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Regulating Pesticides A Report Prepared by the COMMITTEE ON PROTOTYPE EXPLICIT ANALYSES FOR PESTICIDES Environmental Studies Board Commission on Natural Resources National Research Council NATIONAL ACADEMY OF SCIENCES Washington, D.C. 1980
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. 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. This study was supported by the Office of Research and Development, U.S. Environmental Protection Agency, under Contract No. 68-01-3962. Library of Confess Catalog n Publication Data National Research Council. Committee on Prototype Explicit Analyses for Pesticides. Regulating pesticides. Bibliography: p. 1. Pesticides policy-United States-Evaluation. 2. Pesticides-Law and legislation-United States. 3. Pesticides-Evaluation. 4. Pesticides- Environmental aspects. 5. Environmental impact analysis. I. Title. SB970.4.USN37 1980 ISBN 0-309-02946-5 A bailable from Office of Publications National Academy of Sciences 2101 Constitution Avenue, N.W. Washington, D.C. 20418 Printed in the United States of America 363.7'384 8~1 1 103
COMMITTEE ON PROTOTYPE EXPLICIT ANALYSES FOR PESTICIDES ROBERT DORFMAN (Chairman), Department of Economics, Harvard University VIRGIL H. FREED, Department of Agricultural Chemistry, Oregon State University JOSEPH C. HEADLEY, Department of Agricultural Economics, University of Missouri DAVID G. KAUFMAN, Department of Pathology, School of Medicine, University of North Carolina DAVID P~ENTEL, Department of Entomology, Cornell University EUGENE P. SESKIN, Resources for the Future, Washington, D.C. JOSEPH C. STREET, Department of Animal Science, Chemistry, and Biochemistry, Utah State University A. DAN TARtOCK, School of Law, Indiana University Consultants to the Committee ROBERT BUKANTIS, Cornell University JOHN KR~EL, Cornell University Staff ADELE L. KING, Principal Staff Officer CONNIE REGES, Project Secretary RUSSELL SETTLE, Stan Officer (on loan from University of Delaware) LAWRENCE C. WALLACE, Stan Officer . . .
COMMISSION ON NATURAL RESOURCES GILBERT F. WHITE (Chairman), University of Colorado WILLIAM C. ACKERMAN, Illinois State Water Survey, Urbana THOMAS D. BARROW,* Exxon Corporation, New York JOHN E. CANTLON, Michigan State University DAYTON H. CLEWELL, Darien, Connecticut ELLIS B. COWLING, North Carolina State University JULIUS E. JOHNSON, Dow Chemical U.S.A., Midland, Michigan ALLEN V. KNEESE, University of New Mexico CHARLES I. MANKIN, Oklahoma Geological Survey, Norman PERRY L. McCARTY, Stanford University CHESTER O. McCORKLE, JR., University of California, Berkeley H. WILLIAM MENARD, Scripps Institute of Oceanography NORTON NELSON, New York University Medical Center WILLIAM K. REILLY, The Conservation Foundation, Washington, D.C. ALVIN M. WEINBERG, Oak Ridge Associated Universities E. BRIGHT WILSON, Harvard University WALLACE D. BOWMAN, Executive Director *Resigned effective November 22, 1978. V
Contents PREFACE Acknowledgments, xi 1 SUMMARY AND MAJOR RECOMMENDATIONS Introduction, 1 Summary and Major Recommendations, 4 Concluding Remarks, 14 References, 16 FIFRA AND THE RPAR PROCESS Legislative Framework, 18 The RPAR Process: A Description, 28 References, 44 3 SELECTING AND SCHEDULING COMPORTS FOR ASSESSMENT Introduction, 46 Current Approach, 47 Recommendations for Establishing a Preliminary RPAR Queue, 50 Modifications to the Preliminary Ranking: The Role of Alternative Pesticides, 58 References, 63 4 RISK ASSESSMENT Introduction, 65 Hazards to Human Health, 66 Analysis of Environmental Risks, 94 vi 1X 18 46 65
Risks to Structures, Materials, and Crops, 96 Overall Assessment of Risks, 96 References, 96 5 BENEFIT ASSESSMENT Introduction, 99 Analysis of Pesticide Productivity, 101 Estimating Changes in Pest Control Costs, 105 Economic Evaluation of Productivity and Cost Effects, 107 References, 129 6 EVALUATION OF THE ~GULATORY OPTIONS: WEIGHING THE RISKS AND BENEFITS Introduction, 131 Developing Regulatory Options, 131 Selection of Regulatory Options, 135 References, 153 APPLICATION TO CHLOROBENZILATE Introduction, 154 Background, 155 Analysis and Assessment of the Risks, 156 An Economic Evaluation of the Benefits, 190 Comparison of RegulatoIy Options, 218 References, 233 APPENDIXES A Scientific Limitations to Extrapolating Data on Cancer Risk from Animals to Humans, 239 B The Carcinogenic Activity Indicator, 253 C Estimates of the Carcinogenicity of Chlorobenzilate, 258 D Literature Search on the Biological Aspects of the Use of the Pesticide Dimethoate, 262 E Estimates of Acre-Treatments for Chlorobenzilate Substitutes, 279 F Construction of Confidence Intervals for Mathematical Combinations of Random Variables, 283 G List of Abbreviations Used in This Work, 287 vii 99 131 154
Preface Recent years have seen a growing public awareness and concern about the erects of widespread pesticide use on public health and on ecological conditions. At the same time it is realized that pesticides make a great contribution to our ability to produce food and vegetable fibers, to the amenities afforded by parks and decorative plants of all sorts, and to the control of pest borne diseases. These opposing realizations have led to our current policy of regulating the use of pesticides so as to permit it when the beneficial erects are deemed to outweigh the hazards, but not otherwise. This policy, in turn, has required the U.S. Environmental Protection Agency to assess the beneficial erects and the risks entailed in the use of specific pesticides in specific circumstances, so as to determine whether regulation was called for and, if so, which specific regulations would service the public best. In 1970, EPA established the Office of Pesticide Programs (oPP) for discharging this responsibility. Ever since then oPP has been developing and applying methods of analysis that would enable it to reach sound and justifiable judgments. Their procedures are still evolving. The National Research Council's Environmental Studies Board has recently conducted several studies on environmental decision making (Decision Making for Regulating Chemicals in the Environment and Principles for Evaluating Chemicals in the Environment) and decision making in EPA in particular (Decision Making in the Environmental Protection Agency and Pesticide Decision Making, Volumes II and VII, IX
x Preface respectively, in Analytical Studies for the U.S. Environmental Protection Agency). The reports suggest that a methodology that makes explicit the benefits and risks involved can be applied to environmental decision making, although with some difficulties. In the early summer of 1977, therefore, EPA'S Office of Research and Development requested that the NRC put their previous recommendations to a practical test and attempt explicit analyses for pesticides that are actually under consideration for registration or reregistration. The Committee on Prototype Explicit Analyses for Pesticides (PEAP) was established in early 1978 by the Environmental Studies Board within the NRC'S Commission on Natural Resources to respond to EPA'S request. The Committee was charged originally with implementing three prototype explicit analyses independently of EPA'S Office of Pesticide Programs. The Committee soon realized, however, that the study would be substantially more elective if the Committee and oPP worked closely together, with oPP providing data and its analyses and the Committee providing advice and consultation. In this way, the Committee would be aware of the data and resource constraints under which oPP must work and would be in a position to recommend methodologies that could be replicated in the future by EPA without NRC assistance. Thus, before the Committee first met in April 1978, its charge was revised. The Committee was asked to provide a single report (instead of three) describing the procedures and methods it would recommend to oPP and to include illustrations of the recommendations only where oPP's reports deviated from the recommended methodology. By agree- ment between EPA and the NRC, the pesticide chlorobenzilate was chosen as the illustrative example. The study was conducted in two phases: an initial period of observation and self-education followed by the formulation of conclu- sions and recommendations and their illustration. Between the first meeting in April and its second in September 1978, individual Commit- tee members attended EPA working meetings and met in subgroups to exchange observations and ideas. Committee stab gathered information and briefed the Committee. In August, the Committee divided into risk and benefit subgroups, each to focus on its respective aspect of pesticide assessment. From September through the end of the study the subgroups met a total of four times and the full Committee met an additional three times to discuss risk and benefit assessment methodologies and the weighing of the two and to develop recommendations to EPA. The Committee's November meeting was held in the citrus-growing region of Texas, so
Preface Xl that the Committee could meet with individuals directly involved with chlorobenzilate (a miticide used mainly on citrus). ACKNOWLEDGMENTS The nature of this study required exceptional efforts and contributions on the part of the Committee's stab. The stab consisted of Adele King, Principal Staff Officer; Connie Reges, Project Secretary; Russell Settle, Stab Officer; and Lawrence Wallace, Stab Officer. All four were confronted with unexpected responsibilities for contributing to the work of the Committee and discharged them admirably. In fact, in addition to the normal support functions, the stab was called upon to perform most of the research and much of the writing required to prepare our report. Anonymity should not be preserved in these conditions. The appropri- ate credits follow. Chapter 2. Ms. King gathered most of the factual material used in the chapter and wrote about half of it. Chapter 3. All the factual material was gathered by Ms. King, Dr. Settle, and Mr. Wallace. Ms. King and Dr. Settle collaborated in writing the entire chapter, including the discussion and explanations of the recommendations reached by the Committee. Dr. Settle contributed significantly to the discussion on the role of alternative pesticides. Chapter 4. The description of the procedures currently followed is the work primarily of Ms. King. Mr. Wallace provided early drafts of the discussion of the methods used to estimate human and other exposures. Much of the responsibility for writing the chapter and for explaining the Committee's recommendations was borne by Ms. King. Chapter 5. This chapter is essentially the work of Dr. Settle, who both formulated the analysis and prepared the final draft with the benefit (or impediment) of general guidance from members of the Committee. Chapter 6. The description of the procedures currently followed in oPP was prepared and written by Ms. King and Dr. Settle. Chapter 7. The test of chlorobenzilate was conducted and written by Ms. King, Dr. Settle, and Mr. Wallace under the general supervision of members of the Committee. Ms. Connie Rege~s earned the Committee's gratitude by her cheerful and expeditious discharge of the voluminous paperwork, and by the unconquerable patience she exhibited in communicating with the Committee and in coordinating the numerous drafts of this long report. We also appreciate the assistance from the CNR Editorial Office and the Manuscript Processing Unit. It might seem from the forgoing that with such a staff the Committee
. . X11 Preface had nothing to do. This was far from the case, and as Chairman I want to record my gratitude for the many hours that the members of the Committee devoted to their tasks, and for their patience in teaching me the many things that the Chairman of such a Committee has to know about matters far removed from his own field of specialization. The Committee expresses its gratitude to EPA'S Office of Pesticide Programs for its generous cooperation. In particular we thank Deputy Assistant Administrator Edwin L. Johnson for his support of the Committee's purpose; Fred Arnold for his willingness to share his knowledge of oPP's Rebuttable Presumption Against Registration (RPAR) procedure; and Kevin Keaney, who attended Committee meetings, kept the Committee current on oPP's activities, and responded patiently to frequent requests from the Committee and stab for documents and data from oPP. Others in EPA'S pesticide program and Carcinogen Assessment Group (CAG) gave freely of their time in thoughtful discussion, among them Elizabeth Anderson, Arnold Aspelin, Kyle Barbehenn, Nancy Beach, Joe Boyd, Christen Chaisson, Harold Gaede, Mark Luttner, David Severn, Ellen Siegler, and Bill Waugh. There were many others. Our special appreciation is due Roy Albert, Chairman of EPA'S Cancer Assessment Group; Nathan Karch, Acting Senior Staff for Toxic Substances and Environmental Health for the Council on Environmen- tal Quality; and Umberto Saffiotti, Chief of NCI'S Experimental Patholo- gy Laboratory, for their thoughtful discussions with Committee members and their suggestions regarding the Committee's recommended cancer risk assessment methodology. It should be noted that the help of any of the individuals singled out for thanks above does not imply their endorsement of Committee findings. We also thank Michael Wallace, Executive Vice President of Texas Citrus Mutual, who arranged for the Committee to meet in McAllen, Texas, with entomologists, researchers, growers, market specialists, and others directly involved with the pesticide chlorobenzilate and the Texas citrus industry. Drs. Jon Allen, Robert Brooks, and Joseph Knapp also attended this meeting, in addition to providing other intonation. John Krummel searched the literature on biological aspects of chlorobenzilate which provided background for the section in Chapter 7 on yield ejects. Bob Bukantis did the same for biological aspects of dimethoate, as presented in Appendix D. Dr. Alan Carlin, EPA'S Project Officer in charge of our contract, attended most of our meetings and contributed valuable insights to our discussion. He was a supportive and understanding colleague throughout this study, even when its focus shifted from the area he originally intended, when the Committee reached conclusions that conflicted with
Preface . . . X111 his own convictions, and when the study threatened to continue endlessly in bland disregard of his deadlines. Needless to say, Dr. Carlin bears no responsibility for our findings in spite of his indispensable contributions to our work. ROBERT DORFMAN, Chairman Committee on Prototype Explicit Analyses for Pesticides