The Chemistry of Fires at the
Wildland-Urban Interface
_______
Committee on the Chemistry of Urban Wildfires
Board on Chemical Sciences and Technology
Division on Earth and Life Studies
Consensus Study Report
NATIONAL ACADEMIES PRESS 500 Fifth Street, NW Washington, DC 20001
This activity was supported by contracts between the National Academy of Sciences and Centers for Disease Control and Prevention, the National Institute of Standards and Technology, and the National Institutes of Health, Department of Health and Human Services, under Contract No. HHSN263201800029I. Any opinions, findings, conclusions, or recommendations expressed in this publication do not necessarily reflect the views of any organization or agency that provided support for the project.
International Standard Book Number-13: 978-0-309-27705-1
International Standard Book Number-10: 0-309-27705-1
Digital Object Identifier: https://doi.org/10.17226/26460
Library of Congress Control Number: 2022949390
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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.
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COMMITTEE ON THE CHEMISTRY OF URBAN WILDFIRES
Members
DAVID T. ALLEN (NAE), Chair, The University of Texas at Austin
OLORUNFEMI ADETONA, The Ohio State University
MICHELLE BELL (NAM), Yale University
MARILYN BLACK, Underwriters Laboratories Inc.
JEFFEREY L. BURGESS, University of Arizona
FREDERICK L. DRYER (NAE), University of South Carolina
AMARA HOLDER, US Environmental Protection Agency
ANA MASCAREÑAS, Independent Consultant
FERNANDO L. ROSARIO-ORTIZ, University of Colorado Boulder
ANNA A. STEC, University of Central Lancashire
BARBARA J. TURPIN, University of North Carolina at Chapel Hill
JUDITH T. ZELIKOFF, New York University
Staff
MEGAN E. HARRIES, Study Director (until August 2022)
LIANA VACCARI, Study Director
BRENNA ALBIN, Program Assistant
EMILY J. BUEHLER, Consultant
KESIAH CLEMENT, Research Associate (until July 2021)
CHARLES FERGUSON, Senior Board Director
MEGHAN HARRISON, Senior Program Officer (until July 2021)
ELLEN K. MANTUS, Scholar (until April 2021)
JEREMY T. MATHIS, Board Director (until March 2021)
MARILEE SHELTON-DAVENPORT, Senior Program Officer (until January 2021)
ABIGAIL ULMAN, Research Assistant (until May 2022)
BENJAMIN ULRICH, Senior Program Assistant (until March 2022)
Sponsors
CENTERS FOR DISEASE CONTROL AND PREVENTION
NATIONAL INSTITUTE OF ENVIRONMENTAL HEALTH SCIENCES
NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY
BOARD ON CHEMICAL SCIENCES AND TECHNOLOGY
Members
SCOTT COLLICK, Co-chair, DuPont
JENNIFER SINCLAIR CURTIS, Co-chair, University of California, Davis
GERARD BAILLELY, Procter and Gamble
RUBEN G. CARBONELL (NAE), North Carolina State University
JOHN FORTNER, Yale School of Engineering and Applied Science
KAREN I. GOLDBERG (NAS), University of Pennsylvania
JENNIFER M. HEEMSTRA, Emory University
JODIE L. LUTKENHAUS, Texas A&M University
SHELLEY D. MINTEER, University of Utah
AMY PRIETO, Colorado State University
MEGAN L. ROBERTSON, University of Houston
SALY ROMERO-TORRES, Thermo Fisher Scientific
REBECCA T. RUCK, Merck Process Research & Development
ANUP K. SINGH, Lawrence Livermore National Laboratory
VIJAY SWARUP, ExxonMobil
Staff
CHARLES FERGUSON, Senior Board Director
MEGAN E. HARRIES, Program Officer (until August 2022)
LIANA VACCARI, Program Officer
LINDA NHON, Associate Program Officer
THANH NGUYEN, Finance Business Partner
JESSICA WOLFMAN, Research Associate
BRENNA ALBIN, Program Assistant
AYANNA LYNCH, Program Assistant
Acknowledgments
This Consensus Study Report was reviewed in draft form by individuals chosen for their diverse perspectives and technical expertise. The purpose of this independent review is to provide candid and critical comments that will assist the National Academies of Sciences, Engineering, and Medicine in making each published report as sound as possible and to ensure that it meets the institutional standards for quality, 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 thank the following individuals for their review of this report:
Tami Bond, Colorado State University
Shoba Iyer, California Environmental Protection Agency and San Francisco Department of the Environment
Samuel Manzello, REAX Engineering
Sarah McAllister, US Forest Service
Birgitte Messerschmidt, National Fire Protection Association
Jason Sacks, US Environmental Protection Agency
David Sedlak (NAE), University of California, Berkeley
Carsten Warneke, US National Oceanographic and Atmospheric Administration
Christine Wiedinmyer, University of Colorado Boulder
Although the reviewers listed above provided many constructive comments and suggestions, they were not asked to endorse the conclusions or recommendations of this report, nor did they see the final draft before its release. The review of this report was overseen by Susan Brantley, The Pennsylvania State University, and Martin-Jose J. Sepulveda, Florida International University. They were responsible for making certain that an independent examination of this report was carried out in accordance with the standards of the National Academies and that all review comments were carefully considered. Responsibility for the final content rests entirely with the authoring committee and the National Academies.
This study would not have been successful without the assistance of many. The committee is grateful to the people who helped provide research support to the report, including Colette Schissel, The University of Texas at Austin; Yosuke Kimura, The University of Texas at Austin; and the staff of the National Academies Research Center. We are especially grateful to the numerous expert individuals who spoke to the committee during an open information-gathering session or otherwise provided input (see Appendix D).
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Acronyms and Abbreviations
AQI | Air Quality Index |
ASTM | American Society for Testing and Materials |
BBOP | Biomass Burn Observation Project |
CAMS | continuous air quality monitoring station |
CARB | California Air Resources Board |
CDC | Centers for Disease Control and Prevention |
CDD | chlorinated dibenzo-p-dioxin |
CE | combustion efficiency |
CF | combustion factor |
CI | confidence interval |
CMAQ | Community Multiscale Air Quality |
COPD | chronic obstructive pulmonary disease |
CWS | community water system |
DBP | disinfection by-product |
DOM | dissolved organic matter |
ED | emergency department |
EF | emission factor |
EPA | US Environmental Protection Agency |
ER | emission ratio |
FASMEE | Fire and Smoke Model and Evaluation Experiment |
FIREX-AQ | Fire Influence on Regional to Global Environments and Air Quality |
GeoXO | Geostationary Extended Observations |
GOES | Geostationary Operational Environmental Satellite |
GREET | Greenhouse gases, Regulated Emissions, and Energy use in Technologies |
HEPA | high-efficiency particulate air |
HVAC | heating, ventilating, and air conditioning |
IARC | International Agency for Research on Cancer |
IMPROVE | Interagency Monitoring of Protected Visual Environments |
ISO | International Organization for Standardization |
IVOC | intermediate-volatility organic compound |
MCE | modified combustion efficiency |
MDA8 | daily maximum eight-hour average |
MERV | minimum efficiency reporting value |
MODIS | Moderate Resolution Imaging Spectroradiometer |
NAAQS | National Ambient Air Quality Standards |
NIEHS | National Institute of Environmental Health Sciences |
NIFC | National Interagency Fire Center |
NIOSH | National Institute for Occupational Safety and Health |
NIST | National Institute of Standards and Technology |
NTU | nephelometric turbidity unit |
OSB | oriented strand board |
OSHA | Occupational Safety and Health Administration |
PAH | polycyclic aromatic hydrocarbon |
PBDE | polybrominated diphenyl ether |
PCB | polychlorinated biphenyl |
PCDD | polychlorinated dibenzo-p-dioxin |
PCDF | polychlorinated dibenzofuran |
PFAS | perfluoroalkyl and polyfluoroalkyl organic substance |
PiG | plume-in-grid |
PM | particulate matter |
PM10 | coarse particulate matter; particles with diameters of 10 micrometers or less |
PM2.5 | fine particulate matter; particles with diameters of 2.5 micrometers or less |
PTR-ToF-MS | proton-transfer-reaction time-of-flight mass spectrometry |
PVC | polyvinyl chloride |
RAP-Chem | Rapid Refresh with Chemistry |
RISE | Research Institutes of Sweden |
RR | relative rate |
Rx-CADRE | Prescribed Fire Combustion-Atmospheric Dynamics Experiments |
SOA | secondary organic aerosol |
SP | SP Technical Research Institute of Sweden |
SVOC | semi-volatile organic compound |
TCEP | tris(2-chloroethyl) phosphate |
TCPP | tris(1-chloro-2-propyl) phosphate |
TEMPO | Tropospheric Emissions: Monitoring of Pollution |
VIIRS | Visible Infrared Imager Radiometer Suite |
VOC | volatile organic compound |
WE-CAN | Western Wildfire Experiment for Cloud Chemistry, Aerosol Absorption, and Nitrogen |
WUI | wildland-urban interface |
ϕ | equivalence ratio |
CHEMICAL FORMULAS
BrO | hypobromite ion |
C2H2 | acetylene |
C2H4 | ethylene |
C3H4O | acrolein |
C6H6 | benzene |
C7H8 | toluene |
CF3Br | bromotrifluoromethane |
CH2O or HCHO | formaldehyde |
CH3Br | bromomethane |
CH3Cl | chloromethane |
CH4 | methane |
CHOCHO | glyoxal |
ClNO2 | chlorine nitrite |
CO | carbon monoxide |
CO2 | carbon dioxide |
COCl2 | phosgene |
COF2 | carbonyl fluoride |
H2O | water |
H2O2 | hydrogen peroxide |
H2S | hydrogen sulfide |
H2SO4 | sulfuric acid |
H3PO4 | phosphoric acid |
HBr | hydrogen bromide |
HCHO; see CH2O | |
HCl | hydrogen chloride |
HCN | hydrogen cyanide |
HF | hydrogen fluoride |
HNO2 or HONO | nitrous acid |
HNO3 | nitric acid |
HO2 | hydroperoxyl radical |
HO2NO2 | peroxynitric acid |
HOCO | hydrocarboxyl radical |
HONO, see HNO2 | |
N2O5 | dinitrogen pentoxide |
NH3 | ammonia |
NO | nitric oxide radical |
NO2 | nitrogen dioxide |
NO3 | nitrate radical |
NOx | nitrogen oxides |
O3 | ozone |
OH | hydroxyl radical |
POF3 | phosphoryl fluoride |
SO2 | sulfur dioxide |
SO3 | sulfur trioxide |
SOx | sulfur oxides |
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Contents
The Committee’s Approach to Its Task
The Committee’s Approach to Equity
Prior Related Work by the National Academies
2 DEFINING AND CONTEXTUALIZING WUI FIRES
Defining Spatial and Temporal Scales
Factors Contributing to Increasing WUI Fires
Using Examples to Contextualize WUI Fires
Findings from Recent Examples of WUI Fires
3 MATERIALS, COMBUSTION, AND EMISSIONS IN WUI FIRES
4 ATMOSPHERIC TRANSPORT AND CHEMICAL TRANSFORMATIONS
Primary Species with Toxic Potential Downwind of WUI Fires
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
6 HUMAN EXPOSURES, HEALTH IMPACTS, AND MITIGATION
Chemicals of Concern for Human Exposure
Vulnerable Populations, Health Equity, and Environmental Justice
Reducing Exposure Risks and Health Effects
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
Sampling and Analytical Methods
Coordinating Measurements of WUI Fires
8 THE FUTURE OF WUI FIRE RESEARCH
Cross-Disciplinary Coordination
B COMMITTEE BIOGRAPHICAL SKETCHES