NATIONAL ACADEMY PRESS
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NOTICE: The project that is the subject of this report was approved by the Governing Board of the National Research Council, whose members are drawn from the councils of the National Academy of Sciences, the National Academy of Engineering, and the Institute of Medicine. The members of the committee responsible for the report were chosen for their special competences and with regard for appropriate balance.
The Institute of Medicine and the National Research Council act under the 1863 congressional charter for the National Academy Sciences to advise the federal government. They also act on their own initiative to identify important scientific and health issues. The president of the Institute of Medicine is Dr. Kenneth Shine. The president of the National Research Council is Dr. Bruce Alberts.
Support for this project was provided by the U.S. Department of Health and Human Services (Contract Number NO1-OD-4-2139, TO 35). The views presented are those of the National Research Council and Institute of Medicine committees and are not necessarily those of the funding organization.
Library of Congress Catalog Card No. 98-83159
International Standard Book No. 0-309-06175-X
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INSTITUTE OF MEDICINE COMMITTEE ON THYROID CANCER SCREENING
Robert S. Lawrence, Chair, Professor of Health Policy and Associate Dean for Professional Education,
Johns Hopkins University
Catherine Borbas, Executive Director,
Healthcare Education and Research Foundation, Inc., Minneapolis
J. William Charboneau, Professor of Radiology,
Mayo Clinic and Mayo Medical School
Virginia A. Li Volsi, Vice Chair for Anatomic Pathology,
Hospital of the University of Pennsylvania
Ernest L. Mazzaferri, Professor and Chair,
Department of Internal Medicine, Ohio State University
Stephen G. Pauker, Vice Chair for Clinical Affairs,
Department of Medicine, New England Medical Center
Henry D. Royal, Associate Director,
Division of Nuclear Medicine, Mallinckrodt Institute of Radiology, Washington University School of Medicine
Samuel A. Wells, Professor of Surgery,
Washington University School of Medicine
Steven H. Woolf, Private Practice, Family Medicine and Professor,
Department of Family Practice, Virginia Commonwealth University
Staff
Marilyn J. Field, Co-Study Director and Deputy Director,
Health Care Services, IOM
Cecilia Rossiter, Administrative Assistant,
IOM
Vince Knobel, Project Assistant,
IOM
Kay Harris, Financial Associate,
IOM
Clyde Behney, Deputy Executive Officer,
IOM
COMMITTEE ON EXPOSURE OF THE AMERICAN PEOPLE TO I-131 FROM NEVADA ATOMIC BOMB TESTS
William J. Schull Chair, Professor,
Human Genetics Center, School of Public Health, University of Texas, Houston
Keith F. Baverstock, Head of the Radiation Protection Division,
World Health Organization, Rome, Italy
Stephen A. Benjamin, Professor of Pathology,
Radiological Health Sciences, and Environmental Health, Colorado State University
Patricia A.H. Buffler,* Dean and Professor of Epidemiology,
University of California, Berkeley
Sharon Dunwoody, Professor of Journalism and Mass Communication,
University of Wisconsin
Peter G. Groer, Associate Professor,
Department of Nuclear Engineering, University of Tennessee
Robert S. Lawrence,* Professor of Health Policy and Associate Dean for Professional Education,
Johns Hopkins University
Carl M. Mansfield, Chair,
Department of Radiation Oncology, University of Maryland Medical Systems, Baltimore
James E. Martin, Associate Professor of Radiological Health,
University of Michigan
Ernest L. Mazzaferri, Professor and Chair,
Department of Internal Medicine, Ohio State University
Kathryn Merriam,
Synthesis, Incorporated, Pocatello, ID
Dade W. Moeller,†
Dade Moeller & Associates, New Bern, NC
Christopher B. Nelson,
Environmental Protection Agency, Washington, DC
Henry D. Royal, Associate Director,
Division of Nuclear Medicine, Mallinckrodt Institute of Radiology, Washington University School of Medicine
Richard H. Schultz, Administrator,
Department of Health and Welfare, Boise, ID
Daniel O. Stram, Associate Professor of Preventive Medicine,
University of Southern California
Robert G. Thomas,
Kallispell, MT
Consultants
Lynn R. Anspaugh,
University of Utah
F. Owen Hoffman,
SENES Oak Ridge, Inc., Oak Ridge, Tenn.
Donald E. Myers,
University of Arizona
Roy E. Shore,
New York University Medical Center
Staff
Steven L. Simon, Co-Study Director
Karen M. Bryant, Project Assistant
Doris E. Taylor, Staff Assistant
Catherine S. Berkley, Administrative Associate
Evan B. Douple, Director,
Board on Radiation Effects Research
Paul Gilman, Executive Director,
Commission on Life Sciences
David M. Livingston,
Dana-Farber Cancer Institute, Boston
Editor
Anne Kelly
Sponsor's Project Officer
Charles E. Land,
National Cancer Institute
BOARD ON RADIATION EFFECTS RESEARCH
John B. Little, Chair (until June 30, 1998),
Harvard School of Public Health, Boston
S. James Adelstein* (as of July 1, 1998),
Harvard Medical School, Boston
Valerie Beral,
University of Oxford, United Kingdom
Edward R. Epp (as of July 1, 1998),
Weston, MA
Helen H. Evans (as of July 1, 1998),
Case Western Reserve University, Cleveland, OH
R.J. Michael Fry, Chair (as of July 1, 1998),
Oak Ridge, TN
Philip C. Hanawalt† (until June 30, 1998),
Stanford University
Lynn W. Jelinski,
Louisiana State University, Baton Rouge
William F. Morgan (as of July 1, 1998),
University of California, San Francisco
William J. Schull,
The University of Texas Health Science Center, Houston
Daniel O. Stram,
University of Southern California, Los Angeles
Susan W. Wallace (until June 30, 1998),
University of Vermont, Burlington
H. Rodney Withers,
University of California Los Angeles Medical Center
Staff
Evan B. Douple, Director
Rick Jostes, Senior Program Officer
Steven L. Simon, Senior Program Officer
Catherine S. Berkley, Administrative Associate
Doris E. Taylor, Staff Assistant
Peggy Johnson, Project Assistant (until August 12, 1998)
Karen Bryant, Project Assistant (until October 23, 1998)
INSTITUTE OF MEDICINE BOARD ON HEALTH CARE SERVICES
Don E. Detmer, Chair,
The University of Virginia
Barbara J. McNeil, Vice Chair,
Harvard Medical School
Stuart H. Altman,
Brandeis University, Waltham, MA
Paul D. Clayton,
Columbia-Presbyterian Medical Center, NY
Nancy W. Dickey,
Bryan, TX
B. Ken Gray,
Metroplex Emergency Physician Associates, P.A., Dallas, TX
Paul F. Griner,
Association of American Medical Colleges, Washington, DC
Ruby P. Hearn,
Robert Wood Johnson Foundation, Princeton
Peter Barton Hutt,
Partner, Covington & Burling, Washington, DC
Brent C. James,
Institute for Health Care, Salt Lake City, UT
Jacqueline Kosecoff,
Protocare, Santa Monica, CA
Sheila T. Leatherman,
United Health Care Corporation, Minneapolis
John Ludden,
Harvard Pilgrim Health Care, Boston
Russell L. Miller, Consultant,
Washington, DC
Mildred Mitchell-Bateman,
Huntington Hospital, Huntington, WV
Mary Mundinger,
Columbia University, New York
Uwe E. Reinhardt,
Princeton University, NJ
Mary Lee Seibert,
Ithaca College, Ithaca, NY
Gail L. Warden,
Henry Ford Health System, Detroit
IOM Liaison:
Lawrence S. Lewin,
The Lewin Group, Fairfax, VA
Staff
Janet M. Corrigan, Director
Marilyn J. Field, Deputy Director
Evelyn Simeon, Administrative Assistant
COMMISSION ON LIFE SCIENCES
Thomas D. Pollard, Chair,
The Salk Institute for Biological Studies, La Jolla, CA
Frederick R. Anderson,
Cadwalader, Wickersham & Taft, Washington, DC
John C. Bailar, III,
University of Chicago, IL
Paul Berg,
Stanford University School of Medicine, Palo Alto, CA
Joanna Burger,
Rutgers University, Piscataway, NJ
Sharon L. Dunwoody,
University of Wisconsin, Madison
John L. Emmerson,
Indianapolis, IN
Neal L. First,
University of Wisconsin, Madison
Ursula W. Goodenough,
Washington University, St. Louis, MO
Henry W. Heikkinen,
University of Northern Colorado, Greeley, CO
Hans J. Kende,
Michigan State University, East Lansing
Cynthia J. Kenyon,
University of California, San Francisco
David M. Livingston,
Dana-Farber Cancer Institute, Boston, MA
Thomas E. Lovejoy,
Smithsonian Institution, Washington, DC
Donald R. Mattison,
University of Pittsburgh, PA
Joseph E. Murray,
Wellesley Hills, MA
Edward E. Penhoet,
Chiron Corporation, Emeryville, CA
Malcolm C. Pike,
Norris Comprehensive Cancer Center, Los Angeles, CA
Jonathan M. Samet,
The Johns Hopkins University, Baltimore, MD
Charles F. Stevens,
The Salk Institute for Biological Studies, La Jolla, CA
John L. Vandeberg,
Southwest Foundation for Biomedical Research, San Antonio, TX
Staff
Paul Gilman, Executive Director
Alvin G. Lazen, Associate Executive Director (until July 1, 1998)
Barbara B. Smith, Administrative Associate
Jacqueline K. Prince, Administrative Officer
Kit W. Lee, Senior Project Assistant
Preface
When the atomic weapons testing program in the continental United States began in 1951 at the Nevada Test Site, the world was sharply divided between two conflicting political ideologies with global intentions uncertain to the other. Each saw its political adversary as a potential aggressor, and each launched a major nuclear weapons development and testing program. In both instances, national defense was seen as taking precedence over the possible health hazards that these programs might present either to the individuals directly involved in the development or testing or to the public generally.
Governmental decisions related to safety both on and off the Nevada Test Site were undoubtedly influenced by a sense of urgency about national security. One apparent consequence is a history of misleading government statements about the Nevada tests. Government decisions were also shaped by the limited amount of information then available on the potential health hazards of fallout, particularly the later-term effects, such as cancer, that would not be quickly manifested. At the beginning of the test period, the Atomic Energy Commission declared that tests did not present a danger to the public, although some staff expressed concern. Experts were not at that time clearly aware that, in addition to direct radiation exposure and inhalation exposure routes, another exposure route—air-grass-milk—was also important.
Not until 1961, near the end of the period of weapons testing did the Federal Radiation Council set as a goal that the annual limit of I-131 doses to the thyroid for a population group not exceed 0.5 rem and that the individual annual limit not exceed 1.5 rem. Although an annual limit of 15 rem had been recommended for members of the public in 1953 (reduced in 1957 to 1.5 rem for minors), the recommendation was not at the time viewed as applicable to fallout from weapons testing.
These perceptions of urgency and safety notwithstanding, in retrospect, it is clear that the exposure of the public was inadequately monitored. This has resulted in large uncertainties in the doses the public may have received and has
prompted a continuing and often acrimonious debate about the hazards involved and about the release of information about the weapons tests and their consequences.
The report released by the National Cancer Institute in October 1997 was an effort to assess the hazards of radioactive iodine (more specifically iodine-131, also written as I-131) from the Nevada weapons tests. The analytic challenges the NCI faced in developing its report were formidable and, of necessity, time consuming to meet. Evaluating and quantifying thyroid cancer attributable to Nevada test fallout is an exceptionally complex task that is beset with immense uncertainties related to both the estimates of I-131 exposure and estimates of I-131 related thyroid cancers. Nonetheless, the credibility of the federal government in matters relating to exposure to ionizing radiation may be have been compromised by the agency's perceived slowness in releasing the report, once the analysis was largely completed.
It appears likely that a relatively small proportion of the 160,000,000 Americans alive during the weapons testing program received cumulative doses of iodine-131 greater than the exposure limit set forth in 1961, which would have amounted to 5 rem exposure limit over a ten-year period. However, the number of persons receiving much higher doses, up to 100 rem or more, could have numbered in the tens of thousands. It is the estimation of risk to exposed Americans and the steps that might be taken in response to the risk that has been of primary concern to the review panel established by the Institute of Medicine and the National Research Council.
The panel's work focused on (1) assessing the soundness of the NCI analyses and estimates including those developed separately from the main report, (2) the risk of thyroid disease from iodine-131 fallout, (3) evaluating the benefits and harms of recommending a program of routine screening for thyroid cancer, and (4) identifying strategies for communicating with the public about risks and responses. It reaches a somewhat unsettling combination of conclusions, first, that some people (who cannot be easily identified) were likely exposed to sufficient iodine-131 to raise their risk of thyroid cancer and, second, that there is no evidence that programs to screen for thyroid cancer are beneficial in detecting disease at a stage that would allow more effective treatment. To serve the public interest, the major contribution that the government can make is not to launch an ineffective but politically appealing screening program but rather, to develop effective ways to communicate with the public about iodine-131 exposure and health risks and to involve the public in determining what communication strategies people will find understandable, useful, and trustworthy.
William J. Schull, Ph.D.
Co-Chair
Robert S. Lawrence, M.D.
Co-Chair
Acknowledgments
In developing this report, the IOM and NRC committees and staff benefited from the assistance of many individuals and organizations This report has been reviewed in draft form by individuals chosen for their diverse perspectives and technical expertise, in accordance with procedures approved by the National Research Council's Report Review Committee. The purpose of this independent review is to provide candid and critical comments that will assist the institution in making its published report as sound as possible and to ensure that the report meets institutional standards for objectivity, evidence, and responsiveness to the study charge. The review comments and draft manuscript remain confidential to protect the integrity of the deliberative process. We wish to thank the following individuals for their participation in the review of this report: Herbert Abrams (Stanford University), Evan J. Englund (Environmental Protection Agency, Las Vegas), Kristine M. Gebbie (Columbia University), H. Jack Geiger (City University of New York Medical School), Prabodh Gupta (Hospital of the University of Pennsylvania), David G. Hoel (Medical University of South Carolina), Bernd Kahn (Georgia Institute of Technology), Russell Brown (Idaho Falls, ID), Richard A. Kerber (University of Utah School of Medicine), Ralph Lapp (Lapp Inc.), Laura Leonard (Handford Health Information Network), Ross L. Prentice (Fred Hutchinson Cancer Center), Morton Rabinowitz (Media, PA), Marvin L. Rallison (University of Utah), David Ransohoff (University of North Carolina at Chapel Hill), Arthur B. Schneider (University of Illinois at Chicago), Lisa Schwartz (Dartmouth Medical School), Harold C. Sox Jr. (Dartmouth-Hitchcock Medical Center), Lee Wilkins (Columbia, MO), and Stephen Woloshin (Dartmouth Medical School).
While the individuals listed above have provided constructive comments and suggestions, it must be emphasized that responsibility for the final content of this report rests entirely with the authoring committee and the institution. The NRC committee held several public meetings at which presentations were made and public comments were invited. Appendix A lists those who participated. In addition,
the committee appreciates the assistance of Lynn R. Anspaugh (University of Utah), F. Owen Hoffman (Senes, Oak Ridge Inc.), Roy Shore (New York University Medical Center), and Donald E. Myers (University of Arizona) who served as consultants.
The IOM committee particularly benefited from the experience and expertise of the presenters and other participants in the workshop the committee convened March 17 and 18 in Washington, DC. Appendix A lists the workshop participants, presenters, and agenda. It also benefited from the timely and thorough review of the scientific literature and other consultation provided by Mark Helfand and Karen Eden. In addition, the committee benefited from the comments of Christopher Merritt, Leslie De Groot, Kenneth Suen, E. Chester Ridgway, and Martin Surks.