. The absolute neutrophil count(fig. 1) of both younger and older age groups fell to a value of approximately 70 to 80% of that of the controls during the second week, followed by a period of fluctuation until the fifth week. At this time the beginning of a second depression was noted for both age groups, and a low value of approximately 50% of that of the controls was reached. The