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 competencies and with regard for appropriate balance.
This report has been reviewed by a group other than the authors according to procedures approved by a Report Review Committee consisting of members of the National Academy of Sciences, the National Academy of Engineering, and the Institute of Medicine.
International Standard Book Number 0-309-05737-X
Library of Congress Catalog Card Number 91-28051
Cover photograph: LES MOORE/UNIPHOTO
Copyright 1997 by the National Academy of Sciences. All rights reserved.
Printed in the United States of America
COMMITTEE ON ENVIRONMENTAL EPIDEMIOLOGY
ANTHONY B. MILLER (Chairman),
University of Toronto, Toronto, ON, Canada
University of British Columbia, Vancouver, BC, Canada
Department of Veterans Affairs and Harvard School of Public Health (deceased December 1995)
UCLA School of Public Health, Los Angeles, CA
Medical University of South Carolina, Charleston, SC
New York State Department of Health, Albany, NY
Harvard University School of Public Health, Cambridge, MA
US Environmental Protection Agency, was a member of the committee until February 1994
Medical College of Wisconsin, Milwaukee, WI
National Institute for Occupational Safety and Health, Cincinnati, OH
National Center for Health Statistics, Hyattsville, MD
DEVRA LEE DAVIS,
Scholar in Residence until June 1993
LINDA MILLER POORE, Research Associate
AMY REDMON, Editor
NORMAN GROSSBLATT, Editor
PAULETTE ADAMS, Project Assistant
The Committee on Environmental Epidemiology (listed above) prepared the original version of this report. The Commission on Life Sciences of the National Research Council, whose membership is shown on the next page, completed the report. All members of the Committee on Environmental Epidemiology agreed to the present content of the report.
COMMISSION ON LIFE SCIENCES
THOMAS D. POLLARD (Chairman),
Johns Hopkins Medical School, Baltimore, MD
FREDERICK R. ANDERSON,
Cadwalader, Wickersham & Taft, Washington DC
JOHN C. BAILAR III,
University of Chicago, Chicago, IL
Stanford University, Palo Alto, CA
JOHN E. BURRIS,
Marine Biological Laboratories, Woods Hole, MA
SHARON L. DUNWOODY,
University of Wisconsin, Madison, WI
URSULA W. GOODENOUGH,
Washington University, St. Louis, MO
HENRY W. HEIKKENEN,
University of Northern Colorado, Greeley, CO
HANS J. KENDE,
Michigan State University, East Lansing, MI
SUSAN E. LEEMAN,
Boston University, Boston, MA
THOMAS E. LOVEJOY,
Smithsonian Institution, Washington, DC
DONALD R. MATTISON,
University of Pittsburgh, Pittsburgh, PA
JOSEPH E. MURRAY,
Wellesley Hills, MA
EDWARD E. PENHOET,
Chiron Corporation, Emeryville, CA
EMIL A. PFITZER,
Research Institute for Fragrance Materials, Inc., Hackensack, NJ
MALCOLM C. PIKE,
USC School of Medicine, Los Angeles, CA
HENRY PITOT III,
University of Wisconsin, Madison, WI
JONATHAN M. SAMET,
Johns Hopkins University, Baltimore, MD
CHARLES F. STEVENS,
The Salk Institute for Biological Studies, La Jolla, CA
JOHN L. VANDEBERG,
Southwestern Foundation for Biomedical Research, San Antonio, TX
National Research Council Staff
PAUL GILMAN, Executive Director
ALVIN G. LAZEN, Associate Executive Director
SOLVEIG M. PADILLA, Administrative Assistant
VOLUME 1 OF Environmental Epidemiology was published in 1991 and has helped to define a field that seeks to clarify the relationship between exposure to physical, biologic, and chemical agents in the environment and human health. That report examined and evaluated the published scientific literature on health effects that could be linked with exposure to hazardous-waste sites and presented recommendations about filling major data gaps in order to advance the field.
In preparing volume 2, the Committee on Environmental Epidemiology set out to address important issues that were introduced in volume 1, such as the use of biomarkers and principles for drawing inferences from epidemiologic studies. The effects of exposure to an environmental agent can be hard to detect. The populations that have been exposed to the agent at a specific site are often small and the amount of exposure hard to determine. Only small changes in incidence of a disease may have occurred—so small as to make it difficult to determine clearly whether an association exists between the environmental exposure and the effect observed. Yet it is of great public-health importance to know if effects are occurring. Large numbers of people at many different sites may be exposed to the same environmental agent. Small effects detected in a small population could mean that a larger number exposed in the total population are at risk. Volume 2 continues the discussion of environmental epidemiology by examining ways to improve the chances of detecting an effect if one is occurring. Thus, the report focuses on improving how we measure exposure and how we apply the standard methods of epidemiologic research. The committee also examines the so-called gray litera-
ture—reports that have not been published in journals after peer-review but may contain valuable clues about possible hazards to human health. These gray literature reports are often from state and local public-health groups and have usually been reviewed locally.
The committee that prepared volume 1 also prepared the bulk of the report that follows. In particular, it did the long and arduous work of reviewing a collection of gray-literature reports to determine how useful these might be in helping to understand the effects of environmental exposure. They also prepared the original versions of all other chapters. Unfortunately, long delays occurred in the latter stages of the study process, and the original committee could not complete the report. Responsibility for completion was then assumed by the Commission on Life Sciences of the National Research Council, the oversight body for the Committee on Environmental Epidemiology. Thus, though the original committee deserves the gratitude of the scientific community for initiating the preparation of this report and for its initial work, the Commission takes responsibility on behalf of the National Research Council for the contents of the report along with the original committee. Special thanks are due to those members of the Commission—John Bailar, Malcolm Pike, and Jonathan Samet—who played the central role on behalf of the Commission.
We acknowledge the efforts of and thank the Committee on Environmental Epidemiology and the staff of that committee. Their names are listed in the front of this report. We also thank the Agency for Toxic Substances and Disease Registry, sponsor of the study, for its support.
THOMAS D. POLLARD, CHAIRMAN
COMMISSION ON LIFE SCIENCES
The National Academy of Sciences is a private, nonprofit, self-perpetuating society of distinguished scholars engaged in scientific and engineering research, dedicated to the furtherance of science and technology and to their use for the general welfare. Upon the authority of the charter granted to it by the Congress in 1863, the Academy has a mandate that requires it to advise the federal government on scientific and technical matters. Dr. Bruce Alberts is president of the National Academy of Sciences.
The National Academy of Engineering was established in 1964, under the charter of the National Academy of Sciences, as a parallel organization of outstanding engineers. It is autonomous in its administration and in the selection of its members, sharing with the National Academy of Sciences the responsibility for advising the federal government. The National Academy of Engineering also sponsors engineering programs aimed at meeting national needs, encourages education and research, and recognizes the superior achievements of engineers. Dr. William A. Wulf is interim president of the National Academy of Engineering.
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The National Research Council was organized by the National Academy of Sciences in 1916 to associate the broad community of science and technology with the Academy's purposes of furthering knowledge and of advising the federal government. Functioning in accordance with general policies determined by the Academy, the Council has become the principal operating agency of both the National Academy of Sciences and the National Academy of Engineering in providing service to the government, the public, and the scientific and engineering communities. The Council is administered jointly by both academies and the Institute of Medicine. Dr. Bruce Alberts and Dr. William A. Wulf are chairman and interim vice chairman, respectively, of the National Research Council.