Book Review

Effects of Atomic Radiation: A half-century of studies from Hiroshima and Nagasaki

N Engl J Med 1996; 334:545-546February 22, 1996

Article

Effects of Atomic Radiation: A half-century of studies from Hiroshima and Nagasaki
By William J. Schull. 397 pp. New York, John Wiley, 1995. $45. ISBN: 0-471-12524-5

This book discusses the short-term and long-term medical effects of atomic radiation in about 150,000 of the people who survived the atomic bombings of Hiroshima and Nagasaki in 1945. These people have been the subject of a continuing study conducted by the Atomic Bomb Casualty Commission and its successor organization, the Radiation Effects Research Foundation. The book is in one sense a history of the origin, objectives, growth, creative personnel, and contributions to radiobiologic knowledge of these organizations. The detailed evaluation of the medical effects of radiation appropriately occupies most of the book, since the author has been intimately involved with major facets of the atomic-bomb–survivor study for most of his professional career, specifically from 1949 to the present. The experience of the survivors constitutes the most powerful epidemiologic follow-up of radiation exposure, and the results of these studies are widely recognized as the principal source of our information on radiation-induced malignant disease, fetal effects, and genetic aberrations. The author presents an erudite and well-organized description of these studies and their results.

The history begins with a brief account of the human and property damage caused by the bombs, based on the assessment of a joint U.S.–Japanese commission in the autumn of 1945. More than 50 percent of the deaths in the immediate aftermath of the bombings in the two cities were due to burns, about 18 percent were due to the blasts themselves, and possibly as many as 30 percent were due to ionizing radiation. In 1946, the Atomic Bomb Casualty Commission, jointly funded and staffed by the United States and Japan, was created after approval by President Harry Truman. I found descriptions of the early history of space, personnel, and financial problems and diplomatic relations tangential to the main scientific objectives of the book. However, the studies conducted during the period from 1948 to 1955 show that many of the major delayed medical effects were already manifest, particularly in the high-dose region within 1 km of the epicenter of the blasts. Examples are adverse pregnancy outcomes, developmental delays among children, lens opacities (investigated by a team of United States ophthalmologists in 1949), and an excess rate of leukemia. The first 9 cases of leukemia were noted in 1949; there were 50 cases by 1953, with a risk of about 1 in 80 for those who were within 1 km of the epicenter, as compared with a risk of 1 in 12,000 for those who were farther away. In this section, the author provides the first of several excellent primers for general medical readers on the characteristics of important radiation effects — in this case, leukemia.

The initial studies were concerned with particular syndromes and were not part of a central, organized plan of study. This situation was transformed after 1955 by a National Research Council review committee under the leadership of Thomas Francis, Jr., a distinguished epidemiologist. Several long-term plans of study were inaugurated, the most important being the Life Span Study, involving the lifelong follow-up of about 120,000 survivors, including a local but unexposed control population. This study continues because almost half the survivors are still living. The book provides detailed information on the organization and management of this large undertaking and on data storage and processing. A smaller group of about 20,000 survivors (the Adult Health Study) was selected for morbidity surveillance. The main objective of the survivor study has been the estimation of the risk of radiation-induced cancer. Other important objectives are the estimation of genetic risks among children whose mothers or fathers (or both) were exposed to the bombings and of the risks of abnormalities in children exposed in utero. Three detailed and well-documented chapters that make up nearly 50 percent of the book present the design and results of these studies. There are some revealing statistics: in the Life Span Study, 8 percent of the 3172 deaths from cancer through 1985 and 59 percent of the 141 deaths from leukemia were attributed to radiation. In contrast, the incidence of genetic effects of parental exposure to radiation in more than 70,000 children conceived after the bombing was not significantly elevated in comparison with those due to spontaneous mutation.

This book is densely written and will require substantial effort by readers with no background in genetics and epidemiology. The least rewarding chapter for medical readers, since it is so specialized, is the one on radiation dosimetry and its inevitable uncertainties after the event. The chapter is important for risk assessment but fortunately is quite short. In sum, the author has recorded the aftermath of a unique event in history and drawn from it a contribution to medical science.

Edward W. Webster, Ph.D.
Massachusetts General Hospital, Boston, MA 02114