Heat strain in professional firefighters: physiological responses to a simulated smoke dive in extremely hot environments and the subsequent recovery phase

Firefighters risk heat strain during occupational tasks when exposed to extremely hot environmental conditions and performing high-intensity work. Relevant training scenarios are therefore essential. This study investigated the effect of a single simulated smoke dive and the following recovery phase on physiological and perceptual responses. Nineteen professional male firefighters (43 ± 8 yr) performed a 2-min stair walk and a15-min simulated smoke dive in a two-floor heat chamber (110 °C to 272°C) (HEAT), followed by a 5-min stair walk outside the heat chamber. Heart rate (HR), gastrointestinal temperature (Tgi) and skin temperatures were registered continuously during the test. The Tgi increased significantly from the start (37.5 ± 0.3°C) to the end of HEAT (38.4 ± 0.4°C) and further increased after the heat exposure (39.6 ± 0.5°C).The HR also increased significantly from the start (92 ± 14 bpm) to the end of HEAT (185 ± 13 bpm) and increased after the heat exposure to a maximum of 190 ± 13 bpm. The simulated smoke dive induced high physiological strain on the firefighters, and the increase in Tgi and HR after the hot exposure must be considered during live fire events when repeated smoke dives are required.

Advances of polyolefins from fiber to nanofiber: fabrication and recent applications

Polyolefins are a widely accepted commodity polymer made from olefinic monomer consisting of carbon and hydrogen. This thermoplastic polymeric material is formed through reactive double bonds of olefins by the addition polymerization technique and it possesses a diverse range of unique features for a large variety of applications. Among the various types, polyethylene and polypropylene are the prominent classes of polyolefins that can be crafted and manipulated into diversified products for numerous applications. Research on polyolefins has boomed tremendously in recent times owing to the abundance of raw materials, low cost, lightweight, high chemical resistance, diverse functionalities, and outstanding physical characteristics. Polyolefins have also evidenced their potentiality as a fiber in micro to nanoscale and emerged as a fascinating material for widespread high-performance use. This review aims to provide an elucidation of the breakthroughs in polyolefins, namely as fibers, filaments, and yarns, and their applications in many domains such as medicine, body armor, and load-bearing industries. Moreover, the development of electrospun polyolefin nanofibers employing cutting-edge techniques and their prospective utilization in filtration, biomedical engineering, protective textiles, and lithium-ion batteries has been illustrated meticulously. Besides, this review delineates the challenges associated with the formation of polyolefin nanofiber using different techniques and critically analyzes overcoming the difficulties in forming functional nanofibers for the innovative field of applications.

Water-blocking Asphyxia of N95 Medical Respirator During Hot Environment Work Tasks With Whole-body Enclosed Anti-bioaerosol Suit

Background

During hot environment work tasks with whole-body enclosed anti-bioaerosol suit, the combined effect of heavy sweating and exhaled hot humid air may cause the N95 medical respirator to saturate with water/sweat (i.e., water-blocking).

Methods

32 young male subjects with different body mass indexes (BMI) in whole-body protection (N95 medical respirator + one-piece protective suit + head covering + protective face screen + gloves + shoe covers) were asked to simulate waste collecting from each isolated room in a seven-story building at 27-28°C, and the weight, inhalation resistance (Rf), and aerosol penetration of the respirator before worn and after water-blocking were analyzed.

Results

All subjects reported water-blocking asphyxia of the N95 respirators within 36-67 min of the task. When water-blocking occurred, the Rf and 10-200 nm total aerosol penetration (Pt) of the respirators reached up to 1270-1810 Pa and 17.3-23.3%, respectively, which were 10 and 8 times of that before wearing. The most penetration particle size of the respirators increased from 49-65 nm before worn to 115-154 nm under water-blocking condition, and the corresponding maximum size-dependent aerosol penetration increased from 2.5-3.5% to 20-27%. With the increase of BMI, the water-blocking occurrence time firstly increased then reduced, while the Rf, Pt, and absorbed water all increased significantly.

Conclusions

This study reveals respirator water-blocking and its serious negative impacts on respiratory protection. When performing moderate-to-high-load tasks with whole-body protection in a hot environment, it is recommended that respirator be replaced with a new one at least every hour to avoid water-blocking asphyxia.

Impact of surface tension on the barrier performance of gowns and coveralls

BACKGROUND

Health care workers and laboratory workers who are routinely exposed to potentially life-threatening infectious diseases should wear protective clothing when anticipating contact with infectious materials. The most critical property of protective clothing is its ability to prevent liquids and viruses from passing through the garment. There are a number of potentially infectious liquids that workers may be exposed to during routine tasks. Each liquid has different physical and chemical properties that affect penetration. However, the current test methods use a limited number of liquids for classifying the barrier performance. The impact of the surface tension of the challenge liquid on the penetration resistance of gowns and coveralls was investigated in this study.

METHODS

Eight isolation gowns and 2 coveralls were tested in accordance with American Association of Textile Chemists and Colorists 42 and American Association of Textile Chemists and Colorists 127 test methods, which were modified to incorporate the substitute challenge liquids.

RESULTS

Although current standard test methods only use water to categorize the liquid penetration resistance of minimal to moderate barrier performance gowns, a significant difference in the penetration was found when simulated body fluids were used.

CONCLUSIONS

The results suggest that safety professionals and wearers should consider the varying barrier performance of personal protective equipment with different liquids and the use limitations when selecting them for the required tasks. Furthermore, standard development organizations should consider multiple challenge liquids when classifying protective clothing for health care settings.

Evaluation of the physical performance of disposable isolation gowns

BACKGROUND

The threat of emerging infectious diseases has highlighted the need for effective gowns to protect health care workers and patients. Although studies identified end user issues with the physical performance of gowns, the literature that evaluates the performance is scarce. This paper represents 1 of the first efforts to investigate the physical performance of a substantial set of isolation gown models in the marketplace.

METHODS

Physical performance of 20 commercial and 2 experimental disposable isolation gowns was evaluated in this study. Standard test methods were used to investigate a range of properties, including thickness, weight, tensile strength, tearing strength, and seam strength.

RESULTS

In general, due to the differences in the fibers and methods used for the construction, large variations in the tensile, tear, and seam strength results were found. When the gowns were compared to their respective Association for the Advancement of Medical Instrumentation PB70 protection levels, no clear trend was found between protection levels and tear strength or between protection levels and seam strength, while there was a linear relationship between gowns' Association for the Advancement of Medical Instrumentation PB70 levels and their tensile strength. It was found that fabric construction significantly affects the physical performance of gowns.

CONCLUSIONS

Based on this work, a new standard, American Society of Testing and Materials International F3352, was published and has been recognized by the Food and Drug Administration. American Society of Testing and Materials International F3352 is expected to help end users in selecting the appropriate protective clothing.

Evaluation of fluid leakage at the coverall and glove interface in single and double glove conditions

BACKGROUND

Fluid leakage through the glove-protective clothing interface is an area of concern for many health care personnel, including emergency medical service providers, who may wear coveralls to protect themselves from multiple types of hazards. There is currently no established standard test method to specifically evaluate the barrier performance of the glove-protective clothing interface region for any personal protective equipment ensemble.

OBJECTIVE

This study quantifies the fluid leakage at the coverall and glove interface using single and double gloving.

METHODS

A robotic arm, which can simulate upper extremity movements of health care personnel, was used to test 5 coverall models and an extended examination glove model in single and double glove conditions.

RESULTS

The results show that there was a significant difference in fluid leakage amounts between some of the coverall models and the number of glove layers studied. Findings also highlight that there is a high correlation between basis weight and stiffness of the coverall fabrics and the fluid leakage amounts.

CONCLUSIONS

These results underline that coverall constructed from thin and less stiff fabrics can result in lower fluid leakage levels. Also, there was no significant difference in fluid leakage amounts between single and double gloves when tested with each of the coverall models, with the exception of the coveralls with the highest basis weight and stiffness.

A review of test methods for evaluating mobility of firefighters wearing personal protective equipment

This review aimed to suggest useful, potential measurements as standard test methods for evaluating the mobility of structural firefighters wearing personal protective equipment (PPE). Based on our previous research on Japanese firefighters' activities related to mobility as well as previous literature results, the findings were categorized (e.g., simulated firefighting activities, test method for mobility assessment, and participants groups), and discussed. We identified four categories that can be used to test and evaluate mobility: (1) simulated firefighting activities consisting of step-ups, obstacle strides, crawling, dragging, and jumping; (2) in terms of balance ability, the postural sway and functional balance tests (functional reach and timed up and go) were useful measurements; (3) range of motion can be used to estimate the mobility associated with the various designs of PPE, as well as the effect of wearing the PPE itself; and (4) subjective evaluations of individuals wearing PPE were available for the mobility assessments. Professional firefighters who were familiar with wearing PPE were suitable for the suggested test method. This review provides useful information for firefighters, researchers, and PPE manufacturers that can be used to develop more comfortable and safer PPE.

Coronavirus disease 2019 and radiation oncology-survey on the impact of the severe acute respiratory syndrome coronavirus 2 pandemic on health care professionals in radiation oncology

Background

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic has changed the lives of most humans worldwide. The aim of this study was to evaluate the impact of the SARS-CoV‑2 pandemic on health care professionals (HCPs) in radiation oncology facilities.

Methods

We distributed an online survey to HCPs in radiation oncology (physicians, medical physics experts, radiology assistants/radiation therapists, nurses, and administrative personnel). The survey was completed by 334 participants between May 23 and June 9, 2020.

Results

In 66.2% of the cases, HCPs reported a shortage of protective clothing. The protective measures were regarded as very reasonable by 47.4%, while 0.8% regarded them as not reasonable (rather reasonable: 44.0%; less reasonable 7.8%). 29.0% of the participants had children who needed care. The most frequently used care options were public emergency childcare (36.1%) and private childcare (e.g. relatives/friends). HCPs reported about additional work burden (fully agreed: 27.2%, rather agreed: 34.4%, less agreed: 28.2%, not agreed: 10.2%), and reduced work satisfaction (fully agreed: 11.7%, rather agreed: 29.6%, less agreed: 39.8%, not agreed: 18.9%). 12.9% and 29.0% of the participants were fully or rather mentally strained (less mentally strained: 44.0%, not mentally strained: 14.1%).

Conclusion

We must learn from this pandemic how to prepare for further outbreaks and similar conditions. This includes the vast availability of protective clothing and efficient tracing of infection chains among the HCPs, but also secured childcare programs and experienced mental health support are crucial. Further, work satisfaction and appreciation by employers is essential.

Supplementary Information

The online version of this article (10.1007/s00066-022-01903-8) contains supplementary material, which is available to authorized users.

A simulation study to assess fluid leakage through the glove-gown interface in isolation settings

BACKGROUND

Isolation gowns are recommended to protect healthcare personnel, patients, and visitors from transfer of microorganisms and body fluids in patient isolation situations. Standards provide limited information about barrier performance of isolation gowns for possible exposure scenarios. One of the most vulnerable areas of the personal protective equipment ensemble is considered the glove-gown interface. However, current isolation gown classification standards do not consider the interface regions of the personal protective equipment system while assessing the level of protection. The purpose of this study was to quantitatively evaluate the fluid leakage through the glove-gown interface by simulating exposures and healthcare personnel arm movements in patient care for isolation settings.

METHODS

We tested fluid leakage of two examination gloves with different cuff lengths and seven isolation gown models designed with varying levels of barrier resistance and multiple cuff types.

RESULTS

Our results demonstrated that leakage through the glove-gown interface depends on multiple factors, including glove cuff length and gown cuff design. Gowns with the thumb loop design provided better protection than the elastic cuff design, and the elastic cuff design provided better protection compared to the knit cuff design for a given AAMI PB70 level. More importantly, a substantial penetration through gown fabrics was observed.

CONCLUSIONS

This research identifies a need to develop a standardized method to evaluate leakage at the glove-gown interface to improve worker protection.

Validation of ISO 9920 clothing item insulation summation method based on an ambulance personnel clothing system

This study aimed to validate the summation methods suggested by ISO 9920. Twenty seven items from an ambulance personnel clothing system were selected for testing. The basic insulation of each garment item (I_clu) was calculated based on the thermal manikin tests. More than 100 realistic clothing combinations were compiled and basic insulation (I_cl) of these ensembles was calculated according to ISO 9920. These were ranked after the calculated insulation, and 14 sets covering insulation from 0.63 to 3.33 clo were measured on the thermal manikin for acquiring the basic clothing insulation (I_cl). Regression analysis was used to compare the summed and measured I_cl values. The difference between values varied from -18 to 12%. The highest percentual difference was for the lightest clothing sets, while the absolute differences were similar over the whole insulation range ranging between -0.17 to 0.18 clo with an average difference of 0.02 clo (-0.16%). All basic insulation values stayed very close to the line of identity (R²=0.98). The summation equation gave, in the case of this ambulance clothing system, very close results to the measured values. This encourages evaluating and selecting protective clothing combinations for thermal comfort based on individual item measurements.

Physiological interactions with personal-protective clothing, physically demanding work and global warming: An Asia-Pacific perspective

The Asia-Pacific contains over half of the world's population, 21 countries have a Gross Domestic Product <25% of the world's largest economy, many countries have tropical climates and all suffer the impact of global warming. That 'perfect storm' exacerbates the risk of occupational heat illness, yet first responders must perform physically demanding work wearing personal-protective clothing and equipment. Unfortunately, the Eurocentric emphasis of past research has sometimes reduced its applicability to other ethnic groups. To redress that imbalance, relevant contemporary research has been reviewed, to which has been added information applicable to people of Asian, Melanesian and Polynesian ancestry. An epidemiological triad is used to identify the causal agents and host factors of work intolerance within hot-humid climates, commencing with the size dependency of resting metabolism and heat production accompanying load carriage, followed by a progression from the impact of single-layered clothing through to encapsulating ensembles. A morphological hypothesis is presented to account for inter-individual differences in heat production and heat loss, which seems to explain apparent ethnic- and gender-related differences in thermoregulation, at least within thermally compensable states. The mechanisms underlying work intolerance, cardiovascular insufficiency and heat illness are reviewed, along with epidemiological data from the Asia-Pacific. Finally, evidence-based preventative and treatment strategies are presented and updated concerning moisture-management fabrics and barriers, dehydration, pre- and post-exercise cooling, and heat adaptation. An extensive reference list is provided, with >25 recommendations enabling physiologists, occupational health specialists, policy makers, purchasing officers and manufacturers to rapidly extract interpretative outcomes pertinent to the Asia-Pacific.

Monitoring heat strain: the effect of sensor type and location on single-site and mean skin temperature during work in the heat

PURPOSE

Elevations in skin temperature and heat strain reduce tolerance to work in the heat. This study assessed agreement between mean (eight sites) and single-site skin temperature, measured by a conductive or infrared sensor, during exercise in the heat.

METHODS

Twelve males (age: 24.2 ± 3.7 years; height: 180 ± 6.5 cm; body mass: 82.9 ± 9.5 kg; body fat: 16.0 ± 6.5%) volunteered to participate in two trials. Thirty minutes of seated rest was followed by 60 min of treadmill walking (4.5 km·h^-1, 1%) inside an environmental chamber (35.5 ± 0.2 °C dry bulb, 50.7 ± 2.5% relative humidity) wearing either an athletic (ATH: t-shirt, shorts, shoes) or a chemical protective ensemble (CPE: ATH plus coverall and respirator). Skin temperature was measured on the axilla with a conductive sensor (T_sk-C) and an infrared sensor (T_sk-I) and compared to mean skin temperature ([Formula: see text] 8-site conductive sensors). Rectal temperature and heart rate were measured and used to calculate the adaptive physiological strain index (aPSI).

RESULTS

Skin temperature on the chest, scapula, and thigh showed acceptable agreement with [Formula: see text] (mean difference < 0.5 °C and limits of agreement ± 1.0 °C) in both ATH and CPE. Skin temperature on the axilla overestimated [Formula: see text] in ATH (T_sk-C: 1.5 ± 0.8 °C; T_sk-I: 2.2 ± 1.2 °C) and CPE (T_sk-C: 1.1 ± 0.9 °C; T_sk-I: 1.8 ± 1.1 °C). Significant differences (p < 0.001) were observed in aPSI using T_sk-I (ATH: 5.7 ± 1.0, CPE: 8.3 ± 1.1) and T_sk-C (ATH: 5.4 ± 1.0, CPE 7.8 ± 1.0) compared to [Formula: see text] (ATH: 5.2 ± 1.0, CPE: 7.4 ± 1.0).

CONCLUSION

The overestimate of mean skin temperature had a significant influence on the aPSI, which has important implications for real-time monitoring and risk management of personnel working in hot environments.

Establishment of the key Technical Indicators of Positive Pressure Biological Protective Clothing

Objective

Trying to establish the key technical indicators related to positive pressure biological protective clothing (PPBPC), providing technical support for the establishment of PPBPC standards in the future.

Method

We examined the protection standard systems established by the major standards organizations in China and other developed countries. We also analyzed the technical indicators of the gas-tight chemical protective clothing and ventilated protective clothing against particulate radioactive contamination which closely related to PPBPC. And tested the performance of a set of imported dual-purpose PPBPC to verify the fit of its technical indicators with the standards. We aimed to identify the status of China’s standards in the area of personnel protection and put forward feasible suggestions for the production of PPBPC in China.

Results

Developed countries in Europe and North America have a complete system of standard protective clothing. China should also strengthen the construction of standard protective clothing, especially PPBPC.

Conclusion

With the improvements in infectious disease prevention and control on a global scale, the demand for PPBPC continues to increase and consideration should be given to the establishment of standards for this.

Could wearing motorcycle protective clothing compromise rider safety in hot weather?

Motorcycle protective clothing (PPE) effectively reduces the risk of injury in crashes, however in hot conditions many motorcyclists ride unprotected. Recent work found available motorcycle PPE to be thermally inefficient in hot weather with potential to cause significant thermal strain under average Australian summer conditions. The current study investigated the potential for the cognitive and psychophysical concomitants of thermal strain to compromise reaction times, mood and fatigue with potential consequences for motorcyclists' safety.

METHOD

Volunteers wearing motorcycle PPE participated in a 90 min trial (cycling 30 W) in 35 °C, 40%RH with overhead radiant heaters and a fan to simulate wind speed. Heart rate, core and skin temperature were recorded continuously. Reaction time and subjective ratings of thermal sensation and comfort, workload and mood were recorded at baseline, during rest breaks at 25 min intervals and on completion of the trail. Repeated measures analysis assessed each participant's performance against their own baseline.

RESULTS

Core temperatures increased by 2 °C (p < .0001), skin temperatures (3 °C, (p < .0001) and heart rates (66bpm, p < .0001). Reaction times fluctuated 36 ms 8% (p < .0001) over the trial. Subjective workload increased 68% (p = 0.001) and mood deteriorated 33 points (p < .0001) including feeling less alert (p = <.0001), contented (p = 0.001) and calm (p = 0.0004). Multivariate repeated measures analysis found significant associations between core temperature and workload (p = 0.01), mood (p = 0.001) and reaction time (<.0001). Skin temperature and workload (p = 0.02), mood (p = 0.01) and reaction time (<.0001). Subjective ratings of temperature sensation and wetness discomfort were associated respectively with increased workload (p = 0.0001, p = 0.004), mood change (p < .0001, p = 0.04) and reaction time (p < .0001, p < .0001).

CONCLUSIONS

The physiological impact of wearing thermally inefficient motorcycle PPE in hot conditions could impair motorcyclists cognitive and psychophysical functioning and, potentially, their riding performance and safety. These outcomes indicate an urgent need for manufacturers to develop motorcycle PPE that is effective and suitable for use, in hot conditions.

Validity of a noninvasive estimation of deep body temperature when wearing personal protective equipment during exercise and recovery

BACKGROUND

Deep body temperature is a critical indicator of heat strain. However, direct measures are often invasive, costly, and difficult to implement in the field. This study assessed the agreement between deep body temperature estimated from heart rate and that measured directly during repeated work bouts while wearing explosive ordnance disposal (EOD) protective clothing and during recovery.

METHODS

Eight males completed three work and recovery periods across two separate days. Work consisted of treadmill walking on a 1% incline at 2.5, 4.0, or 5.5 km/h, in a random order, wearing EOD protective clothing. Ambient temperature and relative humidity were maintained at 24 °C and 50% [Wet bulb globe temperature (WBGT) (20.9 ± 1.2) °C] or 32 °C and 60% [WBGT (29.0 ± 0.2) °C] on the separate days, respectively. Heart rate and gastrointestinal temperature (T_GI) were monitored continuously, and deep body temperature was also estimated from heart rate (ECTemp).

RESULTS

The overall systematic bias between T_GI and ECTemp was 0.01 °C with 95% limits of agreement (LoA) of ±0.64 °C and a root mean square error of 0.32 °C. The average error statistics among participants showed no significant differences in error between the exercise and recovery periods or the environmental conditions. At T_GI levels of (37.0-37.5) °C, (37.5-38.0) °C, (38.0-38.5) °C, and > 38.5 °C, the systematic bias and ± 95% LoA were (0.08 ± 0.58) °C, (- 0.02 ± 0.69) °C, (- 0.07 ± 0.63) °C, and (- 0.32 ± 0.56) °C, respectively.

CONCLUSIONS

The findings demonstrate acceptable validity of the ECTemp up to 38.5 °C. Conducting work within an ECTemp limit of 38.4 °C, in conditions similar to the present study, would protect the majority of personnel from an excessive elevation in deep body temperature (> 39.0 °C).

Design considerations for low-level risk personal protective clothing: a review

Personal protective clothing (PPC) is mandatory in hazardous industrial workplaces, but can increase thermophysiological strain, causing fatigue, reduced productivity, illness and injury. We systematically reviewed the literature on PPC and heat stress, focusing on research relating to working conditions of high temperature and humidity. PPC must protect industrial workers from a wide variety of hazards, including sun damage, abrasion, chemical spills and electrical burns; these competing demands inevitably compromise thermal performance. Fiber type, textile material construction and treatment need to be considered alongside garment fit and construction to design functional PPC providing wearers with adequate protection and comfort. Several approaches to materials and PPC testing-objective benchtop evaluation, mathematical modelling, and physiological testing-can be combined to provide high-quality thermal and vapor performance data. Our review provides a foundation and directions for further research in low-level risk PPC, where current research in fabrics and clothing in this category is very limited, and will help designers and manufacturers create industrial workwear with improved thermal management characteristics.

Lightweight Lead Aprons: The Emperor's New Clothes in the Angiography Suite?

OBJECTIVE

The aim was to determine whether lead containing and lead free composite garments in current use provide the level of radiation protection stated by manufacturers.

METHODS

Fifteen garments, produced by five different manufacturers using eight different composites, were randomly selected for testing from four hospitals in South Australia. Labelling, material composition, design, and condition of the garments were assessed by direct garment examination, garment label, and product information. Garment attenuation was tested in a simulated angiography suite using a Siemens Ysio Max digital Xray machine. The front and back panels of each garment were tested under direct beam at 100 kVp. A Perspex phantom was used to simulate the density and scatter properties of the human abdomen. The front panels of each garment were tested under scattered radiation at Xray tube voltages of 50 and 70 kVp.

RESULTS

Forty-seven per cent of front panels and 90% of back panels provided lower lead equivalence than claimed by the manufacturer. Twenty per cent of front panels and 62% of back panels tested did not meet the minimum International Electrotechnical Commission requirements for angiographic use. There was a 38 fold difference in front panel performance of garments to scatter radiation, which were all labelled 0.5 mm lead equivalence. 56% of garments had differences in scatter transmission of at least 49% when tested at 50 and 70 kVp.

CONCLUSION

The results show that lead containing and lead free composite garments probably provide less radiation protection than manufacturer stated lead equivalence. The demonstrated wide variations in attenuation of scatter radiation are greater than previously reported. It was found that most garments failed to comply with labelling standards. The study highlights challenges in radiation shielding and the need to identify composites that consistently provide better attenuation per unit weight than lead.

Effectiveness of a new radiation protection system in the interventional radiology setting

OBJECTIVES

The goal of this study was to examine a new weightless-like radiation protection garment regarding its radiation protection efficacy and to compare it to a conventional two-piece apron suit plus thyroid collar and standard ancillary shields.

MATERIAL AND METHODS

All measurements were carried out using a clinical angiography system with a standardized fluoroscopy protocol for different C-arm angulations. An anthropomorphic torso phantom served as a scattering body. In addition, an ionization chamber was used to measure the radiation exposure on five different representative heights and at two different positions of an examiner during a typical fluoroscopic-guided intervention.

RESULTS

The new weightless-like radiation protection garment and the conventional protection concept showed a mean dose reduction of 98.1% (p < 0.01) and 90.1% (p < 0.01) when compared to no shielding, respectively. By adding ancillary shields to both systems, an average reduction of 99.0% (p < 0.01) and 98.2% (p < 0.01) was found. In addition, the efficacy of both systems varied depending on the height, the C-arm angulation and position of the examiner.

CONCLUSION

Combined with ancillary shields as an overall protection system, the recently introduced weightless-like radiation protection garment showed a significant better radiation protection efficacy when compared to conventional radiation protection measures.

Influence of work clothing on physiological responses and performance during treadmill exercise and the Wildland Firefighter Pack Test

This study investigated physiological responses and performance during three separate exercise challenges (Parts I, II, and III) with wildland firefighting work clothing ensemble (boots and coveralls) and a 20.4 kg backpack in four conditions: U-EX (no pack, exercise clothing); L-EX (pack, exercise clothing); U-W (no pack, work clothing); and, L-W (pack and work clothing). Part I consisted of randomly-ordered graded exercise tests, on separate days, in U-EX, L-EX and L-W conditions. Part II consisted of randomly-ordered bouts of sub-maximal treadmill exercise in the four conditions. In Part III, subjects completed, in random-order on separate days, 4.83 km Pack Tests in L-EX or L-W conditions. In Part I, peak oxygen uptake was reduced (p < .05) in L-W. In Part II, mass-specific oxygen uptake was significantly higher in both work clothing conditions. In Part III, Pack Test time was slower (p < .05) in L-W. These results demonstrate the negative impact of work clothing and load carriage on physiological responses to exercise and performance.

Expansion of effective wet bulb globe temperature for vapor impermeable protective clothing

The wet bulb globe temperature (WBGT) is an effective measure for risk screening to prevent heat dISOrders. However, a heat risk evaluation by WBGT requires adjustments depending on the clothing. In this study, we proposed a new effective WBGT (WBGT_eff^*) for general vapor permeable clothing ensembles and vapor impermeable protective clothing that is applicable to occupants engaged in moderate intensity work with a metabolic heat production value of around 174W/m². WBGT_eff^* enables the conversion of heat stress into the scale experienced by the occupant dressed in the basic clothing ensemble (work clothes) based on the heat balances for a human body. We confirmed that WBGT_eff^* was effective for expressing the critical thermal environments for the prescriptive zones for occupants wearing vapor impermeable protective clothing. Based on WBGT_eff^*, we succeeded in clarifying how the weights for natural wet bulb, globe, and air temperatures and the intercept changed depending on clothing properties and the surrounding environmental factors when heat stress is expressed by the weighted sum of natural wet bulb, globe, and air temperatures and the intercept. The weight of environmental temperatures (globe and air temperatures) for WBGT_eff^* for vapor impermeable protective clothing increased compared with that for general vapor permeable clothing, whereas that of the natural wet bulb temperature decreased. For WBGT_eff^* in outdoor conditions with a solar load, the weighting ratio of globe temperature increased and that of air temperature decreased with air velocity. Approximation equations of WBGT_eff^* were proposed for both general vapor permeable clothing ensembles and for vapor impermeable protective clothing.

An integrated approach to develop, validate and operate thermo-physiological human simulator for the development of protective clothing

Following the growing interest in the further development of manikins to simulate human thermal behaviour more adequately, thermo-physiological human simulators have been developed by coupling a thermal sweating manikin with a thermo-physiology model. Despite their availability and obvious advantages, the number of studies involving these devices is only marginal, which plausibly results from the high complexity of the development and evaluation process and need of multi-disciplinary expertise. The aim of this paper is to present an integrated approach to develop, validate and operate such devices including technical challenges and limitations of thermo-physiological human simulators, their application and measurement protocol, strategy for setting test scenarios, and the comparison to standard methods and human studies including details which have not been published so far. A physical manikin controlled by a human thermoregulation model overcame the limitations of mathematical clothing models and provided a complementary method to investigate thermal interactions between the human body, protective clothing, and its environment. The opportunities of these devices include not only realistic assessment of protective clothing assemblies and equipment but also potential application in many research fields ranging from biometeorology, automotive industry, environmental engineering, and urban climate to clinical and safety applications.

Maximum allowable exposure to different heat radiation levels in three types of heat protective clothing

To determine safe working conditions in emergency situations at petro-chemical plants in the Netherlands a study was performed on three protective clothing combinations (operator's, firefighter's and aluminized). The clothing was evaluated at four different heat radiation levels (3.0, 4.6, 6.3 and 10.0 k∙W∙m^-2) in standing and walking posture with a thermal manikin RadMan™. Time till pain threshold (43°C) is set as a cut-off criterion for regular activities. Operator's clothing did not fulfil requirements to serve as protective clothing for necessary activities at heat radiation levels above 1.5 k∙W∙m^-2 as was stated earlier by Den Hartog and Heus¹⁾. With firefighter's clothing it was possible to work almost three min up to 4.6 k∙W∙m^-2. At higher heat radiation levels firefighter's clothing gave insufficient protection and aluminized clothing should be used. Maximum working times in aluminized clothing at 6.3 k∙W∙m^-2 was about five min. At levels of 10.0 k∙W∙m^-2 (emergency conditions) emergency responders should move immediately to lower heat radiation levels.

Thermal comfort sustained by cold protective clothing in Arctic open-pit mining-a thermal manikin and questionnaire study

Workers in the Arctic open-pit mines are exposed to harsh weather conditions. Employers are required to provide protective clothing for workers. This can be the outer layer, but sometimes also inner or middle layers are provided. This study aimed to determine how Arctic open-pit miners protect themselves against cold and the sufficiency, and the selection criteria of the garments. Workers' cold experiences and the clothing in four Arctic open-pit mines in Finland, Sweden, Norway and Russia were evaluated by a questionnaire (n=1,323). Basic thermal insulation (I_cl) of the reported clothing was estimated (ISO 9920). The I_cl of clothing from the mines were also measured by thermal manikin (standing/walking) in 0.3 and 4.0 m/s wind. The questionnaire showed that the I_cl of the selected clothing was on average 1.2 and 1.5 clo in mild (-5 to +5°C) and dry cold (-20 to -10°C) conditions, respectively. The I_cl of the clothing measured by thermal manikin was 1.9-2.3 clo. The results show that the Arctic open-pit miners' selected their clothing based on occupational (time outdoors), environmental (temperature, wind, moisture) and individual factors (cold sensitivity, general health). However, the selected clothing was not sufficient to prevent cooling completely at ambient temperatures below -10°C.

A user-centred design process of new cold-protective clothing for offshore petroleum workers operating in the Barents Sea

Petroleum operations in the Barents Sea require personal protective clothing (PPC) to ensure the safety and performance of the workers. This paper describes the accomplishment of a user-centred design process of new PPC for offshore workers operating in this area. The user-centred design process was accomplished by mixed-methods. Insights into user needs and context of use were established by group interviews and on-the-job observations during a field-trip. The design was developed based on these insights, and refined by user feedback and participatory design. The new PPC was evaluated via field-tests and cold climate chamber tests. The insight into user needs and context of use provided useful input to the design process and contributed to tailored solutions. Providing users with clothing prototypes facilitated participatory design and iterations of design refinement. The group interviews following the final field test showed consensus of enhanced user satisfaction compared to PPC in current use. The final cold chamber test indicated that the new PPC provides sufficient thermal protection during the 60 min of simulated work in a wind-chill temperature of -25°C.

CONCLUSION

Accomplishing a user-centred design process contributed to new PPC with enhanced user satisfaction and included relevant functional solutions.

Validation of the abrasion resistance test protocols and performance criteria of EN13595: The probability of soft tissue injury to motorcycle riders by abrasion resistance of their clothing

INTRODUCTION

Motorcyclists represent an increasing proportion of road users globally and are increasingly represented in crash statistics. Soft tissue injuries are the most common type of injuries to crashed motorcyclists. These injuries can be prevented through the use of protective clothing designed for motorcycle use. However, the quality of such clothing is not controlled in many countries around the world. A European Standard was developed to assess the performance of clothing but as this is not mandatory, clothing certified to this Standard is difficult to obtain. Given the importance of this Standard, and that it has been validated only once, further validation work is required.

METHODS

In-depth crash investigation data were used to investigate the relationship between the abrasion resistance performance of clothing and real-world injury outcome. Clothing was collected from riders who crashed on public roads in Sydney and Newcastle, Australia. This clothing was tested according to the EU Standard and the time to hole was recorded. Hospital medical records were reviewed and the association between a rider suffering a soft tissue injury and the time-to-hole for the garment was examined.

RESULTS

The probability of soft tissue injury for Level 1 Standard garments was between 40-60%, but more than 60% of garments tested failed to meet the minimum requirement.

CONCLUSIONS

The findings of this study provide qualified support for the Standard, with a marginal association between time-to-hole and injury being found.

PRACTICAL IMPLICATIONS

This work supports the need for improved safety performance and an increased number of high performing garments being available to motorcyclists.

Assessment of an active liquid cooling garment intended for use in a hot environment

This paper discusses the construction of a designed active liquid cooling garment (LCG) that has been developed in order to reduce thermal discomfort of persons working in hot environments. It consists of clothing with a tube system distributing a cooling liquid, a sensor measuring the microclimate under the clothing, and a portable cooling unit with a module controlling the temperature of the cooling liquid depending on the microclimate temperature under the clothing. The LCG was validated through tests on volunteers in a climatic chamber at 30 °C, a relative humidity of 40%, and an air movement rate of 0.4 m/s. The obtained test results confirmed the beneficial effects of the cooling system used on mean weighted skin temperature, the physical parameters of the microclimate under the clothing, and the participants' subjective assessments, as well as confirmed that the functioning of the control system regulating liquid temperature in the LCG was correct.

A systematic review on the effectiveness of back protectors for motorcyclists

Background

Motorcyclists are a vulnerable road-user population who are overrepresented in traffic injuries. Utilisation of back protectors may be an effective preventive measure for spine injuries in motorcyclists. Since use of back protectors is increasing it is important that clinical evidence supports their use. The study aimed to investigate the current evidence on the ability of back protectors to reduce the rate of back injuries and patient mortality in motorcycle crashes.

Methods

A systematic literature search was conducted using various electronic databases. Systematic reviews, randomised controlled trials, controlled clinical trials, cohort studies, case series and case reports were included Opinion pieces and laboratory or biomechanical studies were excluded. Back protectors and spine protectors were included as the intervention; neck braces and speed humps were excluded. The target outcomes were any injuries to the back or death. Only English language studies were included.

Results

The search strategy yielded 185 studies. After excluding 183 papers by title and abstract and full-text evaluation, only two small cross-sectional studies were included. Foam inserts in motorcycle jackets and non-standard clothing may possibly be associated with higher risk of injuries, while hard shell and standard back protectors may possibly be associated with a reduced rate of back and spinal injury.

Conclusion

This systematic review highlighted lack of appropriate evidence on efficacy of back protectors. Based on limited information, we are uncertain about the effects of back protectors on spinal injuries. Further research is required to substantiate the effects of back protectors on mortality and other injuries to the back.

Electronic supplementary material

The online version of this article (doi:10.1186/s13049-016-0307-3) contains supplementary material, which is available to authorized users.

Heat strain imposed by personal protective ensembles: quantitative analysis using a thermoregulation model

The objective of this paper is to study the effects of personal protective equipment (PPE) and specific PPE layers, defined as thermal/evaporative resistances and the mass, on heat strain during physical activity. A stepwise thermal manikin testing and modeling approach was used to analyze a PPE ensemble with four layers: uniform, ballistic protection, chemical protective clothing, and mask and gloves. The PPE was tested on a thermal manikin, starting with the uniform, then adding an additional layer in each step. Wearing PPE increases the metabolic rates [Formula: see text], thus [Formula: see text] were adjusted according to the mass of each of four configurations. A human thermoregulatory model was used to predict endurance time for each configuration at fixed [Formula: see text] and at its mass adjusted [Formula: see text]. Reductions in endurance time due to resistances, and due to mass, were separately determined using predicted results. Fractional contributions of PPE's thermal/evaporative resistances by layer show that the ballistic protection and the chemical protective clothing layers contribute about 20 %, respectively. Wearing the ballistic protection over the uniform reduced endurance time from 146 to 75 min, with 31 min of the decrement due to the additional resistances of the ballistic protection, and 40 min due to increased [Formula: see text] associated with the additional mass. Effects of mass on heat strain are of a similar magnitude relative to effects of increased resistances. Reducing resistances and mass can both significantly alleviate heat strain.

Isolation gowns in health care settings: Laboratory studies, regulations and standards, and potential barriers of gown selection and use

Although they play an important role in infection prevention and control, textile materials and personal protective equipment (PPE) used in health care settings are known to be one of the sources of cross-infection. Gowns are recommended to prevent transmission of infectious diseases in certain settings; however, laboratory and field studies have produced mixed results of their efficacy. PPE used in health care is regulated as either class I (low risk) or class II (intermediate risk) devices in the United States. Many organizations have published guidelines for the use of PPE, including isolation gowns, in health care settings. In addition, the Association for the Advancement of Medical Instrumentation published a guidance document on the selection of gowns and a classification standard on liquid barrier performance for both surgical and isolation gowns. However, there is currently no existing standard specific to isolation gowns that considers not only the barrier resistance but also a wide array of end user desired attributes. As a result, infection preventionists and purchasing agents face several difficulties in the selection process, and end users have limited or no information on the levels of protection provided by isolation gowns. Lack of knowledge about the performance of protective clothing used in health care became more apparent during the 2014 Ebola epidemic. This article reviews laboratory studies, regulations, guidelines and standards pertaining to isolation gowns, characterization problems, and other potential barriers of isolation gown selection and use.

Cyclists' clothing and reduced risk of injury in crashes

INTRODUCTION

A majority of cyclists' hospital presentations involve relatively minor soft tissue injuries. This study investigated the role of clothing in reducing the risk of cyclists' injuries in crashes.

METHODS

Adult cyclists were recruited and interviewed through hospital emergency departments in the Australian Capital Territory. This paper focuses on 202 who had crashed in transport related areas. Eligible participants were interviewed and their self-reported injuries corroborated with medical records. The association between clothing worn and injury was examined using logistic regression while controlling for potential confounders of injury.

RESULTS

A high proportion of participants were wearing helmets (89%) and full cover footwear (93%). Fewer wore long sleeved tops (43%), long pants (33%), full cover gloves (14%) or conspicuity aids (34%). The primary cause of injury for the majority of participants (76%) was impact with the ground. Increased likelihood of arm injuries (Adj. OR=2.06, 95%CI: 1.02-4.18, p=0.05) and leg injuries (Adj. OR=3.37, 95%CI: 1.42-7.96, p=0.01) were associated with wearing short rather than long sleeves and pants. Open footwear was associated with increased risk of foot or ankle injuries (Adj. OR=6.21, 95%CI: 1.58-23.56, p=0.01) compared to enclosed shoes. Bare hands were associated with increased likelihood of cuts, lacerations or abrasion injuries (Adj. OR=4.62, 95%CI: 1.23-17.43, p=0.02) compared to wearing full cover gloves. There were no significant differences by fabric types such as Lycra/synthetic, natural fiber or leather.

CONCLUSIONS

Clothing that fully covers a cyclist's body substantially reduced the risk of injuries in a crash. Coverage of skin was more important than fabric type. Further work is necessary to determine if targeted campaigns can improve cyclists' clothing choices and whether impact protection can further reduce injury risk.

A novel approach for fit analysis of thermal protective clothing using three-dimensional body scanning

The garment fit played an important role in protective performance, comfort and mobility. The purpose of this study is to quantify the air gap to quantitatively characterize a three-dimensional (3-D) garment fit using a 3-D body scanning technique. A method for processing of scanned data was developed to investigate the air gap size and distribution between the clothing and human body. The mesh model formed from nude and clothed body was aligned, superimposed and sectioned using Rapidform software. The air gap size and distribution over the body surface were analyzed. The total air volume was also calculated. The effects of fabric properties and garment size on air gap distribution were explored. The results indicated that average air gap of the fit clothing was around 25-30 mm and the overall air gap distribution was similar. The air gap was unevenly distributed over the body and it was strongly associated with the body parts, fabric properties and garment size. The research will help understand the overall clothing fit and its association with protection, thermal and movement comfort, and provide guidelines for clothing engineers to improve thermal performance and reduce physiological burden.

Validation of the principles of injury risk zones for motorcycle protective clothing

INTRODUCTION

The distributions of motorcycle crash impacts and injuries were compared to the four impact risk zones and protective performance specified in the European Standard for motorcycle clothing (EN 13595).

METHODS

Crashed motorcyclists' (n=117) injuries and clothing damage were categorized by body area into the four risk zones. Three levels of protection were defined: protective clothing with impact protection, protective clothing only and non-protective clothing.

RESULTS

The distribution of impact/injury sites corresponded to the predictions of EN 13595, with the proportion of all injuries decreasing from 43.9% in Zone 1, to 18.0%, 16.7%, and 11.5% in Zones 2 to 4, respectively. Protective clothing modified the distribution of injuries with substantially more injuries (OR=2.69, 95% CL: 20.1-3.59) at unprotected impact sites.

PRACTICAL APPLICATION

These findings support an appropriate framework for determining performance specifications for the manufacture of motorcycle clothing that will effectively reduce the risk of injury in crashes.

Quantitative assessment of the relationship between radiant heat exposure and protective performance of multilayer thermal protective clothing during dry and wet conditions

The beneficial effect of clothing on a person is important to the criteria for people exposure to radiant heat flux from fires. The thermal protective performance of multilayer thermal protective clothing exposed to low heat fluxes during dry and wet conditions was studied using two designed bench-scale test apparatus. The protective clothing with four fabric layers (outer shell, moisture barrier, thermal linear and inner layer) was exposed to six levels of thermal radiation (1, 2, 3, 5, 7 and 10kW/m(2)). Two kinds of the moisture barrier (PTFE and GoreTex) with different vapor permeability were compared. The outside and inside surface temperatures of each fabric layer were measured. The fitting analysis was used to quantitatively assess the relationship between the temperature of each layer during thermal exposure and the level of external heat flux. It is indicated that there is a linear correlation between the temperature of each layer and the radiant level. Therefore, a predicted equation is developed to calculate the thermal insulation of the multilayer clothing from the external heat flux. It can also provide some useful information on the beneficial effects of clothing for the exposure criteria of radiant heat flux from fire.

Effects of caffeine and menthol on cognition and mood during simulated firefighting in the heat

This study examined the separate effects of caffeine and menthol on cognition and mood during simulated firefighting in the heat. Participants (N = 10) performed three trials in a counterbalanced order, either with 400 mg caffeine, menthol lozenges, or placebo. The simulated firefighting consisted of 2 bouts of 20-min treadmill exercise and one bout of 20-min stepping exercise in the heat with two brief 15-min rest periods between each exercise phase. Exercise induced significant dehydration (>3%) and elevated rectal temperature (>38.9 °C), for all three conditions. Neither caffeine nor menthol reduced perceived exertion compared to placebo (p > 0.05). Mood ratings (i.e., alertness, hedonic tone, tension) significantly deteriorated over time (p < 0.05), but there was no difference among the three conditions. Simple reaction time, short-term memory, and retrieval memory did not alter with treatments or repeated evaluations. Reaction accuracy from a math test remained unchanged throughout the experimental period; reaction time from the math test was significantly faster after exposure to the heat (p < 0.05). It is concluded that, exhaustive exercise in the heat severely impacted mood, but minimally impacted cognition. These treatments failed to show ergogenic benefits in a simulated firefighting paradigm in a hot environment.