milad abbasi

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.

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.

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.

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.

The purpose of this paper is to identify the most effective technical indicators in the cryptocurrency market, as viewed by market experts, optimize their performance using optimization algorithms, and ultimately compare the performance of the selected trading rules against each other and the buy-and-hold strategy.
 
In this research, technical trading rules are extracted and optimized for trading two cryptocurrencies, i.e. Bitcoin and Ethereum, using a mixed qualitative-quantitative method. The efficiency of the extracted rules is evaluated and compared with the buy-and-hold strategy. In the qualitative phase, the most important technical indicators are selected and ranked based on the cryptocurrency experts’ view using the fuzzy TOPSIS technique. In the quantitative phase, the selected trading rules are implemented for a certain period and the parameters of the indicators are optimized using the grid search and particle swarm optimization (PSO) algorithm. Finally, the performance of the trading strategies selected by the experts and optimized using metaheuristic algorithms is evaluated and compared.
 
In the qualitative part of this study, 18 technical indicators were selected as candidate indicators in cryptocurrency trading, using the results of related studies. The selected indicators were ranked based on a survey of thirteen cryptocurrency market experts using the snowball sampling method. Finally, four technical indicators were chosen as superior indicators, showing a significant difference compared to the other technical indicators. The selected indicators were the exponential moving average, relative strength index, Ichimoku, and moving average convergence divergence. In the quantitative part of the research, the expert-based trading rules were implemented for the Bitcoin and Ethereum markets from 2018/06/30 to 2020/06/30. According to our numerical results, most of the expert-based trading strategies are more profitable than the buy-and-hold strategy. Then, the parameters of the expert-based trading rules were optimized using two metaheuristic algorithms, namely grid search and particle swarm optimization. The implementation results showed that the trading strategies optimized by these algorithms outperform both the expert-based and the buy-and-hold strategies.
 
Based on the experimental results of this research, exponential moving average, relative strength index, Ichimoku, and moving average convergence-divergence trading rules are commonly used and proposed by cryptocurrency market experts. Moreover, the profitability of the well-known technical trading rules could be significantly improved using the grid search and particle swarm optimization algorithms. Also, trading strategies using the combination of several technical indicators always perform better than trading strategies with a single indicator. However, all technical analysis strategies are not necessarily more profitable compared to the buy-and-hold strategy. Using inappropriate technical strategies may not only be better than the buy and hold strategy, but sometimes it causes losses in cryptocurrency trading.

In recent years, iron oxide-based magnetic nanoparticles have been widely used for a variety of environmental and medical applications, including the purification and separation of pharmaceutical, dye, and heavy metal contaminants, as well as drug delivery and labeling systems. Due to the fact that magnetite (Fe3O4) has superior magnetic and electrical properties, iron oxide has attracted the most interest among many nanostructured materials.

In this research, magnetite nanoparticles (Fe3O4) were successfully synthesized using a green process. This method is simple, fast, cost-effective, and biocompatible. Allium hooshidaryae (Alliaceae) plant extract was used as a stabilizing and reducing agent in this process. Green synthesized nanoparticles were characterized by several structural and physical techniques, like Vibrating Sample Magnetometer (VSM), X-ray Diffraction (XRD), Fourier Transform Infrared (FTIR), Energy Dispersive X-ray Spectroscopy (EDS), Transmission Electron Microscope (TEM) ) and scanning electron microscope (SEM).

XRD results showed that the synthesized nanoparticles are FCC structure with high purity. FTIR results proved the binding of functional group present in this plant and Fe3O4 nanoparticles. Also, in FTIR analysis, the presence of two absorption peaks of 559.96 cm-1 and 432.57 cm-1 confirmed the successful green synthesis of Fe3O4 nanoparticles. SEM and TEM images showed that the green synthesized Fe3O4 nanoparticles are mostly spherical and have an average size of 35.73 nm. As a result, the synthesized nanoparticles have the potential to have useful benefits in future nanomedicine

The prevalence of multiple health hazards in various industries is on the rise, with noise and heat being common harmful factors in industrial environments in Iran. This study aimed to examine the immediate effects of simultaneous exposure to thermal stress and noise on human brain waves and perceived workload. Seventy-two students (36 men and 36 women) participated voluntarily in this study. Participants were subjected to varying levels of noise exposure, including four noise levels and heat stress (three levels of Wet Bulb Globe Temperature) for 30 minutes each. EEG recordings were conducted for 10 minutes, with participants allowed a 30-minute rest period between each test condition. The combined exposure to noise and heat at two high levels (SPL95+WBGT34 and SPL95+WBGT29) resulted in a significant increase in perceived mental workload compared to the baseline state (P<0.05). EEG analysis indicated a decrease in absolute alpha power in the two high-level conditions compared to the baseline (t<0), while absolute beta power showed a significant increase in the two high-level conditions compared to the baseline mode (SPL45+WBGT22). The study demonstrated that simultaneous exposure to noise and heat, leading to an elevated perceived mental workload, was associated with decreased absolute alpha power and increased absolute beta power in the frontal and occipital regions. These findings suggest that these changes serve as reliable indicators of cognitive and physiological performance.

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.

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.

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.

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.

Occupational noise exposure can be associated with various psychological effects. The present study was conducted with the aim of determining the relationship between noise exposure, annoyance, and loudness perception and social intelligence and general decision-making styles in workers.

This descriptive study was conducted in a mine in Yazd Province in 2022. In this research, 65 workers were selected by convenience sampling and included in the study. In order to determine the level of noise exposure of workers, dosimetry was performed using a TES-1354 device. According to the sound equivalent level, workers were divided into two groups of permitted and unauthorized noise exposure. Worker's annoyance and loudness perception were determined using a questionnaire. Also, in order to evaluate social intelligence, Silvera et al.'s questionnaire was used. Decision-making styles were evaluated by Scott and Bruce's questionnaire. Data analysis was performed using independent sample t-test, Pearson and Spearman’s correlation coefficients, and chi-square and Mann-Whitney tests.

In the present study, there was no significant difference between the two studied groups in terms of demographic variables (p>0.05). The median score of noise annoyance (p<0.001) and loudness perception (p=0.003) were significantly higher in the workers with unauthorized noise exposure. Also, the mean score of the avoidant decision-making style was significantly higher in the workers with unauthorized noise exposure (p=0.018).

In general, the results of the present study showed that unauthorized noise exposure was related to annoyance, loudness perception, and avoidant decision-making style. Considering the non-auditory effects of noise exposure, it seems necessary to implement a hearing protection program in workplaces with unauthorized noise.

Considering the importance of quality of work life of nurses working in the intensive care unit in providing medical services, it is important to identify the components that affect this index. Therefore, this study was conducted to investigate the relationship between workload and quality of work life in intensive care nurses.

In the present cross-sectional and descriptive-analytical study, 384 nurses of the intensive care unit working in hospitals were studied in Tehran in 1400 year. NASA-TLX mental load questionnaire was used to determine workload and The Quality of Work Life Questionnaire (WRQL) was used to determine the quality of their working life. After extraction, the data were entered into SPSS software.

The results showed that the most effective factor in increasing the workload is physical need.
 And the most important dimension affecting the quality of work life is job satisfaction. The correlation between quantitative demographic parameters with workload and quality of life indicators also showed that there is a significant correlation between age, work experience, number of shifts per month with the mentioned indicators.

The results of the present study showed that there is an inverse relationship between workload and quality of work life, it is necessary for hospital managers to be aware of the existing conditions and reduce the factors affecting workload to increase the quality of work life of nurses and subsequently improve the reception of nursing care.

Noise pollution is one of the urban problems that can affect the exposed individuals’ cognitive function. This study set to investigate the impact of traffic noise on drivers’ cognitive variables including perceptual capacity, speed of perception, and divided attention concerning the role of individual orientation and neuroticism.

This study recruited 35 male student participants. The Eysenck personality questionnaire was used to evaluate the participants’ personalities (neuroticism and extroversion). Participants were then exposed to traffic noise, and the Adaptive Tachistoscopic Traffic Perception Test (ATTPT) was performed to assess their capacity and speed of perception. The Peripheral Perception Test (PPT) was also conducted to evaluate the divided attention using the Vienna test system software.

Introverted and stable individuals had better performance in perceptual capacity and speed of perception tasks after exposure to traffic noise. However, these effects were not observed in extrovert and unstable individuals. This study also showed no significant alterations in variables in extroverted (introverted/extroverted) subjects with neuroticism (unstable/stable) concerning divided attention tasks after traffic noise exposure.

This study showed that divided attention in extrovert individuals with neuroticism was not influenced by traffic noise exposure. But perceptual capacity and perception speed was influenced by traffic noise in introverts and unstable subjects.

People’s participation in more efficient control of the disease and public awareness about the risk of COVID-19 affect their preventive behavior. This study examines the level of fear of COVID-19 infection in Iranian society after returning to social activities and business reopening.

This Cross-Sectional study consisted of urban dwellers in Iran, and the data gathering tool was a researcher-designed questionnaire. To design the instrument, the authors interviewed experts and ordinary people to determine the key questions . Then, the questions were modified and finalized based on the experts’ feedback and a reexamination by the experts after two weeks. An online version of the questionnaire was disseminated using social networks. 168 people were included in the study by the available sampling method. Data were analyzed through descriptive statistics methods. Quantitative data as mean and standard deviation were reported, and the qualitative data were reported as numbers. Chi-square test and Spearman correlation coefficient were used to examine the relationship between questions related to COVID-19 infection fear and demographic variables. Data analyses were done in SPSS 20.

The study was carried out on 168 participants, and 78 of them were employees of different offices. The participants believed that among the ways of spreading the disease, kissing and hugging (n=142, 84.5%), shaking hands (n=127, 75.6%), contact with the saliva of an infected person (n=116, 69.0%), and spread through the air (n=60, 35.7%) had the highest frequencies.

Fear of COVID-19 infection in the participants was at moderate and above moderate levels. The participants also hoped that the vaccine would be found and made available to the public. Policy-makers in the health sector can use the results.

There are several generic and specific models to assess the individual job performance (IJP). While these methods may provide the valuable information, none of them cover the complexity and wide range of the behaviors which express the IJP. This review study aimed to identify all existing models and incorporate them to achieve a comprehensive conceptual model to assess the IJP. 

Databases such as PubMed, Scopus, Embase, and ProQuest were systematically searched to meet the study’s goals. Moreover, references to relevant publications were examined. Finally, suitable publications were discovered and analyzed using the inclusion and exclusion criteria. 

The results of Search in databases, including PubMed, Scopus, Embase, and ProQuest, showed that 12754 articles were found in the initial search. After removing duplicate and unrelated articles, finally, 155 eligible articles were selected. Based on full-text screening, 10 studies were excluded, and 5 studies were not accessible. Finally, by checking the references mentioned in the selected articles, 4 more eligible articles which were not retrieved in the search strategy were added; finally, 61 articles were selected to be reviewed. Ninteen articles were related to the general models, and 19 articles addressed job-specific assessment models. The remaining 23 articles described other existing models. 

To evaluate IJP, a heuristic structure was developed based on the literature research. These dimensions were selected because they can accommodate all of the preceding models’ dimensions. They also include any behaviors that may have an impact on IJP.

Given the importance of maintaining the mental health of workers, the present study was conducted to determine the effect of the individual factors on hypochondriasis and job stress under the corona epidemic condition in a company.

This cross-sectional study was performed on 275 workers in 2020 in one of the industries in southern Iran. To gather the data, demographic, researcher-made, standard hypochondria, and job stress questionnaires were sent electronically along with a guide and study objectives. The participants completed the questionnaires during 2 weeks and send them electronically to the research team. Finally, data were analyzed using tests of one-way ANOVA and linear regression in SPSS software version 22.

The results showed that the mean score of hypochondriasis in different groups of variables, including age, work experience, use of personal protective equipment, corona experience, and attention to preventive measures was significantly different (p<0.05). Based on the results, the mean score of job stress significantly differed in different groups of variables of personal protective equipment use, corona experience, and awareness on corona (p<0.05). Moreover, based on the regression relationships, hypochondriasis could be predicted by variables of personal protective equipment, corona experience, awareness on corona, and attention to preventive measures; and job stress could be predicted by variables of awareness on corona and attention to preventive measures.

Regarding the importance of providing the physical and mental health of employees, the implementation of measures to reduce stress and hypochondriasis of employees, particularly in identified groups, is helpful.

Road traffic accident is one of the leading causes of death in some countries such as Iran. Disability glare due to headlights of vehicles can increase the risk of crashes and make dangerous conditions. This study aimed to investigate the level of glare induced by the headlights of most common vehicles in Iran.

This cross‑sectional study was conducted in a suburban road of Ilam province in 2019. The disability glare resulted from the headlights of Pride Saba GTX, Pride 131SL, Samand Soren, Peugeot 405, Megan, and Peugeot Pars was measured at the distances of 10–100 m away from the headlights. The Threshold Elevation index under the high‑beam and low‑beam conditions (headlight’s operation modes) was obtained for the background luminance condition including 1 and 50 cd/m2 for the age groups of 20, 35, 70, and 83 years old.

When the background luminance was 1 cd/m2 , the mean glare level caused by the high‑beam mode of illumination exceeded the recommended disability glare thresholds of all age groups. When the background luminance was 50 cd/m2 , at certain longitudinal distances, glare level exceeded the disability glare thresholds of the elderly drivers (aged 70 and 83 years). At the background luminance of 1 cd/m2 , low‑beam mode of illumination caused disability glare at certain distances but not in general. At the background luminance of 50 cd/m2 , low‑beam mode of illumination did not cause disability glare at any distance.

The results showed the mutual effect of luminance and the angle of line of sight with respect to glare source on the emergence of disability glare. The age also exhibited a significant association with the disability glare, as the highest glare levels were obtained for older drivers.

Owing to their lower adverse environmental impacts, natural refrigerants have recently attracted a huge deal of attention. In this regard, the present study is aimed to evaluate the thermodynamic properties of different gaseous natural refrigerants at the molecular level using molecular dynamics (MD) simulations. In this context, the density (as a representative of structural features), enthalpy, and specific heat capacity (as representatives of energy properties) of several natural gaseous refrigerants including helium, nitrogen, methane, and ethane were assessed. Lennard-Jones potential was used for simulation of helium and nitrogen while AIREBO potential and OPLS-AA force-fields were employed for simulation of methane and ethane as polyatomic hydrocarbon refrigerants. Simulations are carried out at various temperatures above the boiling point and pressures of 1, 2, and 5 bar. MD results were in good agreement with the experimental data. Among the applied potentials, AIREBO potential offered results closer to the experimental data as compared with OPLS-AA force-field. The methane-ethane mixture was also addressed at different pressures and compared with the Peng-Robinson equation of state. The results of this study indicated that molecular dynamics can be employed as a reliable tool for predicting the thermodynamic properties of natural refrigerants. The results can be used in the refrigeration cycles.

The Swiss cheese model of accident causation is a model used in risk analysis and risk management, including aviation safety, engineering, healthcare, and emergency service organizations, and as the principle behind layered security, as used in computer security and defense in‑depth. This study aimed to develop and weight the occupational health leading indicators using the Swiss cheese model.

The present study was a descriptive, cross‑sectional study; occupational health performance assessment indicators were classified into five main groups of chemical, physical, ergonomic, psychosocial, and biological harmful agents. In addition, potential hazards and their prevention methods were identified using the Swiss cheese model. The leading performance measurement indicators (n = 64) were developed based on preventive methods and were weighted and rated by fuzzy analytic hierarchy process.

Thirty‑six out of 64 indicators were related to the management measures, 25 indicators were related to exposure to harmful occupational agents, and the remaining indicators were occupational‑related illnesses and diseases rate. Considering the importance and frequency of indicators, psychological agents were the most important indicators (40%) and physical agents had the greatest frequency (59%).

Process of indicators’ development has demonstrated that the major occupational health prevention measures in the oil and gas industry are concentrated on physical, psychological, and chemical agents, respectively. Thus, to provide protection for employees against occupational diseases and improve health performance indicators, paying special attention to mentioned agents is essential in the oil and gas industry.

Noise is one of the most harmful physical factors in the workplace that can cause annoyance. Therefore, the aim of this study was to investigate the effect of annoyance caused by occupational noise on employee’s mental distress.

This analytical-descriptive study was performed on 325 employees of the parts manufacturing industry in seven groups and the noise dose received for each group was measured by a dosimeter using ISO9612 standard. Then, psychosis was determined using the Kessler psychosis scale and the degree of annoyance in the face of noise in the face of noise by the standard method of ISO15666 as an individual evaluation with a one-question scale of 11 Likert options.

The results indicated that there was a positive and significant relationship between the received sound dose and noise annoyance (P <0.05). In addition, the dose received from the sound can justify 72.2% of the variable response changes, i.e. the amount of voice annoyance alone. Also, the results of the simultaneous study of four variables of age, work experience, voice exposure and voice annoyance on the state of mental distress using multiple regression indicated that these 4 variables predicted 42% of changes in mental distress. And the main variable influencing psychological distress is voice annoyance (P <0.05).

Occupational noise through noise annoyance harassment can affect the mental health of people working in industry and harassment can act as a mediator due to job noise causing mental distress in people working in industry.

road accidents and their casualties are considerably high. In addition, the headlights of cars, especially on two-way roads, leads to glare in the eyes of oncoming drivers. The purpose of this study was to determine the level of discomfort glare of car headlights and the effects of some variables on creating discomfort glare.

The illuminance of the driverchr(chr('39')39chr('39'))s eye was measured using luxmeter and the discomfort glare caused by the carchr(chr('39')39chr('39'))s headlights was determined using the Schmidt-Clausen and Bindels model and with considering the lateral and longitudinal distance between the two vehicles and the background luminance of the road surface were determined.

In cars, in low beam mode, from 100 meters to 50 meters, the luxmeter fails to record any illuminance. In the high beam mode, discomfort glare gradually increased from the distance of 100 meters by reducing the longitudinal distance between two vehicles. Increasing on the level of discomfort glare for Samand up to 30 meters, Pride Saba GTX up to 20 meters, Pride 131SL, Renault Megan and Peugeot Pars up to 10 meters and the Peugeot 405 depending on the background luminance up to 10 and 20 meters continued. The level of annoying dulling was reduced and from that interval onwards, the level of discomfort glare reduced.

The side distance between vehicles, headlights aiming, voltage and the type of headlightchr(chr('39')39chr('39'))s lamp are affecting in the discomfort glare which can be reduced by changes in road design and vehicle headlights.

One of the major topics related to the very long tunnels is dark hole effect. This is a common phenomenon caused by the sunlight reflected from the surroundings of the tunnel to the eyes of drivers and the lack of sufficient light at the tunnelschr('39') entrance, which decreases the contrast of barriers inside the tunnel and also makes it difficult to see potential obstacles at the entrance. The result is an increased risk of traffic accidents in these tunnels. Therefore, the aim of this research is to subjectively assessment the safe rate of lighting in one of the very long tunnels located in the province of Ilam.

To subject evaluation the safe rate of lighting at the tunnel entrances, two parameters of the average luminance of tunnel entrance and equivalent luminance are required. In this study, Luminancemeter device model S3 was used to measure the average luminance of tunnel entrance. Then, to calculate the equivalent luminance, a YASHICA108 camera with a 35 mm lens was photographed at a distance between the tunnel entrance and a safe stopping point, and then the Holliday polar diagram was used to calculate equivalent luminance (accordance with the standard CIE88-2004).

In this study, the average luminance at tunnelchr('39')s entrance was equal to 17 , the luminance was equal to 127.5  Using the ADRENAL equation, the quality of lightening at the tunnel entrance was less than 1.

Comparison of the results obtained from the healthy and safety rate of lighting levels at the tunnelchr('39')s entrance with the De Boer mental scale indicated that a dark hole effect occurs at the entrance of the tunnel under investigation and the light sources installed at the entrance of this tunnel did not have the sufficient ability to inhibit the dark hole effect.

  Coronavirus disease 2019 (COVID-19) possesses the mental effects such as stress, anxiety ,and hypochondriasis in addition to physical effects .The present study was aimed to investigate the  relationship between of hypochondriasis  and resilience of employees at epidemics conditions of corona virus in an occupational environment.

This cross-sectional study was performed, in spring of 2020, on 275 personnel in one of the southern industries from Iran. Data collection instruments included demographic questionnaire, researcher made questionnaire, CD-RSC resilience questionnaire, and Standard hypochondria questionnaire. The collected data were analyzed using SPSS software version 22 by one-way ANOVA, Pearson  and linear regression.

The results showed that the mean prevalence of hypochondriasis was 33.37 and its standard deviation was 14.87 and the total mean and standard deviation of resilience score was 20.95 ± 78.56. there was a significant relationship between hypochondriasis and variables of age, career length, use of personal protective equipment, experience of corona and attention to preventive measures(P < 0.05). Also There is a significant relationship between resilience and age, career length, attention to preventive measures and the use of personal protective equipment(P < 0.05). A significant negative relationship was observed between hypochondriasis and resilience.   

It is necessary to implement measures for reducing the hypochondriasis disorder and increasing the resilience among employees, especially in the exposure to the hard conditions of corona epidemics.

Abstract

The present study was aimed to determine the effect of individual factors on resilience and productivity loss of employees at epidemics conditions of corona virus in an occupational environment.

This cross-sectional study was performed, in spring of 2020, on 275 personnel in one of the southern industries from Iran. Data collection instruments included demographic questionnaire, researcher made questionnaire, CD-RSC resilience questionnaire, and Hershey and Gold Smith productivity questionnaire. The collected data were analyzed using SPSS software version 22.

The results of One-way ANOVA analysis showed that the subjects with age higher than 50 years, with career length higher than 20 years, with history of low use of personal protective equipment, and with history of low attention to preventive measures had significantly lower score of productivity (P < 0.05). Also, the results of the analysis revealed that the individuals with experience of corona had significantly lower score of productivity (P < 0.05). Moreover, the results showed that there was a significant positive correlation between resilience and productivity (r = 0.249, P < 0.05).

Covid 19 disease has reduced the resilience and productivity of worker. Therefore, adherence to health protocols in the workplace is necessary to reduce the risk of developing Covid disease 19

Analysis of accident data based on social and economic factors can be useful in determining injury patterns and establishing operational policies to improve safety and health. The purpose of this study is to investigate the effect of socio-economic factors in accidents.

This descriptive-analytical study was conducted based on information obtained from the Labor Inspection Office of Qom Province in 2017. In this study, the required information was extracted from recorded accident forms of 1048 accident cases occurred among victims who were over 18 years old. In this study, the dependent variables include the outcome of accidents divided into two groups of accidents leading to death and injury. Data were analyzed using Stata Software version 23 (Stat Crop. USA).

Based on the results, the presence of a safety officer in the industry reduced the risk of accidents leading to injury (AOR = 0.87, 95% CI: 0.72-0.91, P<0.05), people who had received safety training were 0.0009 times less likely to experience accidents leading to injury compared to the other group (AOR = 0.009, 95% CI: 0.0-0.16. P<0.05), and people with undergraduate education were 1.98 times more likely to experience accidents leading to injury (AOR = 0.009, 95% CI: 1.25-2.2. P<0.05). It was further found that people who have experienced the accident beforehand are less likely to have accidents leading to injury than the other group (AOR = 0.05, 95% CI: 0.005-0.72. P<0.05).

Therefore, as indicated, many factors have domino effects on different social damages and problems. Accordingly, to lower accidents and modify workforce cul ture, multi-faceted strategies should be applied properly.

Many studies have been carried out on the effects of heat stress on cognitive functions, but the results are contradictory. Therefore, this study was conducted to review the effect of heat stress on cognitive functions.

 In this study, all English articles conducted on effect of heat stress on cognitive, perceptual, and psychomotor functions from 1970 to 2018 were reviewed. For this, articles with keywords such as heat strain, heat stress, cognitive function, memory, comprehension, psychomotor, reaction time, mental performance, mood, mental response, error, task performance, fatigue, alertness, hyperthermia, and heat exhaustion in the  Scopus, Web of Science, Science Direct, Pub Med, Springer, Wiley Online Library and ProQuest databases were searched. Out of 157 retrieved articles, 39 articles were finally reviewed according to the inclusion criteria.

Out of 157 retrieved articles related to the topic, according to the inclusion criteria, 39 articles were finally considered for review. Among this articles, 9 (%23) articles were published before 2000 and 30 (%77) after 2000. Two articles were in athletes, four articles (%10.2) in workers, four articles (%10.2) in students, four articles (%10.2) in military soldiers and twenty-five articles (%64.2) were conducted in ordinary people.Based on the results, heat stress was identified as a detrimental factor for decreased cognitive functions such as reading comprehension, memory, focus, mathematical processing, tracking test, reaction time, perception  and decoding text and numeric messages, visual alertness, mental computing, text reading , hidden figures test and verbal fluency.

Based on the results of these studies, heat stress has been introduced as a detrimental factor for disrupting cognitive functions, but conclusion based on the results of studies is a systematic method is difficult because many confounding variables such as type of work, exposure time, skill and adaptation plays a big role.

 Although noise characteristics such as intensity and frequency are the main cause of detrimental effects, it is important to pay attention to the personality traits of individuals as the host of adverse health effects. The aim of this study was to investigate the effect of personality traits on sensitivity, annoyance and loudness perception due to exposure to high frequency sound.

 This interventional and experimental study was carried out among 80 undergraduate and postgraduate students in 2017. First, examinee were exposed to a high frequency noise at 65 dBA for one hour in an acoustic room. Then, to determine amount of annoyance, sensitivity, loudness perception and to investigate personality traits, questionnaire of noise annoyance, noise sensitivity, loudness perception and Eysenck personality inventory was used, respectively. Finally, Chi-square, independent t-test and multivariate analysis of variance (MANOVA) were used to data analyze.

 The mean±SD of sensitivity, annoyance and loudness perception were 54.08±7.71, 7.0±1.53, and 2.79±1.13, respectively in this study. The mean scores of sensitivity, annoyance and loudness perception were significantly different in terms of personality traits, so that their average was higher in the neurotic and introverted. Based on MANOVA test results, personality traits had a significant effect on sensitivity, annoyance and loudness perception of individuals. In a way, the neuroticism and introversion had the greatest effect on the sensitivity and annoyance, respectively.

 The results of this study showed that personality traits such as introversion and neuroticism can affect the sensitivity, annoyance and loudness perception of individuals.

Traffic safety is a major concern all around the world. About 1.5 million people die each year from road accidents and 50 million are injured. These figures account for about 1/2 percent of all deaths in the world, making road crashes the ninth most common cause of deaths. In Iran, the number of road accidents and their fatalities is significantly higher than the world standard. As the annual incidence rate of 32 cases per 100,000 is the second leading cause of death and the most common cause of injuries. The need for road tunnels increased with the development of road transport to reduce traffic congestion, reduce travel time and save energy. The construction of these tunnels created visual problems associated with the physiological mismatch of the driverschr('39') eyes at the inlet and outlet of the tunnel resulting in an increased risk of traffic accidents. Therefore, standards were developed to improve safety and reduce traffic accidents in these tunnels, including CIE 88-2004, PR-22-05 and IESNA. In order to safely cross the road tunnel, it is essential that all drivers have sufficient information about the road ahead, potential obstacles, and the presence and performance of other drivers. Therefore, one of the key factors in preventing accidents in road tunnels is the installation of lighting systems. The purpose of lighting in road tunnels is to provide an appropriate degree of safety for drivers during entry, transit and exit of the road tunnel, both over the day and night. According to CIE 88-2004, the purpose of road tunnel lighting is to create a safe and comfortable environment throughout the tunnels so that drivers along the road will have sufficient information on the road, possible obstacles and the direction of movement of other vehicles. According to the CIE Technical Report, drivers have different visual problems as they approach, enter, and exit the tunnel. One of the main causes of road accidents in tunnels is the lack of design of an optimal lighting system. Therefore, the aim of this study is to evaluate the luminance in a road tunnel based on CIE88-2004 standard in order to reduce the number of accidents caused by visual problems. 

In the present study, CIE88-2004 was used to evaluate the luminance in road tunnels. Early stages in assessing and evaluating luminance road tunnels include the determination of safety stop distance, equivalent veiling luminance, atmospheric luminance and wind screen luminance. The safety stop distance is equal to the sum of the distance between the barrier processing in the brain and the driverchr('39')s motor response to the brake, so that this distance prevents the vehicle from colliding with potential obstacles in road tunnels. Equivalent veiling luminance is caused by the reflection of light from the environment around the tunnel, to the driverschr('39') eyes, resulting in reduced contrast in the tunnels. Luminosity caused by factors such as dust in the atmosphere that make light scattering is called atmospheric luminance. One of the main reasons for the reduction of contrast in the eyes of drivers is due to the diffusion of light in the windshield. To determine the equivalent veiling luminance, photographic camera with 35mm lens and Holiday-Stiles was used. In order to determine the brightness of the equivalent view, the percentage of environmental factors (sky, road, rock, building and grassland) were determined by drawing a polarized halide diagram on the tunnel entrance photo and considering the networking of each segment of the rings. It should be noted that in some areas, the luminance level was not included in the luminance calculations due to the dashboard and the roof of the car, which prevents drivers from glaring. To determine the atmospheric luminance and wind screen luminance, HAGNER luminance meter model S3 was used. After determining the equivalent veiling luminance, atmospheric luminance and wind screen luminance of the vehicle, the required luminance in different areas of the study tunnel was designed using the CIE88-2004 standard. According to CIE-88-2004, in order to prevent road accidents caused by poor lighting, road tunnels are divided into 5 areas: access zone, threshold zone, transition zone, interior zone and exterior zone. The access zone is the distance before entering the tunnel which is equal to the length of the safety stop distance. The threshold zone is the first area inside the tunnel that requires a great deal of artificial lighting to manage and control the adverse effects of the black hole phenomenon. In the transition zone, due to the driverchr('39')s transition from the bright environment outside the tunnel to the dark environment inside the tunnel, the eye must adapt to these changes in brightness. The interior zone is the longest area in the tunnel and usually requires low illuminance levels. Exterior zone; this area again prepares the eyes for sunlight and usually requires a high level of illuminance to adapt the eye from the tunnel to the light outside the tunnel.

In determining the safety stop distance, the average reaction time was set to 1 second according to the CIE standard recommendation. Based on the tunnel location and the 10-year data of Ilam Weather Station No. 40780, the average annual rainfall was 73.8 days. According to the Paris recommendation, the coefficient of friction between the road and the tire in places where the average annual rainfall is more than 75 hours, the road condition is considered wet in access zone of tunnel. Therefore, the coefficient of friction between the road and the tire was 0.35, taking into account the wet road surface and the maximum speed allowed by vehicles passing through the tunnel. Then the safety stop distance in the tunnel was set 69.6 m. After estimating luminance in all polarized halide diagram rings, the equivalent veiling luminance was determined equal to 127.5 candela per m2. Also, the wind screen luminance and atmospheric luminance were measured 234.4 and 308 candela per m2, respectively. Then, according to these measurements, the required luminance levels in the first and the end of the second part of the threshold zone were determined as 576 and 230.6 candela/m2, respectively. Then, according to the safety stop distance (69.6 m) and heavy traffic volume, the required luminance level of the interior zone was 6.2 candela/m2. After determining the luminance in the interior zone of the tunnel, the type of tunnel (long, very long) must be specified. Therefore by reducing the length of the threshold zone (69.6 m), transition zone (432 m) and exterior zone (89.6 m) of the entire tunnel length (1200 m), the length of interior zone (608.8 m) was determined. Thus, by dividing the maximum permissible speed of vehicles inside the tunnel by the length of the interior zone, the time interval by the interior zone was determined to be 33.8 seconds. Because the time interval in the interior zone for studied tunnel was more than 30 seconds, the tunnel was classified as very long tunnel and the luminance in the second part of the interior zone was 2.3 Candela/m2. Also, according to the CIE standard, the luminance at the end of the exterior zone increased by 5 times compared to the second part of the interior zone, which equals 11.5 candela per square meter.

Lighting in road tunnels is of particular importance as neglecting it can cause major problems with driver safety such as black hole phenomena (before entering the tunnel), mismatch (during tunnel entry) and white hole phenomena (as exiting the tunnel). In this study, the required luminance (designed) in the initial part of the threshold zone was 576 candela per square meter with respect to the equivalent veiling luminance resulted from the tunnel surrounding, wind screen luminance and atmospheric luminance. This amount of luminosity required at the tunnel entrance can be reduced in appropriate ways such as; installation of asymmetric lighting systems inside the tunnel (of course, asymmetric lighting systems have some disadvantages, such as the high need for the high ceiling, also, not adjusting asymmetric lighting systems in the opposite direction of traffic can increase the flicker effect). Another way to reduce the required luminance is to reduce the luminance of the surrounding of tunnel environment. By changing the surfaces around the tunnel from high reflective materials to low reflective materials (planting grass and trees), the level of luminance can be significantly reduced in the eyes of drivers in the tunnel access zone. In road tunnels, drivers should identify road barriers at least at safety stop distance to prevent accidents. Effective ways to quickly adapt the driverschr('39') eyes to the dark inside the tunnel have been investigated, including the installation of semi-transparent structures to move the threshold zone to the outside of the tunnel. This allows the use of sunlight to achieve the desired luminance. Although most problems occur at tunnel entrances, the eye matching from low luminance inside the tunnel to high luminance outside the tunnel in the exterior zone of tunnel should not be ignored. Although this process is relatively fast, however, a high difference in luminance between the end of the tunnel and the environment outside the tunnels should be avoided.

Noise pollution is considered as a major threat to human society that may affect life quality, efficiency, physical and mental health. Therefore, the present study was aimed to investigate the effects of noise exposure and noise sensitivity on psychological distress in an automobile parts manufacturer's employees. In this descriptive-analytical study, 325 employees of an automobile parts manufacturer who were exposed to different noise levels in seven groups were investigated. Daily personal noise exposure for each group was measured using calibrated sound level meter (SVANTEK-971) based on ISO-9612 standards. Then employees' mental disorder and noise sensitivity were determined using Kessler Psychological Distress Scale and Weinstein's Noise Sensitivity Scale (WNSS), respectively, and data was analyzed using SPSS v. 23. Mean psychological distress was significantly different between noise sensitivity and noise exposure groups (P-value <0.05). Based on the results of multiple regression analysis among four variables including age, work experience, noise exposure and noise sensitivity, noise exposure and noise sensitivity had significant effect on psychological distress and could explain 0.36 and 0.25 of variance of response variable, respectively. Age and work experience at the level of 5% error had no significant effect on psychological distress status. It can be argued that the worsening of psychological distress in these employees is often due to noise exposure and noise sensitivity. As an individual variable, noise exposure has the greatest effect on increase of psychological distress compared to noise sensitivity level and demographic characteristics studied.