Journal of Health and Safety at Work

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Introduction: Universities play a key role in creating a knowledge-based society and its sustainable development. Strategic planning by strategically analyses internal and external environments of the organization, forecast its future, identifying its strategic direction, and strengthening organizational structures, processes, and outcomes, creates and sustains competitive advantages. This study aimed to formulate a strategic plan for the Occupational Health Engineering (OHE) department of School of Public Health (SPH) at Tehran University of Medical Sciences (TUMS).
Material and Methods: In this participatory action research, a strategic planning committee was formed. The strategic planning committee used the strength, weakness, opportunity and threat (SWOT) matrix to evaluate the internal and external environments of the OHE department. Then, the mission, vision, values, goals and objectives of the OHE department were defined. Finally, the operational plan including actions to achieve the goals and objectives were formulated.
Results: Experienced professors and staff, specialized laboratories, professional journals, and high ranked postgraduate students were the most important strengths; and theoretical and non-practical courses, lack of educational protocols, poor communication with industries, lack of resources, and low motivation of employees were some of the weaknesses of the OHE department.  The support of senior managers of TUMS, industry liaison council at school and university, facilities of the university faculties, comprehensive research laboratories of the university, capacities of the private sector and increasing the demand for research in the industry were the opportunities. High inflation, political sanctions, the absence of consulting engineering companies and the uncertainty of research priorities of industries were important threats to the OHE department. Therefore, the OHE department is in a conservative strategic position. The strategic direction of the department, including the mission, vision, values and goals, until 2025 was determined. Improving the structures, working processes and performance of the occupational health department were determined as objectives and 81 actions were formulated to achieve these objectives.
Conclusion: The educational departments, schools and universities must have a strategic plan for progress. The strategic plan of the occupational health department of TUMS was formulated in line with the four-year plan of the university and coordinated with the operational plans of the educational, health and research deputies of TUMS and school of public Health. Proper implementation of this comprehensive and evidence-based strategic plan will improve the performance of the occupational health department.

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Introduction: Human factor analysis has been identified as the most common cause of accidents in natural gas transportation and distribution facilities. The occurrence of accidents at these systems, especially gas reduction stations located in residential and industrial areas, has had catastrophic consequences. Therefore, this study aimed at analyzing critical tasks and human error assessment using the system for predictive error analysis and reduction (SPEAR) method and providing the appropriate framework for error management in the operation and maintenance of city gate stations.
Material and Methods: This descriptive cross-sectional study was conducted using the SPEAR framework and safety critical task analysis guideline to evaluate errors in gas pressure reduction stations. First, critical tasks were screened and evaluated, followed by performing task analysis by the hierarchical task analysis and detecting performance-influencing factors (PIF). Then, human errors were predicted and assessed based on the predictive human error analysis. Finally, error management was developed at three process, equipment, and training improvement levels.
Results: In general, out of 23 operations and 164 sub-tasks, 12 critical tasks were identified based on the results. Criticality level percentages were about 67% high risk, 25% moderate, and 8% low risk. In addition, 134 errors were identified which were mostly related to action (42.53%) and checking (39.55%) errors, respectively. Eventually, communication, retrieval, and selection errors were 8.96, 5.22, and 3.74%, respectively.
Conclusion: The results revealed that action and checking errors had the highest percentages. This method can be applied to appropriate the systems approach to error reduction using the PIF assessment output. The privilege affecting factors include preparing standard operation procedures, implementing a comprehensive training program, and controlling environmental hazards.

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Introduction: Usability is a criterion that indicates a product’s applicability and ease of use. A usable product allows the user to perform a task correctly and quickly, preventing errors and fatigue. The present study aimed to determine the ergonomic usability of the Zanjan University of Medical Sciences website of educational management system from the students’ viewpoint in 2019 and 2020.
Material and Methods: This cross-sectional study evaluated the usability of one of the websites for educational management systems using a standard questionnaire. The study examined the utility of web-based applications in the research processes automation field. The questionnaire was embedded in Google Forms and emailed to Zanjan University of Medical Sciences students, 404 of which returned. The data were analyzed with a 0.05 confidence level using SPSS software version 16.
Results: The 404 participants’ data showed that among the questionnaire nine factors, the highest and intermediate-range mean were for “Ease of Use” at 19 and 4 and for “Ease of Learning” at 18 and 4. Moreover, they were 13 and 3 for “System Capabilities,” 13 and 2 for “System Usability,” and 10 and 2 for “User Satisfaction.” In addition, “Errors Management” received 10 and 2, “Display” 10 and 2, “System Terms and Information” 8 and 2, and “User Environment Personalization” 5.5 and 3 as their highest and intermediate-range mean, respectively. Most questionnaires did not differ significantly depending on the age variable, meaning that different age groups had similar answers to most factors. The two sexes showed a significant difference in the responses to the “Usefulness of the System,” “Ease of Learning,” and “Display.” A significant difference for other factors was found in examining the relationship between educational level and the questionnaire factors. However, the “Error Management” and “Display” factors did not significantly differ, considering the educational levels.
Conclusion: The results showed that more attention should be paid to ease of use and learning in re-designing this website. However, it is necessary to consider all factors affecting usability.

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Introduction: Given the high prevalence of low back pain in manual handling activities, its known relationship with spinal loads, and the role of muscular fatigue and the body’s adaptive mechanisms to counteract fatigue, this study investigated the effect of repetitive lifting tasks on trunk muscular fatigue and the kinematics of the spine and load-in-hand.
Material and Methods: Eighteen male volunteers lifted a box from the floor to their waist height at a pace of ten lifts per minute until they could no longer continue the task and reported the highest level of exhaustion. Kinematic data and muscle electromyographic activity were simultaneously recorded using a motion capture system and an electromyography device. In this study, average trunk flexion angle and trunk angular velocity were calculated as trunk kinematic variables, while average box vertical travel distance, average box horizontal displacement from L5-S1, and average box vertical displacement velocity were considered as box kinematic variables. The median frequency of electromyographic signals from selected muscles was quantified as a muscle fatigue indicator. Since subjects performed different lifting cycles, the total number of cycles was divided into five distinct blocks for data analysis.
Results: The results showed significant effects of lifting trial blocks on trunk angle (p=0.004) and vertical box displacement (p<0.001). Median frequency was significantly affected by lifting blocks for right (p=0.016) and left erector spinae (p=0.014), right (p=0.021) and left multifidus (p<0.001), right latissimus dorsi (p=0.001), and left rectus abdominis (p=0.039).
Conclusion: Overall, the results highlight variations in most kinematic parameters and a reduction in the frequency content of EMG signal spectra. These changes serve as indices of the central nervous system’s control over lifting behavior under dynamic conditions. A better understanding of these central nervous system adaptations could have practical applications in interventions such as workstation design, exoskeleton development, and worker training to manage musculoskeletal disorders.

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Introduction: Reliability is always of particular importance in system design and planning; thus, improving reliability is among the approaches for achieving a safe system. Simulation methods are widely used in system reliability assessment. Therefore, this study aims to assess the reliability of the City Gate Gas Station (CGS) using Monte Carlo Simulation (MCS).
Material and Methods: This descriptive and analytical study was conducted in one of the CGSs of North Khorasan Province in 2021. The CGS process was carefully examined and its block diagram was plotted. Then, failure time data of CGS equipment were collected over 11 years and time between failures of subsystems was calculated. The failure probability distribution function of subsystems was determined using Easy Fit software and Kolmogorov-Smirnov test. Moreover, subsystems’ reliability was estimated by MCS. Finally, station reliability was calculated considering the series-parallel structure of the CGS.
Results: The results revealed that the failure probability density distribution function of CGS subsystems was based on gamma and normal functions. The reliabilities of filtration, heater, pressure reduction system, and odorize were calculated as 0.97, 0.987, 0.98, and 0.992 respectively, and their failure rates were 0.000003477, 0.0000014937, 0.0000023062, and 0.0000009169 failures per hour respectively. The station reliability was calculated as 0.93.
Conclusion: The failure probability distribution function and reliability assessment of subsystems were determined by data modeling and MCS respectively. Filtration and pressure reduction systems had the highest failure rate and required a proper maintenance program.

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Introduction: Fatigue, caused by prolonged standing activities, affects postural stability through disrupting somatosensory system functions. The application of sub-threshold mechanical vibration can enhance the sensitivity of the mechanical receptors in the sole of the feet. Improved sensory function leads to better movement control and balance. Therefore, this study investigated the effectiveness of vibration-based active insoles in reducing the impacts of fatigue on postural stability among military forces.
Material and Methods: Each of the 20 healthy male participants of the study completed three standing balance tests: 1) on both legs, 2) on one leg, and 3) on one leg with a cognitive secondary task for two states of the vibration system (on and off), before and after a fatigue protocol, on a force plate. The activity of leg muscles was also monitored by electromyography (EMG). The mean as a linear index (amount) and the sample entropy (SaEn) as a non-linear index (structure) related to the resultant distance of the body’s center of pressure (CoPRD) displacements, as well as the normalized percentage of the muscle activity level (linear envelope), were used for statistical analyses.
Results: Significant changes in most of the postural and muscular parameters were recorded after the fatigue protocol for the off-mode of the vibration system. Meanwhile, running the vibration system of active insoles was accompanied with no significant differences in the amount and structure of the CoPRD displacements, as well as the activity level of the lateral gastrocnemius and soleus muscles after fatigue, compared to the measurements before fatigue.
Conclusion: The findings confirm the effectiveness of applying sub-threshold mechanical vibration to the sole of the foot in improving standing balance by reducing the negative effects of fatigue on postural stability parameters. Therefore, it is suggested that the use of active insoles can be an effective, feasible, and accessible ergonomic intervention to address fatigue among military forces. 

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Introduction: The purpose of occupational health is to maintain and improve the health of employees and improve their physical, mental and social well-being through the prevention, control and elimination of occupational hazards. It is necessary to integrate educational, research and health service activities to prevent and control potential occupational health hazards in the community. This study aimed to develop a Joint Comprehensive Plan Of Action (JCPOA) for occupational health at Tehran University of Medical Sciences (TUMS).
Material and Methods: In this participatory action research, a strategic planning committee was established, whose members were professors of the occupational health department in the school of public health and managers of the occupational health department in the health deputy of TUMS. The strategic planning committee carried out a strategic evaluation of the internal and external environments of both occupational health deprtments of TUMS and identified the strengths, weaknesses, opportunities and threats. Then, the strategic direction of JCPOA including the vision, mission, values, goals and objectives was determined. Also, the strategies and actions to achieve the goals and objectives were identified. Finally, the action plan to achieve these objectives was developed.
Results: This applied research led to the strategic evaluation of the internal and external environments of the occupational health depratment of the School of Public Health and the occupational health depratment of the Health deputy of TUMS, determining the strategic direction, and finally, developing an action plan to achieve the goals and objectives.
Conclusion: The JCPOA for occupational health was developed using a collaborative and systemic approach. The proper implementation of this plan can lead to the improvement of occupational health indicators in the community. Cooperation between university and industry is necessary for the sustainable development of society.

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Introduction: Emergency technicians face workplace violence and increasing occupational stress. The purpose of this study was to investigate the impact of a virtual self-management training in communication skills on occupational stress and the degree of aggression among emergency technicians.
Material and Methods: This study involved 60 emergency technicians randomly assigned to either the intervention or control group. They completed surveys on workplace violence and occupational stress. The intervention group received six weeks of a virtual self-management training in communication skills. Data was collected after two months and analyzed using SPSS software.
Results: The findings showed that there was no statistically significant difference between the control group (110.08±11.92) and the two intervention groups (114.39±11.25) in terms of the average occupational stress before the intervention; The average job stress score between the intervention (94.0±12,70) and control (98.81± 20,81) groups significantly differed following the intervention (p=0.034); After the intervention, the intervention group had lower verbal and physical abuse frequencies compared to the control group.
Conclusion: The virtual self-management communication training demonstrated the potential to reduce occupational stress but did not significantly decrease the violence towards the emergency technicians. A comprehensive training program addressing violence factors and communication techniques, implemented over a longer period, is recommended.

 

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Introduction: Risk assessment matrix is a tool used in a project’s risk assessment process to identify the probability of risks and evaluate the potential damages caused by those risks. Generally, a risk assessment matrix is drawn in a two-dimensional form, with two factors: the severity of the accident and the probability of its occurrence. So, the purpose of this study is to develop a specific risk assessment matrix in a three-dimensional form by using the accident severity grade (ASG) rating system, the accident probability, and taking into account the preventive approach that helps occupational injury risk assessment in the automobile industry.
Material and Methods: This cross-sectional study was conducted in 1402 (2023) in one of the automobile assembly industries. One hundred cases were randomly selected by examining the reports of this industry’s past accidents. The ASG scoring checklist was designed and completed by the experts to assess the severity of accidents. Then, considering the ASG score, the frequency of the accident, and its preventability, a three-dimensional risk assessment matrix specific to this industry was presented.
Results: According to the findings of the accident analysis, a total of 658 accidents and 15,019 lost working days were recorded in this period. The most influential factor in the occurrence of accidents is related to “surface condition” (influence factor = 0.6), and the least of them belongs to the “weather conditions” (influence factor = 0.028). The results of the three-dimensional matrix show that when the ability to prevent accidents increases, the risk of accidents decreases.
Conclusion: Using the accident severity grade (ASG) and preventability in the proposed three-dimensional risk assessment matrix, the accident severity can be quantified immediately after the accident. This approach allows monitoring workplaces during the accident, leading to timely control and risk management implementation.
 

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Introduction: Fire safety in healthcare centers is crucial due to the limited evacuation capacity of the occupants and the necessity of not disrupting the operation in these centers. In this study, the fire risk of a public hospital was evaluated using the Fire Risk Assessment Method for Engineering (FRAME). Additionally, the factors affecting fire safety in the hospital were analyzed quantitavely, and fire control strategies were presented. 
Material and Methods: First, the fire risk assessment checklist was filled in all the hospital departments. Then, the values of the factors affecting fire safety were obtained. In the next step, the fire risk for the building, occupants and activities were estimated using Excel software-FRAME. Finally, control strategies and intervention measures were presented based on the value of these factors. 
Results: In the hospital under study, 22% of the departments posed an undesirable fire risk to the building and its property. On the other hand, 90% of the departments had risk levels that were undesirable for the occupants. The results of the initial risk (R0) showed that a balance between potential fire risk and risk acceptance can be established by implementing manual fire extinguishing systems and automatic detectors in all departments. 
Conclusion: ased on the condition of the hospital studied, a balance between potential fire risk level and risk acceptance level was not established. Therefore, there is a need for fire control measures, especially fire safety measures for the occupants. The results of this study can be useful for readers and experts in interpreting fire risk assessments and presenting detailed control measures based on the risk assessment and the value of the parameters.

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Introduction: Safety in process industries is of paramount importance, as these industries typically deal with hazardous chemicals and complex processes that can lead to irreparable consequences in the event of accidents. The present study aims to evaluate domino effects and analyze the vulnerability of storage tanks using graph theory and Bayesian networks in a process industry. This approach can help identify system vulnerabilities and facilitate the prediction of potential accidents, ultimately leading to improved safety measures.
Material and Methods: In this study, after collecting initial information related to the location of storage tanks and determining accident scenarios, the tanks under investigation were selected based on the type of stored materials and their layout, with input from experts. These tanks were modeled as nodes in a graph, and the probability of accident spreading among them was represented as edges in the graph based on the amount of heat radiation. Additionally, for modeling domino effects and analyzing vulnerability, graph theory and Bayesian networks were employed.
Results: Based on the target tanks related to the pool fire scenario, domino effects in the tanks were identified and modeled as a theory graph. Tank number 4 was determined to be the most influential and susceptible tank in the spread and initiation of domino effects, with the highest betweenness index (0.2381), outcloseness index (0.35211), and incloseness index (0.3663). Additionally, based on the allcloseness index, the most likely sequence of the tank involvement in fires caused by domino effects was identified.
Conclusion: In order to reduce the likelihood of exacerbating domino effects, modeling the effects using Bayesian networks and graph theory is proposed; the results can also be applied to optimize fire suppression strategies. Additionally, vulnerability analysis through graph theory and the assessment of tanks regarding their potential for fire initiation and spread can be beneficial in managing the risks associated with domino effects.

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Introduction: Barriers are critical to mitigating risks and preventing catastrophic incidents in process industries. Human and Organizational Factors (HOFs) significantly impact safety barrier performance. This systematic review investigates existing frameworks and methods for assessing HOFs' influence on safety barrier performance.
Material and Methods: A systematic search was conducted across Scopus and Web of Science databases, adhering to the PRISMA guidelines. The search aimed to identify studies that presented methodologies for evaluating the impact of HOFs on safety barrier performance in process industries. Subsequently, data were extracted from the 16 included studies.
Results: The 16 studies included in this research presented methods and frameworks that examined the impact of human and organizational factors on various types of safety barriers, including technical, operational, and human barriers, across a wide range of industries such as oil and gas, chemical, and steel. Barrier and Operational Risk Analysis (BORA) was identified as the predominant framework among studies. Studies on operational and human barriers, which rely on human actions and procedures, often identified factors such as competence, training, communication, and supervision as influencing their performance. Regarding technical barriers, studies emphasized the need to assess factors such as maintenance management and procedures.
Conclusion: Thorough HOF assessment is crucial for developing effective risk management strategies in process industries. While progress has been made, the scope of assessment methods should be expanded to cover a wider range of industries and barrier types. To make assessments more objective, integrating data from multiple sources and using techniques based on fuzzy logic and Bayesian networks (BN) can help reduce reliance on expert judgment. The presented methods should also be complemented by dynamic assessment of HOFs with continuous monitoring to ensure the ongoing effectiveness of safety barriers.