Wildfires in America are becoming larger, more frequent, and more destructive, driven by climate change and existing land management practices. Many of these fires occur at the wildland-urban interface (WUI), areas where development and wildland areas overlap and which are increasingly at risk of devastating fires as communities continue to expand into previously undeveloped areas. Unlike conventional wildfires, WUI fires are driven in part by burning of homes, cars, and other human-made structures, and in part by burning vegetation. The interaction of these two types of fires can lead to public health effects that are unique to WUI fires. This report evaluates existing and needed chemistry information that decision-makers can use to mitigate WUI fires and their potential health impacts. It describes key fuels of concern in WUI fires, especially household components like siding, insulation, and plastic, examines key pathways for exposure, including inhalation and ingestion, and identifies communities vulnerable to exposures. The report recommends a research agenda to inform response to and prevention of WUI fires, outlining needs in characterizing fuels, and predicting emissions and toxicants.

Contents

• The National Academies of SCIENCES • ENGINEERING • MEDICINE
• COMMITTEE ON THE CHEMISTRY OF URBAN WILDFIRES
• BOARD ON CHEMICAL SCIENCES AND TECHNOLOGY
• Acknowledgments
• Acronyms and Abbreviations
• Summary
  • FUEL, COMBUSTION, EMISSIONS
  • ATMOSPHERIC TRANSPORT AND CHEMICAL TRANSFORMATIONS
  • WATER, SOIL, AND BUILDING CONTAMINATION
  • HUMAN EXPOSURES, HEALTH IMPACTS, AND MITIGATION
  • MEASUREMENT SCIENCE
  • RESEARCH AGENDA
• 1. Introduction
  • WILDFIRES AT THE WUI
  • THE COMMITTEE AND ITS TASK
  • THE COMMITTEE’S APPROACH TO ITS TASK
  • THE COMMITTEE’S APPROACH TO EQUITY
  • PRIOR RELATED WORK BY THE NATIONAL ACADEMIES
  • ORGANIZATION OF THIS REPORT
  • REFERENCES
• 2. Defining and Contextualizing WUI Fires
  • DEFINING THE WUI
  • DEFINING SPATIAL AND TEMPORAL SCALES
  • FACTORS CONTRIBUTING TO INCREASING WUI FIRES
  • THE IMPACTS OF WUI FIRES
  • USING EXAMPLES TO CONTEXTUALIZE WUI FIRES
  • FINDINGS FROM RECENT EXAMPLES OF WUI FIRES
  • REFERENCES
• 3. Materials, Combustion, and Emissions in WUI Fires
  • MATERIALS
  • COMBUSTION
  • EMISSIONS
  • REFERENCES
• 4. Atmospheric Transport and Chemical Transformations
  • PRIMARY SPECIES WITH TOXIC POTENTIAL DOWNWIND OF WUI FIRES
  • ATMOSPHERIC TRANSFORMATIONS
  • CURRENT PRACTICE IN MODELING FAR PLUMES
  • REFERENCES
• 5. Water and Soil Contamination
  • IMPACTS TO WATER QUALITY RELATED TO COMMUNITY WATER SYSTEMS
  • IMPACTS TO GROUNDWATER AND SOIL CONTAMINATION
  • IMPACTS OF ATMOSPHERIC WET AND DRY DEPOSITION
  • REFERENCES
• 6. Human Exposures, Health Impacts, and Mitigation
  • CHEMICALS OF CONCERN FOR HUMAN EXPOSURE
  • VULNERABLE POPULATIONS, HEALTH EQUITY, AND ENVIRONMENTAL JUSTICE
  • ROUTES OF EXPOSURE
  • HEALTH IMPACTS
  • REDUCING EXPOSURE RISKS AND HEALTH EFFECTS
  • CONCLUSION
  • REFERENCES
• 7. Measurement of WUI Fires: Emissions and Exposures
  • AN OVERVIEW OF DATA AND MEASUREMENT SYSTEMS FOR WUI FIRES
  • DETECTING AND DETERMINING THE AREAL EXTENT OF WUI FIRES
  • MEASURING FUELS AND ESTIMATING EMISSIONS
  • MEASURING EMISSIONS IN THE FIELD
  • MONITORING EMISSIONS USING CONTINUOUS/AMBIENT NETWORKS
  • ASSESSING EXPOSURE
  • SAMPLING AND ANALYTICAL METHODS
  • COORDINATING MEASUREMENTS OF WUI FIRES
  • REFERENCES
• 8. The Future of WUI Fire Research
  • RESEARCH AGENDA
  • CROSS-DISCIPLINARY COORDINATION
  • INFORMATION DISSEMINATION
• Appendix A. Glossary
• Appendix B. Committee Biographical Sketches
• Appendix C. Available Data for Example Fires
• Appendix D. Public Workshop Agenda
• Appendix E. Engineering Calculations for Table 3-2

Suggested citation:

National Academies of Sciences, Engineering, and Medicine. 2022.The Chemistry of Fires at the Wildland-Urban Interface. Washington, DC: The National Academies Press. https://doi.org/10.17226/26460.

Digital Object Identifier: https://doi.org/10.17226/26460

Library of Congress Control Number: 2022949390

This publication is available from the National Academies Press, 500 Fifth Street, NW, Keck 360, Washington, DC 20001; (800) 624-6242 or (202) 334-3313; http://www.nap.edu.

Printed in the United States of America.