International Journal of Occupational Safety and Ergonomics最新文献

This study examines the interplay of weave patterns, picks per inch (PPI) and key performance metrics including heat protective performance (HPP), air permeability, thermal resistance and water vapor transmission rate (WVTR). Three weave structures (twill, sateen and honeycomb) using Nomex-IIIA yarn were tested. Heat flux of 80 ± 2 kW/m² was applied, combining flame and radiative heat. The honeycomb weave exhibited superior heat protection compared to twill and sateen. HPP increased by approximately 24% with the PPI rising from 40 to 64. Air permeability and thermal conductivity decreased by roughly 50% and 38%, respectively, with increasing PPI. Sateen and twill showed similar trends. WVTR increased with PPI up to 52, then declined. Overall, higher PPI enhanced HPP for all weave structures, with the honeycomb structure showing the best performance. Thermal conductivity and air permeability decreased as PPI increased due to the greater compactness in these three fabrics.

Ergonomics plays a significant role in fabric preparation, ensuring that the work environment, equipment and tasks are designed to enhance worker comfort, safety and efficiency. The intricate process of water vapour movement through textile structures is controlled by several variables, e.g., openness, thickness and pore size of the fabric as well as the inherent fibre characteristics. This study investigates the effect of tank temperature, pick density of the shell layer and fan speed on the reduction in relative humidity in the microclimate of the shell layer of fire protective clothing. The Box-Behnken model is used to make predictions and analyse the results. Analyses were performed for 3D surface plots at 22, 32 and 42 pick density for various tank temperature and fan speed combinations. The model is statistically significant (p = 0.0007). The results can be used for design and development of thermal protective clothing.

Objectives. Railway track maintenance is one of the essential tasks for the Indian railway, where millions of workers have musculoskeletal disorders. The main aim of the present investigation is to determine the prevalence of work-related musculoskeletal disorders (WMSDs). Methods. Nordic modified questionnaire studies and posture analysis were performed by the Ovako working posture analyzing system. Physiological stress assessment was carried out by recording the participants' heart rate and blood pressure. Results. The questionnaire study revealed that most of the railway track maintainers complained that the maximum discomfort (pain) felt was in the lower back region (90.3%) of the body, followed by the hands (76.4%), knees (76.0%), wrists (75.2%) and shoulders (68.2%). There was a significant change in heart rate reserve, net cardiac cost, relative cardiac cost and cardiovascular stress index between the railway track maintainers and controls. Conclusion. This study shows that railway track maintainers are constantly engaged in highly repetitive hand-intensive jobs, and by performing such strenuous jobs for several years suffer from discomfort in the upper and lower back regions of the body followed by a decrease in handgrip strength. All of these factors consequently may lead to the development of WMSDs.

Objectives. The purpose of this research was to determine the prevalence and severity of entire-body musculoskeletal system pain (MSSP) in teachers and its association with work stress. Methods. The sample in this descriptive, cross-sectional research consisted of 437 teachers. Research data were collected using a sociodemographic information form, the Cornell musculoskeletal discomfort scale and the work stress scale (WSS). Data were analyzed using SPSS version 23. Results. The most prevalent MSSPs observed in the 20 body regions of the teachers in the study, a profession involving high work-related pain levels, were in the lumbar, neck and back regions. Each one-unit increase in teachers' WSS scores increased the likelihood of work-related lumbar pain by 6% (prevalance ratio [PR] 1.06; 95% confidence interval [CI] [1.04, 1.12]), of neck pain by 11% (PR 1.11; 95% CI [1.08, 1.16]) and of back pain by 8% (PR 1.08; 95% CI [1.05, 1.14]). A significant positive correlation was observed between MSSP scores in the 20 body regions and WSS scores. Conclusions. MSSP is a widespread occupational health problem, and work stress is a cause of significant MSSP in the body as a whole and particularly in the lumbar, neck and back regions.

Phthalate esters (PAEs) are widely used in plastic consumer products and many studies published to date have associated these chemicals with severe human health problems. Particularly, the risks within warehouses, which involve large quantities of PAE sources stored in closed spaces, have not been addressed. This article presents an integrated inventory control model to determine the periods within the supply cycle where concentrations of PAEs are likely to represent a risk for the warehouse personnel. This model considers the dynamic aspect of the warehouse supply and consumption mechanisms, and links it to the release patterns of PAEs in closed environments which depend on the type of materials, temperature and time. Numerical analysis corroborates that, in certain periods of time, concentrations of PAEs in the warehouse can exceed permissible levels for humans, and thus the use of appropriate protective wear and decontamination procedures should be established.

Objectives. This study aimed to examine the prevalence of chronic musculoskeletal pain among employees of a large German chemical company and how it varies depending on occupational group. Methods. Cross-sectional data were collected between 2019 and 2022 during a voluntary occupational health check-up, including a written questionnaire. Chronic musculoskeletal pain was defined as lasting at least 3 months in the past year. Occupational group was operationalized either by self-reported work area or by the International Standard Classification of Occupations 2008 (ISCO-08). Associations between occupational group and chronic musculoskeletal pain were analyzed using robust Poisson regression. Results. The final sample included 13,705 employees. The 12-month prevalence of chronic musculoskeletal pain was 18.6% for the whole sample, and 22.0, 21.9, 20.2 and 15.0% for employees in the work areas other, office, research/laboratory and production/craft, respectively. Regression analyses showed that the prevalence was 24.1% (p < 0.001) lower for employees in production/craft and 11.2% (p < 0.05) lower for employees in research/laboratory compared to office employees in the fully adjusted model. Conclusions. The high prevalence of chronic musculoskeletal pain underscores the importance of both the prevention and management of chronic musculoskeletal pain. Thereby, workplace-specific needs-based offerings could play an important role.

Objectives. This study proposes an effective design method for truck drivers' occupational clothing during public health emergencies, reducing development time and costs, optimizing design resource allocation and enhancing truck drivers' occupational safety and mobility experience. Methods. User journey mapping and questionnaires were employed to obtain design requirements for truck drivers' occupational clothing during public health emergencies. The Kano model was utilized to classify user needs and assign importance weights, while a design system was constructed based on the quality function deployment (QFD) method. A prototype of truck drivers' occupational clothing for public health emergencies was developed, and the effectiveness of the design method was validated using fuzzy comprehensive evaluation. Results. The truck drivers' occupational clothing designed based on the proposed system received a satisfactory rating in the fuzzy comprehensive comparative evaluation, scoring 3.491. This rating surpassed two control group driver uniforms, with overall scores of 28.16 and 30.99% higher, respectively. Conclusion. This study presents an effective design method that provides a theoretical reference for the design and iteration of truck drivers' clothing during public health emergencies.

Waste pickers are crucial to waste management in developing countries like Ghana, yet face challenges due to their practices. This study explores the determinants of occupational health and safety (OHS) practices among these workers, an unexplored area. Using a cross-sectional survey and stratified sampling, data were collected from 240 waste pickers. Results identified factors such as daily earnings (χ²(2) = 31.7, p < 0.000), origin (χ²(2) = 33.9, p < 0.003) and ethnicity (χ²(2) = 6.7, p < 0.037) affecting OHS practices. Waste pickers lack personal protective equipment (PPE) due to cost constraints, risking their health. Ethnic diversity contributes to OHS attitudes, priorities and acceptable work conditions. To improve OHS practices, recommendations include providing PPE training and access, creating supplementary income sources and ensuring safety equipment affordability. These measures will enhance waste pickers' well-being and workplace safety, addressing the challenges they face in their role within the waste management system.

Objectives. This study aimed to evaluate four cooling methods (natural cooling method [NCM], stripping cooling method [SCM], fan cooling method [FCM] and water-spray cooling method [WSCM]) for their effectiveness in reducing heat stress and skin burns in firefighters after heat exposure. Methods. Skin heat flow and fabric temperature were measured on a stored energy test device during the exposure and cooling stages. The study assessed thermal protective performance by comparing the cooling methods, noting the time to second-degree burns and the energy released to the skin. Results. The SCM showed the best thermal protective performance, followed by the FCM, NCM and WSCM. No skin burns were observed with the SCM. Compared to the NCM, the FCM extended the time to second-degree burns by 3.2% (F1 fabric system) and 10.7% (F2 fabric system). The SCM had the lowest accumulated energy released to the skin and the highest cooling efficiency. The accumulated stored energy and released energy of the FCM decreased with increasing wind speed, whereas the values for the WSCM increased with longer water spray durations. These results can guide the development of optimal cooling methods to enhance firefighter safety and protection.

Objectives. This study aimed to verify the responses of skin temperature, oxygen saturation, blood pressure, rate pressure product (RPP), heart rate (HR) and HR variability after continuous and intermittent exposure to heat from a fire, keeping the work load equal between the conditions. Methods. Sixteen men from a fire department were subjected to two experimental conditions: continuous exposure to the heat from a fire for 30 uninterrupted minutes (1 × 30 min); and intermittent exposure to the heat of the fire organized by two 15-min re-entries of exposure to the heat interspersed with 10 min of non-exposure (2 × 15 min). Results. The main finding was lower percentage changes in HR (+1.7% vs +38% vs +26%), mean normal interval (-0.97% vs -26% vs -20%), RMSSD (-5.0% vs -62% vs -48%) and RPP (+0.79% vs +38% vs 34%) in re-exposure (15-30 min) when compared for 0-30 min and 0-15 min, respectively. Conclusion. Under equal workloads, intermittent exposure to heat is an efficient strategy for fire suppression activities. In addition to skin temperature and HR, RPP constitutes another variable to monitor firefighter health between re-entries, as it is easy to administer, inexpensive and reflects cardiac overload.