BIOLOGICAL FACTORS IN THE RADIATION PROBLEM RELATING TO SOCIETY ~ Charles L. Dunham, M. D. Director, Division of Biology and Medicine, U.S. Atomic Energy Commission 1 INTRODUCTION Controlled nuclear fission which ushered in the “Atomic Age,” like all great scientific achievements, has raised more questions than it has answered. It not only raised a myriad of questions which physicists, social scientists, and the United Nations have been busily trying to answer ever since, but for those of us in the health sciences it posed a host of health problems urgently requiring solution. By 1940 the hazards of ionizing radiation were already understood in a general way. The cause and effect relationship between exposure to x-rays or to the emanations of radium and skin cancer was clearly recognized by 1902, a bare seven years after the discovery of x-rays by Roentgen. It has been known since the mid-twenties that radiation of germ celis can result in gene mutation, and radiation exposure during embryonic life results in developmental abnormalities. Only a few years later, radiation-induced leukemia in mice was observed. From 1929 to 1940 what is now named the National Committee on Radiation Protection and Measurement has been cooperating with the International Commission on Radiological Protec- tion in developing recommendations concerning the maximum permissible exposure of the relatively few adult workers using x-ray machines, radium, and later other sources of ionizing radiation. The recommendations were based on Scientific facts, obtained both experimentally and by observation of injury incurred by pioneers in radiology and radiological physics and by the workers in the luminous dial industry. Since then as more and more data on the effects of radiation accumulated, these recommendations have been revised. The Atomic Energy Commission, in all its operations, has endeavored to follow these recommendations. Public concern, and concern by scientists other than radiobiologists, with the effects of ionizing radiation on human beings became widespread as a result of the unfortunate accidental exposure of the Rongelapese to fallout in the spring of 1954 from atomic weapons testing in the Pacific. In June 1956, as a result of the report of the National Academy of Sciences study on the Biologic effects of atomic radiation, this concern spread rapidly from the hazards associated with radioactive fallout to include the hazards inherent in the medical uses of x-rays and in the coming age of nuclear power production. One of the great difficulties in discussing this problem at the present time is that of achieving objectivity. Inherent in the present discussions of the effects of radiation is the matter of whether or not the United States should attempt to build optimal capability in the delivery of atomic weapons in the event of war and even as a deterent to war. The subject has become intimately involved in many people’s emotions. During the 1956 Presidential election campaign it even became a political issue. *Presented at the Symposium on ‘‘Social Aspects of Science’? at the Meetings of the American Association for the Advancement of Science, Indianapolis, Indiana, Dec. 29, 1957. 277