Book Review

Permissible Dose: A History of Radiation Protection in the Twentieth Century

N Engl J Med 2001; 344:1724-1725May 31, 2001

Article

Permissible Dose: A History of Radiation Protection in the Twentieth Century
By J. Samuel Walker. 168 pp. Berkeley, University of California Press, 2000. $35. ISBN: 0-520-22328-4

The importance of radiation to national security, energy policy, and environmental health has always made the determination of the effects of low-dose radiation on health a difficult problem. To establish regulations for the safe use of radiation, federal agencies had to balance the uncertain health consequences of radiation against the government's interest in nuclear weapons and nuclear power. Walker, the historian of the United States Nuclear Regulatory Commission (NRC), provides a fascinating account of these dilemmas. Using extensive archives of the Atomic Energy Commission (AEC), its successor, the NRC, and the Environmental Protection Agency (EPA), Walker traces the subtle interactions among the scientific establishment, businesses, the government, and the public that produced the federal regulatory policy.

Walker begins by showing how the excitement sparked by the discovery of radioactivity in the 1890s dimmed as researchers came to recognize the harmful effects of x-rays and radium. By 1934, the Advisory Committee on X-Ray and Radium Protection had proposed the first tentative guidelines about “tolerance doses” of radiation. The Manhattan Project introduced new forms of radiation and exposed unprecedented numbers of people to them. Established in 1946, the AEC regulated military, industrial, and medical uses of radiation. It established the upper limit of exposure — the “maximum permissible dose” — below which the risk was deemed acceptable.

After providing this background information, Walker focuses on the period from 1950 to 1990. During this time, physicians and scientists struggled to establish consensus about the health effects of radiation. Studies of survivors of the bombing of Hiroshima, power-plant epidemiology, and the atomic-bomb testing program produced a considerable amount of data, but uncertainty remained about the dose–response effects of low levels of radiation. This uncertainty created an eager audience for scientists who were airing their disputes in publications ranging from Science to Esquire. The extreme positions articulated in these debates, rather than the efforts to establish consensus, often drove public and political responses.

Each new crisis captured the public imagination and shifted the focus of the controversy. Concern about fallout from weapons testing in the 1950s and 1960s gave way to fears about effluents from the atomic-power industry in the 1970s. The disasters at Three Mile Island and Chernobyl brought these fears to life. In the 1990s, evidence of radon in homes and revelations of radiation experiments in humans during the Cold War provoked new anxieties. Moreover, the AEC lost credibility for attempting to balance public health against the needs of the weapons-testing program, and the NRC had to weigh fears of atomic energy against the energy crisis of the early 1970s. Regulatory efforts were frequently mired in bureaucratic infighting, especially given the overlapping jurisdictions of the NRC and EPA over environmental radiation. Walker shows how competing interests changed standards from the “maximum permissible dose” to “as low as practical,” “as low as reasonably achievable,” and “below regulatory concern.” Each change generated protests from the public and from industries.

Although Walker focuses on policy, his analysis raises many important issues for medicine and public health. Concern about threats to health, from x-ray burns and infertility to leukemia in workers exposed to radiation and inadvertent overdoses of radiation, motivated every effort at regulation and kept the health risks of radiation in the headlines. The mixture of hope and fear also generated embarrassing episodes for the medical profession. Physicians, for instance, resisted regulations requiring them to notify the NRC and affected patients about the misadministration of radioactive substances.

Walker's overly detailed analysis of federal regulation is the book's only flaw. At times Permissible Dose becomes an exhaustive narrative of committees, debates, and radiation policies that will interest few physicians outside the fields of radiology, radiation oncology, and environmental health. The book would appeal to a broader audience if its scope extended beyond these efforts to the impact of regulations on those who used and suffered from radiation. Strict control might have hindered the deployment of radiation technology (e.g., nuclear power and radiation medicine), but it also provided the aura of safety and legitimacy those forms of technology needed to survive. Regulatory agencies might have acted “responsibly and judiciously” to protect the public from harm, but workers, soldiers, and patients still suffered from exposure to radiation. Walker could have addressed these questions more thoroughly, but his analysis does succeed in raising crucial questions about regulatory policy.

With regard to radiation, it is impossible to live in a risk-free society. Even the most judicious protections allow some people to be exposed to dangerous levels of radiation. Science, politics, and the fears of the public about the invisible effects of radiation interact to create the principles and practices of radiation safety. If looming fears of energy crises reinvigorate nuclear power, Walker's lessons may find wide application in the future.

David S. Jones, M.A.
Harvard Medical School, Boston, MA 02115