ACA LS a ate, tel Ree ¢ Reprinted from IMMEDIATE AND Low Levet EFrects of IONIZING RADIATIONS. Conference held in Venice, June 1959. A Special Supplement to the International Journal of Radiation Biology. Medical survey of Marshallese people five years after exposure to fall-out radiationt RoBerT A. CoNARD JS DD. Bn. Medical Research Center, Brookhaven National Laboratory, Upton, New York SUMMARY A medical survey of the Marshallese people in March 1959, five years after exposureto fall-out radiation, showed that the people had recovered from the acute effects of their radiation exposure and appeared to be generally in good health. The following specific statements can be made in regard to their radiation health status: 1. Noillnesses or diseases were found that could be directly associated with acute radiation effects. 2. One case of cancer and three deaths have occurred, but with no direct relation to radiation effects. 3. Fertility does not appear to have been affected. The incidence of miscarriages and still-births appears to be somewhat higher than in the unexposed Marshallese, but a deficiency of vital statistics precludes definite conclusions as to whetheror not this is a radiation effect. 4, Suggestive evidenceof slight lag in growth and developmentof exposed children noted previously is being re-evaluated on the basis of better age data obtained duringthe past survey. 5. Blood-platelet levels are within the normal range, but somewhat below that for the unexposed population. 6. Only 12 cases show residual changes in the skin from beta-burns. None show any evidence of cancerous change. 7. Possible late effects of radiation, such as shortening of life-span, premature ageing, increased incidence of leukaemia and malignancies, increased incidence of degenerative diseases, opacities of the lens of the eyes, and genetic changes have not been observed. An attempt to measure ageing by a semi-quantitative clinical approach is presented. 8 The original body burdens of internally-absorbed fission products appears to be too lowto have produced any acute or long-term effects. 9, The return of the people to the slightly contaminated island of Rongelap has caused some increase in body burdens of ™’Caesium, *Zinc and *0Strontium. However, the levels are far below the accepted maximum permissible limits and it is not believed any untoward effects will result. edih p ye 1. BACKGROUND This discussion concerns a brief account of the present health status of the Rongelap people, who were exposed to the heaviest dose of radiation from accidental fall-out in March 1954 following detonation of an experimental nuclear device at Bikini in the Marshall Islands. An unpredicted shift in winds caused deposition of significant amounts of fall-out on four nearby inhabited Marshall Islands and on 23 Japanese fishermen aboard their fishing vessel, the Lucky Dragon (see figure 1). Sixty-four inhabitants of the island of Rongelap, 105 nautical miles away from the detonation, received the largest fall-out—an estimated dose of 173 r of whole-body gamma-radiation, indeterminate beta-ray dose to the skin from contamination of the skin and internal + This work is supported by the U.S. Atomic Energy Commission. 17 af