Co-production of Science and Regulation Radiation Health and the Linear No-Threshold Model Richard E. Tontodonato Dissertation submitted to the faculty of the Virginia Polytechnic Institute and State University in partial fulfillment of the requirements for the degree of Doctor of Philosophy In Science and Technology Studies Sonja D. Schmid Barbara L. Allen Rebecca J. Hester David C. Tomblin May 10, 2021 Falls Church, Virginia Keywords: Actor-Network Theory, Co-production, Dose-Effect Model, Imaginaries, Nuclear, Radiation, Regulation, Standards Co-production of Science and Regulation Radiation Health and the Linear No-Threshold Model Richard E. Tontodonato ABSTRACT The model used as the basis for regulation of human radiation exposures in the United States has been a source of controversy for decades because human health consequences have not been determined with statistically meaningful certainty for the dose levels allowed for radiation workers and the general public. This dissertation evaluates the evolution of the science and regulation of radiation health effects in the United States since the early 1900s using actor-network theory and the concept of co- production of science and social order. This approach elucidated the ordering instruments that operated at the nexus of the social and the natural in making institutions, identities, discourses, and representations, and the sociotechnical imaginaries animating the use of those instruments, that culminated in a regulatory system centered on the linear no-threshold dose-response model and the As Low As Reasonably Achievable philosophy. The science of radiation health effects evolved in parallel with the development of radiation-related technologies and the associated regulatory system. History shows the principle of using the least amount of radiation exposure needed to achieve the desired effect became established as a social convention to help avoid inadvertent harm long before there was a linear no-threshold dose-response model. Because of the practical need to accept some level of occupational radiation exposure, exposures from medical applications of radiation, and some de minimis exposure to the general public, the ALARA principle emerged as an important ordering instrument even before the linear no-threshold model had gained wide support. Even before ALARA became the law, it had taken hold in a manner that allowed the nuclear industry to rationalize its operations as representing acceptable levels of risk, even though it could not be proven that the established exposure limits truly precluded harm to the exposed individuals. Laboratory experiments and epidemiology indicated that a linear dose-response model appeared suitable as a “cautious assumption” by the 1950s. The linear no- threshold model proved useful to both the nuclear establishment and its detractors. In the hands of proponents of nuclear technologies, the model predicted that occupational exposures and exposures to the public represented small risks compared to naturally occurring levels of radiation and other risks that society deemed acceptable. Conversely, opponents of nuclear technologies used the model to advance their causes by predicting health impacts for undesirable numbers of people if large populations received small radiation exposures from sources such as fallout from nuclear weapon testing or effluents from nuclear reactor operations. In terms of sociotechnical imaginaries, the linear no- threshold model was compatible with both of the dominant imaginaries involved in the actor-network. In the technocratic imaginary of institutions such as the Atomic Energy Commission, the model served as a tool for qualified experts to make risk-informed decisions about applications of nuclear technologies. In the socially progressive imaginary of the citizen activist groups, the model empowered citizens to formulate arguments informed by science and rooted in the precautionary principle to challenge decisions and actions by the technocratic institutions. This enduring dynamic tension has led to the model retaining the status of “unproven but useful” even as the underlying science has remained contested. Co-production of Science and Regulation Radiation Health and the Linear No-Threshold Model Richard E. Tontodonato GENERAL AUDIENCE ABSTRACT This dissertation provides a social science perspective on an enduring paradox of the nuclear industry: why is regulation of radiation exposure based on a model that everyone involved agrees is wrong? To answer that question, it was necessary to delve into the history of radiation science to establish how safety regulation began and evolved along with the understanding of radiation’s health effects. History shows the philosophy of keeping radiation exposures as small as possible for any given application developed long ago when the health effects of radiation were very uncertain. This practice turned out to be essential as science started to indicate that there may not be a safe threshold dose below which radiation exposure had no potential for health consequences. By the 1950s, a combination of theory, experiments, health studies of the survivors of the World War II atomic bombings, and other evidence suggested that the risk of cancer was proportional to the amount of radiation a person received (i.e., linear). Although this “linear no-threshold” model was far from proven, both sides used it in debates over nuclear weapon testing and safety standards for nuclear reactors in the 1950s through the early 1970s. Since the model predicted small health risks for the levels of radiation experienced by radiation workers and the public, nuclear advocates used it to argue that the risks were smaller than many other risks that people accept every day. At the same time, opposing activists used the model to argue that small cancer likelihoods added up to a lot of cancers when large populations were exposed. This decades-long discourse effectively institutionalized the model. The model’s “unproven but useful” status was strengthened in the early 1970s when the Atomic Energy Commission supplemented its numeric exposure limits by turning the longtime practice of dose minimization into a requirement. This “As Low As Reasonably Achievable” requirement plays a vital role in rationalizing why a non-zero exposure limit is safe enough despite the fact that the linear no-threshold model treats any amount of radiation as harmful. Acknowledgments First and foremost, I wish to thank my spouse, Amy, without whom none of this would have been possible. Beyond being a constant source of support and encouragement, she cheerfully put up with impositions of every sort, ranging from a house filled with an ever- expanding collection of mildewy used books, to evenings, weekends, and vacations permeated with science and technology studies, to dramatic readings from the works of Bruno Latour, Ulrich Beck, and others of their ilk. I will always hold dear the memory of Amy reading Ruth Schwartz Cowan’s More Work for Mother out loud for me during a road trip to Michigan in the fall of 2014. I am deeply indebted to my advisor and committee chair, Dr. Sonja Schmid, Associate Professor, Department of Science, Technology and Society, Virginia Tech. Her limitless patience, extraordinary insights, amazing ability to read reams of doggerel as fast as I churned them out, and (most of all) consistently high standards are the only reason this dissertation was completed. I further owe a great deal of thanks to my exceptional committee members—Dr. Barbara Allen, Dr. Rebecca Hester, and Dr. David Tomblin—who stuck with me throughout the long process of completing my research and producing this dissertation. Their advice and insights significantly added to the quality of the final product. I am likewise grateful to the entire Virginia Tech STS faculty, who made each graduate course intellectually stimulating and of enduring value. Lastly, none of this would have been possible without the tireless efforts of the administrative and technical staff who enable working professionals in Northern Virginia to seamlessly participate in a graduate program based in Blacksburg, VA. Above all, this outstanding group of researchers, educators, administrators, and technicians has equipped me to answer one of life’s most meaningful questions: What’s a Hokie? I am. iv Table of Contents 1 INTRODUCTION 1 1.1 Motivation for This Research 1 1.2 Structure/Overview 1 2 LITERATURE REVIEW 3 2.1 Introduction 3 2.2 Literature on Risk 3 2.3 Literature on Safety Standards and Regulation of Risks 10 2.4 Literature on Citizen Science and Standards 14 2.5 Theoretical Framework for Investigating Social Processes Involved in Science and Regulation 16 2.6 A Note on Sources 22 3 THE SPACE AVAILABLE FOR CONTESTATION 23 3.1 Radiation 23 3.2 Biological Damage from Radiation Exposure 25 3.3 Human Health Effects of Radiation Damage 26 3.4 The Arena of Contestation – Regulation of Ionizing Radiation at Low Doses 37 4 IDENTIFICATION OF ACTORS 40 4.1 Identifying the Actors 40 4.2 Building the Actor-Network 50 5 CONSTRUCTION OF A STANDARDS-SETTING INSTITUTION 52 5.1 Overview 52 5.2 Advisory Committee on X-Ray and Radium Protection 52 5.3 National Committee on Radiation Protection 55 5.4 National Council on Radiation Protection and Measurements 62 5.5 Sociotechnical Imaginaries of the NCRP 65 6 FEDERAL ACTORS 66 6.1 Overview 66 6.2 Atomic Energy Act of 1946 66 6.3 Atomic Energy Act of 1954 67 6.4 Activities of the AEC 67 6.5 National Academy of Sciences’ BEAR