a A= Ca. St o ae A Key - _ . OL Le REPORT OF SUBCOMMITTEE ON ¢ LONG TERM PRIMATE RADIATION PROBLEMS The Committee met on January 20, 1953 at the National Institutes of Health, Bethesda. Those present were H. J. curtis, Jacob Furth, R. S. Snider, Earl Engle, N. W. Shock. Discussion was confined to eighttopics as follows: (1) The desirability of a project to study the long-term radiation effects in primates: It was pointed out emphatically that there has been 4 a tremendous effort expended in studying the acute effects of radiation damage in animals and man, but relatively little in studying the long-term effects. During the war a fairly large group of rodents was studied for the long-term effects of gamma rays, fast neutrons, and slow neutrons, but tese studies have never been completely finished. A few experiments by Lorenz and others are under way in rodents, but it is a small effort. The studies of the Japanese population subjected to the atomic bombings is being carried on, but even at an enormous effort the results will be slow in coming and preliminazy in nature at best. Dosages were difficult to estimate and the population has been widely scattered. Present indications are that the late effects of radiations are qualitatively about the same for x-rays, gamma rays, fast neutrons and slow neutrons. The animals die prematurely, and from about the same causes as do normal animals. There may be quantitative differences in tumor incidence for particular tumor types, etc., but so far no qualitative differences, other than decreased life span, have been noted between irradiated and control animals. animals higher than rodents. However, there i» literally no data on The group was unanimous“in feeling that the extrapolation from mouse to man, in this case, would be virtually worthless. There was some feeling expressed that man might be considerably more susceptible to this type of radiation injury than the lower animals because of the relatively poor circulation in man, but this is admittedly a guess. It appears that the problem is closely linked with, or perhaps identical with, the problem of aging. Dr. Shock gave a review of the present state of research in the field of gerontology. There are a very few studies of the fundamental mechanisms of aging; a few studies with rodents, especially with reference to the effect of nutrition on life span; and a few clinical studies on aging, the most extensive one being his own DOsARCHIVES