Climatic Change Particulate Air Pollution from Wildfires in the Western US under Climate Change --Manuscript Draft-- Manuscript Number: Full Title: Particulate Air Pollution from Wildfires in the Western US under Climate Change Article Type: Research Article Corresponding Author: Jia Coco Liu Yale University New Haven, CT UNITED STATES Corresponding Author Secondary Information: Corresponding Author's Institution: Yale University Corresponding Author's Secondary Institution: First Author: Jia Liu First Author Secondary Information: Order of Authors: Jia Liu Loretta J. Mickley, Ph.D Melissa P. Sulprizio, Ph.D Francesca Dominici, Ph.D Xu Yue, Ph.D Keita Ebisu, Ph.D Georgiana Brooke Anderson, Ph.D Rafi F. A. Khan Mercedes A. Bravo, Ph.D Michelle L. Bell, Ph.D Order of Authors Secondary Information: Funding Information: National Institutes of Health Francesca Dominici (R21 ES022585-01) National Institutes of Health Not applicable (R01 ES019560) National Institutes of Health Not applicable (R21 ES020152) National Institutes of Health Not applicable (R21 ES024012) National Institutes of Health Michelle L. Bell (R21 ES021427) National Institutes of Health Not applicable (R01 ES024332) Yale Institute for Biospheric Studies Ms. Jia Liu (Doctoral Dissertation Improvement Grant) Abstract: Wildfire can impose a direct impact on human health under climate change. While the potential impacts of climate change on wildfires and resulting air pollution has been studied, it is not known who will be most affected by the growing threat of wildfires. Identifying communities that will be most affected will inform development of fire management strategies and disaster preparedness programs. We estimated levels of fine particulate matter (PM2.5) directly attributable to wildfires in 561 western US counties during fire seasons for the present-day (2004-2009) and future (2046-2051), using a fire prediction model and GEOS-Chem, a 3-D global chemical transport model. Powered by Editorial Manager® and ProduXion Manager® from Aries Systems Corporation Future estimates were obtained under a scenario of moderately increasing greenhouse gases by mid-century. We created a new term "Smoke Wave," defined as >2 consecutive days with high wildfire-specific PM2.5, to describe episodes of high air pollution from wildfires. We developed an interactive map to demonstrate the counties likely to suffer from future high wildfire pollution events. For 2004-2009, on days exceeding regulatory PM2.5 standards, wildfires contributed an average of 71.3% of total PM2.5. Under future climate change, we estimate that more than 82 million individuals will experience a 57% and 31% increase in the frequency and intensity, respectively, of Smoke Waves. Northern California, Western Oregon and the Great Plains are likely to suffer the highest exposure to widlfire smoke in the future. Results point to the potential health impacts of increasing wildfire activity on large numbers of people in a warming climate and the need to establish or modify US wildfire management and evacuation programs in high-risk regions. The study also adds to the growing literature arguing that extreme events in a changing climate could have significant consequences for human health. Suggested Reviewers: Ana Rappold Statistician at US EPA, US Environmental Protection Agency [email protected] Expert in wildfire research Patrick Kinney Professor of environmental health sciences, Columbia University [email protected] Expert in environmental sciences and interdisciplinary study in environmental sciences; expert in climate change Petros Koutrakis Professor of environmental health sciences, Harvard University [email protected] Expert in environmental sciences and air pollution research Randall Martin Professor, Dalhousie University [email protected] Michael Brauer Professor , University of British Columbia [email protected] Expert in air pollution and health studies Arden Pope Professor of Economics, Brigham Young University [email protected] Expert in environmental studies and broader impact in health and climate change Powered by Editorial Manager® and ProduXion Manager® from Aries Systems Corporation LIU_Manuscript Click here to download Manuscript LIU_mapping paper Dec 2015.docx Click here to view linked References 1 2 3 4 Title: Particulate Air Pollution from Wildfires in the Western US under Climate Change 5 6 Authors and affiliations: 7 1 2 2 3 2 8 Jia Coco Liu , Loretta J. Mickley , Melissa P. Sulprizio , Francesca Dominici , Xu Yue , Keita 1 4 1 5 1 9 Ebisu , Georgiana Brooke Anderson , Rafi F. A. Khan , Mercedes A. Bravo , Michelle L. Bell 10 11 1School of Forestry and Environmental Studies, Yale University, 195 Prospect Street, New 12 Haven, CT, USA, 06511 13 2School of Engineering and Applied Sciences, Harvard University, 29 Oxford Street, Cambridge, 14 15 MA, USA, 02138 3 16 Department of Biostatistics, T.H. Chan School of Public Health, Harvard University, Building II, 17 Room 441, 655 Huntington Avenue, Boston, MA, USA, 02115 18 4Department of Environmental & Radiological Health Sciences, College of Veterinary Medicine 19 & Biomedical Sciences, Colorado State University, 146 Environmental Health Building, Fort 20 21 Collins, CO, USA, 80521 22 5School of Natural Resources and Environment, University of Michigan, Ann Arbor, MI, USA, 23 48109 24 25 Corresponding author: 26 Jia Coco Liu 27 Email: [email protected] 28 29 Phone: 203-432-9869 30 Fax: 203 436-9158 31 Address: Room 8B, 205 Prospect St, New Haven, CT, 06511 32 33 Abstract 34 35 Wildfire can impose a direct impact on human health under climate change. While the potential 36 37 impacts of climate change on wildfires and resulting air pollution has been studied, it is not 38 known who will be most affected by the growing threat of wildfires. Identifying communities 39 that will be most affected will inform development of fire management strategies and disaster 40 preparedness programs. We estimated levels of fine particulate matter (PM2.5) directly 41 attributable to wildfires in 561 western US counties during fire seasons for the present-day 42 43 (2004-2009) and future (2046-2051), using a fire prediction model and GEOS-Chem, a 3-D 44 global chemical transport model. Future estimates were obtained under a scenario of moderately 45 increasing greenhouse gases by mid-century. We created a new term “Smoke Wave,” defined 46 as >2 consecutive days with high wildfire-specific PM2.5, to describe episodes of high air 47 48 pollution from wildfires. We developed an interactive map to demonstrate the counties likely to 49 suffer from future high wildfire pollution events. For 2004-2009, on days exceeding regulatory 50 PM2.5 standards, wildfires contributed an average of 71.3% of total PM2.5. Under future climate 51 change, we estimate that more than 82 million individuals will experience a 57% and 31% 52 increase in the frequency and intensity, respectively, of Smoke Waves. Northern California, 53 54 Western Oregon and the Great Plains are likely to suffer the highest exposure to widlfire smoke 55 in the future. Results point to the potential health impacts of increasing wildfire activity on large 56 numbers of people in a warming climate and the need to establish or modify US wildfire 57 management and evacuation programs in high-risk regions. The study also adds to the growing 58 literature arguing that extreme events in a changing climate could have significant consequences 59 60 for human health. 61 62 1 63 64 65 1 2 3 4 Keywords: wildfire, climate change, air pollution, PM2.5 5 6 Acknowledgments: 7 8 We received funding support from NIH/NIEHS R21 ES022585-01 (Dominici); NIH R01 9 10 ES019560 (Peng); NIH R21 ES020152 (Peng); NIH R21 ES024012 (Zanobetti); NIH R21 11 ES021427 (Bell); NIH/NIEHS R01 ES024332 (Zanobetti), and the Yale Institute for Biospheric 12 Studies. 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 2 63 64 65 1 2 3 4 1 Introduction 5 6 7 8 Climate change has increased the frequency, intensity and spread of wildfires (Spracklen et al., 9 10 2009). In the coming decades, wildfires are anticipated to pose a growing threat (Interagency 11 12 13 Working Group on Climate Change and Health, 2010), especially in the western US, where 14 15 wildfires are common (Brown et al., 2004; Littell et al., 2009; Westerling et al., 2006). Smoke 16 17 18 from wildfires contains large abundances of fine airborne particulate matter (PM2.5) (Ammann et 19 20 al., 2001; Dennis et al., 2002; Lighty et al., 2000; Sapkota et al., 2005). This pollutant is known 21 22 23 to harm human health when produced by other sources (e.g., transportation, industry). While 24 25 wildfires are estimated to contribute ~18% of the total PM2.5 atmospheric emissions in the US 26 27 (Phuleria et al., 2005), the contribution of smoke on days exceeding regulatory PM standards is 28 2.5 29 30 not known. Current literature on wildfires and climate change has been limited to estimates of 31 32 future area burned (Balshi et al., 2009; Flannigan et al., 2005) and changes in the locations and 33 34 35 intensity of wildfires (Fried et al., 2004; Krawchuk et al., 2009). A few studies have examined 36 37 the impacts of increasing wildfire in the western US on regional levels of particulate matter 38 39 40 (Spracklen et al., 2009; Yue et al., 2013), but no study has quantified which if any populations 41 42 will experience increased smoke exposure. It is not clear, for example, what effect wildfires in 43 44 45 remote regions of the western US will have on human health. There is thus a need to understand 46 47 on fine spatial scales how levels of PM2.5 generated specifically from wildfires affect present-day 48 49 air quality, how these levels will change in the future under climate change, and which 50 51 52 communities are anticipated to be most affected.