Epidemiology of injuries to wildland firefighters

Occupational Injuries of Spanish Wildland Firefighters: A Descriptive Analysis

The work of wildland firefighters, especially of the so-called 'Brigadas de Refuerzo contra Incendios Forestales', is characterised by high physical demands and extreme operating conditions. These professionals face long workdays (12 h), walking with heavy loads (~25 kg), being exposed to high temperatures (>30 °C), and handling specialised tools in high-risk environments. This study aimed to describe the prevalence of occupational injuries among members of the 'Brigadas de Refuerzo contra Incendios Forestales' and its relationship to variables such as age and work experience. A total of 217 wildland firefighters (18 female and 199 male) correctly answered a questionnaire developed on an ad hoc basis to meet the study's objectives. A high prevalence of occupational injuries was observed among them (~76%). Age and work experience were shown to be significantly associated with injuries. Individuals over 35 years of age with more than 10 years' experience had a higher probability of injury (OR = 2.14, CI = 1.12-4.06 and OR = 2.46, CI = 1.30-4.67, respectively). Injuries occurred mainly during physical training (~46%), followed by preventive work (~33%) and forest fires (~20%). The most common injuries were tendonitis and muscle pain (~44% and ~21% respectively), followed by sprains (~21%). The results underline the need for physical activity programmes adapted to help wildland firefighters, especially older and more experienced individuals. The identification of risk factors such as age and work experience can contribute to the prevention and management of occupational injuries among this group of highly specialised forestry workers. Specific preventative measures during training are required to mitigate the risk of injury among these crews, who play a crucial role in protecting the environment and public safety.

Attitudes and Beliefs of Wildland Firefighters Toward Occupational Health Services

CONTEXT

Wildland firefighters (WLFFs) are at an increased risk of health conditions, injuries, and illnesses related to sustained levels of intense physical activity. The purpose of this study was to identify and explore the current attitudes and beliefs of WLFFs regarding health services. Methods: We used consensual qualitative research design for this study. Participants engaged in an online, semistructured interview. Results: We identified four domains: (1) risk mitigation strategies, (2) culture of fire services, (3) access to health care services, and 4) identification of health care gap. Conclusions: Access to occupational health services for WLFFs is readily available in the form of emergency medical care. However, a lack of regular access to physical medicine and the continuation of care beyond acute treatment was apparent.

Effect of cooling on static postural balance while wearing firefighter's protective clothing in a hot environment

Objectives. Postural imbalance can result from hyperthermia-mediated muscular fatigue and is a major factor contributing to injuries from falling. The objective of this study was to investigate the effect of exercise-induced hyperthermia and the impact of cooling on postural balance while wearing firefighters' protective clothing (FPC) in a hot environment. Methods. A portable force platform measured postural balance characterized by postural sway patterns using center of pressure metrics. Twelve healthy, physically fit males were recruited to stand on the force platform once with eyes open and once with eyes closed before and after treadmill exercise (40% V ˙ O 2 max ) inside an environmental chamber under hot and humid conditions (30 °C and 70% relative humidity) while wearing FPC. Subjects participated in two randomly assigned experimental phases: control and cooling intervention. Results. A significant increase in physiological responses and postural balance metrics was observed after exercising in the heat chamber while wearing FPC. Cooling resulted in a significant effect only on postural sway speed after exercise-induced hyperthermia. Conclusions. Hyperthermia can negatively alter postural balance metrics, which may lead to an increased likelihood of falling. The utilization of body cooling reduced the thermal strain but had limited impact on postural balance stability.

Tarp-Assisted Cooling for Exertional Heat Stroke Treatment in Wildland Firefighting

INTRODUCTION

Exertional heat stroke is a life-threatening emergency necessitating immediate treatment with rapid body cooling. A field-expedient alternative may be tarp-assisted cooling, requiring only water and a tarp. The objective of this study was to compare core temperature (Tc) cooling rates of tarp-assisted cooling using the limited resources available to a wildland firefighter and the current standard care provided in wilderness settings.

METHODS

This cross-over, randomized control trial of 17 healthy individuals consisted of exercise in a 42±1°C, 32±4% relative humidity environment while wearing wildland firefighter attire, followed by cooling. Body cooling consisted of either pouring 11 L of 25±1°C water over the torso while lying supine on a tarp configured to hold water close to the individual (Tarp) or dousing the water on the participant followed by lying supine with a light breeze, current standard care in the wilderness (Current Care). Cooling occurred until Tc reached 38°C.

RESULTS

Participants walked until a similar Tc was achieved in Tarp (39.59±0.04°C) and Current Care (39.55±0.22°C; P=0.36). Core temperature cooling rate was not different between Tarp (0.076±0.042°C·min-1) and Current Care (0.088±0.046°C·min-1; P=0.41).

CONCLUSIONS

In hyperthermic individuals, Tarp did not provide a faster cooling rate compared to the current exertional heat stroke care provided in the wilderness, and both provided a slower cooling rate than that provided by the traditional method of cold water immersion (>0.20°C·min-1) to treat exertional heat stroke patients.

A Web-Based Total Worker Health Intervention for Those Fighting Wildland Fires: Mixed Methods Development and Effectiveness Trial

BACKGROUND

Fire seasons are longer, with more and larger wildfires, placing increased demands and risks on those fighting wildland fires. There are multiple agencies involved with fighting wildland fires and unique worksite conditions make meeting these workers' needs a challenge.

OBJECTIVE

The aim of the study is to develop and establish the effectiveness of a web-based safety and health program for those fighting wildland fires.

METHODS

This mixed methods project had 3 phases. The initial qualitative phase assessed the needs of 150 diverse firefighters through interviews and focus groups across 11 US sites to establish and prioritize program content. Interview transcripts were read for thematic content with iterative readings used to identify, code, and rank health and safety issues. The second phase used that information to build a comprehensive Total Worker Health program for those fighting wildfires. The program content was based on the qualitative interview data and consisted of 6 core and 8 elective 30-minute, web-based modules primarily done individually on a smartphone or computer. The final, third phase evaluated the program with a quantitative prospective proof-of-concept, usability, and effectiveness trial among wildland firefighter participants. Effectiveness was assessed with paired 2-tailed t tests for pre- and post-Likert agreement scale survey items, adjusted for multiple comparisons. In addition to assessing mean and SD at baseline and postsurvey, observed effect sizes were calculated (Cohen d). Usability and reaction to the program among firefighters who responded to postsurvey were also assessed.

RESULTS

The qualitative themes and subthemes were used to inform the program's content. For the effectiveness trial, 131 firefighters completed the presurvey, and 50 (38.2%) completed the postsurvey. The majority of the participants were White (n=123, 93.9%), male (n=117, 89.3%), with an average age of 41 (SD 12.9) years. Significant increases in knowledge and desired health and safety behaviors were found for both cancer (P<.001) and cardiovascular risk (P=.01), nutrition behaviors (P=.01), hydration or overheating (P=.001), binge drinking (P=.002), and getting medical checkups (P=.001). More than 80% (n=40) of postsurvey respondents agreed or strongly agreed that the program was easy to use and would recommend it to others.

CONCLUSIONS

An innovative web-based safety and health promotion program for those fighting wildland fires was feasible, scalable, and usable. It improved the health and safety of those fighting wildland fires.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05753358; https://classic.clinicaltrials.gov/ct2/show/NCT05753358.

Wildland Firefighter Critical Training Elicits Positive Adaptations to Markers of Cardiovascular and Metabolic Health

INTRODUCTION

The purpose of this study was to identify physiologic changes in body composition and resting metabolic markers of health across 2 wk of critical training (CT) in wildland firefighters (WLFFs).

METHODS

Twenty-two male and 3 female participants were recruited from 2 hotshot crews across the western United States prior to the 2022 fire season and monitored over their 80-h CT. Body weight (BW) and skinfolds were recorded before and after CT to estimate body fat (BF) and lean body weight (LBW). Blood was analyzed for changes in hematocrit, hemoglobin, plasma volume, and resting values of a lipid and metabolic panel.

RESULTS

The high physical demands of CT resulted in improvements in total cholesterol (-19.3 mg/dL, P<0.001), triglycerides (-34.4 mg/dL, P<0.001), low-density lipoprotein cholesterol (-18.1 mg/dL, P<0.001), very-low-density lipoprotein cholesterol (-5.2 mg/dL, P<0.001), high-density lipoprotein cholesterol (+4.0 mg/dL, P=0.002), non-high-density lipoprotein cholesterol (-19.3 mg/dL, P<0.001), and fasting glucose (-4.3 mg/dL, P=0.008) from before CT to after CT. Significant decreases in hemoglobin and hematocrit were also seen (P<0.001) with corresponding increases in estimated plasma volume (+6.1%, P<0.001). These alterations were seen despite maintenance of BW, LBW, and BF. Lower pretraining BF was associated with a greater magnitude of improvements in fasting glucose and cholesterol markers.

CONCLUSIONS

The observed improvements in baseline metabolic and cardiovascular markers along with plasma volume expansion suggest a positive response to the physical stress of WLFF CT. It appears that higher preseason fitness was associated with greater adaptations to the CT stressor.

Occupational Hazards in Firefighting: Systematic Literature Review

Background

Firefighting involves exposure of firefighters to risks related to this activity, serious injuries, and occupational diseases are recorded. There are other consequences such as thermal and emotional stress. This systematic review is proposed in order to analyze the risks and consequences faced by these workers and thus provide elements to improve safety management systems in institutions.

Method

A descriptive observational study of systematic literature review on the risks and consequences of exposure to firefighters' activity was proposed, and the information was analyzed and described based on the available data and according to the variables determined.

Results

The studies showed data on mechanical, physical, chemical, psychosocial risks, workers' perception and resilience, and epidemiological data. Information related to firefighters' activity on falls and slips, exposure to noise, and high concentrations of carbon monoxide is detailed. In addition, the relationship between burnout, cognitive, and physical fatigue as adverse effects on health and performance is mentioned.

Conclusions

Among the preventive measures, the use of personal protective equipment is suggested, incorporation in prevention programs of information on exposure to risk factors, as well as the implementation of models that can predict the perception of workers, additionally, the generation of management systems with safety climate models for fire departments.

Working hours, sleep, and fatigue in the public safety sector: A scoping review of the research

BACKGROUND

The public safety sector includes law enforcement officers (LEO), corrections officers (CO), firefighter service (FF), wildland firefighting (WFF), and emergency medical services (EMS), as defined in the National Occupational Research Agenda (NORA) of the National Institute for Occupational Safety and Health (NIOSH). Across these occupations, shiftwork, long-duration shifts, and excessive overtime are common. Our objective was to identify research gaps related to working hours, sleep, and fatigue among these workers.

METHODS

We used a scoping review study design that included searches of MEDLINE, Embase, CAB Abstracts, Global Health, PsychInfo, CINAHL, Scopus, Academic Search Complete, Agricultural and Environmental Science Collection, ProQuest Central, Cochrane Library, Safety Lit, Homeland Security Digital Library, and Sociological Abstracts using a range of occupational search terms and terms related to working hours, sleep, and fatigue.

RESULTS

Out of 3415 articles returned from our database search, 202 met all inclusion criteria. Six common outcomes related to working hours, sleep, and fatigue emerged: sleep, fatigue, work performance, injury, psychosocial stress, and chronic disease. Nearly two-thirds (59%, n = 120) of the studies were observational, of which 64% (n = 77) were cross sectional and 9% were (n = 11) longitudinal; 14% (n = 30) of the studies were reviews; and 19% (n = 39) were experimental or quasi-experimental studies. Only 25 of the 202 articles described mitigation strategies or interventions. FFs, LEOs, EMS, and WFFs were the most studied, followed by COs.

CONCLUSIONS

In general, more longitudinal and experimental studies are needed to enrich the knowledge base on the consequences of long working hours, poor sleep, and fatigue in the public safety sector. Few experimental studies have tested novel approaches to fatigue mitigation in diverse sectors of public safety. This gap in research limits the decisions that may be made by employers to address fatigue as a threat to public-safety worker health and safety.

The Wildland Firefighter Exposure and Health Effect (WFFEHE) Study: Rationale, Design, and Methods of a Repeated-Measures Study

The wildland firefighter exposure and health effect (WFFEHE) study was a 2-year repeated-measures study to investigate occupational exposures and acute and subacute health effects among wildland firefighters. This manuscript describes the study rationale, design, methods, limitations, challenges, and lessons learned. The WFFEHE cohort included fire personnel ages 18-57 from six federal wildland firefighting crews in Colorado and Idaho during the 2018 and 2019 fire seasons. All wildland firefighters employed by the recruited crews were invited to participate in the study at preseason and postseason study intervals. In 2019, one of the crews also participated in a 3-day midseason study interval where workplace exposures and pre/postshift measurements were collected while at a wildland fire incident. Study components assessed cardiovascular health, pulmonary function and inflammation, kidney function, workplace exposures, and noise-induced hearing loss. Measurements included self-reported risk factors and symptoms collected through questionnaires; serum and urine biomarkers of exposure, effect, and inflammation; pulmonary function; platelet function and arterial stiffness; and audiometric testing. Throughout the study, 154 wildland firefighters participated in at least one study interval, while 144 participated in two or more study interval. This study was completed by the Centers for Disease Control and Prevention's National Institute for Occupational Safety and Health through a collaborative effort with the U.S. Department of Agriculture Forest Service, Department of the Interior National Park Service, and Skidmore College. Conducting research in the wildfire environment came with many challenges including collecting study data with study participants with changing work schedules and conducting study protocols safely and operating laboratory equipment in remote field locations. Forthcoming WFFEHE study results will contribute to the scientific evidence regarding occupational risk factors and exposures that can impact wildland firefighter health over a season and across two wildland fire seasons. This research is anticipated to lead to the development of preventive measures and policies aimed at reducing risk for wildland firefighters and aid in identifying future research needs for the wildland fire community.

Examining the effects of a weighted pack on functional movements in smokejumpers

BACKGROUND: Smokejumpers are required to parachute from planes, carry gear weighing more than 50 kg, and hike on steep terrain. With a majority of injuries sustained to the lower extremity, it is imperative to understand the influence a weighted pack may have on functional performance. OBJECTIVE: To examine the effects of external load on functional movements in Smokejumpers. METHODS: Using repeated measures design, ten Smokejumpers completed two trials consisting of 3 movements in weighted (50 kg) and unweighted conditions. Nine males and one female (age of 40.1±8.4 years, mass 81.1±8.3 kg) performed overhead squat, hurdle step and anterior reach. Movements were scored based on established guidelines. The mean of three trials was recorded for anterior reach on both limbs. RESULTS: Differences between weighted and unweighted scores in the overhead squat (p = 0.001), ND hurdle step (p = 0.005), D hurdle step (p = 0.000) and overall composite scores (p = 0.006) were found to be significantly different. Differences were also noted in D (p = 0.035) and ND (p = 0.045) anterior reach. CONCLUSIONS: The addition of a weighted pack negatively influences functional movements in Smokejumpers, which may lead to greater injury risk. Implementation of injury prevention strategies to reduce occupational injury risk should be explored.

Chronic Pain in Spanish Wildland Firefighters

The work performed by wildland firefighters (WFFs) is very demanding owing to the conditions in which they have to operate. It has been reported that these professionals walk long distances over unstable and steep terrain carrying heavy loads, handle tools manually and repeatedly and are subject to a high level of thermal stress. Under such conditions, the risk of developing chronic pain (CP) is high, although despite this, there are no available data pertaining to CP among WFFs, to the best of our knowledge. As such, the aim of this study is to describe CP in Spanish helitack crews, for which purpose 221 WFFs (203 men and 18 women) completed an online self-report questionnaire. Approximately 60% of WFFs reported suffering from CP, of which 45.5% had CP in more than one body region at the same time. Age and length of service were associated with the probability of suffering from CP. Likewise, the age and height of WFFs and weight of the protective equipment used increased the prevalence of CP. Lastly, gender and job position affected CP location, with women and forepersons reporting greater prevalence of CP in the lower limbs. To conclude, the results obtained suggest the major prevalence of CP among Spanish WFFs, with current data suggesting in turn the importance that age, stature, gender, length of service, weight of protective equipment and job position have on the prevalence and location of CP.

Health research priorities for wildland firefighters: a modified Delphi study with stakeholder interviews

OBJECTIVES

The increase in global wildland fire activity has accelerated the urgency to understand health risks associated with wildland fire suppression. The aim of this project was to identify occupational health research priorities for wildland firefighters and related personnel.

DESIGN

In order to identify, rank and rate health research priorities, we followed a modified Delphi approach. Data collection involved a two-stage online survey followed by semi-structured interviews.

SETTING

British Columbia, Canada.

PARTICIPANTS

Participants included any current or past wildland firefighter or individuals engaged in related roles. There were 132 respondents to the first survey. Responses to the first survey were analysed to produce 10 research topics which were ranked by 75 participants in the second survey (response rate: 84%).

PRIMARY AND SECONDARY OUTCOME MEASURES

The primary outcome was the identification, ranking and level of agreement of research priorities through a two-round online survey. We contextualised these findings through deductive and inductive qualitative content analysis of semi-structured interviews.

RESULTS

The most important research priorities identified were (% consensus): effects of smoke inhalation on respiratory health (89%), fatigue and sleep (80%), mental health (78%), stress (76%) and long-term risk of disease (67%). Interviews were completed with 14 individuals. Two main themes were developed from an inductive content analysis of interview transcripts: (1) understanding the dynamic risk environment; and (2) organisational fit of mitigation strategies.

CONCLUSIONS

Participants expressed a general concern with the unknown mental and physical health impacts of their jobs, including the long-term risk of morbidity and mortality. Future research must address knowledge gaps in our understanding of the health impacts of wildland fire and work to develop appropriate mitigation strategies while considering the needs of workers and unpredictable workplace environment.

TRIAL REGISTRATION NUMBER

Open Science Framework, https://osf.io/ugz4s/.

Health risks and mitigation strategies from occupational exposure to wildland fire: a scoping review

OBJECTIVES

Due to accelerating wildland fire activity, there is mounting urgency to understand, prevent, and mitigate the occupational health impacts associated with wildland fire suppression. The objectives of this review of academic and grey literature were to: 1. Identify the impact of occupational exposure to wildland fires on physical, mental, and emotional health; and 2. Examine the characteristics and effectiveness of prevention, mitigation, or management strategies studied to reduce negative health outcomes associated with occupational exposure to wildland fire.

METHODS

Following established scoping review methods, academic literature as well as government and industry reports were identified by searching seven academic databases and through a targeted grey literature search. 4679 articles were screened using pre-determined eligibility criteria. Data on study characteristics, health outcomes assessed, prevention or mitigation strategies studied, and main findings were extracted from each included document. The results of this scoping review are presented using descriptive tables and a narrative summary to organize key findings.

RESULTS

The final sample was comprised of 100 articles: 76 research articles and 24 grey literature reports. Grey literature focused on acute injuries and fatalities. Health outcomes reported in academic studies focused on respiratory health (n = 14), mental health (n = 16), and inflammation and oxidative stress (n = 12). The identified studies evaluated short-term outcomes measuring changes across a single shift or wildland fire season. Most research was conducted with wildland firefighters and excluded personnel such as aviation crews, contract crews, and incident management teams. Five articles reported direct study of mitigation strategies, focusing on the potential usage of masks, advanced hygiene protocols to reduce exposure, fluid intake to manage hydration and core temperature, and glutamine supplementation to reduce fatigue.

CONCLUSIONS

While broad in scope, the evidence base linking wildland fire exposure to any one health outcome is limited. The lack of long-term evidence on changes in health status or morbidity is a clear evidence gap and there is a need to prioritize research on the mental and physical health impact of occupational exposure to wildland fire.

Relationship Between Physical Activity, Coronary Artery Disease Risk Factors and Musculoskeletal Injuries in the City of Cape Town Fire and Rescue Service

Musculoskeletal injuries in firefighters are a common occurrence, that increase as firefighters age, and may be related to the firefighters’ physical activity habits outside of the job. Certain CAD risk factors, such as obesity, cigarette smoking and ageing may be linked to increased injury risk in firefighters. Although firefighters may meet the recommended minimum physical activity minutes, they may remain at risk for sustaining musculoskeletal injuries. Therefore, this study aims to determine the relationship between physical activity and CAD risk factors, between CAD risk factors and musculoskeletal injuries and between physical activity and musculoskeletal injuries. A total of 124 full-time firefighters, males and females, were conveniently recruited from the City of Cape Town Fire and Rescue Service. A researcher-generated questionnaire was used to collect injury, CAD risk factor and physical activity data. The proportion of firefighters who participated in leisure-time physical activity (LTPA) was 63.7%, and those who were physically inactive was 69.4%. The prevalence musculoskeletal injuries among all firefighters was 27.4%. The most prevalent musculoskeletal injury was shoulder injuries in 35.3% of firefighters, followed by multiple injuries in 26.5% and back injuries in 14.7%. Age was a significant predictor of physical inactivity in firefighters [P = .002, OR = 1.08], BMI was a significant predictor of physical inactivity [P = .050, OR = 1.08], cigarette smoking was a significant predictor of firefighters not exercising [P = .007, OR = 2.31] and the total amount of vigorous-intensity exercise was a significant predictor of musculoskeletal injuries [P = .050, OR = 1.00]. In conclusion, older firefighters were more physically inactive and had a higher prevalence of musculoskeletal injuries, and the latter decreased significantly after the age of 50 years. Emphasis should be placed on firefighters exercising in their leisure-time, especially as they aged.

Integration of Athletic Training Services on a Smokejumper Base: A Descriptive Study

OBJECTIVE

To examine utilization of an athletic trainer (AT) at a Smokejumper base throughout fire season and document Smokejumper satisfaction with services provided.

METHODS

The AT documented patient encounters with Smokejumpers who were invited to complete a five-part injury prevention movement and mobility assessment (MMS) during fire season with follow up consultations to incorporate injury prevention strategies. Smokejumpers were asked to complete an AT satisfaction survey (ATSS) at the end of season.

RESULTS

One hundred ninety-two documented patient encounters revealed four primary reasons for AT consultation: exercise prescription (31%, n = 59/192); MMS (30%, n = 58/192); injury consultation (27%, n = 51/192); and patient education (12%, n = 24/192). Likert scores on the ATSS ranged from 4.67 to 4.92 out of a possible 5.

CONCLUSIONS

Although continued research into Smokejumper injuries is critical, it is evident that Smokejumpers are interested in having direct access to AT services.

Medical Care at California Wildfire Incident Base Camps

OBJECTIVE

The California Emergency Medical Services Authority manages and deploys California Medical Assistance Teams (CAL-MAT) to disaster medical incidents in the state. This analysis reviews diagnoses for ambulatory medical visits at multiple wildland fire incident base camp field sites in California during the 2020 fire season.

METHODS

Clinical data without personal health information were extracted retrospectively from patient care records from all patients seen by a provider. Results were entered into Excel spreadsheets with calculation of summary statistics.

RESULTS

During the 2020 fire season, CAL-MAT teams deployed 21 times for a total of 327 days to base camps supporting large fire incidents and cared for 1756 patients. Impacts of heat and environmental smoke are a constant factor near wildfires; however, our most common medical problem was rhus dermatitis (54.5%) due to poison oak. All 2020 medical missions were further complicated by prevention and management of coronavirus disease (COVID-19).

CONCLUSIONS

There is very little literature regarding the acute medical needs facing responders fighting wildland fires. Ninety-five percent of clinical conditions presenting to a field medical team at the wildfire incident base camp during a severe fire season in California can be managed by small teams operating in field tents.

Exposure to Particulate Matter and Estimation of Volatile Organic Compounds across Wildland Firefighter Job Tasks

Wildland firefighters are exposed to smoke-containing particulate matter (PM) and volatile organic compounds (VOCs) while suppressing wildfires. From 2015 to 2017, the U.S. Forest Service conducted a field study collecting breathing zone measurements of PM₄ (particulate matter with aerodynamic diameter ≤4 μm) on wildland firefighters from different crew types and while performing various fire suppression tasks on wildfires. Emission ratios of VOC (parts per billion; ppb): PM₁ (particulate matter with aerodynamic diameter ≤1 μm; mg/m³) were calculated using data from a separate field study conducted in summer 2018, the Western Wildfire Experiment for Cloud Chemistry, Aerosol Absorption, and Nitrogen (WE-CAN) Campaign. These emission ratios were used to estimate wildland firefighter exposure to acrolein, benzene, and formaldehyde. Results of this field sampling campaign reported that exposure to PM₄ and VOC varied across wildland firefighter crew type and job task. Type 1 crews had greater exposures to both PM₄ and VOCs than type 2 or type 2 initial attack crews, and wildland firefighters performing direct suppression had statistically higher exposures than those performing staging and other tasks (mean differences = 0.82 and 0.75 mg/m³; 95% confidence intervals = 0.38-1.26 and 0.41-1.08 mg/m³, respectively). Of the 81 personal exposure samples collected, 19% of measured PM₄ exposures exceeded the recommended National Wildland Fire Coordinating Group occupational exposure limit (0.7 mg/m³). Wildland fire management should continue to find strategies to reduce smoke exposures for wildland firefighters.

Fatigue profile among petrochemical firefighters and its relationship with safety behavior: the moderating and mediating roles of perceived safety climate

The present study aimed to investigate fatigue among firefighters and its relationship with their safety behavior. The moderation and mediation effects of perceived safety climate on this relationship were also investigated. Firefighters from 10 petrochemical companies in Iran were investigated. Moderation analysis was performed based on hierarchical regression analyses and mediation effects were studied using structural equation modeling. A total number of 261 firefighters participated in this study. The mean scores of general fatigue, physical fatigue, reduced activity, reduced motivation and mental fatigue were 10.5, 9.0, 8.2, 7.6 and 8.7, respectively. Fatigue had a negative significant effect on firefighters' safety behavior. Perceived safety climate had a mediation but not moderation effect on the relationship between fatigue and safety behavior of firefighters. Generally, the fatigue level among firefighters was fairly low, but had a significant negative effect on firefighter's safety behavior. Perceived safety climate can mediate such a negative effect.

Participatory Development Process of Two Human Dimension Intervention Programs to Foster Physical Fitness and Psychological Health and Well-Being in Wildland Firefighting

Intervention programs designed, delivered, and evaluated by and within organizations are a critical component in the promotion of employee health and well-being and in the prevention of occupational injury. Critical for transference of findings across complex occupational settings is a clearly articulated development process, a reliance on and evaluation of underlying theoretical foundations, and the inclusion of relevant outcomes emerging out of participatory action processes. To date, there have been no documented efforts outlining the development, implementation, or evaluation of human dimension intervention programs targeting wildland firefighters. The purpose of this paper is to outline the development of two collaborative and participatory intervention programs, targeting wildland firefighters’ physical and psychological health and well-being. Two human dimension intervention programs were developed in a collaborative, iterative and participatory process following the Context–Content–Process–Outcomes Framework. First, a physical fitness training intervention program was designed to maintain wildland firefighter’s physical fitness levels and attenuate risk of injury. Second, a psychosocial education intervention program was developed to mitigate the impact of psychosocial risk factors, foster work engagement, and decrease job stress. The current study provides evidence for the capacity of researchers and organizations to collaboratively develop practical programs primed for implementation and delivery.

Muscle Damage and Overreaching During Wildland Firefighter Critical Training

OBJECTIVE

To document the effects of wildland firefighter (WLFF) critical training (CT) on physiologic markers of muscle damage and acute overreaching.

METHODS

Eighteen male and three female WLFFs were studied during an 11-day CT. Upper-body (US), lower-body (LS) muscle soreness and body weight (BW) were collected daily. Blood was collected on days 1, 4, 8, and 11 to measure creatine kinase (CK), lactate dehydrogenase (LDH), cortisol, and testosterone. Skinfolds were taken on days 1 and 11 to estimate body fat (BF) and lean body weight (LBW).

RESULTS

CT resulted in a significant depression in BF and elevation in LBW, while main effects of time were seen in US, LS, CK, LDH, cortisol, and testosterone/cortisol ratio (P < 0.05).

CONCLUSION

These data suggest WLFFs undergo significant physiological stressors resulting in muscle soreness, damage, and possible overreaching during CT.

Wildland firefighter exposure to smoke and COVID-19: A new risk on the fire line

Throughout the United States, wildland firefighters respond to wildfires, performing arduous work in remote locations. Wildfire incidents can be an ideal environment for the transmission of infectious diseases, particularly for wildland firefighters who congregate in work and living settings. In this review, we examine how exposure to wildfire smoke can contribute to an increased likelihood of SARS-CoV-2 infection and severity of coronavirus disease (COVID-19). Human exposure to particulate matter (PM), a component of wildfire smoke, has been associated with oxidative stress and inflammatory responses; increasing the likelihood for adverse respiratory symptomology and pathology. In multiple epidemiological studies, wildfire smoke exposure has been associated with acute lower respiratory infections, such as bronchitis and pneumonia. Co-occurrence of SARS-CoV-2 infection and wildfire smoke inhalation may present an increased risk for COVID-19 illness in wildland firefighters due to PM based transport of SARS CoV-2 virus and up-regulation of angiotensin-converting enzyme II (ACE-2) (i.e. ACE-2 functions as a trans-membrane receptor, allowing the SARS-CoV-2 virus to gain entry into the epithelial cell). Wildfire smoke exposure may also increase risk for more severe COVID-19 illness such as cytokine release syndrome, hypotension, and acute respiratory distress syndrome (ARDS). Current infection control measures, including social distancing, wearing cloth masks, frequent cleaning and disinfecting of surfaces, frequent hand washing, and daily screening for COVID-19 symptoms are very important measures to reduce infections and severe health outcomes. Exposure to wildfire smoke may introduce additive or even multiplicative risk for SARS-CoV-2 infection and severity of disease in wildland firefighters. Thus, additional mitigative measures may be needed to prevent the co-occurrence of wildfire smoke exposure and SARS-CoV-2 infection.

Wildland Firefighting: Adverse Influence on Indices of Metabolic and Cardiovascular Health

Objective:

The purpose of this study was to evaluate pre- and postseason measures of body composition, skeletal muscle, and blood parameters/liver lipid in wildland firefighters (WLFF) over the fire season.

Methods:

Alaskan WLFF (N = 27) crews were evaluated pre- and postwildfire season, which included 63 ± 10 operational days. Body composition, thigh muscle area, and liver lipid were quantified using dual-energy radiograph absorptiometry and magnetic resonance imaging, respectively. Blood metabolic and lipid panels were also collected and analyzed.

Results:

Total body, fat, and visceral fat mass increased from pre- to postseason (P < 0.05). Total cholesterol, LDL, and total globulin also increased (P < 0.05). There was a trend (P = 0.06) towards an increase in intrahepatic lipid.

Conclusions:

The observed maladaptive changes in adipose tissue, blood lipids, and hepatic function may reflect adaptations/consequences to occupational demands/conditions and warrant evaluation of appropriate countermeasures.

Fatigue and sleep patterns among Canadian wildland firefighters during a 17-day fire line deployment

The purpose of this investigation was to enhance our understanding of the effects the current British Columbia Wildfire Service (BCWS) firefighting schedule have on the development of fatigue and sleep deprivation. This was a cohort study that objectively and subjectively measured sleep quantity, sleep quality, and fatigue throughout a 17-day British Columbia wildland firefighting deployment. Wildland firefighters (n = 30) conducted daily testing of sleep and fatigue measures during 14 days of activity on the fire line and three days immediately post deployment during their three-day rest period, for a total of 17 days of data collection. Sleep was assessed using wrist-worn actigraphy (ActiGraph LLC, Pensacola, FL) and subjective sleep questionnaires. Fatigue was assessed using subjective fatigue questionnaires and cognitive performance through the psychomotor vigilance test. Total sleep time was less on fire days (M = 6.6 h ± 49.2 min) compared to non-fire days (M = 6.8 h ± 92.2 min). Participants performed poorer on cognitive performance tests, (p = 0.288), and reported being significantly sleepier, (p = 0.038), toward the end of their 17-day deployment compared to day 1. Participants continued to report high levels of sleepiness, fatigue, and poor quality of sleep on their rest days compared to their fire line days. Working 14 consecutive days was associated with increased levels of objective fatigue and suboptimal sleep in wildland firefighters. Wildland firefighters reported significantly higher levels of fatigue and decreased alertness with increasing days on deployment and these levels did not improve following a three-day rest period.

A Profile of Injuries Sustained by Firefighters: A Critical Review

Firefighters, along with other tactical personnel, are at a high risk of work-related physical injury above that of the private sector. The aim of this critical narrative review was to identify, critically appraise and synthesise key findings from recent literature investigating firefighting musculoskeletal injuries to inform injury reduction programs. The methodological approach (search terms, databases, etc.) was registered with PROSPERO and reported following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Study quality was assessed using the Downs and Black checklist with scores graded according to the Kennelly grading system. Levels of evidence were ranked according to the Australian National Health and Medical Research Council. Of the 8231 studies identified, 17 met the criteria for inclusion. The methodological quality of the studies was ‘fair’ with a level of evidence of III-2. Reported injury rates ranged from 9% to 74% with the lower extremities and back the leading aggregated bodily sites of injury. Sprains and strains were the leading nature of musculoskeletal injury, often caused by slips, trips and falls, although muscle bending, lifting and squatting or muscle stressing were also prevalent. This review may inform injury reduction strategies and given that injuries reported in firefighters are similar to those of other tactical populations, safety processes to mitigate injuries may be of benefit across the tactical spectrum.

Oral Glutamine Supplement Reduces Subjective Fatigue Ratings during Repeated Bouts of Firefighting Simulations

Wildland firefighting requires repetitive (e.g., consecutive work shifts) physical work in dangerous conditions (e.g., heat and pollution). Workers commonly enter these environments in a nonacclimated state, leading to fatigue and heightened injury risk. Strategies to improve tolerance to these stressors are lacking. Purpose: To determine if glutamine ingestion prior to and after consecutive days of firefighting simulations in the heat attenuates subjective ratings of fatigue, and evaluate if results were supported by glutamine-induced upregulation of biological stress responses. Methods: Participants (5 male, 3 female) ingested glutamine (0.15 g/kg/day) or a placebo before and after two consecutive days (separated by 24 h) of firefighter simulations in a heated chamber (35 °C, 35% humidity). Perceived fatigue and biological stress were measured pre-, post-, and 4 h postexercise in each trial. Results: Subjective fatigue was reduced pre-exercise on Day 2 in the glutamine group (p < 0.05). Peripheral mononuclear cell expression of heat shock protein 70 (HSP70) and serum antioxidants were elevated at 4 h postexercise on Day 1 in the glutamine trial (p < 0.05). Conclusions: Ingestion of glutamine before and after repeated firefighter simulations in the heat resulted in reduced subjective fatigue on Day 2, which may be a result of the upregulation of biological stress systems (antioxidants, HSPs). This response may support recovery and improve work performance.

Relationships Between Neuromuscular Function and Functional Balance Performance in Firefighters

The purpose of the present study was to examine the relationships between neuromuscular function and functional balance performance in firefighters. Fifty career firefighters (35.1 ± 7.5 yr) performed isometric leg extension and flexion muscle actions to examine peak torque (PT), and absolute (aTQ) and normalized (nTQ; %PT) rapid torque variables at 50, 100, 150, and 200 ms. A performance index (PI) was determined from the functional balance assessment completion time. Partial correlations were used to examine the relationship between the PI and the maximal and rapid TQ variables for each muscle and the composite value, while controlling for demographic data related to the PI. Multiple regression analyses examined the relative contributions of the maximal and rapid aTQ variables, and demographic data on the PI. After controlling for age and %BF, the majority of the later aTQ and nTQ variables (100–200 ms) and PT were associated with the PI (r = −0.501–−0.315). Age, %BF, and aTQ₁₀₀ explained 42–50% of the variance in the PI. Lower rapid strength, increased age, and poorer body composition were related to worse performance during the functional balance assessment. Strategies to improve rapid strength and %BF, especially in aging firefighters may impact dynamic balance abilities in firefighters.

An Overview of Occupational Risks From Climate Change

Changes in atmosphere and temperature are affecting multiple environmental indicators from extreme heat events to global air quality. Workers will be uniquely affected by climate change, and the occupational impacts of major shifts in atmospheric and weather conditions need greater attention. Climate change-related exposures most likely to differentially affect workers in the USA and globally include heat, ozone, polycyclic aromatic hydrocarbons, other chemicals, pathogenic microorganisms, vector-borne diseases, violence, and wildfires. Epidemiologic evidence documents a U-, J-, or V-shaped relationship between temperature and mortality. Whereas heat-related morbidity and mortality risks are most evident in agriculture, many other outdoor occupational sectors are also at risk, including construction, transportation, landscaping, firefighting, and other emergency response operations. The toxicity of chemicals change under hyperthermic conditions, particularly for pesticides and ozone. Combined with climate-related changes in chemical transport and distribution, these interactions represent unique health risks specifically to workers. Links between heat and interpersonal conflict including violence require attention because they pose threats to the safety of emergency medicine, peacekeeping and humanitarian relief, and public safety professionals. Recommendations for anticipating how US workers will be most susceptible to climate change include formal monitoring systems for agricultural workers; modeling scenarios focusing on occupational impacts of extreme climate events including floods, wildfires, and chemical spills; and national research agenda setting focusing on control and mitigation of occupational susceptibility to climate change.

A cross-sectional survey of occupational history as a wildland firefighter and health

BACKGROUND

Little is known regarding the impact of long-term wildland firefighting on health. Our objective was to investigate associations between duration of wildland firefighting experience and the prevalence of self-reported health outcomes.

METHODS

We ascertained employment, health, and demographic information on 499 current wildland firefighters (WLFFs) via questionnaire.

RESULTS

Relative to those with less than 10 years of experience as a WLFF, those with 10-19 years of experience had significantly greater odds of having ever been diagnosed with hypertension, as did those with 20 or more years of experience. Significant associations were observed for report of physician-diagnosed heart arrhythmia and previous knee surgery.

CONCLUSIONS

We observed significant links between a greater number of years as a WLFF and self-report of two subclinical cardiovascular risk factors as well as markers of musculoskeletal health. Additional studies are needed to determine if findings can be generalized to all WLFFs.

First Approximations of Prescribed Fire Risks Relative to Other Management Techniques Used on Private Lands

Fire is widely recognized as a critical ecological and evolutionary driver that needs to be at the forefront of land management actions if conservation targets are to be met. However, the prevailing view is that prescribed fire is riskier than other land management techniques. Perceived risks associated with the application of fire limits its use and reduces agency support for prescribed burning in the private sector. As a result, considerably less cost-share support is given for prescribed fire compared to mechanical techniques. This study tests the general perception that fire is a riskier technique relative to other land management options. Due to the lack of data available to directly test this notion, we use a combination of approaches including 1) a comparison of fatalities resulting from different occupations that are proxies for techniques employed in land management, 2) a comparison of fatalities resulting from wildland fire versus prescribed fire, and 3) an exploration of causal factors responsible for wildland fire-related fatalities. This approach establishes a first approximation of the relative risk of fatality to private citizens using prescribed fire compared to other management techniques that are readily used in ecosystem management. Our data do not support using risks of landowner fatalities as justification for the use of alternative land management techniques, such as mechanical (machine-related) equipment, over prescribed fire. Vehicles and heavy machinery are consistently leading reasons for fatalities within occupations selected as proxies for management techniques employed by ranchers and agricultural producers, and also constitute a large proportion of fatalities among firefighters. Our study provides the foundation for agencies to establish data-driven decisions regarding the degree of support they provide for prescribed burning on private lands.