Journal of Health and Safety at Work

Studying the Impact of Geometric Characteristics of Internal Tubes in Expansion Mufflers on Sound Transmission Loss

2026-04-27T10:50:25+00:00

Introduction: A significant contributor to noise pollution in urban areas is automobile exhaust systems, wherein mufflers, as passive devices, are designed to mitigate the noise produced. The dimensions, shape, and configuration of the muffler, along with its associated components and pipes, influence its effectiveness in sound transmission loss. This study investigates the impact of varying the length of the muffler’s connecting pipes and their associated holes on sound transmission loss in reactive mufflers, utilizing software simulation for analysis.

Material and Methods: The research utilized COMSOL 5.5 to simulate the effects of different geometric factors on sound transmission loss in mufflers. Modifying factors such as the length of connecting pipes and the existence of holes led to the development of various designs. Analysis of the results was conducted to assess the impact of each parameter on sound attenuation, enabling a straightforward comparison of acoustic efficiency.

Results: Studies demonstrate that changing the form of pipes at different frequencies produces diverse outcomes. Introducing a perforation prior to the tube and utilizing elongated connecting tubes with expansion chambers can enhance transmission attenuation. On the other hand, transmission loss decreases with longer pipes that lack holes. Lower pitches experience minimal attenuation, whereas higher pitches undergo more loss. Reactive mufflers work best at certain frequencies, where the length of the connecting pipe affects both the acoustic mass and the effectiveness of the muffler.

Conclusion: The results obtained from this study can inform the optimal design of mufflers aimed at enhancing their efficacy in sound transmission loss. Furthermore, it is essential to consider the synergistic impact of the geometrical configurations of the internal pipes within the muffler to minimize sound emissions from the exhaust outlet.

A Multifaceted Investigation of Factors Contributing to General Fatigue in Hot Work Environments

2026-04-27T10:50:24+00:00

Introduction: Heat stress is a common environmental risk factor for many occupations, which can lead to increased fatigue during cognitive tasks. Fatigue is a multifactorial phenomenon that is affected by various environmental, physiological, and psychological factors, and can affect biomechanical, physiological, and psychological components. This study focuses on the impact of environmental, individual, and physiological factors, and burnout on general fatigue.

Material and Methods: This descriptive-analytical study was conducted among 189 employees of the Iran Oil Company at both indoor and outdoor workstations. Heat stress was measured using the (WBGT) index, and thermal strain risk was evaluated. Variables such as skin temperature, ear temperature, blood pressure, and heart rate were also monitored. To assess general fatigue and occupational burnout, (MFI) and the Maslach Burnout Inventory were completed by the employees.

Results: The results revealed that 79.9% of the employees were exposed to heat stress, with repair workers experiencing the highest levels of emotional exhaustion (23/38), depersonalization (15/34), general fatigue (10/00), and physical fatigue (9/05). Statistically significant relationships were found between heat stress and fatigue and decreased motivation, between all components of burnout and general fatigue, and between core temperature, blood pressure, and general fatigue (p<0.05). Notably, demographic factors such as marital status, smoking status, and education level did not significantly influence fatigue scores.

Conclusion: Fatigue is strongly associated with heat stress, physiological variables such as body temperature and blood pressure, burnout, personal habits such as sleep duration and exercise, and the type of job. These findings suggest that in hot work environments, monitoring physiological variables and environmental factors can help identify and address fatigue issues.

Investigating the Effect of Adding Carbon Nanotubes to RGO/Tio2 Aerogel on The Efficiency of Photocatalytic Removal of Gaseous Toluene

2026-04-27T10:50:23+00:00

Introduction: One of the most common pollutants in industrial and confined environments is toluene. Toluene can be removed in various ways. The simultaneous and integrated use of two methods— adsorption and photocatalytic degradation—in a single process is an important innovation in the removal of gaseous toluene. The aim of this study is to determine the efficiency of a synthesized reduced graphene oxide/carbon nanotube/titanium dioxide (RGO/CNT/TiO2) nanocomposite aerogel in the photocatalytic degradation and adsorption of toluene vapors.
Material and Methods: In this study, RGO/CNT/TiO2 and RGO/TiO2 aerogels were prepared using a one-pot hydrothermal self-assembly method. The properties of the photocatalytic aerogels were investigated using BET testing, scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier-transform infrared spectroscopy (FT-IR). Aerogels were loaded on a substrate in a photoreactor with two UV-C lamps using dynamic flow. Adsorption efficiency was measured when irradiation was off, and photocatalytic degradation efficiency was measured when irradiation was on using an instantaneous reading device.
Results: Adding CNTs to RGO/TiO2 affects the specific surface area (SSA) and the porous structure of the aerogels. During the processes of adsorption and photocatalytic degradation using RGO/CNT%5/TiO2, the concentration of toluene vapor pollutant decreased from 20 ppm to 3.4 ppm, indicating an efficiency of 81%. In contrast, RGO/TiO2 demonstrated an efficiency of 43.41%.
Conclusion: The results demonstrated that adding CNTs to RGO/TiO2 aerogel significantly improves photocatalytic performance for the degradation of toluene vapor. This enhanced performance is attributed to increased light absorption, an improved electron and hole recombination rate, as well as the facilitation of electron transition from titanium nanoparticles to the graphene structure.

Health in the Workplace: The Impact of Reverse Mentoring and Job crafting Mediated by Work Engagement

2026-04-27T10:50:22+00:00

Introduction: Employee health is a critical predictor of organizational productivity. Accordingly, the purpose of this research was to investigate the effects of reverse mentoring and job crafting on mental and physical health, with engagement playing a mediating role.
Material and Methods: This research employed a descriptive survey design with an applied focus, conducted cross-sectionally using survey methods for data collection. The statistical population consisted of 330 employees from the Amirkabir Kashan Steel Company. A sample size of 180 was determined using Cochran’s formula, and a simple random sampling method was utilized. Data were collected via a standardized questionnaire comprising 63 questions. The questionnaire’s validity was confirmed through convergent and divergent validity tests, and its reliability was supported by Cronbach’s alpha, which exceeded 0.7 for all variables. Data analysis was performed using descriptive statistics (SPSS) and inferential statistics (PLS).
Results: The findings confirmed all hypotheses and demonstrated the appropriate fit of the research model. Results revealed significant impacts of reverse mentoring on mental health (β = -0.482, t = 5.899) and physical health (β = 3.460, t = 4.430), as well as job crafting on mental health (β = -0.545, t = 6.193) and physical health (β = -0.756, t = 8.979) among employees and managers of the Amirkabir Kashan Steel Company. Moreover, engagement was found to mediate the effects of reverse mentoring on mental health (β = -0.510, t = 5.948) and physical health (β = -0.242, t = 3.799). Engagement also mediated the effects of job crafting on mental health (β = -0.345, t = 4.186) and physical health (β = -0.405, t = 4.751).

Conclusion: The results indicate that by implementing reverse mentoring and job crafting methods, managers can effectively control engagement levels, thereby maintaining organizational productivity and improving the health and well-being of employees.

Assessment and Comparison of Occupational Health and Safety Management Performance in Two Edible Oil Production Factories Utilizing the Total Quality Safety Management (TQSM) Model

2026-04-27T10:50:21+00:00

Introduction: The Total Quality Safety Management (TQSM) model is a tool used to assess the performance of occupational health and safety (OHS) management. This study evaluated the OHS management performance in two edible oil production factories using the TQSM model.
Material and Methods: A total of 78 OHS-related evaluation criteria across four main areas of the TQSM model were assessed at the Saboos Mazand (Factory 1) and Mino Caspian (Factory 2) factories, located in Mazandaran Province, Iran. The four areas included Total Quality Management (TQM), the ISO 9001 Quality Management System guidelines, the Voluntary Protection Program (VPP), and Process Safety Management (PSM). The study population consisted of 20 individuals from each factory, including managers, supervisors, and members of the OHS Committee, all with at least one year of experience in their respective roles. Participants were selected using a convenience sampling method.
Both factories had established active management systems for quality management (ISO 9001), customer satisfaction management (ISO 10002), and Hazard Analysis and Critical Control Points (HACCP) at the time of the study, reflecting the nature of the industry.
Results: The total scores achieved by Factory 1 and Factory 2 across the four main areas were as follows: 52.11 and 51.8 in the TQM area, 43.94 and 45.5 in the QMS-ISO 9001 area, 45.23 and 46.45 in the VPP area, and 30.22 and 30.06 in the PSM area. The overall scores obtained in the TQSM model were 171.51 for Factory 1 and 173.81 for Factory 2, corresponding to 54.97% and 55.7% of the maximum achievable score, respectively. No significant difference was observed between the mean scores across the four areas of the TQSM model for the two factories (p > 0.05).
Conclusion: Both factories exhibited an overall average performance level in OHS management. The evaluation criteria across the four areas of the TQSM model indicated weak to moderate conditions in the assessed subareas. Effectively using this model highlighted the organizational and operational areas requiring increased effort and focus to enhance OHS management performance in both factories.

Psychometric Evaluation of the Persian PSSUQ Third Edition and Usability Assessment of a Library Website

2026-04-27T10:50:20+00:00

Introduction: Computer-based systems have become integral to every aspect of daily life, with the successful performance of such systems heavily reliant on error-free software. Given the significance of these systems, tools are essential for evaluating their usability. One such tool is the Post-Study System Usability Questionnaire (PSSUQ). The present study aimed to localize and psychometrically evaluate the Persian version of the third edition of the PSSUQ and assess the usability of the library website at Mazandaran University of Medical Sciences.
Material and Methods: This descriptive cross-sectional study employed the Backward-Forward method for translating the questionnaire. The study population included 314 participants for cultural adaptation of the scale and 147 postgraduate students for evaluating the library website, all from Mazandaran University of Medical Sciences. Content validity was assessed using the Content Validity Index (CVI) and Content Validity Ratio (CVR). Reliability was determined via Cronbach’s alpha, and exploratory factor analysis was performed. Data analysis was conducted using SPSS version 16, adhering to ethical guidelines at all stages of the study.
Results: The overall content validity index (CVI) of the questionnaire was 0.96, while the overall content validity ratio (CVR) was satisfactory, with clarity and simplicity both scoring 0.91 and necessity at 0.75. Cronbach’s alpha coefficient was 0.95, with correlations between items exceeding 0.30. No significant differences in the usability of the library website were observed based on age, gender, field of study, educational level, or year of admission.
Conclusion: The Persian version of the third edition of the PSSUQ is a valid and reliable tool for evaluating system usability and user satisfaction with digital systems. It holds substantial potential for identifying system weaknesses and areas requiring improvement.

Presenting a Business Intelligence Dashboard to Analyze the State of Safety Risks by the Predictive Risk Index (PRI) in a Pharmaceutical Company

2026-04-27T10:50:19+00:00

Introduction: One of the most critical factors supporting industry managers and decision-makers in adapting to changes is the Business Intelligence (BI) dashboard. Dashboards, enriched with indicators, reports, and charts, enable managers to monitor industry performance at any given time.
Material and Methods: To evaluate safety status and prevent future accidents, risk factors within the industry were assessed using the RI risk index. In this study, the index was calculated through a geometric averaging relationship. Additionally, the ARIMA (2,0,0) time series model was applied, converting the average daily Risk Index into the Predicted Risk Index.
Results: Based on the occurrence of accidents, when the trend of the Risk Predictor Index is below 3, it is considered a safe zone in that industry. When the index trend is between 3 and 4, it represents a warning zone. If the index exceeds 4, there is a high probability of accidents, categorizing it as an action zone. According to the presented dashboard and zoning, the industry manager can conclude that 33% of risks are in the action area, 24% of the risks are in the warning area and 43% of the identified risks are in the safe area.
Conclusion: The results of this study demonstrated that leveraging business intelligence for prioritization can enhance decision-making and analytical processes for senior organizational managers.

Translation and Cross-Cultural Adaptation of the Individual Work Performance Questionnaire (IWPQ) into Persian and Assessing its Psychometric Properties

2026-04-27T10:50:18+00:00

Introduction: Individual work performance (IWP) plays a crucial role in both organizational effectiveness and employee well-being. To address the limitations of existing job performance questionnaires, the Individual Work Performance Questionnaire (IWPQ) was developed based on a holistic and systematic framework. This study aimed to translate, culturally adapt, and evaluate the psychometric properties of the Persian/Farsi version of the IWPQ.
Material and Methods: This descriptive methodological study was conducted in two stages: (1) translation and cultural adaptation (assessment of face and content validity), and (2) psychometric evaluation (assessment of internal consistency, test-retest reliability, and construct validity). The sample consisted of 206 administrative employees with a mean age of 34.29 years (SD = 7.66) and an average work experience of 8.48 years (SD = 7.39). The IWPQ was translated using forward and backward translation methods, and its validity was evaluated using exploratory and confirmatory factor analyses.
Results: The Persian IWPQ demonstrated acceptable face and content validity. Exploratory factor analysis confirmed a three-factor structure: task performance, contextual performance, and counterproductive work behavior. Confirmatory factor analysis indices (e.g., CFI = 0.87, SRMR = 0.08 and RMSEA = 0.09) indicated a approached model fit acceptability. Internal consistency and test-retest reliability were satisfactory across all dimensions (Cronbach’s alpha > 0.70 and ICC > 0.80).
Conclusion: The Persian version of the IWPQ is a reliable and valid instrument for assessing individual work performance across diverse occupational groups. It provides a valuable resource for evaluating workplace interventions and strategies aimed at enhancing performance.

Profile of Occupational Health Services in Iran: A Mixed-Methods Study Focusing on Service Coverage and Interventions

2026-04-27T10:50:17+00:00

Introduction: This study aimed to profile Iran’s occupational health services and identify the challengesand implementation strategies, focusing on the coverage of these services and interventions.

Material and Methods: This mixed-method research utilized a triangulation approach to generatequalitative data through document reviews from international organizations such as the WHO andILO, examinations of national occupational health systems, laws and regulations, previous studies, andinterviews. Quantitative data were collected from a national portal using a standard inspection checklistand secondary data from the National Statistics Center. Qualitative data were analyzed using both inductiveand deductive content analysis, while quantitative data were analyzed using descriptive statistics.

Results: The occupational health services profile for Iran comprised 45 indicators across 9 areas and6 types. The coverage of inspection services for identified workplaces and workers was 93% and 92%,respectively. However, the estimated coverage of inspection services for all existing workplaces andworkers was only 39% and 15%. Among the included workplaces, access to full health facilities was at48%, while occupational exposure control was at 18%. For the covered workers, the coverage rates foroccupational medical examinations, occupational health training, and utilization of personal protectiveequipment were 58%, 63%, and 66%, respectively.

Conclusion: The key intervention for improving service coverage and stability—aside from inspections,which are governed—lies in outsourcing services to various providers. This approach involves removingexisting barriers and enhancing service provision for small workshops. Additionally, redesigning occupationalhealth services should focus on modifying educational curricula, research, and implementation programs,emphasizing the economic aspects of controls, and prioritizing low-cost and effective measures, especiallyin small workplaces.

Identifying and Modeling the Causes of Gas Pipeline Excavation and Piping Operation Accidents Using Bayesian Network (BN) and Fuzzy DEMATEL: Case Study on Trench Collapse

2026-04-27T10:50:16+00:00

Introduction: Identifying and modeling the root causes of accidents can play an important role inpreventing them. The purpose of this study is to identify and model the causes of gas pipeline excavationand piping operation accidents using the Bayesian network (BN) and fuzzy DEMATEL.

Material and Methods: In this study, industrial accidents during gas pipeline excavation and pipingoperations were analyzed using the Bowtie method. The fuzzy DEMATEL method was employed todetermine relationships between accident root causes, and the fuzzy AHP method was used to comparepairs of causes and determine their weight. Finally, Bowtie and DEMATEL outputs were mapped inBayesian networks to determine the important risk factors for accidents.

Results: The most important risk factors for trench collapse accidents were as follows: risk management(16% impact weight), competency assessment (14.2% impact weight), supervision (13.8% impact weight),work permit system (13.7% impact weight), compliance with requirements and guidelines (13.4% impactweight), training (11.4% impact weight), HSE system (9.5% impact weight), and contractor management(8% impact weight).

Conclusion: Based on the results, it was demonstrated that risk management and competency assessment,having the highest weight percentages, play the most significant roles in the occurrence of trench collapseaccidents. The findings of this study can inform the prioritization of corrective measures to prevent trenchcollapse accidents in gas pipeline excavation and piping operations.

Tools for Assessing Mental Health Conditions at Work: A Scoping Review

2026-04-27T10:50:15+00:00

Introduction: Mental health in the workplace is a critical concern that influences both employee well-being and organizational productivity. However, issues such as stress, anxiety, depression, and burnoutcan significantly impair job performance and overall quality of life. While numerous tools have beendeveloped to assess mental health, many are not specifically designed or updated for work environments.As the complexity of the workplace continues to increase, accurate identification and evaluation of theseconditions become increasingly essential. This study aims to review available tools and identify the mosteffective methods for screening and assessing mental health issues in the workplace.

Material and Methods: A scoping review approach was employed to identify mental health assessmenttools applicable to workplace settings. The PubMed, PsycINFO, Web of Science, and Scopus databases weresearched using keywords related to mental health at work. Studies published after 2020 were included,with a focus on tools developed and validated for work environments. Two authors independentlyextracted and reviewed data from the selected studies. Tools were categorized based on their objectivesand specific characteristics.

Results: After screening, 12 studies were selected from an initial set of 746 papers. The extracted toolswere designed to assess stress, anxiety, depression, and burnout. While most tools were originallydeveloped for general settings or the public, some were tailored to specific occupational groups, suchas military personnel and healthcare workers. Burnout assessment tools were the most frequentlyreferenced category.

Conclusion: Newer tools, such as the Work Stress Screener, Occupational Depression Inventory, andBurnout Assessment Tool, offer potential advantages over older instruments. Shorter, specialized tools arerecommended for effectively assessing job-related anxiety. Organizations should prioritize selecting toolsthat align with their employees’ specific working conditions to promote mental health and productivity.

A Systematic Review of Methodologies for Assessing the Impact of Human and Organizational Factors on Safety Barrier Performance in Process Industries

2026-04-27T10:50:13+00:00

Introduction: Barriers play a critical role in mitigating risks and preventing catastrophic incidents inprocess industries. Human and Organizational Factors (HOFs) significantly influence the performance ofsafety barriers. This systematic review investigates existing frameworks and methods for assessing theimpact of HOFs on safety barrier performance.

Material and Methods: A systematic search was conducted across the Scopus and Web of Sciencedatabases, following the PRISMA guidelines. The search aimed to identify studies presenting methodologiesfor evaluating the influence of HOFs on safety barrier performance in process industries. Data weresubsequently extracted from the 16 included studies.

Results: The 16 studies included in this research presented various methods and frameworks examiningthe impact of HOFs on different types of safety barriers, including technical, operational, and humanbarriers, across industries such as oil and gas, chemical, and steel. Barrier and Operational Risk Analysis(BORA) emerged as the predominant framework among the studies. Research on operational andhuman barriers, which depend on human actions and procedures, frequently identified factors such ascompetence, training, communication, and supervision as key influencers of performance. In contrast,studies on technical barriers highlighted the importance of assessing factors such as maintenancemanagement and procedural compliance.

Conclusion: This research highlights the critical role of HOFs in safety barrier performance within processindustries. By systematically reviewing existing methodologies, the study identified their strengths andweaknesses. Findings underscore the need to account for uncertainties in expert judgments and theinterplay between HOFs in evaluation models. The integration of fuzzy logic and Bayesian networks isproposed to enhance evaluation processes. Future research should prioritize the development of unifiedframeworks that address the limitations of current approaches while expanding their applicability acrossdiverse industries