Journal of Health and Safety at Work

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Introduction: Fire in hospitals and medical centers can lead to unfortunate and dire accidents due to the immobility of most patients, the presence of expensive medical equipment, and the essential role of hospitals in providing health services to people. This study aims to increase fire safety in a healthcare training center in Qazvin.
Material and Methods: The latest NFPA 101A was used for fire risk assessment in seven departments of an educational hospital in Qazvin City in 2021-2022. The study calculated the residential risk factor for residents of each area, examined fire safety parameters and determined their risk factor, calculated the obtained points of the area under evaluation, determined the minimum required points in different areas of fire safety, and estimated the fire risk level.
Results:  ICU 1 and 2 departments, CCU 1 and 2, central warehouse, pharmacy warehouse, and hospital facilities were selected for fire risk assessment. The ICU building had the best condition with a total fire safety point of 21.1. The facility building, with a total fire safety point of -14.5, was in the worst condition.
Conclusion: The results showed the need for more attention from researchers to conduct studies in outdoor environments, in various parts of the country, on development and validation of novel heat stress indices, and on implementation and evaluation of control measures in environments with high heat stress.

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Introduction: Many general indicators have been proposed to assess an organization’s safety performance. However, due to their holistic nature, these indicators may not always reflect safety-specific aspects of an organization’s performance. In other words, the nature of an organization’s activities necessitates the use of specific criteria to better reflect safety performance. This study aimed to identify and measure key safety performance indicators using the Delphi method in Alborz Province Electric Power Distribution Company.
Material and Methods: This descriptive, survey-based study utilized the Delphi method to collect the opinions of 11 safety experts in the electric power distribution industry. Opinions were gathered in four phases, and key indicators were determined in the last phase of the study. These indicators were subsequently used to evaluate the safety performance of Alborz Electric Power Distribution Company for three months.
Results: This study identified and documented 34 safety activities. The expert group proposed 20 indicators in the first phase of the Delphi method. In the second and third phases, four and one indicators were eliminated, respectively, because they did not receive the required score. The content validity ratio (CVR) and content validity index (CVI) were calculated for the remaining 15 indices in the fourth phase. The results revealed that the mean quarterly performance scores of Alborz Province electric power distribution districts and departments in 2016, including Nazarabad, Savojbolagh, Mehrshahr, Fardis, West, East, Taleghan, and Eshtehard, were 78.9, 54.7, 78.8, 75.9, 75.7, 80.8, 61, and 83.5 out of 100 points, respectively.
Conclusion: The Delphi method is useful for identifying key safety performance indicators. The indicators discovered using this technique are active indicators (pre-accident) that are crucial in determining Alborz Electric Power Distribution Company’s safety performance. These indicators are suggested for use in evaluating the safety performance of other electric power distribution companies.

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Introduction: Physical fatigue is one of the major risk factors for work-related musculoskeletal disorders and has many life and financial costs. The impact of physical/biomechanical, psychosocial, environmental, and individual risk factors on muscle fatigue is undeniable. The aim of this study is to model the phenomenon of muscle fatigue (as output) in the hand in work environments based on these risk factors (as input) using soft computing methods.
Material and Methods: In the first step, associated risk factors of fatigue for 156 subjects (in three job categories) were assessed using Copenhagen environmental, psychosocial, demographic, and Man-TRA tools. Then, the Roman-Liu equation and mean square amplitude of acceleration waves were used to measure fatigue with a dynamometer and a three-axis accelerometer, respectively. Finally, according to the nature of risk factors and the phenomenon of fatigue, six categories (24 methods) of supervised machine learning (SML) based on classification were selected. MatLab software (MatLab R2017b, The Mathworks Inc., MA, U.S.A.) was used to fit the models using SML.
Results: The best-fitted models in the first and second half of the work shift were obtained using support vector machine methods. Physical risk factors had a significant impact on physical fatigue. After filtering low-priority risk factors, in the first half of the work shift, the most optimal model had an accuracy of 71.8%, precision of 72.5%, sensitivity of 76.9%, specificity of 70.8%, and discrimination power equal to 73%. In the second half of the work shift, the accuracy, precision, sensitivity, and specificity of the optimized model were 60.3%, 57.5%, 50%, and 46.9%, respectively, and the discrimination power was obtained at about 62%.
Conclusion: The fitted models for hand fatigue had acceptable performance in both sections of the shift but can still be optimized. Therefore, it is necessary for future studies to improve the quality of input and output data and include other dimensions affecting fatigue such as cognitive workload and type of work shift in future models.

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Introduction: Pipelines are widely used to transport large volumes of oil and gas over long distances. Risk assessment can help identify risk factors and create an appropriate action plan and strategy to reduce or eliminate them. The main goal of this research is to provide a method for assessing the risk of pipelines based on the Fuzzy Inference System (FIS), creating a systematic format that is expected to be a more effective, accurate, and reliable model for controlling risks related to oil and gas pipelines.
Material and Methods: In this article, fuzzy logic is used to model uncertainty and present a model for assessing pipeline risk. The Muhlbauer method, one of the most common risk assessment methods for oil and gas pipelines, has been employed to determine critical factors affecting the lines. This method has been implemented using the Mamdani algorithm and based on expert knowledge in the fuzzy logic toolbox of MATLAB software. To validate the results of the proposed model, data from the interphase pipelines of the fifth refinery of the South Pars Gas Field have been used as a study sample.
Results: The findings from the implementation of the model created in South Pars Phases 9-10 pipelines (on shore) show that the studied pipelines are divided into three parts (A, B, and C) based on indicators such as population density and equipment deployment. Part C of the pipeline has the highest risk, with third-party damage and design being the most important factors affecting it. Part B has the lowest level of risk and results in the fewest consequences for human accidents. It was also observed that corrosion is essential in increasing leakage and risk in all three pipeline parts.
Conclusion: To verify the developed model, the inter-phase shore pipe of phase 9-10 refinery in the South Pars Gas Field was considered as a case study. The findings indicate that the proposed method provides more accurate and reliable results than traditional methods. Factors such as improper operation, dispersion, receptors, leakage volume, and product risk, which are other factors affecting pipeline risk, were not considered in traditional methods. Therefore, the risk level of oil and gas pipelines can be calculated using this model as a comprehensive and intelligent tool.

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Introduction: In many occupations, users must sit for prolonged periods during their job activities. Prolonged sitting is associated with fatigue, leading to postural changes that can increase spinal loads. Despite the importance of this topic in terms of the extent of prolonged sitting and its subsequent adverse consequences, little attention has been given to this occupational activity. Hence, this study investigates changes in neck, trunk, and muscle activities and fatigue levels in prolonged sitting computer tasks.
Material and Methods: Twenty healthy subjects (gender-balanced) from the student community with at least five years of experience in computer work aged between 20-30 years were asked to randomly perform three types of computer tasks for 90 minutes (each task for 30 minutes). Electromyographic (EMG) activities of right and left cervical (ESCR and ESCL), thoracic (ESTR and ESTL), and lumbar (ESLR and ESLL) erector spine and upper trapezius (UTR and UTL) muscles were continuously recorded. Root mean square (RMS) and median frequency were extracted as EMG metrics. Subjects also rated their perceived discomfort using a Visual Analogue Scale (VAS). The effect of time, gender, and their interaction on muscle EMG activities, fatigue, and discomfort were explored.
Results: Time had a statistically significant effect on UTR, ESCR, and ESTR muscle activities. UTL and ESCR muscle activities significantly differed between male and female subjects. Further, the findings confirmed the interactive effect of time and gender on ESTR muscle activity. UTR, ESCR, ESCL, ESTL, and ESLL muscles’ fatigue index changed statistically over time.
Conclusion: The findings confirmed neck and trunk muscles’ fatigue by increasing muscular activity and reducing frequency contents over time, per the subjective rating of discomfort.

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Introduction: With the spread of the COVID-19 pandemic and the lack of adequate protection by existing protective equipment, many researchers’ attention has turned to developing improved respiratory protection equipment. Considering their special properties and nanoscale dimensions, electrospun nanofibers are a suitable option for improving operational characteristics of substrates used in conventional facemasks. This study aimed to optimize the electrospinning process of polyacrylonitrile nanofibers (PAN) containing ZIF8 and use the optimized substrate in medical facemasks to increase their protective performance.
Material and Methods: This study employed an environmentally friendly method to synthesize ZIF8 in an aqueous environment. Then, PAN/ZIF8 polymer solutions were prepared in dimethylformamide. The effects of electrospinning parameters, including electrospinning voltage, polymer solution concentration, electrospinning distance, and polymer injection flow rate on diameter and uniformity of nanofibers were investigated. Electrospinning conditions were optimized using response surface methodology (RSM) and central composite design (CCD) to obtain desired values for response (dependent) variables. Finally, optimized PAN/ZIF8 and PAN nanofibers were electrospun on spun-bond substrate. Base weight, average diameter of fibers, filtration performance, pressure drop, and quality factor of fabricated substrates were assessed.
Results: According to results, optimal conditions for electrospinning of PAN/ZIF8 polymeric solution for polymer concentration (A), electrospinning voltage (B), electrospinning distance (C), and polymer injection flow rate (D) were respectively 70 w/v%, 20 kV, 18 cm, and 0.4 ml/h. Moreover, despite lower base weight of PAN/ZIF8 nanofiber mask, it displayed higher filtration performance (98.51%), lower pressure drop (31.42 Pa), and higher quality factor (0.140 Pa-1) in comparison to other studied masks.
Conclusion: Experimental models developed in this study provide acceptable values for filtration efficiency and quality factor for filtration applications. Additionally, they serve as a guideline for subsequent experiments to produce uniform and continuous nanofibers with desired diameter for future applications in absorbent media (intermediate absorbent layers) of respirators.

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Introduction: Iran has the most extensive maritime transport fleet in the Middle East, with 2700 km of water border with other countries in the region. However, the complex and hazardous marine environment has turned this advantage into a disadvantage. On the other hand, technological advancement has added to the complexity. Thus, new accident analysis tools should be developed to bring unity to marine casualty analysis and improve the analyst’s power of discovery from incident information. The current project aims to develop a specialized AcciMap-based marine accident investigation method.
Material and Methods: The primary stages of this applied descriptive study include data collection, method development, and validation. The necessary information about the factors leading to marine accidents was initially gathered through a review of previous studies, expert interviews, and analysis of actual cases. The AcciMap technique was then partially developed, and marine experts approved the designed model.
Results: This study’s results included an AcciMap model established on three levels: external influences (national and international), intra-organizational factors, and environmental/individual conditions and individual activities. Whereas external factors (international and national) are categorized into three main layers, two sublayers, and 13 secondary sublayers, intra-organizational factors are categorized into two main layers, 11 sublayers, and 35 secondary sublayers, and environmental/individual conditions and individual activities are organized in one main layer, three sublayers, and 11 secondary sublayers.
Conclusion: The developed approach can identify flawed levels and determine who is responsible for implementing corrective action. Because it includes emerging components that are effective in accidents, the method used in this study can better examine data from marine accidents.

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Introduction: The aim of this study was to investigate the effect of particle size (mesh) on the sound absorption coefficient of the absorbers made from Arundo Donax reed and to determine the optimal mesh for sound absorption.
Material and Methods: After crushing the reed stems in 10, 30, 20, 16, and 40 mesh sizes, they were washed with 5% NaOH. To make the samples 3 and 10 cm in diameter, 10% PVA was used as a binder, and the impedance of the two-channel tube was used according to ISO 10534-2 standard to determine the absorption coefficient. 22 samples of meshes 16 and 20 were made to achieve the optimal mesh based on the optimized RSM method, and the SAA index was used to compare the samples and determine the optimal mesh.
Results: The highest absorption peak was related to meshes 16 and 20 at the frequency of 2500 Hz, which is 0.94 and 0.98 ,respectively. The effect of increasing the thickness and density on the absorption coefficient is evident. The results have shown the effect of increasing the thickness and density on the absorption coefficient in mesh 20 in such a way that by increasing the density from 150 to 250 and the thickness from 10 to 30 mm, the absorption coefficient has increased from 35 to 63.5%. The optimal sample was mesh 20 with a thickness of 30 and a density of 250 kg/m3, which had the highest average absorption (SAA=0.57). The greater distance between the real and imaginary parts of the impedance shows the reactivity of the sample. In mesh 16 this distance is greater, as a result, mesh 16 has more reactivity and correspondingly less absorption.
Conclusion: The role of particle mesh as one of the important and influencing parameters on absorption coefficient has been investigated in this study.

 

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Introduction: Strategic management involves determining the organization’s direction, preparing a strategic vision and mission statement, and providing the basis for growth, profitability, and production. It also includes the inclusion of employee safety and health programs throughout the organization. The existence of a strategic plan for the scientific and practical strengthening of occupational health and safety is one of the country’s academic and industrial priorities. The purpose of this study is to present a strategic plan for developing the specialized field of occupational health and safety engineering in Iran.
Material and Methods: The current study is a collaborative action research study that was conducted in 2021. The strategic planning committee consisted of 20 professors, experts, and doctoral students. Over the course of 14 weeks, they held regular weekly meetings, collected information from inside and outside the organization, analyzed the organization’s internal and external environment, and identified its strengths, weaknesses, opportunities, and threats. Based on this analysis, the committee determined the organization’s mission, perspective, values, and general and specific goals for 2021-2024. They also identified the necessary measures to achieve these goals and developed an operational plan to improve the performance of the specialized field of occupational health and safety.
Results: Conducting this applied research led to the strategy of internal and external analysis of the specialized OHS field, determining the direction of the basic strategy, mission, perspective, values, and general goals. Finally, seven specific goals and 286 actions were determined to improve the performance of OHS. The SWOT analysis of OHS’s internal and external environment identified 27 strengths, seven weaknesses, 26 opportunities, and 12 threats. According to the results of the SWOT matrix, the strategic position of the OHS field is to implement preventive strategies and maintain existing conditions.
Conclusion: This plan aligns with the 4-year OHS plan. In developing the program, attention has been paid to the documents and policies of upstream organizations. The strategic position of occupational health and safety engineering is a prudent strategy. In this situation, strategies for maintaining existing conditions can be applied. Therefore, it is suggested to reduce the weaknesses of OHS as much as possible and increase its strategic capabilities by focusing on prudent strategies. From the second year of implementing the strategic plan, the OHS field can gradually focus on developing activities.

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Introduction: Air traffic control is a very complex process, including multiple human-machine interactions. Human mental workload plays an important role in this process. Nowadays, electroencephalography indexes are considered as new indicators in the field of assessment of mental workload. The purpose of the present study was to investigate the relationship between EEG theta power and mental workload in air traffic control simulation.
Material and Methods: Fourteen air traffic controllers participated in this study. Controllers carried out two scenarios, including low and high workload, based on task load factors in an air traffic control simulator. Mental workload was assessed in these two scenarios by the NASA-TLX questionnaire. EEG signals were continuously recorded during air traffic control tasks. Afterward, absolute theta power was extracted from participants’ EEG using Fast Fourier Transform (FFT) by the MATLAB software and was compared with each other in terms of high and low workload.
Results: The results showed a significant relationship in absolute theta power during low and high workload scenarios in all regions of the brain (p < 0.05). Absolute theta power increased primarily in the frontal region during the high workload scenario. Also, there was a significant increase in the relationship between work experience and absolute theta power at the F3 region during the high workload scenario (P=0.021, r=0.607).
Conclusion: Absolute theta power provides a good parameter to assess mental workload at different levels of air traffic control tasks. Therefore, it can be used as a tool for the design of human-machine complex systems.

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Introduction: Toluene, benzene, xylene, and ethylbenzene (BTEX) belong to the class of monocyclic aromatic hydrocarbons and are identified as toxic volatile compounds due to their harmful properties. The reliable biomarkers for occupational exposure to these toxic compounds are hippuric acid (HA), trans,trans-muconic acid (tt-MA), mandelic acid (MA), and methylhippuric acid (MHA), which correlate with toluene, benzene, ethylbenzene, and xylene, respectively.
Material and Methods: A novel magnetized imine-linked covalent organic framework (Fe3O4@TFPA-Bd) was synthesized, marking its inaugural use as a sorbent in microextraction by packed sorbent (MEPS). The synthesis of Fe3O4@TFPA-Bd was executed in a straightforward and efficient manner, using Fe3O4 nanoparticles as the magnetic core and benzidine (Bd) and Tris (4-formyl phenyl) amine (TFPA) as the structural building blocks. This newly produced sorbent was tested for the microextraction of hippuric acid (HA), mandelic acid (MA), trans, trans-muconic acid (tt-MA), and m-methyl hippuric acid (m-MHA) from urine samples, which were then analyzed using high-performance liquid chromatography (HPLC). In order to optimize the extraction performance, parameters like sample volume, elution volume, extraction cycles, pH, and sample solution temperature were thoroughly adjusted. The synthesized adsorbent underwent thorough characterization via scanning and transmission electron microscopy (SEM and TEM), Fourier transforms infrared spectrometer (FTIR), and X-ray diffraction (XRD).
Results: The developed method showcased promising attributes: low detection limits (0.02 µg/ml for tt-MA, S/N=3), low quantification limits (0.06 µg/ml for tt-MA, S/N=10), a solid linear range (0.5-320 µg/ml for MA, R > 0.99), and commendable intra- and inter-day precision (2.4%-4.3% and 3.1%-7.8%, respectively) for volatile organic compound (VOC) biomarkers. Furthermore, the method demonstrated recoveries in the 81-87.5% range for spiked samples, indicating its practicality and effectiveness.
Conclusion: The developed procedure was suitable for the determination of BTEX biomarkers from urine samples and can be an alternative to previous methods.

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Introduction: Prolonged sitting postures are among the risk factors for musculoskeletal disorders in occupational settings, leading to increased musculoskeletal discomfort in various body regions. This discomfort can negatively impact individuals’ health and impose high costs on society in terms of work absences, early disabilities, and reduced productivity. The purpose of this study is to investigate the effect of stretching exercises on the level of discomfort, muscle activity, and muscle fatigue in the neck and trunk region during prolonged sitting tasks.
Material and Methods: This experimental study was conducted among 20 healthy male and female participants under two test conditions: control and intervention. In the control condition, participants performed cognitive tasks (watching videos, typing, text editing, and nback cognitive test) without any intervention. In the intervention condition, participants performed stretching exercises before each task. The Visual Analogue Scale was used to assess perceived discomfort. Also, muscle fatigue was evaluated using an electromyography (EMG) device and RMS and MPF measures.
Results: Discomfort in hands and arms (p-value=0.04) and lower back (p-value=0.03) during video-watching was higher in the control condition than in the intervention. Regarding muscle activity, the activity of the right cervical erector spinae during the video-watching task was lower in the control condition than in the intervention. In the n-back cognitive test and text editing, the right lumbar erector spinae muscle activity was significantly higher in the control condition than in the stretching exercises intervention. Regarding the left cervical erector spinae, a significant difference was observed between fatigue in control and intervention conditions during the video-watching task. Also, right thoracic erector spinae fatigue in text editing was higher in the control condition than in the exercise intervention; however, for the n-back test, the level of fatigue was lower in the control condition compared to the intervention.
Conclusion: The perceived discomfort in seated computer tasks is generally lower in the exercise intervention compared to the control condition. The stretching exercises used in this study improved muscle activity and reduced fatigue in some of the trunk muscles, although the effects of the exercises depend on the type of task. Overall, muscle fatigue in two cognitive tasks, text editing and n-back, was more affected by stretching exercises than other tasks.

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Introduction: Toluene is significant pollutants in the air. Long-term exposure to toluene can lead to adverse effects.  Biofiltration is one of the air pollutant control methods. In this study, Pseudomonas putida was selected as a microorganism capable of hydrocarbon degradation and its ability to biodegrade toluene in a suspension growth reactor was also investigated.
Material and Methods: Experiments were conducted in two days and in five hours. Each method consisted of three sample reactors (A, B, C) and one control reactor (D). In the first method, the amount of bacteria in the sample reactors is 0.5, 1 and 2 McFarland and the amount of toluene injection into the reactors is the same (0.5 microliters) and in the second method, the amount of toluene injection into the sample reactors is 0.5, 1 and 1.5 microliter and 1.5 microliter in the control reactor and the amount of bacteria in them was the same (1 McFarland).Toluene gas samples and carbon dioxide were periodically analyzed.
Results: In the first method of toluene decomposition, there was a significant difference between the three reactors (p-value = 0.002). The results of the second method were also significantly different between the three reactors (p-value<0.001). The decomposition of toluene in two methods also had a significant difference (p-value = 0.232). The amount of CO2 production was significantly different in the second method (p-value=0.003) and the first method (p-value<0.001), but no significant difference was observed in the comparison of the two methods (p-value=0.15).
Conclusion: Increasing bacterial in suspension growth reactor resulted in increased toluene biodegradation in shorter time while increasing toluene in suspension growth reactor may not have an additive effect on the biodegradation process.

 

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Introduction: The COVID-19 pandemic caused many businesses to face problems and created job insecurity, leaving many workers and employees stressed about losing their jobs. Therefore, the current research aimed to analyze the impact of workplace safety management measures on the behavior of organizational citizens concerning the role of job insecurity and the perceived risk of COVID-19 among the employees of Mashhad Social Security Organization.
Material and Methods: The current applied research is a descriptive survey. The research population is all 560 employees of the social security organization of Mashhad city. The sample size was estimated based on Morgan’s table using a convenience sampling method, with a total number of 225. The data collection instrument was Wu et al.’s (2022) standard questionnaire, used to check construct validity and confirmatory factor analysis. Cronbach’s alpha coefficient and composite reliability were used to measure reliability, and the results showed that the questionnaire was adequately valid and reliable. The data analysis also involved structural equation modeling conducted in Smart PLS.
Results: The results showed that workplace safety management measures have an impact on organizational citizenship behavior and the perceived risk of COVID-19. Also, the perceived risk of COVID-19 has a positive effect on perceived job insecurity. Yet, the perceived risk of COVID-19 does not influence organizational citizenship behavior and does not mediate the relationship between workplace safety management measures and organizational citizenship behavior. Workplace safety management measures have an impact on perceived job insecurity, and job insecurity has an impact on organizational citizenship behavior.
Conclusion: In light of the present findings, it can be concluded that workplace safety management measures are among the most important programs and strategies of organizations to increase citizenship behaviors, support employees, and provide safe conditions in an organization.

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Introduction: Many industries have multiple factors harmful to health, leading to simultaneous exposure of these factors to each other. Noise is one of the most common physical parameters in the work environment. On the other hand, heat is also increasing due to various energy processes in industries. Therefore, this study was conducted with the aim of determining changes in physiological parameters and visual-auditory attention in acute exposure to heat and noise.
Material and Methods: In this experimental study, 72 individuals (36 men and 36 women) aged between 23 and 33 years participated according to the inclusion criteria. In total, 12 different test modes were performed (3 temperature levels and 4 noise pressure levels). The test was conducted for each person in 4 steps during a specific day. The duration of exposure to each condition was half an hour, and a half-hour rest was given between each test condition. Saliva samples of each subject were collected before and immediately after exposure to noise and heat. Also, The Integrated Visual and Auditory (IVA) was recorded by the participants simultaneously.
Results: The results of combined exposure to noise and heat on visual and auditory attention showed that only two modes of combined exposure, SPL95+WBGT34 and SPL95+WBGT29, caused a significant increase (P < 0.05) in mental workload and a significant decrease (P < 0.05) in visual and auditory attention. In addition, the results showed that independent exposure to noise at the levels of 85 and 95 dB and exposure to heat at higher temperature levels of 34 and 29 degrees Celsius cause a significant increase (P < 0.05) in salivary cortisol after exposure. The results of the effect of combined exposure to noise and heat on salivary cortisol showed that three experimental modes of combined exposure (SPL85+WBGT34, SPL95+WBGT29, and SPL95+WBGT34) caused a noticeable and significant (P<0.001) increase in salivary cortisol.
Conclusion: Indeed, salivary cortisol can be recommended as a physiological index to evaluate noise and heat exposure. It’s also noteworthy that salivary cortisol is more affected by noise and heat exposure than cognitive performance.

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Introduction: Several extraction techniques have been developed in recent years to determine the concentration of volatile metabolites in a biological sample. This study conducted with the aim of using the needle trap device- molecularly imprinted polymer (NTD-MIP) for the co-extraction of n-hexane and methyl ethyl ketone (MEK) in the urine matrix.
Material and Methods: Characterization of MIP was investigated by fourier-transfer infrared spectroscopy (FT-IR), field emission scanning electron microscopy (FE-SEM), and brunauer–emmett–teller (BET). The response surface methodology - central composite design (RSM-CCD) was used to optimize the extraction conditions of n-hexane and MEK with the input variables of absorption temperature, absorption time, salt percent, and stirring speed. Method validation was performed with determination of the precision, accuracy, the limit of detection (LOD), limit of quantification (LOQ), and dynamic linear range.
Results: The optimum conditions were an extraction time of 60 min, an absorption temperature of 65 °C, 22% of salt, and a stirring speed of 250 rpm. The linear ranges of n-hexane and MEK were determined in ranges of 30-500 and 30-4000 µg/L, respectively. The intra-day and enter-day relative standard deviation were evaluated in the range of 3 to 10 and 1 to 7, respectively. The average recovery of n-hexane and MEK were estimated 99.3 ± 0.8 and 99 ± 0.9, respectively.
Conclusion: The HS-NTD method is suggested as a suitable method for determining very low amounts of MEK in urine along with n-hexane.


 

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Introduction: Nurses’ high workload may affect their ability to work, cause health problems, and reduce nurses’ quality of life. Considering the important role of nurses in society’s health, it is important to identify the factors affecting their physical and mental health. The current study investigates and correlates nurses’ workload, quality of life, workability, and contextual variables.
Material and Methods: In this descriptive-analytical and cross-sectional study, 142 subjects from the ICU, CCU, emergency department, and other departments of Qazvin educational-therapeutic hospital participated. Data collection tools included a demographic information questionnaire, NASA-TLX (Task Load Index), Short Form Health Survey (SF-36), and work ability index (WAI). Data were analyzed with an independent t-test, Pearson’s correlation coefficient, and a one-way ANOVA test.
Results: The mean and standard deviation of nurses’ age and work experience were 31.3±6.1 and 7.6±5.8, respectively. The mean and standard deviation of nurses’ workload score, quality of life, and workability were 80.4±13.4, 55.5±18.7, and 31.8±7.3, respectively. According to the results, nurses’ workload had a significant relationship with quality of life (P-value=0.001) and workability (P-value=0.000). Significant relationships were also observed between quality of life and workability (P-value=0.001). Quality of life had a significant negative correlation with age, work experience, and the number of nurses’ shifts per month (P-value<0.05). Nurses with higher education had lower workload and higher workability.
Conclusion: Nurses working in ICU and CCU units had a higher workload. Nurses with higher education levels had less workload and more ability to work. There was an inverse correlation between workload quality of life and nurses’ workability. It is possible to reduce nurses’ workload by reducing their tasks and working hours.

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Introduction: Compared to other hospital departments, emergency department (ED) nurses experience higher levels of occupational fatigue. However, despite the importance of fatigue in EDs, limited studies have investigated the issue. Therefore, the present study aimed to identify factors affecting ED nurses’ fatigue with a systemic approach and provide a comprehensive model of fatigue.
Material and Methods: The present study was the first phase of a mixed-methods study with an exploratory sequential design that was conducted qualitatively. Data was collected using a semi-structured interview technique among ED nurses in TUMS hospitals in Tehran. The data was analyzed with a systematic approach and qualitative content analysis method. To check the credibility and trustworthiness of the study results, Goba and Lincoln criteria, including transferability, peer review, and member check, were used.
Results: Extensive factors were identified in the four levels of nurses’ work system, including individual factors, work unit, organization, and extra-hospital factors that could facilitate or prevent nurse fatigue. Specifically, the categories that were mentioned the most by the nurses were aggression and conflict with visitors, ED workload, understaffing, crowding and noise, obligatory overtime, acknowledgement, visitor’s expectations, reporting (paperwork), and clients’ distrust of nurses. Finally, based on the qualitative results, a conceptual model of factors affecting occupational fatigue of ED nurses in Tehran was presented.
Conclusion: Traditionally, fatigue management programs in hospitals only consider issues related to work shifts and sleep hygiene. However, the results of the present study revealed other fatiguing factors in the work system of ED nurses. These findings can help health system decision makers and HFE experts in designing effective fatigue risk management systems in Iranian hospitals, especially in emergency departments.

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Introduction: Studies have demonstrated that teaching carries a substantial burden of health risks. Prevalent health issues among teachers include asthma, respiratory diseases, musculoskeletal problems, and mental disorders. These problems can be attributed to the specific attributes of their work environment. Consequently, this study aims to investigate the correlation between air quality within educational establishments and the overall health of teachers.
Material and Methods: This systematic review aims to examine the impact of temperature, humidity, and ventilation rates within educational environments on teachers’ health status and thermal comfort. Relevant studies were searched for using the PubMed and Web of Science databases, employing keywords such as teacher, temperature, humidity, ventilation, school, classroom, health symptoms, and thermal comfort (2000-2022). The inclusion criterion was that articles examined teachers’ health and comfort with temperature, relative humidity, and ventilation of the educational place.
Results: Out of the 103 articles found in the initial search, 13 articles were finally reviewed. Six studies investigated the voice abnormalities of teachers due to various factors (including temperature, relative humidity, and the ventilation rate of the educational place) and found that these abnormalities were affected by these factors. Two studies explored the relationship between the prevalence and exacerbation of respiratory symptoms and quality parameters of the indoor environment of educational places. Additionally, five studies investigated the relationship of air quality parameters of educational places with common non-specific symptoms among teachers.
Conclusion: Teachers frequently experience symptoms such as voice disorders, respiratory difficulties, allergies, and other nonspecific ailments, which may be associated with the quality parameters of the indoor environment in educational settings. These parameters include temperature, humidity, and ventilation rate. Consequently, controlling and regulating these parameters within the recommended values can help prevent the onset or exacerbation of these symptoms.

 

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Introduction: Medical centers, as complex technical-social systems, are exposed to the risk of fire incidents. This study analyzes the causes and contributing factors of the fire accident at Sina Mehr Clinic to prevent similar accidents, resulting in 19 deaths and 14 injuries.
Material and Methods: The causes and contributing factors for accidents in medical centers are found through studies related to laws and regulations, official accident reports, expert reports of regulatory bodies, interviews with experts, and review of past studies, extraction, and categorization. Accident analysis methods included AcciMap and STAMP. Finally, experts’ opinions were used to confirm and strengthen the findings.
Results: The most critical root and hierarchical causes of the weakness of medical center management in the field of safety, dangerous conditions, fire accidents, and emergency response are the issuance of a legal building completion permit for a building that violates national building regulations and the issuance of a legal permit for a medical institution for a building with residential use, as well as the insufficiency of supervision by government and public institutions with horizontal relationships with each other and vertical relationships with universities of medical sciences, labor offices, and firefighting organizations, as the direct supervisors of medical centers.
Conclusion: The AcciMap and STAMP findings indicate that the priority is to amend the regulations for the establishment, operation, and activity of medical centers with an emphasis on safety regulations, as well as the frequency and shortening of feedback loops such as inquiring about the building completion permit from the municipality, announcing the establishment of a medical center to other governmental and public supervisory authorities, and the reporting of unsafe cases directly by supervisors to the Ministry of Health. Legal authorities are the most crucial cycle in the resilience of fire incidents and their consequences in medical centers.