Research Database
Displaying 1 - 20 of 127
COVID‐19 Fueled an Elevated Number of Human‐Caused Ignitions in the Western United States During the 2020 Wildfire Season
Year: 2025
The area burned in the western United States during the 2020 fire season was the greatest in the modern era. Here we show that the number of human-caused fires in 2020 also was elevated, nearly 20% higher than the 1992–2019 average. Although anomalously dry conditions enabled ignitions to spread and contributed to record area burned, these conditions alone do not explain the surge in the number of human-caused ignitions. We argue that behavioral shifts aimed at curtailing the spread of COVID-19 altered human-environment interactions to favor increased ignitions. For example, the number of…
Publication Type: Journal Article
Assessing wildland fire suppression effectiveness with infrared imaging on experimental fires
Year: 2025
Background: Suppression effectiveness is often evaluated by measuring the extent to which it slows fire spread and reduces fireline intensity. Although studies have used infrared (IR) imaging methods to explore suppression effectiveness, most do not measure or assess the influence of water application on energy release.Aims: This preliminary analysis uses IR imagery to quantify the impact of suppression on fire behaviour and the reduction in energy released from a flaming fire.Methods: We conducted a series of small-scale experimental burns…
Publication Type: Journal Article
The 2023 wildfires in British Columbia, Canada: impacts, drivers, and transformations to coexist with wildfire
Year: 2025
In 2023, all regions of British Columbia (BC) experienced record-breaking fire weather and wildfires, with extreme behavior and social-ecological effects. In total, 2245 wildfires burned 2840 545 hectares. Contemporary wildfires are the culmination of a century of altered human–forest–wildfire relationships, exacerbated by climate change. Transformative change is urgently needed for the ecosystems and communities to be resilient to wildfire. We present six interrelated strategies needed to amplify the pace and scale of change in response to recent wildfire extremes: (1) Immediately diversify…
Publication Type: Journal Article
Fine Particulate Matter From 2020 California Wildfires and Mental Health–Related Emergency Department Visits
Year: 2025
Importance: A growing body of research suggests that exposure to fine particulate matter (PM2.5; particle size 2.5 microns or smaller) may be associated with mental health outcomes. However, the potential impact of wildfire-specific PM2.5 exposure on mental health remains underexplored.Objective: To investigate whether wildfire-specific PM2.5 exposure may be associated with emergency department (ED) visits for mental health conditions, including all-cause and for psychoactive substance use, nonmood psychotic disorders, anxiety, depression, and other mood-affective disorders during the…
Publication Type: Journal Article
Future enhanced threshold effects of wildfire drivers could increase burned areas in northern mid- and high latitudes
Year: 2025
Wildfires exhibit extensive nonlinear characteristics and threshold effects in response to environmental changes. However, how threshold effects affect wildfire responses and their future changes remains unclear. Here we identified thresholds where wildfire-driver relationships shift and estimated the impact of threshold effects on wildfire dynamics in the 21st century in northern mid- and high latitudes (>30°N). Wildfire-driver thresholds, coregulated by gradient differences in heat and moisture conditions, vegetation productivity, and human activities, effectively explain the spatial…
Publication Type: Journal Article
Enhancing fire emissions inventories for acute health effects studies: integrating high spatial and temporal resolution data
Year: 2025
Background: Daily fire progression information is crucial for public health studies that examine the relationship between population-level smoke exposures and subsequent health events. Issues with remote sensing used in fire emissions inventories (FEI) lead to the possibility of missed exposures that impact the results of acute health effects studies.Aims: This paper provides a method for improving an FEI dataset with readily available information to create a more robust dataset with daily fire progression.Methods: High temporal and spatial resolution burned area information from two FEI…
Publication Type: Journal Article
Wildland Firefighters Suffer Increasing Risk of Job-Related Death
Year: 2025
Wildland firefighting is a niche specialization in the fire service - inherently dangerous with unique risks. Over the past decade, fatalities amongst all firefighters have decreased; however, wildland firefighter fatalities have increased. This subject has only been described in the grey literature, and a paucity of medical literature exists. The United States Fire Administration's online fatality database was queried for on duty mortality between 1990 and 2022. The year 2001 was excluded due to the 340 deaths that occurred on September 11th. Data collected included demographics, incident…
Publication Type: Journal Article
Assessing costs and constraints of forest residue disposal by pile burning
Year: 2025
Pile burning of thinned residues is a critical tool to dispose of fuels and to reduce wildfire risk in overstocked, fire-prone forests globally. However, cost estimates of pile burning are limited. In the Western United States, where fuel reduction and pile burning are key strategies to mitigate risk of severe wildfire, previous reports estimate that the average cost of pile burning after machine treatment is $543 ac−1 ($1,343 ha−1). There is, however, limited information on the costs of hand thinning and pile burning. In response, this study quantified the costs of cutting and yarding,…
Publication Type: Journal Article
Household needs among wildfire survivors in the 2017 Northern California wildfires
Year: 2025
Wildfires are impacting communities globally, with California wildfires often breaking records of size and destructiveness. Knowing how communities are affected by these wildfires is vital to understanding recovery. We sought to identify impacted communities' post-wildfire needs and characterize how those needs change over time. The WHAT-Now study deployed a survey that was made publicly available for communities affected by the October 2017 Northern California wildfires or the accompanying smoke at beginning approximately four months post-fire with the vast majority completed by nine months…
Publication Type: Journal Article
Mental health risk for wildland firefighters: a review and future directions
Year: 2025
Wildland fire is increasingly a consequence of the climate crisis, with growing impacts on communities and individuals. Wildland firefighters are critical to the successful management of wildland fire, yet very limited research has considered mental health in this population. Although a wealth of research in mental health risk and associated risk and protective factors exists for structural firefighters, unique demands of wildland firefighting such as the seasonal nature of work, the length and intensity of shifts, and the often geographically isolated working conditions, among other factors…
Publication Type: Journal Article
Enhancing fire emissions inventories for acute health effects studies: integrating high spatial and temporal resolution data
Year: 2025
Background: Daily fire progression information is crucial for public health studies that examine the relationship between population-level smoke exposures and subsequent health events. Issues with remote sensing used in fire emissions inventories (FEI) lead to the possibility of missed exposures that impact the results of acute health effects studies.Aims: This paper provides a method for improving an FEI dataset with readily available information to create a more robust dataset with daily fire progression.Methods: High temporal and spatial…
Publication Type: Journal Article
Mental Health and Traumatic Occupational Exposure in Wildland Fire Dispatchers
Year: 2024
Wildland fire dispatchers play a key role in wildland fire management and response organization; however, to date, wildland fire studies have largely focused on the physical hazards and, to a lesser extent, mental health hazards of wildland firefighting operational personnel, and dispatcher studies have primarily focused on 911 and police dispatchers. Studies of other dispatchers have provided some limited insight into potential strains impacting this workforce, including work-related fatigue, burnout, and traumatic exposure. However, the specific job hazards that are faced by wildland fire…
Publication Type: Journal Article
Bacterial Emission Factors: A Foundation for the Terrestrial-Atmospheric Modeling of Bacteria Aerosolized by Wildland Fires
Year: 2024
Wildland fire is a major global driver in the exchange of aerosols between terrestrial environments and the atmosphere. This exchange is commonly quantified using emission factors or the mass of a pollutant emitted per mass of fuel burned. However, emission factors for microbes aerosolized by fire have yet to be determined. Using bacterial cell concentrations collected on unmanned aircraft systems over forest fires in Utah, USA, we determine bacterial emission factors (BEFs) for the first time. We estimate that 1.39 × 1010 and 7.68 × 1011 microbes are emitted for each Mg of biomass consumed…
Publication Type: Journal Article
Characterising ignition precursors associated with high levels of deployment of wildland fire personnel
Year: 2024
BackgroundAs fire seasons in the Western US intensify and lengthen, fire managers have been grappling with increases in simultaneous, significant incidents that compete for response resources and strain capacity of the current system.AimsTo address this challenge, we explore a key research question: what precursors are associated with ignitions that evolve into incidents requiring high levels of response personnel?MethodsWe develop statistical models linking human, fire weather and fuels related factors with cumulative and peak personnel…
Publication Type: Journal Article
Retention of highly qualified wildland firefighters in the Western United States
Year: 2024
Federal agencies responsible for wildland fire management face increasing needs for personnel as fire seasons lengthen and fire size continues to grow, yet federal agencies have struggled to recruit and retain firefighting personnel. While many have speculated that long seasons, challenging working conditions, and low wages contribute to recruitment and retention challenges, there has been…
Publication Type: Journal Article
Mortality attributable to PM 2.5 from wildland fires inCalifornia from 2008 to 2018
Year: 2024
In California, wildfire risk and severity have grown substantially in the last several decades. Research has characterized extensive adverse health impacts from exposure to wildfire-attributable fine particulate matter (PM2.5), but few studies have quantified long-term outcomes, and none have used a wildfire-specific chronic dose-response mortality coefficient. Here, we quantified the mortality burden for PM2.5 exposure from California fires from 2008 to 2018 using Community Multiscale Air Quality modeling system wildland fire PM2.5 estimates. We used a concentration-response function for PM2…
Publication Type: Journal Article
The cost of operational complexity: A causal assessment of pre-fire mitigation and wildfire suppression
Year: 2024
Pre-fire mitigation efforts that include the installation and maintenance of fuel breaks are integral to wildfire suppression in Southern California. Fuel breaks alter fire behavior and assist in fire suppression at strategic locations on the landscape. However, the combined effectiveness of fuel breaks and wildfire suppression is not well studied. Using daily firefighting personnel to proxy the quantity and diversity of potential fire suppression operations (i.e., operational complexity), we examined 15 wildfires from 2017 to 2020 in the Los Padres, Angeles, San Bernardino, and Cleveland…
Publication Type: Journal Article
Exploring spatial heterogeneity in synergistic effects of compound climate hazards: Extreme heat and wildfire smoke on cardiorespiratory hospitalizations in California
Year: 2024
Extreme heat and wildfire smoke events are increasingly co-occurring in the context of climate change, especially in California. Extreme heat and wildfire smoke may have synergistic effects on population health that vary over space. We leveraged high-resolution satellite and monitoring data to quantify spatially varying compound exposures to extreme heat and wildfire smoke in California (2006–2019) at ZIP Code Tabulation Area (ZCTA) level. We found synergistic effects between extreme heat and wildfire smoke on daily cardiorespiratory hospitalizations at the state level. We also found spatial…
Publication Type: Journal Article
From flexibility to feasibility: identifying the policy conditions that support the management of wildfire for objectives other than full suppression
Year: 2024
Background. Intentional management of naturally ignited wildfires has emerged as a valuable tool for addressing the social and ecological consequences of a century of fire exclusion in policy and practice. Policy in the United States now allows wildfires to be managed for suppression and other than full suppression (OTFS) objectives simultaneously, giving flexibility to local decision makers. Aims. To extend existing research on the history of wildfire management, investigate how wildfire professionals interpret current policy with respect to OTFS management, and better understand how they…
Publication Type: Journal Article
The Efficacy of Red Flag Warnings in Mitigating Human-Caused Wildfires across the Western United States
Year: 2024
Red flag warnings (RFWs) are issued by the U.S. National Weather Service to alert fire and emergency response agencies of weather conditions that are conducive to extreme wildfire growth. Distinct from most weather warnings that aim to reduce exposure to anticipated hazards, RFWs may also mitigate hazards by reducing the occurrence of new ignitions. We examined the efficacy of RFWs as a means of limiting human-caused wildfire ignitions. From 2006 to 2020, approximately 8% of wildfires across the western United States and 19% of large wildfires (≥40 ha) occurred on days with RFWs. Although the…
Publication Type: Journal Article