The present workshop had its orlglns in discussions among Alexander Hollaender, Oddvar Nygaard, Donald Borg, Richard Setlow and Victor Bond on the need for a symposium that would deal with a broad spectrum of pressing subjects related to the physics, chemistry, and biological actions of ionizing radiations, and the theoretical and practical problems of risk assessment. It soon became apparent that the spectrum of subjects considered was too broad for the desired depth of coverage; in fact, it seemed un likely that the conference participants would have the background knowledge to span the gamut. Therefore, two separate meetings were decided upon, the first of which, Comparison of Mechanisms of Carcinogenesis by Radiation and Chemical Agents, was held at the National Bureau of Standards, Gaithersburg on December 6-7, 1983. The meeting was sponsored by the NCI. The second meeting has emerged as the present workshop at Brookhaven National Laboratory. An interface between the two conferences has been provided by Michael Fry and Donald Borg, who have summarized the salient points emanating from the NCI Symposium. We intended that the first conference should focus on the basic mechanisms of radiation and chemical carcinogenesis, while the second, the present meeting, would emphasize exposure-response relationships, particularly the theoretical and practical similar ities and differences between exposure to chemical carcinogens compared to exposure to ionizing radiation.

This year we remember the 39th anniversary of the atomic bomb explo sions in Hiroshima and Nagasaki, which led to the exposure of thou sands of people to high doses of ionizing radiations. Nearly 18 years earlier, on the 15th of September, 1927, H. J. Muller presented his paper The Problem of Genic Modification at the Fifth International Congress of Genetics in Berlin, in which he brilliantly demonstrated the muta genic activity of X-rays. In 1928, K. H. Bauer formulated his mutation theory of the origin of cancer, and already in 1914, Th. Boveri speculat ed that tumor cells originate from an abnormal chromosomal comple ment. In the meantime we have learned that also nonionizing radiation and an immense number of environmental chemicals, both, man-made and naturally occurring, are mutagenic in a variety of test systems, in cluding human cells. In no case has it been shown unequivocally that physical or chemical mutagens have led to an elevation of the mutation rate in the germ cells of man, but in view of the huge body of experi mental data this seems to be a problem of detection. It can be expect ed that germ cell mutations are induced as a consequence of exposure to mutagens in man, as yet undetectable with the methods at hand. An uncontrolled addition of mutations to the human gene pool may well have unforeseen and catastrophic consequences in future genera tions for whom we should feel responsible.

Congress Proceedings

First multi-year cumulation covers six years: 1965-70.

The Symposium on Radionuclides in the Food Chain, sponsored by the Interna tional Life Sciences Institute in association with the International Institute for Applied Systems Analysis, was intended to bring together policymakers and other representatives of the food industry with radiation experts involved in measuring and assessing radioactivity in foodstuffs. The symposium was made timely by the problems arising from the nuclear reactor accident at Chernobyl, in the USSR, which brought out the lack of international agreement on guidance for responding to such radionuclide contamination of food and foodstuffs. The presentations by the radiation experts covered the sources of radionu clides-natural radioactivity, fallout from nuclear weapons tests, routine releases from nuclear facilities, and various nuclear accidents. The speakers represented a broad distribution in both scientific disciplines and international geographic origin. They summarized the available data on measurements and indicated the current procedures for assessing radiation exposure. It was hoped that the food industry representatives would bring out the problems posed to industry and governments by the presence of radioactivity in food.

The biologic effects of radiation on normal tissues and tumors represent a complex area for investigation. These effects are of far-reaching consequence to the diagnostic radiologist and the radiation oncologist having a significant impact not only in concepts relative to radiation protection but also in concepts relative to tumor biology and its response to radiation injury. The volume edited by SCHERER, STREFFER, and TROTT represents an extension of basic radiation biology data into the effects of radiation in producing pathology in organs and tissues. The data presented by the multiple authors involved in this text cover essentially all tissues in the body with specific definition of radiopathology changes and their impact on clinical care of the patient. This volume represents an important and significant contribution toward a better understanding of these effects and the pathology produced by radiations. L. W. BRADY H.-P. HEILMANN F. HEUCK M. W. DONNER Philadelphia Hamburg Stuttgart Baltimore Preface This book represents an attempt to describe the clinical radiobiology of complications arising in different organs after radiotherapy of cancer patients. Since by their very nature malignant tumors infiltrate the organ in which they have arisen and the neighboring tissues, curative radiotherapy requires the planned irradiation of considerable amounts of healthy but potentially or microscopically involved normal tissues and organs with the full target dose. This may lead to early or late normal tissue radiation injury.

This open access book summarizes the latest scientific findings regarding the biological effects of the Fukushima Daiichi Nuclear Power Plant (FNPP) accident in 2011. Various cases of changes in animals and organisms have been reported since the FNPP accident. However, it is often unknown whether they are actually due to radiation, since the dose or dose-rate are not necessarily associated with the changes observed. This book brings together the works of radiation biologists and ecologists to provide reliable radioecology data and gives insight into future radioprotection. The book examines the environmental pollution and radiation exposure, and contains valuable data from abandoned livestock in the ex-evacuation zone and from wild animals including invertebrates and vertebrates, aqueous and terrestrial animals, and plants that are subjected to long-term exposure in the area still affected by radiation. It also analyzes dose evaluation, and offers new perspectives gained from the accident, as well as an overview for future studies to promote radioprotection of humans and the ecosystem. Since the biological impact of radiation is influenced by various factors, it is difficult to scientifically define the effects of low-dose/low-dose-rate radiation. However, the detailed research data presented can be combined with the latest scientific and technological advances, such as artificial intelligence, to provide new insights in the future. This book is a unique and valuable resource for researchers, professionals and anyone interested in the impact of exposure to radiation or contamination with radioactive materials.