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.

Quantification of suppressor effects on breech and action noise from AR-15 pattern firearms and its implications for the protection of human hearing.

Noise from firearms is well known to be harmful to human hearing. This problem has been addressed by various military units through the use of muzzle suppressors. However, as suppressor technology has advanced, shooters report hearing the mechanical action of gas-operated semi-automatic rifles (ArmaLite Rifle Model 15 style aka AR-15) as being louder than the suppressed muzzle noise. This study aims to evaluate if harmful noise is present in the shooter's ear, even when impulse noise emanating from the muzzle is suppressed. To characterize the impulse noise of the firearm action caused by the reciprocation of the bolt carrier group (BCG) and subsequent impact when it returns to battery (the forward locked position), the muzzle of a rifle was placed through a constructed plywood wall, and the noise of the action/breech was measured independently from the muzzle noise. This research finds that the impact of the BCG returning to battery (132 dBZ) has the potential to be harmful to the shooter's hearing even when the noise from the muzzle is effectively suppressed.

Preliminary analyses of accumulation of carcinogenic contaminants on retired firefighter ensembles.

Personal protective equipment (PPE) is designed to protect firefighters from hazards encountered on the fire scene, including heat and products of combustion. Decontamination practices for firefighter turnout gear have been developed to remove combustion products and other contaminants from the fabric of structural firefighting ensembles (i.e., turnout or bunker gear). Chronic exposures to residual polycyclic aromatic hydrocarbons (PAH) are a contributing cause of firefighter cancers. To identify and quantify residual contamination of PAH, samples were taken from two individual decommissioned structural firefighting ensembles and analyzed by layer (outer canvas shell, moisture barrier, and the thermal protective liner) for (1) textile integrity via field emission scanning electron microscopy and (2) quantity of PAH contamination by high-pressure liquid chromatography with ultraviolet/fluorescence detection. The results of these analyses show the presence of the PAH compounds pyrene (35% of the total mass of PAH), phenanthrene (21%), benzo(a)pyrene (14%), and benzo(a)anthracene (14%) which present a risk for dermal absorption. The data also revealed that PAH penetration through the layers of the firefighting ensemble was strongly inhibited by the moisture barrier layer.

Face-to-face with scorching wildfire: potential toxicant exposure and the health risks of smoke for wildland firefighters at the wildland-urban interface.

As wildfire risks have elevated due to climate change, the health risks that toxicants from fire smoke pose to wildland firefighters have been exacerbated. Recently, the International Agency for Research on Cancer (IARC) has reclassified wildland firefighters' occupational exposure as carcinogenic to humans (Group 1). Wildfire smoke contributes to an increased risk of cancer and cardiovascular disease, yet wildland firefighters have inadequate respiratory protection. The economic cost of wildland fires has risen concurrently, as illustrated by the appropriation of $45 billion for wildfire management over FYs 2011-2020 by the U.S. Congress. Occupational epidemiological studies of wildland firefighters are crucial for minimizing health risks; however, they must account for the mixture of exposures in wildfire smoke. This review focuses on four aspects of wildland firefighters' health risks at the wildland-urban interface: 1) economic costs and health impact, 2) respiratory protection, 3) multipollutant mixtures, and 4) proactive management of wildfires.

Characterization of Sweat Drying Performance of Single Layered Thermal Protective Fabrics Used in High-Risk Sector Workers' Clothing.

Absorption and transportation of moisture from sweat are the crucial properties of the fabrics used in performance clothing. Sweat moisture is a significant factor that may cause discomfort to the wearer. The majority of the injuries and fatalities that happen to the high-risk sector workers in their line of duty may be caused by inadequate comfort provided by the protective uniform. The purpose of this study is to scientifically investigate the sweat drying performance of the different protective fabrics used in high-risk sectors' workers' clothing. Firstly, this study experimentally analyzed the sweat drying of protective fabrics with different attributes under various ambient environments and wearers' internal physiology. Secondly, this study explained the phenomena of sweat drying in protective fabric through the theory of heat and mass transfer. Sweat drying performance of the fabrics used in functional clothing mainly depends on the evaporative resistance regardless of the presence of water and oil repellent coating on the fabric surface. The drying performance increases with the increased wetted area and increased air flow. The wetted area depends on the absorption and wicking properties of the fabrics. The findings of this research will advance the field by developing knowledge on sweat drying performance of fabrics used in protective clothing; in turn, this could provide better comfort and safety to high-risk sectors' workers.

Urinary Metabolites of Polycyclic Aromatic Hydrocarbons in Firefighters: A Systematic Review and Meta-Analysis.

Firefighters are intermittently exposed to complex, mixed pollutants in random settings. Of those pollutants, PAHs (polycyclic aromatic hydrocarbons) are the most commonly studied and best understood. PAH exposure can occur via multiple routes; therefore, the levels of hydroxylated metabolites of PAHs in urine have been used as a biomonitoring tool for risk assessment. We performed a systematic review and meta-analysis of the literature to estimate the levels of urinary hydroxylated PAH (OHPAH) among firefighters, determine risk attributions, and, finally, evaluate the scope of preventive efforts and their utility as diagnostic tools. The meta-regression confirmed increases in OHPAH concentrations after fire activities by up to 1.71-times (p-values: <0.0001). Samples collected at a time point of 2−4 h after a fire suppression showed a consistent, statistically significant pattern as compared with baseline samples. The National Fire Protection Association (NFPA) standard 1582 Standard on Comprehensive Occupational Medical Program for Fire Departments lists various health examinations, including a urinalysis for occupational chemical exposure if indicated and medical screening for cancers and cardiovascular diseases. Biomonitoring is a valuable screening tool for assessing occupational exposure and the results of this meta-analysis support their inclusion in regular health screenings for firefighters.

Characterizing the Tensile Strength of the Fabrics Used in Firefighters' Bunker Gear under Radiant Heat Exposure.

More than 60,000 firefighters' injuries were reported by the National Fire Protection Association in the U.S. in 2019. Inadequate protection by bunker gear could be a reason for most of the injuries. Firefighters repeatedly encounter thermal hazards due to their job responsibilities. Degradation could occur on bunker gear fabric during thermal exposure. It has been found that the presence of moisture affects performance as well, which may come from wearers' sweat. Proper evaluation of the tensile strength of the fabrics used in bunker gear could provide information essential for maintenance the overall integrity of the gear. An evaluation of the tensile strength of fabrics when exposed to 10, 15, and 20 kW/m2 radiant heat flux in the presence of moisture is reported. In each fabric system, a total of sixty-four different samples were prepared for four different types of fabric and four levels of moisture which were exposed to three different radiant heat flux for five minutes. Heat flux and moisture levels have significant impact on tensile strength. The effect of moisture on tensile strength in a three-layered fabric system is higher than that for a single layer fabric. An understanding of the impact of heat and moisture on fabric strength has been achieved.

Using Artificial Neural Network Modeling to Analyze the Thermal Protective and Thermo-Physiological Comfort Performance of Textile Fabrics Used in Oilfield Workers' Clothing.

Most of the fatalities and injuries of oilfield workers result from inadequate protection and comfort by their clothing under various work hazards and ambient environments. Both the thermal protective performance and thermo-physiological comfort performance of textile fabrics used in clothing significantly contribute to the mitigation of workers' skin burns and heat-stress-related deaths. This study aimed to apply the ANN modeling approach to analyze clothing performance considering the wearers' sweat moisture and the microclimate air gap that is generated in between their body and clothing. Firstly, thermal protective and thermo-physiological comfort performance of fire protective textiles used in oilfield workers' clothing were characterized. Different fabric properties (e.g., thickness, weight, fabric count), thermal protective performance, and thermo-physiological comfort performance were measured. The key fabric property that affects thermal protective and thermo-physiological performance was identified as thickness by statistical analysis. The ANN modeling approach could be successfully implemented to analyze the performance of fabrics in order to predict the performance more conveniently based on the fabric properties. It is expected that the developed models could inform on-duty oilfield workers about protective and thermo-physiological comfort performance and provide them with occupational health and safety.

Characterization and Modeling of Thermal Protective and Thermo-Physiological Comfort Performance of Polymeric Textile Materials-A Review.

In 2017, more than 60,000 firefighters and oilfield-workers injuries and fatalities occurred while they were working under various thermal hazards such as flame, radiant heat, steam, etc., or due to their significant heat stress related discomfort. The majority of these burn injuries and fatalities results from an inadequate protection and comfort provided by firefighters' and oilfield-workers' fire protective polymeric textile materials used in their workwear. Hence, both the thermal protective and thermo-physiological comfort performance of fabrics used in workwear significantly contribute to limit firefighters' and oilfield-workers' skin burns and heat stress. Considering this, previous studies have focused on characterizing and developing empirical models to predict the protective and comfort performance based on physical properties of the fabrics. However, there are still some technical knowledge gaps in the existing literature related to this. This paper critically reviewed the literature on characterization and modeling of thermal protective and thermo-physiological comfort performance of fire protective textile fabric materials. The key issues in this field have been indicated in order to provide direction for the future research and advance this scientific field for better protection and comfort of the firefighters and oilfield-workers.

Health Risks of Structural Firefighters from Exposure to Polycyclic Aromatic Hydrocarbons: A Systematic Review and Meta-Analysis.

Firefighters have an elevated risk of cancer, which is suspected to be caused by occupational and environmental exposure to fire smoke. Among many substances from fire smoke contaminants, one potential source of toxic exposure is polycyclic aromatic hydrocarbons (PAH). The goal of this paper is to identify the association between PAH exposure levels and contributing risk factors to derive best estimates of the effects of exposure on structural firefighters' working environment in fire. We surveyed four databases (Embase, Medline, Scopus, and Web of Science) for this systematic literature review. Generic inverse variance method for random effects meta-analysis was applied for two exposure routes-dermal and inhalation. In dermal, the neck showed the highest dermal exposure increased after the fire activity. In inhalation, the meta-regression confirmed statistically significant increases in PAH concentrations for longer durations. We also summarized the scientific knowledge on occupational exposures to PAH in fire suppression activities. More research into uncontrolled emergency fires is needed with regard to newer chemical classes of fire smoke retardant and occupational exposure pathways. Evidence-based PAH exposure assessments are critical for determining exposure-dose relationships in large epidemiological studies of occupational risk factors.

An Instrument for the Determination of a Hydropneumograph in a Bubbling Spring.

In order to enable greater accuracy in the determination of the mass discharge of gas and water-gas ratios (WGR) in groundwater from springs, we have developed a field-deployable instrument using commercially available components to independently measure the gas and water mass flow rates in springs with bubbling mixed-phase flow. Collecting and measuring the free gas phase will allow for further compositional analysis that may be useful in improving gas-derived parameters such as recharge temperature and age, as well as quantification of methanogenesis and flux of crustal/mantle gasses. By installing a phase separator at the spring discharge, a thermal mass flow sensor is utilized to measure the gas flow rate (ebullition + flux) generated from a spring. The water flow rate is determined by a standard weir. Field performance of the device was tested on a spring discharging from the Arbuckle-Simpson aquifer near the town of Connerville in south-central Oklahoma, USA.

Why Springs Bubble: A Framework for Gas Discharge in Groundwater.

The mechanisms leading to the formation of bubbles in springs and wells have received minimal attention beyond causation. Free-phase gas quantification provides insight into a range of topics, from hazards that need to be managed to the economic value of soda waters. The presence of free-phase gas or vapor bubbles in groundwater may provide valuable information about the subsurface flow system. Additionally, free-phase gas or vapor bubbles may strip dissolved gasses from solution and introduce error into the assessment of gasses in springs, affecting analyses such as groundwater dating techniques. Similar to Meinzer's (1927) classification of springs by discharge rate, this paper proposes a framework for discussing free-phase gas and bubble phenomenon in groundwater to organize literature and foster future research. The naming, description, and categorization of free-phase gas or bubbles in groundwater provided in this review use seven common bubble manifestations or facies. These facies are based upon the processes in which the groundwater is charged with a gaseous species and the processes that bring the gas out of solution. Gas bubbles found in groundwater rarely occur as a single gas; therefore, these facies may overlap, but the proposed structure provides a useful framework. A glossary of bubble terms is provided to assist in clarity of describing free-phase gas phenomena.