-exposure the mean 3). By four years During the first six weeks over half of the exposed people lost weight even though their diet was satisfactory and appetites good during this period. This possibly reflects an effect of radiation exposure on general metabolism. However, factors associated with a change in environment cannot be ruled out as being responsible. he time of the five (Fig. 4). A rapid there was slower e unexposed mean sut 13 per cent and . of the comparison 1 the normal range. els, were about the There were no abnormalities noted at birth in four babies irradiated in ‘utero; two in the first trimester, one in the second trimester, and one in the third trimester. The five year survey revealed that the people were generally in a good state of health and nutrition. The incidences of diseases was about the same in the exposed and unexposed groups. One case of ovarian cancer developed during the past year in a 61 year old exposed woman. Late effects of gamma irradiation wy 4 a: ~~ Late effects of radiation exposure constitute an important part of the examinations in the Marshallese. Very little is known about such effects in human beings. From experiences with the Japanese exposed at Hiroshima and Nagasaki and from animal studies, certain late effects of radiation may possibly develop in the Marshallese. Results of observations for such effects will be presented accompanied by appropriate discussion related to findings of others. Shortening of life span. Thus far the three deaths in the exposed group represent about the same death rate as has been observed in the Marshall Islands as a whole over the same period of time (about seven deaths per 1000 per year). _ J > e of exposure through ‘ison populations Numerous investigators have reported shortening of the life span of animals exposed to acute and chronic radiation [Blair (1956), Bennett (1953), Brues and Sacher (1952) and others]. The chronic exposure of radiologists at Ailingnae Island so shown a similar n the more heavily in the United States was claimed to result in shortening of their average life span compared with other physicians [Dublin and Spiegelman (1958), Warren (1956)]. In view of these findings, some life shortening may be expected in the Marshallese, although in view of the small size of the population, das remained about Three deaths have rear after exposure e time of exposure; sosure of coronary > year old man at it may be difficult or impossible to detect such an effect. Premature aging and degenerative diseases. From clinical observations over the past five years the impression is that the exposed Marshallese do not appear to have aged faster nor be older than unexposed Marshallese of the same age. No doubt the subtle changes which occur with aging would bedifficult to detect over this short period of time. The incidence of degenerative diseases has been about the same in the exposed and unexposed groups. m 319