Grantee Research Project Results
Final Report: Wildfires in the Rocky Mountains Region: Current and Future Impacts on PM2.5, Health, and Policy
EPA Grant Number: R835869Title: Wildfires in the Rocky Mountains Region: Current and Future Impacts on PM2.5, Health, and Policy
Investigators: Liu, Yang , Strickland, Matthew J , Chang, Howard , Fu, Joshua , Liu, Yongqiang
Institution: Rollins School of Public Health, Emory University , University of Nevada - Reno , University of Tennessee , U.S. Forest Service
EPA Project Officer: Keating, Terry
Project Period: January 1, 2016 through December 31, 2018 (Extended to December 31, 2020)
Project Amount: $786,089
RFA: Particulate Matter and Related Pollutants in a Changing World (2014) RFA Text | Recipients Lists
Research Category: Air Quality and Air Toxics , Air , Climate Change
Objective:
In recent decades, the western United States has seen heightened wildfire activity, characterized by a higher frequency of large wildfires a longer fire season, larger fire size, and a greater total area burned. With projected temperature increases, soil moisture reduction, and more frequent air stagnation, the burden of wildfires on air quality, public health, and environmental management will likely increase. With state-of-the-art global climate, regional climate, and air quality models; ground and satellite measurements; and detailed health information, we propose to investigate the impacts of historical and future wildfires on air quality, public health, and environmental management in the Rocky Mountains Region under various climate change scenarios and population growth patterns.
Conclusions:
Exposure modeling work
Epidemiological studies on wildfire PM2.5 are limited by the lack of accurate high-resolution PM2.5 exposure data over fire days. Satellite-based aerosol optical depth (AOD) data can provide additional information in ground PM2.5 concentrations and has been widely used in previous studies. However, the low background concentration, complex terrain and large wildfire sources add to the challenge of estimating PM2.5 concentrations in the western U.S. In this study, we applied a Bayesian ensemble model that combined information from the 1 km resolution AOD products derived from the Multi-angle Implementation of Atmospheric Correction (MAIAC) algorithm, CMAQ model simulations and ground measurements to predict daily PM2.5 concentrations over fire seasons (April to September) in Colorado for 2011−2014. Our model had a ten-fold cross validated R2 of 0.66 and root-mean-squared error of 2.00 μg/m3, outperformed the multi-stage model, especially on fire days. Elevated PM2.5 concentrations over large fire events were successfully captured. The modeling technique demonstrated in this study could support future short-term and long-term epidemiological studies of wildfire PM2.5. This work was published in the Journal of Geophysical Research-Atmosphere.
Using a hybrid downscaling approach, we evaluated the separate impact of climate change and emission control policies on O3 levels and associated excess mortality in the US in the 2050s under two Representative Concentration Pathways (RCPs). We show that, by the 2050s, under RCP4.5, increased O3 levels due to combined climate change and emission control policies, could contribute to an increase of approximately 50 premature deaths annually nationwide in the US. The biggest impact, however, is seen under RCP8.5, where rises in O3 concentrations are expected to result in over 2,200 additional premature deaths annually. The largest increases in O3 are seen in RCP8.5 in the Northeast, the Southeast, the Central, and the West regions of the US. Additionally, when O3 increases are examined by climate change and emissions contributions separately, the benefits of emissions mitigation efforts may significantly outweigh the effects of climate change mitigation policies on O3-related mortality. This work was published in Environment International.
Health effects of smoke exposure
The modeling data generated for the Colorado 2011-2014 wildfire seasons was used to estimate human exposure to smoke specific PM2.5 for the same period. Using statewide health data for emergency department visits and hospitalizations (ED) during the study period, we explored the potential associations between smoke PM2.5 exposure and both cardiovascular and respiratory health outcomes. Health data was collected on a 4km grid to protect patient privacy. Exposure data was aggregated from 1km resolution to 4km and matched to health data for analysis. Per 1 µg/m3 increase in fire smoke PM2.5, significant associations were observed for asthma (OR=1.081 (1.058, 1.105)) and combined respiratory disease (OR=1.021 (1.012, 1.031)). No significant positive associations were observed for cardiovascular outcomes. Some effect modification was evident when stratified by age, especially for asthma, bronchitis, and COPD outcomes. Notably, no significant positive associations were seen in older adult populations (65+) with respiratory health outcomes. These results point to potential higher toxicity in wildfire smoke PM2.5 compared to ambient PM2.5. This is especially true when looking at asthma outcomes alone, where OR values are much higher than those previously shown for ambient PM2.5 exposure. This work was published in Environment International.
Fire smoke emissions
Numerous devastating air pollution events from wildfire smoke occurred in most fire seasons in this century in the western United States. Efforts have been made to understand the climate drivers for devastating events and project their future trends under climate change. we projected future fire emissions in the western US with a focus on comparing the relative contributions from future changes in burned area, fuel loading, and fuel moisture. The three properties were projected using an empirical fire model, a dynamical global vegetation model, and meteorological conditions, respectively. The regional climate change scenarios for the western US were obtained by dynamical downscaling of global climate projections. The results show overall increasing wildfires and fuel loading and decreasing fuel moisture. As a result, fire emissions are projected to increase by approximately 50% from 2001-2010 to 2050-2059. The changes in wildfires and fuel loading contribute nearly 75% and 25% of the total fire emission increase, respectively, while the contribution from fuel moisture change is minimal. The findings suggest that the air pollution events due to wildfire smoke could become much more serious in the western US by the middle of this century and that it would be essential to take the future changes in fuel conditions into account to improve the accuracy of fire emission projections. This work was submitted to Int J Wildland Fire.
Journal Articles on this Report : 9 Displayed | Download in RIS Format
| Other project views: | All 24 publications | 14 publications in selected types | All 14 journal articles |
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Huang K, Xiao Q, Meng X, Geng G, Wang Y, Lyaptin A, Gu D, Liu Y. Predicting monthly high-resolution PM2.5 concentrations with random forest model in the North China Plain. ENVIRONMENTAL POLLUTION 2018;242:675-683. |
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Huang K, Yang X, Liang F, Liu F, Li J, Xiao Q, Chen J, Liu X, Cao J, Shen C, Yu L, Lu F, Wu X, Zhao L, Wu X, Li Y, Hu D, Huang J, Liu Y, Lu X, Gu D. Long-Term Exposure to Fine Particulate Matter and Hypertension Incidence in China:The China-PAR Cohort Study. HYPERTENSION 2019;242:675-683. |
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Li J, Liu F, Liang F, Huang K, Yang X, Xiao Q, Chen J, Liu X, Cao J, Chen S, Shen C, Yu L, Lu F, Wu X, Zhao L, Wu X, Li Y, Hu D, Huang J, Liu Y, Zu X, Gu D. Long-Term Effects of High Exposure to Ambient Fine Particulate Matter on Coronary Heart Disease Incidence:A Population-Based Chinese Cohort Study. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2020;242:675-683. |
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Liang F, Xiao Q, Wang Y, Lyapustin A, Li G, Gu D, Pan X, Liu Y. MAIAC-based long-term spatiotemporal trends of PM2.5 in Beijing, China. SCIENCE OF THE TOTAL ENVIRONMENT 2018;616:1589-1598. |
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Liang F, Xiao Q, Gu D, Xu M, Tian L, Guo Q, Wu Z, Pan X, Liu Y. Satellite-based short-and long-term exposure to PM2.5 and adult mortality in urban Beijing, China. ENVIRONMENTAL POLLUTION 2018;242:492-499. |
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Liang F, Yang X, Liu F, Li J, Xiao Q, Chen J, Liu X, Cao J, Shen C, Yu L, Lu F, Wu X, Zhao L, Qu X, Li Y, Hu D, Huang J, Liu Y, Lu X, Gu D. Long-term exposure to ambient fine particulate matter and incidence of diabetes in China:A cohort study. ENVIRONMENT INTERNATIONAL 2019;126:568-575. |
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Stowell J, Yang C, Fu J, Scovronick N, Strickland M, Liu Y. Asthma exacerbation due to climate change-induced wildfire smoke in the Western US. ENVIRONMENTAL RESEARCH LETTERS 2022;17(1). |
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Wang Y, Hu X, Chang H, Waller L, Belle J, Liu Y. A Bayesian Downscaler Model to Estimate Daily PM 2.5 Levels in the Conterminous US. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2018;15(9). |
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Xiao Q, Wang Y, Chang H, Meng X, Geng G, Lyapustin A, Liu Y. Full-coverage high-resolution daily PM2.5 estimation using MAIAC AOD in the Yangtze River Delta of China. REMOTE SENSING OF ENVIRONMENT 2017;199:437-446. |
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Supplemental Keywords:
Particulate Matter, PM2.5, Wildfires, CESM, WRF-CMAQ, dynamical downscalingProgress and Final Reports:
Original AbstractThe perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.
Project Research Results
- 2019 Progress Report
- 2018 Progress Report
- 2017 Progress Report
- 2016 Progress Report
- Original Abstract
14 journal articles for this project