Evolution of Reactive Organic Compounds and Their Potential Health Risk in Wildfire Smoke.
Havala O T Pye, Lu Xu, Barron H Henderson, Demetrios Pagonis, Pedro Campuzano-Jost, Hongyu Guo, Jose L Jimenez, Christine Allen, T Nash Skipper, Hannah S Halliday, Benjamin N Murphy, Emma L D'Ambro, Paul O Wennberg, Bryan K Place, Forwood C Wiser, V Faye McNeill, Eric C Apel, Donald R Blake, Matthew M Coggon, John D Crounse, Jessica B Gilman, Georgios I Gkatzelis, Thomas F Hanisco, L Gregory Huey, Joseph M Katich, Aaron Lamplugh, Jakob Lindaas, Jeff Peischl, Jason M St Clair, Carsten Warneke, Glenn M Wolfe, Caroline Womack
Author Information
Havala O T Pye: Office of Research and Development, US Environmental Protection Agency, Durham, North Carolina 27711, United States. ORCID
Lu Xu: Energy, Environmental & Chemical Engineering, Washington University in St. Louis, St. Louis, Missouri 63130, United States. ORCID
Barron H Henderson: Office of Air and Radiation, US Environmental Protection Agency, Durham, North Carolina 27711, United States. ORCID
Demetrios Pagonis: Cooperative Institute for Research in Environmental Sciences, University of Colorado Boulder, Boulder, Colorado 80309, United States. ORCID
Pedro Campuzano-Jost: Cooperative Institute for Research in Environmental Sciences, University of Colorado Boulder, Boulder, Colorado 80309, United States. ORCID
Hongyu Guo: Cooperative Institute for Research in Environmental Sciences, University of Colorado Boulder, Boulder, Colorado 80309, United States.
Jose L Jimenez: Cooperative Institute for Research in Environmental Sciences, University of Colorado Boulder, Boulder, Colorado 80309, United States.
Christine Allen: GDIT, Durham, North Carolina 27709, United States.
T Nash Skipper: Office of Research and Development, US Environmental Protection Agency, Durham, North Carolina 27711, United States.
Hannah S Halliday: Energy, Environmental & Chemical Engineering, Washington University in St. Louis, St. Louis, Missouri 63130, United States. ORCID
Benjamin N Murphy: Office of Research and Development, US Environmental Protection Agency, Durham, North Carolina 27711, United States. ORCID
Emma L D'Ambro: Office of Research and Development, US Environmental Protection Agency, Durham, North Carolina 27711, United States. ORCID
Paul O Wennberg: California Institute of Technology, Pasadena, California 91125, United States. ORCID
Bryan K Place: Office of Research and Development, US Environmental Protection Agency, Durham, North Carolina 27711, United States.
Forwood C Wiser: Columbia University, New York, New York 10027, United States.
V Faye McNeill: Columbia University, New York, New York 10027, United States. ORCID
Eric C Apel: National Center for Atmospheric Research, Boulder, Colorado 80301, United States.
Donald R Blake: University of California Irvine, Irvine, California 92697, United States.
Matthew M Coggon: NOAA Chemical Sciences Laboratory, Boulder, Colorado 80305, United States. ORCID
John D Crounse: California Institute of Technology, Pasadena, California 91125, United States. ORCID
Jessica B Gilman: NOAA Chemical Sciences Laboratory, Boulder, Colorado 80305, United States. ORCID
Georgios I Gkatzelis: Cooperative Institute for Research in Environmental Sciences, University of Colorado Boulder, Boulder, Colorado 80309, United States. ORCID
Thomas F Hanisco: NASA Goddard Space Flight Center, Greenbelt, Maryland 20771, United States. ORCID
L Gregory Huey: Georgia Institute of Technology, Atlanta, Georgia 30332, United States. ORCID
Joseph M Katich: Cooperative Institute for Research in Environmental Sciences, University of Colorado Boulder, Boulder, Colorado 80309, United States. ORCID
Aaron Lamplugh: Cooperative Institute for Research in Environmental Sciences, University of Colorado Boulder, Boulder, Colorado 80309, United States. ORCID
Jakob Lindaas: Department of Atmospheric Science, Colorado State University, Fort Collins, Colorado 80523, United States.
Jeff Peischl: Cooperative Institute for Research in Environmental Sciences, University of Colorado Boulder, Boulder, Colorado 80309, United States. ORCID
Jason M St Clair: NASA Goddard Space Flight Center, Greenbelt, Maryland 20771, United States. ORCID
Carsten Warneke: NOAA Chemical Sciences Laboratory, Boulder, Colorado 80305, United States. ORCID
Glenn M Wolfe: NASA Goddard Space Flight Center, Greenbelt, Maryland 20771, United States. ORCID
Caroline Womack: NOAA Chemical Sciences Laboratory, Boulder, Colorado 80305, United States. ORCID
Wildfires are an increasing source of emissions into the air, with health effects modulated by the abundance and toxicity of individual species. In this work, we estimate reactive organic compounds (ROC) in western U.S. wildland forest fire smoke using a combination of observations from the 2019 Fire Influence on Regional to Global Environments and Air Quality (FIREX-AQ) field campaign and predictions from the Community Multiscale Air Quality (CMAQ) model. Standard emission inventory methods capture 40-45% of the estimated ROC mass emitted, with estimates of primary organic aerosol particularly low (5-8��). Downwind, gas-phase species abundances in molar units reflect the production of fragmentation products such as formaldehyde and methanol. Mass-based units emphasize larger compounds, which tend to be unidentified at an individual species level, are less volatile, and are typically not measured in the gas phase. Fire emissions are estimated to total 1250 �� 60 g��C of ROC per kg��C of CO, implying as much carbon is emitted as ROC as is emitted as CO. Particulate ROC has the potential to dominate the cancer and noncancer risk of long-term exposure to inhaled smoke, and better constraining these estimates will require information on the toxicity of particulate ROC from forest fires.
