Urine proteome profile of firefighters with exposure to emergency fire-induced smoke: A pilot study to identify potential carcinogenic effects

Firefighters are frequently exposed to a variety of chemicals formed from smoke, which pose a risk for numerous diseases, including cancer. Comparative urine proteome profiling could significantly improve our understanding of the early detection of potential cancer biomarkers. In this study, for the first time, we conducted a comparative protein profile analysis of 20 urine samples collected from ten real-life firefighters prior to and following emergency fire-induced smoke. Using a label-free quantitative proteomics platform, we identified and quantified 1325 unique protein groups, of which 45 proteins showed differential expressions in abundance in response to fire-smoke exposure (post) compared to the control (pre). Pathway analysis showed proteins associated with epithelium development (e.g., RHCG, HEG1, ADAMTSL2) and Alzheimer's disease (SORL1) were significantly increased in response to smoke exposure samples. A protein-protein-network study showed a possible link between these differentially abundant proteins and the known cancer gene (TP53). Moreover, a cross-comparison analysis revealed that seven proteins-ALDH1A1, APCS, POMC, COL2A1, RDX, DDAH2, and SDC4 overlapped with the previously published urine cancer proteome datasets, suggesting a potential cancer risk. Our findings demonstrated that the discovery proteomic platform is a promising analytical technique for identifying potential non-invasive biomarkers associated with fire-smoke exposure in firefighters that may be related to cancer.

Patterns of comorbid PTSD, depression, alcohol use disorder, and insomnia symptoms in firefighters: A latent profile analysis

BACKGROUND

Firefighters are an at-risk population for multiple psychiatric conditions, including posttraumatic stress disorder (PTSD), depression, alcohol use disorders (AUDs), and insomnia. These disorders are likely to co-occur; however, patterns of comorbidity have scarcely been investigated in firefighters. We aimed to identify subgroups of comorbidity of PTSD, depression, AUDs, and insomnia in a nationwide population of firefighters in South Korea.

METHODS

A total of 54,054 firefighters responded to an online survey. Latent classes of comorbidity were categorized using latent profile analysis (LPA) based on the symptom scores of PTSD, depression, AUDs, and insomnia. Analysis of variance was performed to compare the characteristics of the identified classes, and multinomial logistic regression was conducted to examine whether anger reactions, resilience, and number of traumatic events predicted class membership.

RESULTS

The LPA identified four subgroups: minimal symptoms (n = 42,948, 79.5 %), predominant PTSD (n = 2858, 5.3 %), subthreshold symptoms and comorbidity (n = 7003, 13.0 %), and high symptoms and comorbidity (n = 1245, 2.3 %). Three comorbidity classes were defined based on severity and one class showed predominant PTSD symptoms. Number of traumatic exposures predicted predominant PTSD, while resilience and anger reactions predicted severity of comorbidities.

LIMITATIONS

The cross-sectional design and usage of self-reported questionnaires are limitations of this study.

CONCLUSIONS

The severity of PTSD, depression, AUDs and insomnia tend to correlate and co-occur in firefighters. Our findings highlight the need to assess comorbid symptoms in firefighters and need to reduce anger reactions and enhance resilience in those with multiple comorbidities.

Evaluating workplace protection factors (WPFs) of different firefighter PPE interface control measures for select volatile organic compounds (VOCs)

Structural firefighters are exposed to a complex set of contaminants and combustion byproducts, including volatile organic compounds (VOCs). Additionally, recent studies have found structural firefighters' skin may be exposed to multiple chemical compounds via permeation or penetration of chemical byproducts through or around personal protective equipment (PPE). This mannequin-based study evaluated the effectiveness of four different PPE conditions with varying contamination control measures (incorporating PPE interface design features and particulate blocking materials) to protect against ingress of several VOCs in a smoke exposure chamber. We also investigated the effectiveness of long-sleeve base layer clothing to provide additional protection against skin contamination. Outside gear air concentrations were measured from within the smoke exposure chamber at the breathing zone, abdomen, and thigh heights. Personal air concentrations were collected from mannequins under PPE at the same general heights and under the base layer at abdomen and thigh heights. Sampled contaminants included benzene, toluene, styrene, and naphthalene. Results suggest that VOCs can readily penetrate the ensembles. Workplace protection factors (WPFs) were near one for benzene and toluene and increased with increasing molecular weight of the contaminants. WPFs were generally lower under hoods and jackets compared to under pants. For all PPE conditions, the pants appeared to provide the greatest overall protection against ingress of VOCs, but this may be due in part to the lower air concentrations toward the floor (and cuffs of pants) relative to the thigh-height outside gear concentrations used in calculating the WPFs. Providing added interface control measures and adding particulate-blocking materials appeared to provide a protective benefit against less-volatile chemicals, like naphthalene and styrene.

Development and validation of the trauma-specific emotional counting Stroop paradigm for fMRI study

BACKGROUND

The emotional-counting Stroop (ecStroop) is a cognitive task to evaluate emotional information processing. This study aimed to develop a trauma-specific ecStroop protocol for firefighters and assess its validity as a functional magnetic resonance imaging (fMRI) activation paradigm.

METHODS

To develop the ecStroop protocol, trauma-related words for firefighters were selected from previous studies, and general negative and neutral words were matched corresponding to the number of letters and syllables, parts of speech, and frequency in the Korean language. The negative emotional valence of whole words was investigated in 520 healthy participants. To compare brain activation between three categories, 25 healthy individuals underwent fMRI during the ecStroop task.

RESULTS

Eight trauma-related words, eight general negative words, and sixteen neutral words were selected by emotional valence scores. The general negative words were related to increased activation in the right inferior and middle temporal gyrus, right medial frontal gyrus, and left superior frontal gyrus compared to the neutral words. When exposed to the trauma-related words, participants' brain activation was increased in the right inferior temporal gyrus, right medial frontal gyrus, left superior temporal gyrus, and left inferior frontal gyrus as compared to when exposed to the neutral words.

LIMITATIONS

The fact that all participants in the phase 2 fMRI study were male could limit generalization to all genders.

CONCLUSIONS

These findings suggest that the ecStroop paradigm successfully activated the brain regions for emotional processing. This paradigm could be valuable in assessing the trauma-specific neural changes in firefighters.

Assessment of PAH exposure and health risks among South Korean firefighters based on urinary PAH metabolites

Polycyclic aromatic hydrocarbons (PAHs) comprise a group of compounds resulting from the incomplete combustion of organic matter. Firefighters engaged in fire suppression are highly exposed to PAHs. This study centered on evaluating the exposure levels and health risks of PAHs in South Korean firefighters involved in firefighting activities. The concentrations of 10 PAH metabolites in the urine of firefighters were measured immediately after, and two weeks post their engagement in extinguishing a large tire factory fire. The levels of OH-PAHs in urine samples immediately after fire suppression were elevated by a factor of 1.01-1.84 compared to urine samples from non-exposed period. The median concentration of total PAH metabolites (OH-PAHs) was higher in urine samples immediately after fire suppression (5910 ng/g creatinine) than in urine samples from non-exposed periods (5020 ng/g creatinine). However, the ∑OH-PAH levels in firefighters' urine were related to personal habits such as smoking. The concentrations of all individual OH-PAHs in the urine samples of nonsmokers exhibited a substantial increase, ranging from 1.37 to 2.3 times, clearly demonstrating that firefighting activities were a substantial source of PAH exposure. The calculated values associated with the health risks stemming from exposure to PAHs, including carcinogenic risk, total estimated daily intake (TEDI), and hazard quotients/index (HQs/HI), all fell within acceptable limits, indicating negligible risk. However, the HQ/HI values and TEDI for individual and total PAH exposures, except those for naphthalene, were 1.36-2.00 times higher in firefighters' samples taken after firefighting operations compared to those during regular duty. This underscores the need for more comprehensive investigations to comprehend the singular impact of firefighting activities due to the diverse sources of PAH emissions in the environment.

Occupational stress and musculoskeletal disorders in firefighters: the mediating effect of depression and job burnout

The firefighting profession carries a heightened risk of musculoskeletal disorders. A firefighter's job is physically demanding and includes activities such as running, climbing, dragging, and lifting. Often, these tasks are unpredictable, performed in harsh environments, and have been found to cause psychological stress. The purpose of this study was to investigate the effects of occupational stress on work-related musculoskeletal disorders (WRMSD) in firefighters. In addition, the mediating effects of depression and job burnout on proposed relationships were examined. Data informing this study were collected using a survey questionnaire. The survey questionnaire included the Beck Depression Inventory, the Center for Epidemiological Studies Depression Scale (CES-D), the Maslach Burnout Inventory, the Post Traumatic Stress Disorder Inventory (PCL), and the Nordic Musculoskeletal Questionnaire. Collected data were analyzed using structural equation modeling approach in AMOS. The results of the 2339 responding firefighters suggest that work related stress is positively related to WRMSDs in firefighters and can lead to musculoskeletal symptoms through four paths, being emotional exhaustion, personal accomplishment, CES-D total score, and depersonalization. Through depersonalization, job stress had the most significant impact on musculoskeletal symptoms (coefficient = 0.053). Furthermore, the results showed that post-traumatic stress disorders (PTSD) can affect musculoskeletal symptoms through ten paths, again through depersonalization, PTSD had the most significant impact on musculoskeletal symptoms (coefficient = 0.141). The results of this study suggest that organizations should design interventions and policies to prevent and manage occupational stress, depression, and job burnout to negate its undesired consequences on firefighters' health (i.e. WRMSD).

A comparison between the effects of simulation of basic CPR training and workshops on firefighters' knowledge and skills: experimental study

BACKGROUND

One of the most common causes of death worldwide is cardiopulmonary arrest. Firefighters are among the first responders at the scenes of accidents and can, therefore, play a key part in performing basic cardiopulmonary resuscitation (CPR) for victims who need it. The present study was conducted to compare the effects of simulation training against workshops on the CPR knowledge and skills of firefighters in the south of Iran.

METHODS

This experimental (Interventional) study was conducted on 60 firefighters of south of Fars province, Iran. The study was undertaken from March to July 2023. Through random allocation, the participants were divided into two groups: simulation-based training (30 members) and traditional workshop training (30 members). The participants' CPR knowledge and practical skills were measured before, immediately after, and three months after intervention.

RESULTS

The findings of the study revealed a statistically significant difference between the pretest and posttest CPR knowledge and skill mean scores of the simulation groups as compared to the workshop group (p < 0.001). As measured three months after the intervention, the firefighters' knowledge and skill mean scores were still significantly different from their pretest mean scores (p < 0.001); however, they had declined, which can be attributed to the fact that the study population did not frequently exercise CPR.

CONCLUSION

Based on the findings of the study, even though both methods of education were effective on enhancing the firefighters' CPR knowledge and skill, simulation training had a far greater impact than training in workshops. In view of the decline in the participants' knowledge and skill scores over time, it is recommended that short simulation training courses on CPR should be repeated on a regular basis.

Effects of implementing a mandatory and consequential annual fitness assessment in a fire department over the initial 4-year period

BACKGROUND

Despite the physical nature of the occupation many firefighters have low levels of physical fitness which is associated with poor performance of occupational tasks and increased injury rates. For many fire departments an initial step in promoting health and wellness within the department is to conduct annual fitness testing.

OBJECTIVE

To examine the effects of implementing a consequential fitness assessment within a fire department.

METHODS

A retrospective repeated measures design was used to analyze annual fitness assessment data of professional firefighters (n = 1415) from 2019 to 2022 within a large urban fire department located in the mid-Atlantic region of the United States. The fitness tests included assessments of pull-ups, push-ups, sit-ups, aerobic capacity, and body composition. Repeated measure analyses of variances (ANOVAs) assessed the effect of year and a 2-way ANOVA was conducted to investigate the effects of sex and age on fitness measures on 2022 data.

RESULTS

All fitness measures were found to be maintained over the 4-year period. Significant main effects of age and sex across all fitness measures, but no significant interactions were found. Older firefighters (50 + years) exhibited lower performance (p <  0.001, d >  0.80) on muscular fitness assessments than young firefighters (20-29 years). A large effect of sex (males >  females) was found for pull-ups (d = 1.04), push-ups (d = 1.23), and aerobic capacity (d = 1.38).

CONCLUSIONS

The results suggest that implementing a consequential fitness assessment could help maintain firefighters' fitness levels over a multi-year period.

Identifying firefighters' situation awareness requirements for fire and non-fire emergencies using a goal-directed task analysis

A firefighter's situation awareness (SA) is considered crucial to making effective tactical decisions and actions at the scene. Despite the importance of the firefighter's SA, there have been limited research efforts to understand what cues and information firefighters use to assess ongoing situations and predict future conditions. In addition to fire events, contemporary firefighters respond to an increasing volume of non-fire incidents. Thus, this study aims to identify firefighters' SA during three fire incidents (single house fire, vehicle fire, and passenger aircraft fire) and three non-fire incidents (medical emergency, hazardous materials, and urban search and rescue). A goal-directed task analysis was conducted via focus group discussions with eight career firefighters. Findings indicate that firefighters build their SA by processing various cues from hazards (e.g., fire, ignition source), humans (e.g., occupants, bystanders, drivers, passengers), spatial elements (e.g., building structure, location of hazards), and surrounding conditions (e.g., traffic, weather). Our findings provide insights into SA measurement, SA-oriented work processes, training for SA, and designing technologies to support firefighters' SA during all-hazard responses.

Sleep Quality and Associated Factors Among Firefighters in Bangkok, Thailand: A Cross-sectional Study

OBJECTIVES

Professional firefighters face various health hazards and are required to maintain both physical and mental fitness to effectively mitigate crises and respond to emergencies. Moreover, the long working hours and shift work of this profession impact sleep quality. This study investigated the quality of sleep and its associated factors among firefighters in Bangkok, Thailand.

METHODS

This was a cross-sectional study of firefighters affiliated with the Bangkok Fire and Rescue Department, Bangkok Metropolitan Administration, Thailand between January 2023 and March 2023. A cluster random sampling technique was utilized to distribute 600 questionnaires to firefighters in 15 fire stations. The questionnaire addressed demographic, work-related, and environmental factors. Sleep quality was assessed using the Thai version of the Pittsburgh Sleep Quality Index (PSQI). Data analysis involved both descriptive and inferential statistics. Bivariate and multiple logistic regressions were performed.

RESULTS

The response rate was 78.7% (n=472), and 44.1% of the firefighters reported poor sleep quality (PSQI score >5). Sleep quality was statistically associated with conflicting family relationships (odds ratio [OR], 1.8; 95% confidence interval [CI], 1.1 to 2.9), additional part-time jobs (daytime, OR, 2.4; 95% CI, 1.3 to 4.4; or nighttime, OR, 4.3; 95% CI, 1.1 to 16.7), noisy sleeping areas (OR, 1.7; 95% CI, 1.1 to 2.8), and the availability of adequate bedding (OR, 3.0; 95% CI, 1.8 to 4.9).

CONCLUSIONS

Poor sleep quality among firefighters was associated with various personal, work-related, and environmental factors. Organizations should promote policies that improve sleep quality through good sleep hygiene practices and facilities.

Air pollution inside fire stations: State-of-the-art and future challenges

Firefighters are frequently exposed to products of combustion and pyrolysis. Exposure to these substances occurs not only during fires but also at fire stations, particularly where fire equipment and fire uniforms are stored after firefighting operations. The aims of this study were to review the research on the concentrations of various air pollutants in fire stations, identify the limitations and strengths of such research, identify research gaps and related future challenges, and highlight potential solutions for reducing firefighter exposure to air pollution at fire stations. A total of 32 articles published in international journals during 1987-2023 were selected for analysis. The most frequently studied pollutants in fire stations were polycyclic aromatic hydrocarbons, particulate matter, and diesel particulate matter. Research was most often conducted on changing rooms and garages. Firefighting equipment, personal protective equipment, fire trucks, and combustion tools were identified as the main sources of pollution at fire stations. Recommendations aimed at reducing the concentration of pollutants in fire stations were mainly concerned with the systematic decontamination of equipment and the introduction of ventilation solutions that would remove exhaust fumes from garages. This in-depth literature review indicates a lack of comprehensive research on the state and quality of air at fire stations. It also highlights the emerging need for more knowledge on the concentrations of air pollutants in fire stations, health exposure related to these substances, and an analysis of the effectiveness of the proposed solutions.

Use of silicone wristbands to measure firefighters' exposures to polycyclic aromatic hydrocarbons (PAHs) during live fire training

Firefighters experience exposures to carcinogenic and mutagenic substances, including polycyclic aromatic hydrocarbons (PAHs). Silicone wristbands (SWBs) have been used as passive samplers to assess firefighters' exposures over the course of a shift but their utility in measuring short term exposures, source of exposure, and correlations with other measurements of exposure have not yet been investigated. In this study, SWBs were used to measure the concentrations of 16 priority PAHs inside and outside of firefighters' personal protective equipment (PPE) while firefighting. SWBs were placed on the wrist and jacket of 20 firefighters conducting live fire training. Correlations were made with matching data from a sister project that measured urinary concentrations of PAH metabolites and PAH concentrations from personal air samples from the same participants. Naphthalene, acenaphthylene and phenanthrene had the highest geometric mean concentrations in both jacket and wrist SWB, with 1040, 320, 180 ng/g SWB for jacket and 55.0, 4.9, and 6.0 ng/g SWB for wrist, respectively. Ratios of concentrations between the jacket and wrist SWBs were calculated as worker protection factors (WPFs) and averaged 40.1 for total PAHs and ranged from 2.8 to 214 for individual PAHs, similar to previous studies. Several significant correlations were observed between PAHs in jacket SWBs and air samples (e.g., total and low molecular weight PAHs, r = 0.55 and 0.59, p < 0.05, respectively). A few correlations were found between PAHs from SWBs worn on the wrist and jacket, and urinary concentrations of PAH metabolites and PAH concentrations in air samples. The ability of the SWBs to accurately capture exposures to various PAHs was likely influenced by short sampling time, high temperatures, and high turbulence. Future work should further examine the limitations of SWBs for PAH exposures in firefighting, and other extreme environments.

A biomechanical evaluation of firefighters' musculoskeletal loads when carrying self-contained breathing apparatus in walking and running

INTRODUCTION

Musculoskeletal loading data are needed to design ergonomic intervention for firefighters. This study aimed to quantify the firefighters' musculoskeletal loads during self-contained breathing apparatus (SCBA) carriage and evaluate the effectiveness of shoulder strap length variation for the prevention of SCBA-related injuries.

METHOD

Twelve firefighters (height: 174.6 ± 2.4 cm, mass: 67 ± 3.5 kg, BMI = 22 ± 1 kg/m2) participated the walking and running protocols with no SCBA equipped and three varying-strapped SCBAs conditions. Joint range of motion and surface electromyography (sEMG) were synchronously measured. Subsequently, joint kinematics was inputted for subject-specific musculoskeletal modeling to estimate muscle forces and joint reaction forces, while the sEMG was used to validate the model. Repeated measures analysis of variance was used for the main effects (p < 0.05). Independent samples t-test was performed to determine differences between walking and running.

RESULTS

Walking with SCBA increased the rectus femoris force and hip reaction force by 34.92% [F = 53.629; p < 0.001; η2 = 0.317] and 34.71% [F = 53.653; p < 0.001; η2 = 0.517], the growth rate was 54.2% [F = 76.487; p < 0.001; η2 = 0.418] and 51.19% [F = 69.201; p < 0.001; η2 = 0.652] during running, respectively. Running with SCBA significantly increased the knee reaction force by 63.04% [F = 83.960; p < 0.001; η2 = 0.797], while only 18.49% increase during walking. Adjusting SCBA shoulder strap length significantly altered the rectus abdominis force and L4/L5 reaction force during walking and running.

CONCLUSIONS

Results revealed that rectus femoris activity, hip and knee exertion was sensitive to SCBA carriage. The variation of shoulder strap length has potential to influence the risk of low back pain (LBP).

PRACTICAL APPLICATIONS

The findings suggest that fire services promote targeting physical training at firefighters' hip and knee regions. Test firefighters in this study were not advisable to adjust their shoulder strap at loose-fitting condition. The compatibility design of the trunk morphology and SCBA back-mounted frame was suggested for the management of LBP.

Suicides among American Indian/Alaska Native firefighters: Data from the National Violent Death Reporting System, 2003 - 2017

Suicide is a significant public health problem in the United States and disproportionally affects male American Indian/Alaska Natives (AI/AN). Suicide is particularly problematic among AI/AN firefighters who are more likely to report suicide ideation, planning, attempts, and risk compared to non-Hispanic white (NHW) firefighters. The aim of the current study was to compare non-Hispanic AI/AN firefighter and NHW firefighter suicide decedents by demographics and risk/precipitating factors using National Violent Death Reporting System data for 45 male non-Hispanic AI/AN firefighter and 588 male NHW firefighter decedents who died by suicide. Compared to NHW firefighter decedents, AI/AN firefighter decedents were significantly younger and had significantly higher odds of experiencing alcohol use problems and a recent death/suicide of a family member/friend. AI/AN firefighter decedents had significantly lower odds of documented mental health problems, documented diagnosis of depression/dysthymia, receipt of mental health treatment, or leaving a suicide note compared to NHW firefighter decedents. Results from this study may inform tailored suicide prevention and screening efforts among first responders with the goal of lowering suicide mortality among AI/AN firefighters and fire service as a whole.

Toward the future of firefighter gear: Assessing fluorinated and non-fluorinated outer shells following simulated on-the-job exposures

In 2022, the occupation of firefighting was categorized as a "Group 1" carcinogen, meaning it is known to be carcinogenic to humans. The personal protective equipment that structural firefighters wear is designed to safeguard them from thermal, physical, and chemical hazards while maintaining thermo-physiological comfort. Typically, the outer layer of structural turnout gear is finished with a durable water and oil-repellent (DWR) based on per- and polyfluoroalkyl substances (PFAS) that helps limit exposure to water and hazardous liquids. The PFAS-based aqueous emulsion typically used in DWR finishes is highly persistent and can cause various health problems if absorbed into the body through ingestion, inhalation, and/or dermal absorption. In response, the U.S. Fire Service has begun using non-PFAS water repellants in firefighter turnout gear. This study aims to evaluate the performance of both traditional PFAS-based and alternative non-PFAS outer shell materials. The study involved exposing both PFAS-based and non-PFAS DWR outer shell materials in turnout composites to simulated job exposures (i.e., weathering, thermal exposure, and laundering) that artificially aged the materials. After exposures, samples were evaluated for repellency, durability, thermal protection, and surface chemistry analysis to determine any potential performance trade-offs that may exist. Non-PFAS outer shell fabrics were found not to be diesel/oil-repellent, posing a potential flammability hazard if exposed to diesel and subsequent flame on an emergency response. Both PFAS-based and non-PFAS sets of fabrics performed similarly in terms of thermal protective performance, tearing strength, and water repellency. The surface analysis suggests that both PFAS and non-PFAS chemistries can degrade and shed from fabrics during the aging process. The study indicates that firefighters should be educated and trained regarding the potential performance trade-offs, such as oil absorption and flammability concerns when transitioning to non-PFAS outer shell materials.

Occupational exposures of firefighting and urinary tract cancer risk among men in the Norwegian Fire Departments Cohort

OBJECTIVES

Increased risks of bladder cancer and mesothelioma were the strongest evidence for the recent reclassification of firefighting as carcinogenic (Group 1) by the International Agency for Research on Cancer. Our study aim was to develop indicators for specific firefighting exposures and examine associations with urinary tract cancer (UTC), including bladder cancer.

METHODS

We developed indicators for exposure from employment at a fire department or in firefighting jobs, to fire and smoke, and to diesel exhaust for men in the Norwegian Fire Departments Cohort (n=4250). Incident UTC cases were obtained from the Cancer Registry of Norway (1960-2021). Poisson regression was used to estimate incidence rate ratios (IRR) with cumulative exposures grouped into tertiles (reference: lowest exposed tertile) with 0-year, 10-year and 15-year lagging of exposures.

RESULTS

During 125 090 person-years of follow-up, there were 76 cases of UTC. IRRs were mostly non-significantly increased in the middle tertile and at or below 1 in the highest tertile for total duration of employment, number of fires attended and fire exposure score with and without lags. In the middle tertile for diesel exhaust exposure, UTC risk was elevated over twofold with 10-year (IRR 2.27, 95% CI 1.22 to 4.20) and 15- year (2.21, 1.18 to 4.16) lags, and near 1 in the highest tertile. Findings for bladder cancer were similar to those for UTC.

CONCLUSIONS

Dose-response associations between the exposure indicators and UTC were not observed. Future studies using the indicators with more cases are needed.

Exploring Canadian Career Firefighters' Understanding of the Return-to-Work Process After Musculoskeletal Injuries

PURPOSE

Firefighters perform dangerous and physically demanding work, increasing their risk of musculoskeletal injuries that can lead to work absences. Return-to-work procedures can help firefighters return-to-work sooner and safely. The purpose of this study was to explore what firefighters understand about return-to-work procedures in their workplaces, and what firefighters believe the facilitators and barriers to return-to-work are.

METHODS

Thirty-eight Canadian career firefighters were recruited for semi-structured interviews. Qualitative descriptive methods were used to analyze the transcripts. Two researchers performed the inductive coding and thematic analysis.

RESULTS

Five themes were identified: 1. Variation in the return-to-work process knowledge among firefighters based on their experiences; 2. Accessible medical resources and treatments to support injury recovery; 3. Light duties must be meaningful and suitable; 4. Pressures to return-to-work too soon may lead to negative consequences; and 5. Heavy physical demands of firefighting may become a barrier for return-to-work. 'Factors affecting RTW depended on personal experiences and context' was the overarching theme identified, as many reported facilitators for return-to-work were also reported as barriers in different contexts. There was a variation in the experiences and understanding of return-to-work.

CONCLUSION

There is a lack of knowledge of the return-to-work processes. Firefighters require access to clear return-to-work policies and procedures and treatments that are targeted to firefighting duties to support recovery from injuries and regain physical abilities after an injury. Firefighters must be able to perform all essential duties before returning to firefighting work, as returning to work too soon can lead to further injury.

Stamp Out Stigma: a national campaign to decrease stigma and increase behavioral health in fire service

Firefighters are at risk for behavioral health problems; however, mental health stigma is a barrier to seeking treatment. Although effective treatments exist, many firefighters report that internal stigma prohibits presentation for effective care. This study aimed to decrease stigma about behavioral health in fire service through the development and delivery of a peer-led anti-stigma intervention campaign called Stamp Out Stigma (SOS). SOS consisted of three related phases. During Phase 1 (n = 12), we produced testimonials and piloted the videos with firefighters to determine which were most compelling. During Phase 2 (n = 23), we beta-tested our training curriculum with two departments, resulting in a significant decrease in internalized stigma but not in self-stigma. During Phase 3 (n = 73), we presented the curriculum to two cohorts of firefighters. Participation in the SOS workshop was associated with a significant decrease in firefighters' self-stigma from pre-, M = 22.7, SD = 6.3, to post-workshop, M = 20.8, SD = 5.5, t(66) = 3.2, p = 0.002. Participation in the SOS workshop was associated with a significant decrease in firefighters' internalized stigma, M = 2.0, SD = 0.5, to post-workshop, M = 1.8, SD = 0.4, t(66) = 2.8, p = 0.007. The SOS approach to stigma reduction is promising for modifying negative attitudes toward mental health and treatment seeking among professional firefighters.

Risk assessment of firefighting job using hybrid SWARA-ARAS methods in fuzzy environment

Identification and risk assessment of hazards using classic methods have various flaws, such as ambiguity and uncertainty in the data, inability to correctly reflect the human thinking style, failure to assign weight to criteria, use of predetermined data and tables, and the evaluator's role in the results of the risk assessment process. Therefore, developing these methods and creating approaches with higher accuracy and sensitivity is necessary. This study utilized a developed method that integrated SWARA's weighting methods and ARAS prioritization using Fine-Kinney criteria in a fuzzy environment to evaluate the risks of the firefighting job. The sensitivity analysis results confirmed the accuracy and applicability of the proposed method. Based on the study's results, the inhalation of harmful gases and smoke (R3) was identified as the most critical risk, while concern about the optimal operation (R21) was considered the least dangerous risk in firefighting.

Network analysis of posttraumatic stress disorder in a treatment-seeking sample of US firefighters and emergency medical technicians

BACKGROUND

First responders, including firefighters and emergency medical technicians (EMTs), are under extreme stress from repeated exposure to potentially traumatic events. To optimize treatment for this population, it is critical to understand how the various posttraumatic stress disorder (PTSD) symptom factors are associated with one another so these relations may be targeted in treatment.

METHOD

Using a sample of treatment-seeking firefighters/EMTs (N = 342), we conducted a partial correlation network analysis of the eight-factor model. A Bayesian directed acyclic graph (DAG) was used to estimate causal associations between clusters.

RESULTS

Approximately 37 % of the sample screened positive for probable PTSD. Internal re-experiencing and external re-experiencing had the strongest edges. In the DAG, internal re-experiencing was the parent node and was potentially predictive of external re-experiencing, negative affect, dysphoric arousal, and avoidance.

LIMITATIONS

Data were drawn from a treatment-seeking sample that may not generalize to all firefighters/EMTs.

CONCLUSIONS

The current findings are consistent with prior research suggesting re-experiencing plays a critical role in developing and maintaining PTSD symptoms. Future research should investigate non-treatment-seeking first responders, as well as EMTs and firefighters as individual populations.

A geospatial dataset of urban infrastructure for emergency response in Portugal

Emergency response plays a critical role in mitigating the impact of disasters and ensuring public safety. Understanding a city's capability for emergency response is vital for effective disaster management and urban planning. This paper describes a comprehensive geospatial dataset that assesses the emergency response capability of cities in Portugal based on their urban infrastructure, accounting for the number of hospitals, police stations, fire department units, and metro/railway stations. These infrastructures are essential for attending to victims, mitigating emergency situations, and performing rescue operations. Besides that, the GeoJSON definitions of all Portuguese cities are also provided in the dataset, which were used to compute the number of the target facilities based on data from OpenStreetMap. The potential applications of this dataset are numerous, ranging from urban planning and resource allocation to disaster response strategy development. Moreover, it indicates where public investments are most required, especially when combined with others continuously updated public datasets with incidents in urban areas.

Urinary concentrations of organophosphate esters and associated health outcomes in Korean firefighters

Although firefighters are at an increased risk of occupational exposure to chemicals, such as flame retardants, research on the exposure of Korean firefighters to organophosphate esters (OPEs)-a group of emerging flame retardants-remains limited. Therefore, in the present study, OPE metabolite concentrations in the urine samples of 149 former and current Korean firefighters were measured. Based on the data obtained, the estimated daily intakes (EDIs) of OPEs were calculated. Subsequently, the association between the urinary concentrations of OPE metabolites and the potential determinants of OPE exposure and health outcomes (e.g., obesity and serum lipids) was investigated. We found that bis(1-chloro-2-propyl) phosphate (BCIPP) and bis(2-chloroethyl) phosphate (BCEP) were the most prevalent urinary OPE metabolites, with median concentrations of 2.33 and 1.80 ng/mL, respectively; these concentrations were higher than those reported previously in other countries, such as the USA and China. Moreover, their parent compounds-tris(1-chloro-2-propyl) phosphate (TCIPP) and tris(2-chloroethyl) phosphate (TCEP)-exhibited EDIs of 126 and 94.8 ng/kg bw/day, respectively. Unlike the high detection rate of bis(1,3-dichloro-2-propyl) phosphate (BDCIPP) in other populations, its detection rate in this study was low (6.7%), suggesting regional differences in the exposure pattern of OPEs among countries. Furthermore, occupational characteristics, such as recent participation in firefighting activity, were identified as determinants of the urinary concentrations of OPE metabolites. Total OPE metabolites were inversely associated with body mass index and positively associated with high-density lipoprotein cholesterol. Overall, our findings demonstrate that Korean firefighters are highly exposed to several occupation-related OPEs. Further prospective studies will help elucidate the potential health implications of occupational exposure to OPEs among firefighters.

Assessment of the condition of psychic health of French firefighters: Burnout

To date, there has been little research on burnout in firefighters despite the acknowledged impact of occupational stress on both individuals and society. According to a survey conducted by the French National Research and Security Institute, the annual cost to society of occupational stress in France is 2-3 billion euros. The aim of the present study was to assess the prevalence of occupational burnout in a large and representative sample of French firefighters. A nationwide survey was conducted in 2021, targeting all categories of firefighters (except for military firefighters in Paris and Marseille) both in metropolitan France and in its overseas departments and territories. This survey came in two parts: questions eliciting basic sociodemographic and job-related data, followed by the Burnout Assessment Tool which assesses the intensity of job-related burnout. We collated results for 3038 firefighters: 2418 men (79.59%), 619 women (20.38%), and 1 gender neutral (0.03%). Findings revealed that while 2455 respondents (80.8%) did not meet the criteria for burnout, 345 (11.4%) reported mild/moderate symptoms of burnout, and 238 (7.8%) could be deemed to have severe burnout symptoms. Further research is warranted into the causes of burnout and its prevention in this specific population.

Pandemic Grief Reaction and Intolerance of Uncertainty on the Cognitive-Behavioral Model of COVID-Related Hypochondriasis Among Firefighters

OBJECTIVE

This study aimed to explore the feasibility of cognitive-behavioral model hypochondriasis regarding coronavirus disease-2019 (COVID-19) among firefighters. In addition, we examined the possible role of their grief reaction and intolerance of uncertainty in the model of COVID-related hypochondriasis.

METHODS

An anonymous online survey was done on October 27-28, 2022, among firefighters who witnessed people's death. Demographic characteristics were collected, and their psychological states were assessed using rating scales such as the Obsession with COVID-19 Scale (OCS), Coronavirus Reassurance-Seeking Behaviors Scale (CRBS), Fear of COVID-19 Scale (FCV-19S), Pandemic Grief Scale (PGS), and Intolerance of Uncertainty Scale-12 (IUS-12).

RESULTS

Their OCS score was expected by the CRBS (β=0.30, p<0.001), FCV-19S (β=0.10, p<0.001), PGS (β=0.29, p<0.001), and IUS12 (β=0.04, p=0.024) (F=134.5, p<0.001). The COVID-related cognitive-behavioral model of hypochondriasis was feasible among firefighters who witnessed people's death. Their pandemic grief reaction and intolerance of uncertainty directly influenced their preoccupation with coronavirus, and viral anxiety and coronavirus reassurance-seeking behavior mediated the relationship.

CONCLUSION

Firefighters' viral anxiety and coronavirus reassurance-seeking behavior mediated the influence of pandemic grief reaction or intolerance of uncertainty on the preoccupation with coronavirus.

Stress response and experiential avoidance among firefighters: Preliminary insights from network analyses

Firefighters are at increased risk of developing posttraumatic stress disorder (PTSD) due to exposure to potentially traumatic events during their careers. However, little is known about the prevalence of PTSD among this population, particularly when taking moderating variables into account. Using Gaussian Graphical Models and Directed Acyclic Graphs, we conducted network analyses to examine the interactions between clusters of PTSD symptoms, perceived stress, hardiness, and experiential avoidance among 187 firefighters. The data and code are published with the paper. Experiential avoidance, as part of psychological inflexibility, was found to be the only variable that interacted with PTSD symptomatology. Strong positive associations were observed between experiential avoidance and the "negative mood and cognitions" subscale of the PTSD Checklist for DSM-5 (PCL-5). Through this association, other PTSD symptoms were activated, particularly avoidance and arousal. Our findings suggest that experiential avoidance and negative mood and cognition symptoms are particularly important in the expression of PTSD symptomatology in firefighters. In addition, experiential avoidance may be used as a coping strategy to reduce perceived stress during potentially traumatic events. Therefore, experiential avoidance may be a prime target for future interventions and training focused on flexible self-regulation strategies in this population.

Translating community-based participatory research into broadscale sociopolitical change: insights from a coalition of women firefighters, scientists, and environmental health advocates

BACKGROUND

We report on community-based participatory research (CBPR) initiated by women firefighters in order to share successful elements that can be instructive for other community-engaged research. This CBPR initiative, known as the Women Worker Biomonitoring Collaborative (WWBC) is the first we are aware of to investigate links between occupational exposures and health outcomes, including breast cancer, for a cohort of exclusively women firefighters.

METHODS

In order to be reflective of the experiences and knowledge of those most intimately involved, this article is co-authored by leaders of the research initiative. We collected leaders' input via recorded meeting sessions, emails, and a shared online document. We also conducted interviews (N = 10) with key research participants and community leaders to include additional perspectives.

RESULTS

Factors contributing to the initiative's success in enacting broadscale social change and advancing scientific knowledge include (1) forming a diverse coalition of impacted community leaders, labor unions, scientists, and advocacy organizations, (2) focusing on impacts at multiple scales of action and nurturing different, yet mutually supportive, goals among partners, (3) adopting innovative communication strategies for study participants, research partners, and the broader community, (4) cultivating a prevention-based ethos in the scientific research, including taking early action to reduce community exposures based on existing evidence of harm, and (5) emphasizing co-learning through all the study stages. Furthermore, we discuss external factors that contribute to success, including funding programs that elevate scientist-community-advocacy partnerships and allow flexibility to respond to emerging science-policy opportunities, as well as institutional structures responsive to worker concerns.

CONCLUSIONS

While WWBC shares characteristics with other successful CBPR partnerships, it also advances approaches that increase the ability for CBPR to translate into change at multiple levels. This includes incorporating partners with particular skills and resources beyond the traditional researcher-community partnerships that are the focus of much CBPR practice and scholarly attention, and designing studies so they support community action in the initial stages of research. Moreover, we emphasize external structural factors that can be critical for CBPR success. This demonstrates the importance of critically examining and advocating for institutional factors that better support this research.

Individual responses to the implementation of mandatory fitness testing within a fire department

OBJECTIVES

To examine the effects of implementing a consequential fitness assessment (pull-ups, curl-ups, push-ups, 3 min step test) in a fire department on an individual level.

METHODS

We used a repeated-measures design to analyse fitness assessment data from 2019 to 2020 in Northern Virginia. A total of 631 professional firefighters completed the fitness assessment in both years. Repeated measures analysis of variances (ANOVAs) and multiple regression modelling were used to examine the effects of the fitness assessment and factors associated with changes in fitness, respectively.

RESULTS

Overall all aspects of fitness improved over the first year of implementation with a majority of firefighters improved on all components of the fitness assessment except for pull-ups (16.1% improved). Greater levels of baseline fitness and being female were negatively associated with changes in all fitness measures. Older firefighters had smaller changes in pull-up, curl-up and push-up performance.

CONCLUSIONS

During the first year of fitness assessment implementation, the fire department generally improved. The findings suggest that fire departments which enforce mandatory fitness assessments must establish policies for dealing with inadequate performance and offer resources to aid individual firefighters.

Nonsuicidal Self-Injury and Its Mediation Effect on the Association Between Posttraumatic Stress Disorder, Depression, and Suicidal Behavior in Firefighters

OBJECTIVE

This study aimed to investigate the prevalence, clinical characteristics, and the correlates of nonsuicidal self-injury (NSSI) in firefighters. We also investigated the mediating role of NSSI frequency in the association between posttraumatic stress disorder (PTSD), depression, and suicidal behavior.

METHODS

A total of 51,505 Korean firefighters completed a web-based self-reported survey, including demographic and occupational characteristics, NSSI, PTSD, depression, and suicidal behavior. Multivariable logistic regression analyses and serial mediation analyses were performed.

RESULTS

The 1-year prevalence of NSSI was 4.67% in Korean firefighters. Female gender, the presence of recent traumatic experience, and PTSD and depression symptoms were correlated with NSSI. Serial mediation analyses revealed that NSSI frequency mediated the association between PTSD, depression, and suicidal behavior; it indicates more severe PTSD was sequentially associated with more severe depression symptoms and more frequent NSSI, leading to higher risk of suicidal behavior.

CONCLUSION

NSSI is prevalent and may play a significant mediating role when PTSD is associated with suicidal behavior in firefighters. Our results imply the need for screening and early intervention of NSSI in firefighters.

Firefighters and the liver: Exposure to PFAS and PAHs in relation to liver function and serum lipids (CELSPAC-FIREexpo study)

INTRODUCTION

Firefighting is one of the most hazardous occupations due to exposure to per- and polyfluoroalkyl substances (PFAS) and polycyclic aromatic hydrocarbons (PAHs). Such exposure is suspected to affect the cardiometabolic profile, e.g., liver function and serum lipids. However, only a few studies have investigated the impact of this specific exposure among firefighters.

METHODS

Men included in the CELSPAC-FIREexpo study were professional firefighters (n = 52), newly recruited firefighters in training (n = 58), and controls (n = 54). They completed exposure questionnaires and provided 1-3 samples of urine and blood during the 11-week study period to allow assessment of their exposure to PFAS (6 compounds) and PAHs (6 compounds), and to determine biomarkers of liver function (alanine aminotransferase (ALT), gamma-glutamyl transferase (GGT), aspartate aminotransferase (AST), alkaline phosphatase (ALP) and total bilirubin (BIL)) and levels of serum lipids (total cholesterol (CHOL), low-density lipoprotein cholesterol (LDL) and triglycerides (TG)). The associations between biomarkers were investigated both cross-sectionally using multiple linear regression (MLR) and Bayesian weighted quantile sum (BWQS) regression and prospectively using MLR. The models were adjusted for potential confounders and false discovery rate correction was applied to account for multiplicity.

RESULTS

A positive association between exposure to PFAS and PAH mixture and BIL (β = 28.6%, 95% CrI = 14.6-45.7%) was observed by the BWQS model. When the study population was stratified, in professional firefighters and controls the mixture showed a positive association with CHOL (β = 29.5%, CrI = 10.3-53.6%) and LDL (β = 26.7%, CrI = 8.3-48.5%). No statistically significant associations with individual compounds were detected using MLR.

CONCLUSIONS

This study investigated the associations between exposure to PFAS and PAHs and biomarkers of cardiometabolic health in the Czech men, including firefighters. The results suggest that higher exposure to a mixture of these compounds is associated with an increase in BIL and the alteration of serum lipids, which can result in an unfavourable cardiometabolic profile.

Impact of Covid-19 pandemic on psychological well-being of firefighters

Background

Covid-19 pandemic represented a unique stressful event that affected the physical health and the psychological well-being (PWB) of individuals and communities. Monitoring PWB is essential to clarify the burden on mental health effects but also to define targeted psychological-supporting measures. This cross-sectional study evaluated the PWB of Italian firefighters during the pandemic.

Methods

Firefighters recruited during the pandemic period filled out a self-administered questionnaire the Psychological General Well-Being Index during the health surveillance medical examination. This tool is usually used to assess the global PWB and explores six subdomains: anxiety, depressed mood, positive well-being, self-control, general health, and vitality. The influencing role of age, gender, working activities, Covid-19 and pandemic restrictive measures was also explored.

Results

A total of 742 firefighters completed the survey. The aggregate median PWB global score was in the "no distress" range (94.3±10.3) resulting higher than that observed in studies conducted using the same tool in the Italian general population during the same pandemic period. Similar findings were observed in the specific subdomains thus suggesting that investigated population was in good PWB condition. Interestingly, significantly better outcomes were detected in the younger firefighters.

Conclusion

Our data showed a satisfactory PWB situation in firefighters that could be related to different professional factors such as work organization, mental and physical training. In particular, our results would suggest the hypothesis that in firefighters, the maintaining of a minimum/moderate level of physical activity (consisting of even just going to work) might had a profoundly positive impact on psychological health and well-being.

Assessment of coarse, fine, and ultrafine particulate matter at different microenvironments of fire stations

The concentrations of respirable particulate matter (PM) and the impact on indoor air quality in occupational settings remains poorly characterized. This study assesses, for the first time, the cumulative and non-cumulative concentrations of 14 fractions of coarse (3.65-9.88 μm), fine (0.156-2.47 μm), and ultrafine (0.015-0.095 μm) PM inside the garage of heavy vehicles, firefighting personal protective equipment' storage room, bar, and a common area of seven Portuguese fire stations. Sampling campaigns were performed during a regular work week at the fire stations. Levels of daily total cumulative PM ranged from 277.4 to 413.2 μg/m³ (maximum values of 811.4 μg/m³), with the bar (370.1 μg/m³) and the PPE' storage room (361.3 μg/m³) presenting slightly increased levels (p > 0.05) than the common area (324.8 μg/m³) and the garage (339.4 μg/m³). The location of the sampling site, the proximity to local industries and commercial activities, the layout of the building, the heating system used, and indoor sources influenced the PM concentrations. Fine (193.8-301.0 μg/m³) and ultrafine (41.3-78.2 μg/m³) particles were predominant in the microenvironments of all fire stations and accounted for 71.5% and 17.8% of daily total cumulative levels, respectively; coarse particles (23.3-47.1 μg/m³) represented 10.7% of total PM. The permissible exposure limit (5.0 mg/m³) defined by the Occupational Safety and Health Organization for respirable dust was not overcome in the evaluated fire stations. Results suggest firefighters' regular exposure to fine and ultrafine PM inside fire stations which will contribute to cardiorespiratory health burden. Further studies are needed to characterize firefighters' exposure to fine and ultrafine PM inside fire stations, identify main emission sources, and evaluate the contribution of exposures at fire stations to firefighters' occupational health risks.

Heat strain of Japanese firefighters wearing personal protective equipment: a review for developing a test method

The aim of this review was to develop a test method for the evaluation of heat strain for structural firefighters wearing personal protective equipment (PPE) in Japan. We analysed a series of our laboratory's questionnaires and experimental studies and reviewed international standards on test methods. We investigated the actual average working conditions (total firefighting time on one incidence, working time with full PPE, maximum temperature and humidity during firefighting) at structural firefighting site in Japan by conducting a large-scale questionnaire survey of Japanese firefighters. We discussed test subjects (firefighters vs. non-firefighters; body size; physical fitness), exercise intensity (absolutes vs. relative; light vs. heavy) and duration, experimental temperature and relative humidity, experimental clothing items including station uniforms (shorts vs. long), and measurement variables (physiological and subjective responses), and suggested a standard test method to evaluate the heat strain of firefighters in hot and humid environments.Practitioner summary: We reviewed studies on human wear trials of firefighting personal protective equipment (PPE) in hot environments and suggested a standard test method to evaluate the heat strain of firefighters. The test method can be internationally utilised to examine the comfort functions and heat stress of PPE in hot, humid environments.

The exposure of Czech firefighters to perfluoroalkyl substances and polycyclic aromatic hydrocarbons: CELSPAC - FIREexpo case-control human biomonitoring study

The CELSPAC - FIREexpo biomonitoring study investigates the long-term effects of chemical exposure on firefighters' wellness and fitness. It aims to provide science-based measures to minimize the health risks of the firefighting occupation. Here, we present the study design, cohort profile, and first results with respect to internal per- and polyfluoroalkyl substances (PFAS) and polycyclic aromatic hydrocarbons (PAH) levels in study participants. Participants (n = 166) were divided into three subcohorts: i) newly recruited firefighters, ii) professional firefighters with several years' experience, and iii) the control group. Participants underwent physical performance tests, provided information on their lifestyle and diet, and urine and blood samples 1-4 times within an 11-week period. 12 serum PFAS and 10 urinary hydroxylated PAH (OH-PAH) levels were determined using HPLC-MS/MS and compared between subcohorts and samplings. The association of internal exposure with reported lifestyles and occupational factors was investigated using Spearman's correlation, principal component analysis, and multivariate regression analysis. ΣPFAS levels in firefighters were significantly higher than in the control group and were mostly associated with the length of firefighting career, age, blood donation, and population size. 10.9 % and 7.6 % of measurements exceeded the HBM-I or HBM-II value for PFOS and PFOA, respectively. Urinary ΣPAH levels increased significantly after training with burning wooden pallets, but none of them exceeded the no observed genotoxic effect level. Firefighters' occupational exposure, its sources, and pathways, need to be systematically monitored and investigated on a long-term and individual basis. The CELSPAC - FIREexpo study helps to clarify the degree of occupational exposure to the given compounds and the subsequent risks to firefighters.

Incomplete off-duty work hours and sleep quality among firefighters: a cross-sectional study, Taiwan

OBJECTIVE

We examined whether firefighters in Taiwan have a sleep problem and investigated the related factors of poor sleep quality.

METHODS

In this cross-sectional study, 2123 male shift firefighters in the Greater Taipei area were invited, and 37.7% of them satisfactorily completed the questionnaire online. The Chinese version of Pittsburgh sleep quality index (PSQI) was used to evaluate sleep quality. Multiple logistic and linear regression analyses were used to determine the associations among demographic characteristics, work-related characteristics, and poor sleep quality.

RESULTS

As revealed by 801 valid questionnaires, 77.2% were poor sleepers (PSQI cutoff score > 6), and 61.2% reported incomplete off-duty in the past month. Moreover, 42.6% of incomplete off-duty workers reported extended overtime of more than 5 h on off-duty days in the past month. Poor sleep quality was associated with the following factors: (1) demographic characteristics: age, working tenure, having children, and chronotype and (2) work-related characteristics: shift schedule and incomplete off-duty. The final model for poor sleep quality as per PSQI included age, chronotype, shift schedule, and incomplete off-duty hours in the past month. Longer hours of incomplete off-duty work were associated with increased risks of overall poor sleep quality and of poor subjective sleep quality, long sleep latency, sleep disturbances, and daytime dysfunction.

CONCLUSION

Firefighters are advised to have a complete off-duty day to avoid poor sleep quality, long sleep latency, short sleep duration, sleep disturbances, and daytime dysfunction. Our results confirm the need for implementing appropriate shift schedules to ensure adequate rest time for firefighters.

Perfluoroalkyl substances exposure in firefighters: Sources and implications

Firefighters are at risk of occupational exposure to long-chain per- and poly-fluoroalkyl substances (PFASs), most notably from PFASs present in Class B aqueous film-forming foam (AFFF). Firefighters have been found to have elevated serum levels of long-chain PFASs. Due to the persistence of PFAS chemicals in the human body and their ability to bioaccumulate, firefighters experience the latent and cumulative effects of PFAS-containing AFFF exposure that occurs throughout their careers. This article summarizes the history of AFFF use by firefighters and current AFFF use practices. In addition, this paper describes PFAS levels in firefighter serum, PFAS serum removal pathways, PFAS exposure pathways, and occupational factors affecting PFAS levels in firefighters. International, national, and state agencies have concluded that PFOA, a long-chain PFAS, is potentially carcinogenic and that carcinogens have an additive effect. From the cancer types that may be associated with PFAS exposure, studies on cancer risk among firefighters have shown an elevated risk for thyroid, kidney, bladder, testicular, prostate, and colon cancer. Thus, exposure to PFAS-containing AFFF may contribute to firefighter cancer risk and warrants further research.

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.

Excretion of polybrominated diphenyl ethers and AhR activation in breastmilk among firefighters

Excretion of toxicants accumulated from firefighter exposures through breastmilk represents a potential hazard. We investigated if firefighting exposures could increase the concentration of polybrominated diphenyl ethers (PBDEs) and aryl hydrocarbon receptor (AhR) activation in excreted breastmilk. Firefighters and non-firefighters collected breastmilk samples prior to any firefighting responses (baseline) and at 2, 8, 24, 48, and 72 hours after a structural fire (firefighters only). Five PBDE analytes (BDEs 15, 28, 47, 99, and 153) detected in at least 90% of samples were summed for analyses. The AhR in vitro DR CALUX® bioassay assessed the mixture of dioxin-like compounds and toxicity from breastmilk extracts. Baseline PBDEs and AhR response were compared between firefighters and non-firefighters. Separate linear mixed models assessed changes in sum of PBDEs and AhR response among firefighters over time and effect modification by interior or exterior response was assessed. Baseline PBDE concentrations and AhR responses did not differ between the 21 firefighters and 10 non-firefighters. There were no significant changes in sum of PBDEs or AhR response among firefighters over time post-fire, and no variation by interior or exterior response. Plots of sum of PBDEs and AhR response over time demonstrated individual variation but no consistent pattern. Currently, our novel study results do not support forgoing breastfeeding after a fire exposure. However, given study limitations and the potential hazard of accumulated toxicants from firefighter exposures excreted via breastfeeding, future studies should consider additional contaminants and measures of toxicity by which firefighting may impact maternal and child health.

Development of a job-exposure matrix (JEM) for exposure to smoke particle mass among firefighters of the Fire Department of the City of New York (FDNY)

OBJECTIVES

A refined job exposure matrix (JEM) based on incident types and severities and response characteristics was developed for firefighters to estimate quantities of smoke particles emitted during structural and non-structural fire incidents from 2010 to 2021.

METHODS

The cohort included a subset of 3237 Fire Department of the City of New York firefighters who responded to at least one incident between 2010 and 2021, prior to retirement. Fire incident data included dates, type, severity (alarm level) and location. Response data included dates worked, firehouse, position titles and shift lengths for each firefighter. The quantity of smoke particle mass generated during structural and non-structural fires adjusted by individual firefighter engagement was computed using the United States Environmental Protection Agency AP-42 emissions framework. Correlations between years of employment, fire responses and career total particle mass concentration by firefighter were examined. Linear regression models were fit and corresponding R² values were calculated.

RESULTS

Firefighters responded to a median of 424.7 (IQR=202.3-620.0) annual incidents/person; 17.6% were fire incidents (median=77.1; IQR=40.4-114.0). Structural fires were the most common type of fire incident (72.5% of annual incidents/person; median=55.9; IQR=29.6-85.5). Incident severity (alarm level) and firefighter engagement (position title) appeared to differentiate between high and low exposure regimes (R²=0.43). Incident severity explained most of the variability of particle exposures (R²=0.90).

CONCLUSIONS

Using the JEM, job-related smoke particle concentrations were estimated to vary by incident type, incident severity and firefighter engagement, highlighting the importance of using refined measures, so that future studies can more accurately evaluate associations between firefighting and health outcomes.

Firefighter occupational factors and the risk of preterm birth: results from a survey of women firefighters in the USA

OBJECTIVES

Previous research has suggested that women firefighters may have a greater risk of adverse reproductive outcomes compared with non-firefighting women. In this study, we investigated the association between firefighter occupational factors and risk of preterm birth.

METHODS

This cross-sectional analysis of US firefighters surveyed in 2017 compared preterm birth among firefighters to non-firefighters using age-at-pregnancy-standardised prevalence ratios. Generalised estimating equations estimated relative risks and 95% CIs between firefighter occupational factors (career or volunteer, wildland status, shift schedule, fire responses, work restriction) and preterm birth risk. We adjusted for age-at-pregnancy, education, gravidity, BMI, and smoking and considered effect modification by age-at-pregnancy and career versus volunteer status.

RESULTS

Among 934 women who reported 1356 live births, 12% were preterm (n=161). Preterm birth prevalence among firefighters was 1.41 times greater than non-firefighters (95% CI 1.18 to 1.68). Among wildland and combination wildland/structural firefighters, volunteers had 2.82 times the risk of preterm birth (95% CI 1.19 to 6.67) compared with career firefighters. Firefighters who started restricting their work in the 2nd trimester had a nonsignificant 0.67 times lower risk of preterm birth than those who started in the 3rd trimester or did not restrict work at all (95% CI 0.43 to 1.03).

CONCLUSIONS

Firefighters may have greater risk of preterm birth than non-firefighters, which could be influenced by roles in the fire service and work restrictions taken.

Global prevalence and associated factors of sleep disorders and poor sleep quality among firefighters: A systematic review and meta-analysis

Lack of sleep can affect the health and performance of firefighters. This systematic review and meta-analysis estimated the global prevalence of sleep disorders and poor sleep quality among firefighters and reported associated factors. Four academic databases (Scopus, PubMed, Web of Science, and Embase) were systematically searched from January 1, 2000 to January 24, 2022. These databases were selected as they are known to index studies in this field. The search algorithm included two groups of keywords and all possible combinations of these words. The first group included keywords related to sleep and the second group keywords related to the firefighting profession. The relevant Joanna Briggs Institute checklist was used to evaluate study quality. Data from eligible studies were included in a meta-analysis. In total, 47 articles informed this review. The pooled prevalence of sleep disorders and poor sleep quality in firefighters were determined as 30.49% (95% CI [25.90, 35.06]) and 51.43% (95% CI [42.76, 60.10]), respectively. The results of a subgroup analysis showed that individuals in low- and middle-income countries (LMICs) had a higher prevalence of sleep disorders than those in high-income countries (HICs) but HICs had a higher prevalence of poor sleep quality than LMICs. Various factors, including shift work, mental health, injuries and pain, and body mass index were associated with sleep health. The findings of this review highlight the need for sleep health promotion programs in firefighters.

Terrorist Attacks Against Firefighters, 1970-2019

Firefighters are a critical component of the emergency response system and therefore a potential target for organizations seeking to disrupt this system. Terrorist organizations may deliberately attack firefighters to both increase the devastation of an attack and impair the affected community's ability to respond to an attack. We performed a focused search of the Global Terrorism Database to identify terrorist attacks against firefighters worldwide. The database includes incidents from 1970 through 2019, with a total of 201,183 entries. These entries were searched for incidents involving firefighters or fire trucks. We analyzed trends in the number of incidents occurring per year, regions of the world impacted, methods employed, and number of casualties inflicted. A total of 42 attacks involving firefighters were identified in the Global Terrorism Database resulting in 26 deaths and 95 wounded. Of the 42 attacks, 12 (28.6%) were secondary attacks, where firefighters responding to an initial attack were themselves targeted. The most common method for both primary and secondary attacks was the use of a bomb or explosive. Although attacks against firefighters are uncommon, they highlight both the strategic value and vulnerability of firefighters to terrorist attacks. Increased efforts must be made to protect firefighters from future terrorist attacks.

Assessment of firefighter-training effectiveness in China based on human-factor parameters and machine learning

BACKGROUND

The emergency rescue ability of firefighters is particularly important in the event of major disasters or accidents. Therefore, an assessment of the firefighter-training effectiveness is necessary.

OBJECTIVE

This paper aims to achieve a scientific and effective assessment of the firefighter-training effectiveness in China. An assessment method based on human factor parameters and machine learning was proposed.

METHOD

The model is constructed by collecting the corresponding human factor parameters such as electrocardiographic signals, electroencephalographic signals, surface electromyographic signals, and photoplethysmographic signals through wireless sensors and using them as constraint indicators. For the problems of weak human factor parameters and high noise proportion, an improved flexible analytic wavelet transform algorithm is used to denoise and extract the corresponding feature values. To overcome the limitations of traditional assessment methods, improved machine learning algorithms are used to comprehensively assess the training effectiveness of firefighters and provide targeted training suggestions.

RESULTS

The effectiveness of this study's evaluation method is verified by comparing it with the expert scoring method and considering firefighters from a special fire station in Xhongmen, Daxing District, Beijing, as an example.

CONCLUSION

This study can effectively guide the scientific training of firefighters and the method is more objective and accurate than the traditional method.

Antibody responses elicited by mRNA vaccination in firefighters persist six months and correlate inversely with age and directly with BMI

Knowledge regarding the sustainability of immune responses after COVID-19 vaccination is important, e.g., to decide whom and when to booster. Thus, we analyzed antibody titers in firefighters six months after vaccination with the mRNA-based vaccine Comirnaty. SARS-CoV-2 spike-binding antibodies (bAb) were quantified and compared to peak responses determined in healthcare workers (HCW). For the firefighters, neutralizing antibodies (nAb) were also analyzed. Six months after the second vaccine dose, all analyzed firefighters had detectable bAb, and 91% exhibited nAb titers above 1:16. However, actual titers six months after vaccination were over 12-fold lower than in the HCW control group four weeks after vaccination. bAb and nAb responses showed a significant correlation, and age correlated inversely with antibody responses. Unexpectedly, participants with a body mass index over 25 had higher neutralization titers after six months. All participants with very low neutralization titers were offered booster vaccination. The booster vaccination improved the extent and sustainability of antibody responses.

Predicting PTSD symptoms in firefighters using a fear-potentiated startle paradigm and machine learning

This study develops a fear-potentiated startle paradigm (FPS) and a machine learning approach to accurately predict PTSD symptoms using electrogram data. A three-phase fear-potentiated startle paradigm was designed to assess the conditioning, generalization, and extinction of fear. Electrooculogram and electrocardiogram signals were collected during the FPS. A total of 1107 Chinese firefighters participated in the study. The Chinese version PCL-C was administered to all subjects. A cutoff of 38 or higher is used to indicate PTSD symptoms. Electrogram features were extracted and selected to build a machine learning model to classify individuals. The machine learning model was 5-fold cross validated. The importance of the selected features was calculated. Classification performance metrics were evaluated for the machine learning model. The machine learning model can identify firefighters with a PCL-C score of 38 or above with sensitivity and specificity both above 0.85 when 5-fold cross validated on a 1107-person sample. The area under the receiver operating characteristic curve of the model is 0.93. Features related to fear generalization are found to be the most important. The proposed fear-potentiated startle paradigm and machine learning approach can accurately predict PTSD symptoms in Chinese firefighters, which can improve the screening and diagnosis of PTSD.

A review of infectious disease epidemiology in emergency medical service clinicians

BACKGROUND

The emergency medical service (EMS) workforce is at high risk of occupationally-acquired infections. This review synthesized existing literature on the prevalence, incidence, and severity of infections in the EMS workforce.

METHODS

We searched PubMed, Embase, CINAHL, and SCOPUS from January 1, 2006 to March 15, 2022 for studies in the US that involved EMS clinician or firefighter populations and reported 1 or more health outcomes related to occupationally-acquired infections.

RESULTS

Of the 25 studies that met the inclusion criteria, most focused on severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, with prevalence rates ranging from 1.1% to 36.2% (median 6.7%). The prevalence of methicillin-resistant Staphylococcus aureus (MRSA) in 4 studies ranged from 1.9% to 6.4%, and the prevalence of Hepatitis C in 1 study was 1.3%. Few studies reported incidence rates. The prevalence or incidence of these infections generally did not differ by age or gender, but 4 studies reported differences by race or ethnicity. In the 4 studies that compared infection rates between EMS clinicians and firefighters, EMS clinicians had a higher chance of hospitalization or death from SAR-CoV-2 (odds ratio 4.23), a higher prevalence of Hepatitis C in another study (odds ratio 1.74), and no significant difference in MRSA colonization in a separate study.

CONCLUSIONS

More research is needed to better characterize the incidence and severity of occupationally-acquired infections in the EMS workforce.

The Moderating Role of Emotional Intelligence on the Relationship Between Conflict Management Styles and Burnout among Firefighters

Background

While the organizational factors that account for firefighters' burnout have been extensively explored, the individual factors related to how they regulate interpersonal conflicts and emotions remain to be investigated. Previous research has demonstrated the association between emotional intelligence and conflict management styles and burnout, but no study has looked at the interrelationships among these factors in high-risk sectors. The present exploratory study aimed to fill this research gap by investigating the relationships between conflict management style, emotional intelligence and burnout in a sample of firefighters.

Methods

A cross-sectional study was conducted with 240 French firefighters. Measures comprised validated scales of conflict management styles, emotional intelligence and burnout.

Results

Results showed that the integrating conflict style reduced burnout. They also revealed the effects of emotion regulation on burnout, whereby the awareness and management of one's own emotions reduced burnout. Moreover, awareness of one's own emotions moderated the relationship between integrating conflict resolution style and burnout, whereby the effect of integrating style on reduced burnout was higher when awareness of one's own emotions was high.

Conclusion

These results reveal that strategies used by firefighters to regulate their emotions in order to meet the emotional demands specific to their job are important for reducing the emotional exhaustion component of burnout. Training programs for conflict and emotion management are needed to preserve the mental health of firefighters and ensure the safety of interventions.

Non-cancer health risks in firefighters: a systematic review

osFirefighters are occupationally exposed to hazardous factors that may increase their risk of disease. However, non-cancer disease risk in firefighters has not been systematically examined. This systematic review aimed to identify non-cancer disease risk in firefighters and determine whether the risk differs according to job characteristics. We searched the Cochrane Library, Embase, PubMed, and KoreaMed databases using relevant keywords from their inception to April 30, 2021. The Risk of Bias Assessment Tool for Non-randomized Studies version 2.0 was used to assess the quality of evidence. Due to study heterogeneity, a narrative synthesis was presented. The systematic literature search yielded 2,491 studies, of which 66 met the selection and quality criteria. We confirmed that the healthy worker effect is strong in firefighters as compared to the general population. We also identified a significant increase in the incidence of lumbar disc herniation, lower back pain, angina pectoris, acute myocardial infarction, and post-traumatic stress disorder (PTSD) in firefighters compared to other occupational groups. Contradictory results for the risk of PTSD and anxiety disorders related to rank were reported. Sufficient evidence for increased risk of lumbar disc herniation, lower back pain, angina pectoris, acute myocardial infarction, and PTSD was available. The risk of non-cancer diseases varied depending on job type, years of service, and rank. However, caution should be exercised when interpreting the results because the classification criteria for firefighters' jobs and ranks differ by country.

The effect of blood cadmium levels on hypertension in male firefighters in a metropolitan city

Background

This study investigated the effect of dispatch frequency on blood cadmium levels and the effect of blood cadmium levels on hypertension in male firefighters in a metropolitan city.

Methods

We conducted a retrospective longitudinal study of male firefighters who completed the regular health checkups, including a health examination survey and blood cadmium measurements. We followed them for 3 years. To investigate the effect of dispatch frequency on blood cadmium levels and the effect of blood cadmium levels on hypertension, we estimated the short-term (model 1) and long-term (model 2) effects of exposure and hypothesized a reversed causal pathway model (model 3) for sensitivity analysis. Sequential conditional mean models were fitted using generalized estimating equations, and the odds ratios (ORs) and the respective 95% confidence intervals (CIs) were calculated for hypertension for log-transformed (base 2) blood cadmium levels and quartiles.

Results

Using the lowest category of dispatch frequency as a reference, we observed that the highest category showed an increase in blood cadmium levels of 1.879 (95% CI: 0.673, 3.086) μg/dL and 0.708 (95% CI: 0.023, 1.394) μg/dL in models 2 and 3, respectively. In addition, we observed that doubling the blood cadmium level significantly increased the odds of hypertension in model 1 (OR: 1.772; 95% CI: 1.046, 3.003) and model 3 (OR: 4.288; 95% CI: 1.110, 16.554). Using the lowest quartile of blood cadmium levels as a reference, the highest quartile showed increased odds of hypertension in model 1 (OR: 2.968; 95% CI: 1.121, 7.861) and model 3 (OR: 33.468; 95% CI: 1.881, 595.500).

Conclusions

We found that dispatch frequency may affect blood cadmium levels in male firefighters, and high blood cadmium levels may influence hypertension in a dose-response manner.

Association between sleep quality and type of shift work in Korean firefighters

Background

Shift work that interferes with normal sleep patterns, is known to be a cause of sleep disturbance and has been studied through various occupational groups. However, it is not known which shift type is better for sleep health.

Methods

This study included 568 firefighters. Sleep quality was evaluated using Pittsburgh Sleep Quality Index. Sleep quality was categorized into 2 groups; good quality (≤ 5 points) and poor quality (≥ 6 points). Demographic variables, depression, anxiety, type of shift, and job were collected by self-reported questionnaires. The χ² test, t-test, and multiple logistic regression analysis were used to evaluate the effect of shift type on the sleep quality of firefighters.

Results

Three hundred thirty-seven firefighters (59.3%) have poor sleep quality. Compared to day workers, the odds ratios (ORs) of poor sleep quality were 2.169 (95% confidence interval: 1.137-4.134) in 6-day cycle, 2.161 (1.150-4.062) in 9-day cycle, 1.805 (1.087-2.997) in 21-day cycle, and 1.485 (0.718-3.069) in 3-day cycle. The ORs of poor sleep quality were 1.697(1.021-2.823) in fire suppression and 2.325 (1.213-4.455) in emergency medical service compared to administration.

Conclusions

All shift work type except for the 3-day cycle was associated with poor sleep quality compared to day work.