Journal of Health and Safety at Work

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Introduction: one of the most important complications of exposure to ionizing radiation is emergence of cancer tumors, which happens as a result of oxidative DNA.  Therefore, the present study was conducted, aimed to measuring 8-DIHYDROxy- 2’- DEOXYGUANOSINE (8-OHdG) level in radiographers’ urine as oxidative damage biomarker, as well as comparing this biomarker with cumulative effective doses.  
Material and Methods: In the present study, the samples were selected into two categories, 35 of whom were from different radiography groups (including nuclear medicine, radiology, radiotherapy, CT scan), and 35 subjects were from the staff, who had no exposure to radiation. The results of the film badge were gathered from the hospitals. Since film badge monitoring period was found to be 2 months, the collective effective dose was obtained according to the respective formula for 30 last period and 6 last period. Then, at the end of the work shift, the urine samples were taken to determine the 8-OHdG concentration. The samples were obtained via the SPE (solid-phase extraction) method. After that, the 8-OHdG concentration was read by the GC/MS analyzer. Finally, the data extracted from the 8-OHdG concentration and the collective effective dose of the radiation were analyzed by SPSS software.
Results: The results showed an increase in the level of 8-OHdG, as one of the oxidative biomarkers in the body of radiographers, but the level of 8-OHdG showed a direct relation in the body of the radiographers with an average collective effective dose of radiation in the last 30 as well as the last 6 periods.
Conclusion: Observing the radiation protection principles by radiation workers results in decreased radiation and, in turn, reduces the level of oxidative stress, thus, reducing the potential effects of radiation.

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Introduction: Each country needs to preserve its human capital through preventing accidents for its development. Therefore, this study is carried out to study the relationship between safety investments and safety performance indices considering the interactive effect of the project hazard level in construction industry.
Material and Methods: This study was conducted using multiple case studies in 5 major construction worksites, in Tehran, in 2019. Data was collected using questionnaire, checklists and interview as well as evaluating the safety documents. The data analysis in this study was carried out using SPSS 18.
Results: There was a strong inverse correlation between safety investments (total safety investment, basic safety investment, and voluntary safety investment) and accident frequency rate (AFR) (r=-0.936, P-value<0.05), and there was a direct strong correlation between safety investment and safety performance (P-value<0.05, r=0.939). Also, the effect of various safety investments on safety performance indices under various project conditions (project hazard levels) was not the same; when the project hazard level was high, the effect of safety investments on safety performance was higher.
Conclusion: Increasing safety investment improves safety performance through decreasing the accidents. Also, investment in both safety components (basic safety investment and voluntary safety investment) might improve safety performance. The results of the current study can be used as a basis by the contractors and construction companies to invest in safety and to determine proper budget for managing safety of construction projects.

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Introduction: The noise could affect some aspects of human health, including the cognitive performance. In addition to sound pressure level and exposure time, the psychoacoustic features of noise may cause destructive effects on humans. A few recent studies have been conducted on effect of sound quality on cognitive performance. This study aims to find the noise loudness and sharpness levels as the most destructive effects on human cognitive performance.
Material and Methods: This was a cross-sectional study on 10 male students of Tehran University of Medical Sciences. The Noises were generated in two channels that the left channel produced the pink noise as a background noise. The pink noise loudness and sharpness were 19.7 sone and 2.49 acum, respectively. The right channel generated noises with different loudness and sharpness levels the noise loudness ranged from 8.87 to 67.9 sone and the noise sharpness ranged from 1.07 to 6.4 acum. Finally, ten noises with different loudness and sharpness were applied. The students were exposed to ten different types of noise and a silent condition. The Mathematical Problem Solving Task (MPST) test was performed to assess cognitive performance. The reaction time and the accuracy rate were measured after 5 minutes of noise exposure. Data were analyzed by SPSS (ver. 22). P< 0.05 was considered as significant level.
Results: The mean reaction time and the mean accuracy rate increased with the sharpness level.  However, alteration in the loudness and sharpness levels had no significant effect on the speed and accuracy of students. Performance speed increased in noise 3 with the highest loudness (L=67.9, SH=1.07) in comparison with the silent condition (p-value=0.05). The mean accuracy rate in exposure to the noise 9 reduced in comparison with silence (p-value=0.04)
Conclusion: Different levels of psychoacoustic features had no significant effect on the cognitive performance parameters. Although, the accuracy rate and the reaction time decreased in noises 9, the sharpest noise, and 3, the loudest noise, in comparison to the silence, respectively.

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Introduction: Rapid population growth and industrialization have increased chemical pollutants. Some studies show that employee exposure to formaldehyde in industrial places, hospitals, and laboratory settings is more than the allowed limits. Therefore, it is necessary to implement a proper control system to reduce this exposure. This study aimed to synthesize Ag3PO4/TiO2 nanocomposite, determine its morphological and structural characteristics, and test the degradation efficiency of this photocatalyst on formaldehyde.
Material and Methods: Ag3PO4/TiO2 composites were synthesized via an in-situ precipitation method. The physicochemical, morphological, and optical properties of the synthesized sample were investigated by employing the BET method, X-ray diffraction (XRD), UV–visible absorption spectroscopy, and scanning electron microscopy (SEM). The photocatalyst degradation efficiency test was performed on gaseous formaldehyde in a 3.2-liter photoreactor under visible light radiation.
Results: The UV–Vis absorption spectrum of the Ag3PO4/TiO2 sample noticeably shifted to the visible light region compared to that of the TiO2. The bandgap energy of the nanocomposite was 2.3 eV. The SEM image demonstrated that the average particle size of the nanocomposite was about 102 nm. The result of the degradation efficiency tests revealed that 63% of the formaldehyde was removed under visible light irradiation after 90 minutes by the Ag3PO4/TiO2 photocatalyst.
Conclusion: The adopted synthesis method adopted was highly efficient and appropriate for the synthesis of Ag3PO4/TiO2 nanocomposite according to the analyses. The Ag3PO4/TiO2 photocatalyst performed well under visible light radiation and could be used in pollution control systems.

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Introduction: Numerous studies have been conducted on the development of modern insulators, including nano-insulators. However, a comprehensive study has yet to be performed to review and investigate the thermal properties of these insulators. Consequently, this study aimed to examine the effect of nanomaterials on thermal insulation function.
Material and Methods: In this review, articles were searched for in English databases (PubMed, Web of Science, and ScienceDirect), Persian databases (Magiran, SID), and Google Scholar. The keywords used in the search were Nano Material, Nano Insulation, Thermal Insulation, Thermal Insulator Stability, and Thermal Conductivity in both English and Persian.
Results: Of the 4068 studies identified through search databases, 15 were selected according to the entry criteria. Among the studies, the three types of silicone, composite, and aerogel insulation had the highest frequency (each 26.67%), and SiO2 nanoparticles were the most prevalent nanomaterial (26.67%). According to the studies, the type of nanomaterial used in insulation will improve its properties such as thermal resistance, mechanical strength, dielectric strength, tensile strength, elasticity, and hardness.
Conclusion: The results of this study showed that using nanotechnology could be an effective step in improving the properties of insulation materials, the most important of which is increased thermal resistance. Moreover, nanotechnology insulators can prevent thermal energy loss, reduce costs, and provide safety and comfort.

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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: VOCs are harmful air pollutants that must be detected, monitored and eliminated. Adsorber tubes are standard tools for this task, specifically activated carbon tubes with high adsorption and selectivity. This research aims to compare the structural and functional characteristics of domestically produced activated carbon tubes with the conventional commercial ones for sampling toluene, a volatile organic compound.
Material and Methods: The characteristics of each adsorbent, such as structure, morphology, porosity, and element composition, were examined by SEM photography, BET testing, and EDAX analysis. The central composite design (CCD) method was employed to investigate the adsorption properties of the adsorbents. The input concentration and readsorption time of the samples were the variables considered in this study. Additionally, a field phase of personal air sampling was performed to evaluate the effectiveness of adsorbent tubes.
Results: SEM and BET analyses indicated that the porous structure of domestic activated carbon was comparable to the model produced by SKC. EDAX analysis detected a minor impurity (1%) in the domestic activated carbon adsorbent. The adsorption performance was significantly influenced by the variations in readsorption time and pollutant input concentration. The accuracy and precision of the performance of the domestic adsorbent tube were obtained as 90.77% and 91.76%. The field phase results demonstrated that the amount of pollutant adsorbed in the SKC-activated charcoal adsorber did not differ significantly during 0 to 30 days. However, the domestic adsorber showed a significant difference in the same period. The overall performance of the two adsorbers did not exhibit a significant difference between 0 and 30 days.
Conclusion: Despite minor structural differences, the adsorption efficiency of toluene by domestic adsorbent tubes in sampling high concentrations is very similar to its commercial type. However, it is not recommended for use in low-concentration environments (10 ppm and less).

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Introduction: Due to the increase in the provision of electronic services to citizens in government offices, the number of computer users and the occurrence of musculoskeletal disorders have increased. Therefore, this study aimed to predict and model the complex relationships between the risk factors of musculoskeletal disorders in computer users working in government offices by an artificial neural network.
Material and Methods: The current cross-sectional study was conducted in 2020 on 342 employees of various government offices in Saveh city. First, the researcher visited the work environment to identify the problems and measure the environmental factors. Then, ergonomic risk assessment and psychosocial factors were evaluated using the Nordic questionnaire and the ROSA method. The effect of various factors in causing musculoskeletal disorders was investigated using a logistic regression test.Then the resulting data were collected and modeled by one of the neural network algorithms. Finally, artificial neural networks presented an optimal model to predict the risk of musculoskeletal disorders.
Results: The results showed that by increasing the level of social interactions, the level of demand, control, and leadership in the job, musculoskeletal disorders in men and women decrease. There was a significant relationship between the prevalence of musculoskeletal disorders and job demand, job control levels, social interaction levels, leadership levels, organizational climate levels, job satisfaction levels, and stress levels, in addition between reports of pain in the neck and shoulder and wrist/hand region. There was a significant relationship with the overall ROSA score. Also, there was a significant relationship between the report of pain or discomfort in the neck area with the phone screen risk score, wrist/hand with the keyboard-mouse risk score, and shoulder, upper back, elbow, and lower back with the chair risk score. The accuracy of the presented model for predicting musculoskeletal disorders was also about 88.5%, which indicates the acceptability of the results.
Conclusion: The results showed that several factors play a role in causing musculoskeletal disorders, which include individual, environmental, psychosocial, and workstation factors. Therefore, in the design of an ergonomic workstation, the effects of the mentioned factors should be investigated. Also, predicting the effectiveness of each of the mentioned factors using an artificial neural network showed that this type of modeling can be used to prevent musculoskeletal disorders or other multifactorial disorders.

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Introduction: For years, chemical process industries have reported the unexpected release of highly hazardous liquids and gases. A disaster could not be avoided when these materials were not adequately controlled. The issue of Process Safety Management (PSM) is still being discussed in developing and developed countries. PSM was established to manage the risks of a company’s personnel, properties, products, environment, and credit risks. This study aimed to review the challenges and achievements of PSM implementation and provide recommendations for improvement.
Material and Methods: A collection of scholarly articles published from 2000 to 2023, such as Science Direct, WOS, PubMed, and Scopus, was chosen through a systematic, meticulous review. After thoroughly examining these abstracts, titles, and complete contexts, 49 articles were finally selected for inclusion in the study and classified based on different criteria, such as publication year, authors, achievements, and challenges.
Results: PSM in the United States has been chiefly studied due to the high number of chemical process industries and its presence in the form of OSHA legislation in this country. The areas of operations, audits, and resources have the most challenges in implementing PSM. On the other hand, reducing the severity of incidents in chemical processes and increasing productivity are considered the most significant achievements of PSM implementation.
Conclusion: PSM as an interdisciplinary field has improved  and become more effective over the years.. However, incidents still exist, and the number can increase, considering the growth of industries’ chemical processes. Therefore, a deep look at the issues of risk-based regulations, competency, operational excellence, and learning from incidents is necessary to achieve excellence in PSM.

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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.