Journal of Health and Safety at Work

Evaluating the Employment Status of the Occupational Health and Safety Engineering Graduated at Kashan University of Medical Sciences

Mahdi Malakoutikhah

Introduction: Given the importance of the employment status of graduates for countries, the current study aims to investigate the employment status of occupational health and safety engineering (OHS) graduates from Kashan University of Medical Sciences (KAUMS), from the establishment of the field in 1996 up until 2023
Material and Methods: The cross-sectional study examined the employment status of OHS graduates of KAUMS using a researcher-developed Google form questionnaire. The questionnaire included demographic characteristics, five questions for unemployed individuals, and 60 questions for employed individuals. Finally, descriptive and analytical analyses of the study were performed using SPSS v16 software.
Results: A total of 229 graduates participated in this study. The results regarding the frequency of employed and unemployed participants showed that 198 (86.5%) participants were employed, and 31 (13.5%) were unemployed at the time of the study. Most employed participants (46%, or 90 individuals) work in the industry and mining sector. Evaluating the effectiveness of the educational course of employed participants in relation to their jobs revealed that 88 participants (44.4%) believe that the subjects taught in the courses are moderately compatible with work needs.
Conclusion: With the advancement of industries and the expansion of production, the need to control harmful factors and improve workers’ health is more evident than ever before, making it likely that graduates of this field will have favorable job prospects in the future. On the other hand, the academic conditions should be improved, particularly regarding the quality of the educational and curriculum programs of KAUMS.

Modeling and Weighting of Factors Affecting Sustained Attention and Working Memory of Workers Exposed to Different Sound Pressure Levels using Deep Learning and Random Forest Algorithms: A Case Study of a Steel Industry

Reza Esmaeili

Introduction: Cognitive functions play a vital role in how tasks are performed; for this, temporary cognitive and mental dysfunctions could lead to grave consequences, especially when an accurate and prompt response is required. Attention and reaction time to noise are among the most effective exogenous factors on the brain processing mechanism. This study aimed to measure the sustained attention of workers in the steel industry exposed to different sound pressure levels.
Material and Methods: The study was conducted in 4 general stages, including 1- Selecting predictive orientation variables (age, work history, different sound pressure levels); 2- Conducting the Cognitive Performance Test (CPT); 3 Conducting N-BACK Cognitive Performance Test and 4- Modeling cognitive performance changes using model precision methods.
Results: Continuous Performance Test (CPT) results indicated that all three groups’ omission error, commission error, and response time were affected by shift time. All three components increased significantly as the shift ended, decreasing individuals’ cognitive function. Also, the higher noise impact in modeling CPT and N-Back tests indicated reduced workers’ concentration.
Conclusion: These study findings suggested that greater noise weight obtained in test modeling in three-time intervals, i.e., in the beginning, middle, and end of the shift, affected the continuous performance components of the CPT and working memory performance of the N-back test, including workers’ response time and reaction time, with workers’ rate of error increasing and their focus decreasing during the shift.

Investigating the Cognitive and Psycho-social Consequences Related to Shift Work: A Cross-Sectional Study Among Nurses

Ahmad Soltanzadeh

Introduction: Shift work combined with the nature of duty in occupations such as nursing can lead to the spread of psychological consequences and disorders in nurses. The aim of this study was investigating the cognitive and psycho-social consequences associated with shift work in nurses.
Material and Methods: This study was performed in 7 hospitals in 2023. The study population was 636 nurses. Data collection tool in this study was part of a comprehensive questionnaire that translated and modified by Choobineh et al. The data were analyzed using IBM SPSS software v. 22.0, and significance level in this study was considered 0.05.
Results: Out of 636 studied nurses, 474 were shift workers and 162 were day workers. The means of age and work experience of the study population were 37.26±5.25 years and 11.60±4.78 years, respectively. The results showed that the prevalence of psychological consequences in the shift workers group was significantly more than day work nurses (p<0.05). The highest prevalence of cognitive and psycho-social consequences in shift work nurses were related to fatigue (39.66%), insomnia (36.08) and decreased sleep quality (35.44%), respectively.
Conclusion: The findings of this study indicated that the parameters of the shift work system, working hours per week, education and hospital ward are the most important factors affecting the prevalence of cognitive and psycho-social consequences and sleep disorders in the nurses. Therefore, it is suggested that a separate program should be designed and implemented for each hospital ward to control and manage the psychological consequences associated with shift work in nurses.

Evaluation of Different Wipes’ Performance for Sampling the Antineoplastic Drug 5-Fluorouracil from Various Surfaces

Jamaleddin Shahtaheri

Introduction: The use of antineoplastic drugs in cancer treatment, while essential, poses risks due to their non-selective action on both cancerous and healthy cells. Assessing and controlling environmental contamination with these drugs in workplaces is crucial. This study aimed to evaluate the efficacy of various commercial wipes in sampling the antineoplastic drug 5-fluorouracil from surfaces to develop standardized sampling methods.
Material and Methods: This study assessed the efficiency of commonly used commercial wipes (Whatman cellulose filter, cotton swab, Millipore™ filter, sterile gauze pad, and alcohol pad) for sampling 5-fluorouracil from different surfaces (stainless steel, vinyl, and ceramic). The sampling area was defined using disposable cardboard frames, and 1000 microliters of a 1 µg/mL 5-fluorouracil solution were applied to each surface. Sampling and extraction were conducted following NIOSH guidelines. The frame dimensions were 10 × 10 cm, limiting the sampling area to 100 square centimeters. Analysis was performed using high-performance liquid chromatography (HPLC), and results were analyzed using Prism GraphPad software, version 8.
Results: The sampling efficiency varied across wipes and surfaces, ranging from 11.2% to 86.2%. Alcohol pads showed the highest efficiency on stainless steel surfaces, while the Millipore™ filter had the lowest efficiency across all surfaces. Extraction efficiency ranged from 43.8% to 98.8%, with alcohol pads providing the highest recovery. Sample stability was maintained over 15 days.
Conclusion: Alcohol pads were most effective in collecting and extracting 5-fluorouracil, particularly from hard, smooth surfaces such as stainless steel and ceramic. These findings may improve sampling methods, thereby reducing occupational exposure to antineoplastic drugs. Further research on different wipes and extraction parameters could refine drug analysis techniques.

Developing a Model for Occupational Safety and Health Rrisk Assessment During the Construction Phase of a Metro Tunnel Using Internet of Things (IoT) Technology

Mohsen Falahati

Introduction: Nowadays, the statistics prove that the underground construction projects in the country are increasing, as well as the number of accidents arising from the unsafe condition of these projects. The purpose of this study was to create a framework of safety and health risk management in the construction phase of the Tehran Metro Line 7 tunnel, using IoT technology.
Material and Methods: In the first stage, the national safety and health standards, laws and requirements related to the mentioned hazards were collected. In the second stage, the criteria and permissible limits of exposure to occupational hazards were determined. Next, sensors with optical, auditory, gas detection, and visual capabilities connected to the network were examined, and computer programming and comparing sensor information with the specified standards were carried out. Finally, intelligent warning and control systems related to the determined hazards were proposed.
Results: In this study, a combined model of risk management utilizing IoT for controlling and monitoring safety and health hazards such as sound, light, explosive and toxic gases was proposed. According to the model, sensors for detecting the mentioned hazards were determined and coded based on the permissible limit of each of the harmful factors.
Conclusion: This study has shown that by employing specialized IT and safety knowledge and utilizing relevant software and hardware, the concept of the Internet of Things can be utilized in precise monitoring of the concentration levels of flammable and toxic gases, as well as monitoring of physical agents such as noise and light in various workplace, such as metro tunnel construction sites.

Optimizing Microperforated Panel Sound Absorbers Using Response Surface Methodology: Measurement, Modeling, and Performance Evaluation

Mohammad Javad SheikhMozafari

Introduction: Microperforated panels (MPPs), often considered as potential replacements for fiber absorbers, have a significant limitation in their absorption bandwidth, particularly around the natural frequency. This study aims to address this challenge by focusing on the optimization and modeling of sound absorption in a manufactured MPP.
Material and Methods: The study employed Response Surface Methodology (RSM) with a Central Composite Design (CCD) approach using Design Expert software to determine the average normal absorption coefficient within the frequency range of 125 to 2500 Hz. Numerical simulations using the Finite Element Method (FEM) were conducted to validate the RSM findings. An MPP absorber was then designed, manufactured, and evaluated for its normal absorption coefficient using an impedance tube. Additionally, a theoretical Equivalent Circuit Model (ECM) was utilized to predict the normal absorption coefficient for the manufactured MPP.
Results: The optimization process revealed that setting the hole diameter to 0.3 mm, the percentage of perforation to 2.5%, and the air cavity depth behind the panel to 25 mm resulted in maximum absorption within the specified frequency range. Under these optimized conditions, the average absorption coefficient closely aligned with the predictions generated by RSM across numerical, theoretical, and laboratory assessments, demonstrating a 13.8% improvement compared to non-optimized MPPs.
Conclusion: This study demonstrates the effectiveness of using RSM to optimize the parameters affecting MPP performance. The substantial correlation between the FEM numerical model, ECM theory model, and impedance tube results positions these models as both cost-effective and reliable alternatives to conventional laboratory methods. The consistency of these models with the experimental outcomes validates their potential for practical applications.

Investigating the Usability and Comfort of Safety Harness in Construction Projects: The Reasons for Non-Use among Iranian Workers

Parvin Sepehr

Introduction: The safety harness is a critical device for preventing falls from height, particularly in the construction industry. This study aimed to identify the factors contributing to the non-use of safety harnesses during work at height and to evaluate the comfort, satisfaction, and usability of these harnesses among construction workers in Tehran using a custom-designed tool.
Material and Methods: A semi-structured interview was conducted with construction workers to identify the factors influencing the non-use of safety harnesses. The collected data were analyzed using MAXQDA 10 software. Based on the results, which revealed dissatisfaction with the current safety harnesses, the levels of comfort, satisfaction, and usability were assessed using the Safety Harness Usability and Comfort Assessment Tool (SHUCAT) questionnaire.
Results: The reasons for not using safety harnesses were categorized into four main groups: management factors, worker attitudes, comfort, and harness design. These were further subdivided into 27 subgroups. The average satisfaction and comfort scores for safety harnesses were 26.8 ± 6.25, indicating that workers generally felt uncomfortable and dissatisfied with their harnesses. The average usability score was 38.70 ± 5.60, reflecting poor usability of the harnesses.
Conclusion: Improving the safety harness design could enhance workers’ comfort and satisfaction, increasing their willingness to use the equipment. Incorporating feedback from users and experts into the design process can help address the identified shortcomings and result in better product development.

Evaluating the Relationship Between Occupational Exposure to Polycyclic Aromatic Hydrocarbons (PAHs) and Urinary Metabolite Levels in Built-Up Roofing Asphalt Workers in Ilam City

Hojatollah Kakaei

Introduction: Exposure to various chemicals can occur in the workplace. Polycyclic aromatic hydrocarbons (PAHs) are among these compounds. The aim of this study was to investigate the relationship between exposure to PAHs and urinary metabolites among built-up roofing installers.
Material and Methods: The current case-control study, conducted in 2021 in Ilam City, involved 35 built-up roofing workers as the case group and 15 non-exposed workers as the control group. In this study, in addition to the workers’ respiratory area, samples were taken from the urine to determine the amount of PAHs metabolites. HPLC was used to analyze the samples. The collected data were analyzed using SPSS software version 22.
Results: The mean concentrations of PAHs including naphthalene, phenanthrene, fluorne, pyrene, benzo(a)pyrene, benzo (ghi)perylene and indeno 1,2,3 cd pyrene were 440.26±80.07, 70.49±24.36, 15.18±5.98, 31.21±10.36, 2.15±1.41, 2.25±0.07 and 1.18±0.06 ng/m3, respectively, in respiratory area of the workers. Also, the average level of compounds 1- naphthol, 2- naphthol, 2-hydroxyfluorene, 3-hydroxyfluorne, 1-hydroxyfenanterol, 2+3-hydroxyfenanterol and 1- hydroxypyrene, present in the urine of the population, was obtained equal to 2±1.02, 6.03±2.5, 0.18±0.15, 0.14±0.1, 0.19±0.08, 0.04±0.02 and 0.34±0.26 μg/g creatinine, respectively. Statistical test showed that the values of these compounds were significantly different in the two groups (p <0.05).
Conclusion: Estimating the concentration of aromatic hydrocarbons in the respiratory area of built-up roofing workers showed the noticeable exposure to these compounds, although lower than the allowable limits. However, due to the high carcinogenic nature of these compounds, it is recommended to use appropriate personal protective equipment such as respirators and appropriate work outfits in addition to the technical strategies to combat the exposure.

Application of Bayesian networks in fire domino effects modeling in gasoline storage tanks area

Leila Omidi

Introduction: Domino effects are a chain of low-probability and high-consequence accidents in which a primary event (fire or explosion) in one unit causes secondary events in adjacent units. Bayesian networks have been used to model the propagation patterns of domino effects and to estimate the probability of these effects at different levels. The unique modeling and flexible structure provided by Bayesian networks allow the analysis of domino effects through a probabilistic framework, taking synergistic effects into account.
Material and Methods: Firstly, collecting the basic information related to the location of the storage tanks and determining the scenario of the accidents were done. Furthermore, the values of the heat radiation as escalation vectors in case of a fire in one tank were determined using ALOHA software. The received heat flux values were compared with the heat radiation threshold of 15 kw/m² and the escalation probability of the primary unit and the propagation of the initial scenario to nearby storage tanks were determined using Bayesian networks.
Results: The analysis of the heat flux values showed that among the 8 studied storage tanks, two storage tanks had the highest potential for spreading domino effects due to their location in a tank farm. Also, the implementation of Bayesian networks in GeNIe revealed that, compared to other storage tanks, the probability of domino effects propagating to other nodes is higher when a primary fire accident occurs in the two mentioned tanks, while considered as primary units.
Conclusion: Domino effect modeling and appropriate preventative measures can decrease the escalation probability in the process industries. Consideration of the synergistic effects of events at different levels by taking the escalation vectors into account leads to proper risk management and the determination of emergency response measures in storage tank farms.

Investigating the effect of the Dominant Hand on Grip Strength and Hand Dexterity

Mehrane Shabani

Introduction: In all societies, tools and equipment are generally designed for right-handed people, who make up approximately 90% of the population, but left-handed and ambidextrous people (those who use both hands in manual activities) also live among us. Even in delicate and sensitive jobs. This research investigated the relationship between the spectral effect of the dominant hand and grip strength and hand dexterity.
Material and Methods: A cross-sectional study was designed to measure the power and precision grip of 182 adult participants (56% female and 44% male). The dominant hand of the participants was determined using the Edinburgh Dominant Hand Questionnaire. Power grip strength was measured using the Constant 14192-709E. Pinch grip test was performed using Saehan Hydraulic Pinch Gauge SH5005 for both hands separately. Dexterity of both hands was also measured using the Pegboard 32020A tool.
Results: Power and precision grips were more common in men than in women (P<0.001). Power grip differed between right- and left-handed women (P=0.019), with right-handed women having greater grip strength. The Precision grip of left-handed men was significantly (P<0.001) greater than that of right-handed men. Hand dexterity of left-handed men was significantly (P<0.001) higher than that of right-handed men. Two-handed agility (P<0.001) and assembly dexterity (P<0.001) are significantly higher in ambidextrous people than in right- and left-handed people.
Conclusion: The power, precision grip and dexterity are different between women and men. The grip strength of men is stronger than that of women. Ambidextrous people have more dexterity and assembly agility, so in jobs that require the use of two hands, they perform better and will be recommended for employment in this category of jobs.

Determining and Analyzing Factors Affecting Fire Safety Based on Fire Risk Assessment Method for Engineering and providing Control Solutions: A Case Study in a Hospital

Ali Karimi

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.

A Systematic Review on the Improvement of Thermoregulating Properties of Cotton Fabrics with Nanocapsules of Phase Change Materials

Farideh Golbabaei

Introduction: Workers who work in warm situations need clothes with better thermal regulation. Nowadays, improving the thermal regulation properties of cotton fabric by treating it with phase change materials (PCMs) has been considered. The type of fabric plays an important role in providing thermal comfort. Cotton fabric is the most popular raw material in the textile industry due to its distinctive features. Therefore, this systematic review aims to investigate the effects of PCM nanoencapsulation in commonly used cotton fabrics, including morphology, thermal properties, thermal stability, tensile strength, abrasion resistance, leakage, water absorption, washing ability, and breathability of the fabric, related challenges, and future research trends.
Material and Methods: This research was conducted with the papers obtained from the systematic search in Science Direct, Web of Sciences, Scopus, and PubMed databases. Keywords “nanoencapsulated phase change materials”, “nanoenhanced phase change materials”, “cotton”, “cotton fabric”, and “cotton textiles” were used.
Results: Of the 1251 studies identified through search databases, 13 were selected according to the entry criteria. The results revealed that in all the studies, PCM nanocapsules were successfully synthesized and inserted into the cotton fabric, improving the fabric’s thermal properties. Most studies used in situ polymerization and mini-emulsion polymerization for nanoencapsulation. The pad-dry-cure method was also widely used for applying nanocapsules to cotton fabric.
Conclusion: This systematic review showed that synthesized nanocapsules of phase change materials and applied them to cotton fabric can improve the thermoregulating properties of the fabric. It is suggested to expand the research to design thermoregulating clothes made from treated fabrics and investigate their cooling performance.