The U.S. Environmental Protection Agency (EPA) is one of several federal agencies responsible for protecting Americans against significant risks to human health and the environment. As part of that mission, EPA estimates the nature, magnitude, and likelihood of risks to human health and the environment; identifies the potential regulatory actions that will mitigate those risks and protect public health1 and the environment; and uses that information to decide on appropriate regulatory action. Uncertainties, both qualitative and quantitative, in the data and analyses on which these decisions are based enter into the process at each step. As a result, the informed identification and use of the uncertainties inherent in the process is an essential feature of environmental decision making.

EPA requested that the Institute of Medicine (IOM) convene a committee to provide guidance to its decision makers and their partners in states and localities on approaches to managing risk in different contexts when uncertainty is present. It also sought guidance on how information on uncertainty should be presented to help risk managers make sound decisions and to increase transparency in its communications with the public about those decisions. Given that its charge is not limited to human health risk assessment and includes broad questions about managing risks and decision making, in this report the committee examines the analysis of uncertainty in those other areas in addition to human health risks. Environmental Decisions in the Face of Uncertainty explains the statement of task and summarizes the findings of the committee.

Contents

• THE NATIONAL ACADEMIES
• COMMITTEE ON DECISION MAKING UNDER UNCERTAINTY
• Reviewers
• Preface
• Abbreviations and Acronyms
• Summary
  • MULTIPLE SOURCES OF UNCERTAINTY
  • APPROACH TO THE CHARGE
  • UNCERTAINTY IN EPA'S ESTIMATES OF HEALTH RISK
  • UNCERTAINTY IN COMPONENTS OF DECISION MAKING OTHER THAN ESTIMATES OF HUMAN HEALTH RISK
  • UNCERTAINTY: OTHER PUBLIC HEALTH SETTINGS
  • INCORPORATING AND USING UNCERTAINTY IN DECISION MAKING
  • COMMUNICATING UNCERTAINTY IN DECISIONS
  • FINDINGS AND RECOMMENDATIONS
• 1. Introduction
  • UNCERTAINTY AND ENVIRONMENTAL DECISION MAKING
  • THE CONTEXT OF THIS REPORT AND THE CHARGE TO THE COMMITTEE
  • COMMITTEE PROCESS
  • COMMITTEE'S APPROACH TO THE CHARGE
  • TYPES OF UNCERTAINTY
  • OVERVIEW OF THE REPORT
  • REFERENCES
• 2. Risk Assessment and Uncertainty
  • RISK ASSESSMENT
  • UNCERTAINTY AND RISK ASSESSMENT
  • THE HISTORY OF UNCERTAINTY ANALYSIS
  • NEWER APPROACHES TO DEALING WITH UNCERTAINTIES
  • EXAMPLES OF EPA'S RISK ASSESSMENTS
  • KEY FINDINGS
  • REFERENCES
• 3. Uncertainty in Technological and Economic Factors in EPA's Decision Making
  • TECHNOLOGY AVAILABILITY
  • ECONOMICS
  • OTHER FACTORS
  • KEY FINDINGS
  • REFERENCES
• 4. Uncertainty and Decision Making: Lessons from Other Public Health Contexts
  • UNCERTAINTY AND PUBLIC HEALTH DECISIONS
  • SECONDHAND SMOKE
  • LISTERIA MONOCYTOGENES
  • BOVINE SPONGIFORM ENCEPHALOPATHY
  • CONTAMINATION OF THE FOOD SUPPLY WITH MELAMINE
  • AVANDIA^®
  • VACCINATION DECISIONS
  • LESSONS FROM HISTORY
  • U.S. PREVENTIVE SERVICES TASK FORCE RECOMMENDATIONS
  • KEY FINDINGS
  • REFERENCES
• 5. Incorporating Uncertainty into Decision Making
  • INCORPORATING UNCERTAINTY INTO A DECISION-MAKING FRAMEWORK
  • OTHER CONSIDERATIONS
  • STAKEHOLDER ENGAGEMENT
  • KEY FINDINGS
  • REFERENCES
• 6. Communication of Uncertainty
  • COMMUNICATION OF UNCERTAINTY IN RISK ESTIMATES
  • PRESENTATION OF UNCERTAINTY
  • CONSIDERATIONS WHEN DECIDING ON A COMMUNICATIONS APPROACH
  • KEY FINDINGS
  • REFERENCES
• 7. Synthesis and Recommendations
  • FINDINGS AND RECOMMENDATIONS
  • REFERENCES
• APPENDIXES
  • Appendix A Approaches to Accounting for Uncertainty
  • Appendix B Committee Member Biographical Sketches
  • Appendix C Meeting Agendas

This study was supported by Contract No. EP-C-09-003, TO#6 between the National Academy of Sciences and the Environmental Protection Agency. Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the organizations or agencies that provided support for this project.

Suggested citation:

IOM (Institute of Medicine). 2013. Environmental decisions in the face of uncertainty. Washington, DC: The National Academies Press.

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.