How Do Scientists Determine the Long-Term Risks from Radiation?

The Atomic Century

After the war's end, the network of radiation researchers, government and military officials, and physicians mobilized for the Manhattan Project did not disband. Rather, they began working on government programs to promote both peaceful uses of atomic energy and nuclear weapons development.

Having harnessed the atom in secret for war, the federal government turned enthusiastically to providing governmental and nongovernmental researchers, corporations, and farmers with new tools for peace--radioisotopes--mass-produced with the same machinery that produced essential materials for the nation's nuclear weapons. Radioisotopes, the newly established Atomic Energy Commission (AEC) promised, would create new businesses, improve agricultural production, and through "human uses" in medical research, save lives.

From its 1947 creation to the 1974 reorganization of atomic energy activities, the AEC produced radioisotopes that were used in thousands of human radiation experiments conducted at universities, hospitals, and government facilities.[1] This research brought major advances in the understanding of the workings of the human body and the ability of doctors to diagnose, prevent, and treat disease.

The growth of radiation research with humans after World War II was part of the enormous expansion of the entire biomedical research enterprise following the war. Although human experiments had long been part of medicine, there had been relatively few subjects, the research had not been as systematic, and there were far fewer promising interventions than there were in the late 1940s.

With so many more human beings as research subjects, and with potentially dangerous new substances involved, certain moral questions in the relationship between the physician-researcher and the human subject--questions that were raised in the nineteenth century--assumed more prominence than ever: What was there to protect people if a researcher's zeal for data gathering conflicted with his or her commitment to the subjects' well-being? Was the age-old ethical tradition of the doctor-patient relationship, in which the patient was to defer to the doctor's expertise and wisdom, adequate when the doctor was also a researcher and the procedures were experimental?

While these questions about the role of medical researchers were fresh in the air, the Manhattan Project, and then the Cold War, presented new ethical questions of a different order.

In March 1946, former British Prime Minister Winston Churchill told an audience in Fulton, Missouri, that an "iron curtain" had descended between Eastern and Western Europe--giving a name to the hostile division of the continent that had existed since the end of World War II. By the following year, Cold War was the term used to describe this state of affairs between the United States and its allies on the one hand and the Soviet bloc on the other. A quick succession of events underscored the scope of this conflict, as well as the stakes involved: In 1948 a Soviet blockade precipitated a crisis over Berlin; in 1949, the American nuclear monopoly ended when the Soviet Union exploded its first atomic bomb; in 1950, the Korean War began.

The seeming likelihood that atomic bombs would be used again in war, and that American civilians as well as soldiers would be targets, meant that the country had to know as much as it could, as quickly as it could, about the effects of radiation and the treatment of radiation injury.

This need for knowledge put radiation researchers, including physicians, in the middle of new questions of risk and benefit, disclosure and consent. The focus of these questions was, directly and indirectly, an unprecedented public health hazard: nuclear war. In addressing these questions, medical researchers had to define the new roles that they would play.

As advisers to the government, radiation researchers were asked to assist military commanders, who called for human experimentation to determine the effects of atomic weapons on their troops. But these researchers also knew that human experimentation might not readily provide the answers the military needed.

As physicians, they had a commitment to prevent disease and heal. At the same time, as government advisers, they were called upon to participate in making decisions to proceed with weapons development and testing programs that they knew could put citizens, soldiers, and workers at risk. As experts they were asked to ensure that the risks would not be excessive. And as researchers they saw these programs as an opportunity for gathering data.

As researchers, they were often among the first to volunteer to take the risks that were unavoidable in such research. But the risks could not always be disclosed to members of the public who were also exposed. In keeping with the tradition of scientific inquiry, these researchers understood that their work should be the subject of vigorous discussion, at least among other scientists in their field. But, as government officials and advisers, they understood that their public statements had to be constrained by Cold War national security requirements, and they shared in official concern that public misunderstanding could compromise government programs and their own research.

Medical researchers, especially those expert in radiation, were not oblivious to the importance of the special roles they were being asked to play. "Never before in history," began the 1949 medical text Atomic Medicine, "have the interests of the weaponeers and those who practice the healing arts been so closely related." [2] This volume, edited by Captain C. F. Behrens, the head of the Navy's new atomic medicine division, was evidently the first treatise on the topic. It concluded with a chapter by Dr. Shields Warren, the first chief of the AEC's Division of Biology and Medicine, who would become a major figure in setting policy for postwar biomedical radiation research. While the atomic bomb was not "of medicine's contriving," the book began, it was to physicians "more than to any other profession" that atomic energy had brought a "bewildering array of new problems, brilliant prospects, and inescapable responsibilities." The text, a prefatory chapter explained, treats "not of high policy, of ethics, of strategy or of international control [of nuclear materials], as physicians these matters are not for us."[3] Yet what many readers of Atomic Medicine could not know in 1949 was that Behrens, along with Warren and other biomedical experts, was already engaged in vigorous but secret discussions of the ethics underlying human radiation experiments. At the heart of these discussions lay difficult choices at the intersection of geopolitics, science, and medicine that would have a fundamental impact on the federal government's relationship with the American people.

This chapter provides a brief survey of the development of radiation research and the changing roles of the biomedical researcher, from the discovery of x rays by a single individual to the complex world of government-sponsored human radiation experimentation. Finally, at the end of this chapter, an aid to the reader titled "The Basics of Radiation Science" provides information needed to understand technical concepts in this report.