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Background: In many workplaces, many factors exist as sources of stress such as environmental and physical factors, (eg, noise, overcrowding, poor lighting), human factors (conflict with another person), organizational factors (such as workload, Incorrect policy). if the person is not able to deal effectively with them, undergoing several physical and behavioral and psychological symptoms are happen. While prolonged stress may cause decreased job satisfaction and burnout that results is boredom, apathy, loss of effectiveness, fatigue, frustration, and even disappointment. Burnout in nursing profession, is a serious problem health care and has negative effects on clinical outcomes. The aim of this study was to assess the level of burnout ,job demand - control and also The relationship between burnout and job demand - control among nurses. Methods: in this cross- sectional study, 415 randomly selected nurses from hospital of Hamedan university of medical sciences participated. The Persian version of job content questionnaire(P-JCQ) and maslach burnout inventory used for data collection. Using SPSS16 software , descriptive statistics and multiple logestic regression and x2 test were applied for data analysis. Results: the finding of present study indicated that burnout levels were relatively high. Mean and standard deviation score for Emotional exhaustion, Depersonalization and Reduced personal accomplishment dimensions were (25.3±12.42),(5.91±5.1),(33.30±9.59) respectively. About 51% of nurses reported high job demands and 57% of them had high control over their tasks. About 30% of nurses reported that their job were active, 21% passive, 22% high strain and 27% low strain. And غیر فعال job supported reduced personal accomplishment dimension of burnout (OR=0.433). Conclusion: Based on the results of the study should be stated that if job control and psychological job demand were high, nurses will not be prone to burnout. And also occurrence of burnout in reduced personal accomplishment dimension among nurses who reported their job had low psychosocial demand and low control, was more than others.

Introduction: Emergencies are unforeseen and unpredictable situations. In these situations, people’s performance is affected by various factors that cause stress. People’s performance in such situations can also affect human error probability. The purpose of this study was to evaluate human error in emergency situations based on the fuzzy CREAM and Fuzzy Analytical Hierarchy Process (FAHP). Material and Methods: This descriptive-analytical study was performed in a petrochemical industry in Markazi province in 2019. The FAHP was used to prioritize emergency situations. To evaluate human error in these conditions, the weights of Common Performance Conditions (CPC) was determined using Analytical Hierarchy Process (AHP) method. Human error probability was calculated using a fuzzy CREAM method in the most important emergency situations. Results: The results of the FAHP showed that “Hydrogen leak from the cylinder joints in the olefin unit” was the most important emergency. The highest relative weight was related to crew collaboration quality (0.06) in the emergency situation. Conclusion: This method can also be used to identify the important factors in human error occurrence and high weighted CPCs and plan to control them.

Introduction: Recent evidence indicates that lighting can affect physiological and neurobehavioral human functions, referred to as non-image forming (NIF) effects of lighteffects. This study aimed to determine the effects of illumination levels and correlated color temperature (CCT) on alertness and performance under NIF conditions. Material and Methods: In this study, 22 participants were exposed to light at various levels of illumination, including very low illuminance (

Abstract Introduction: Mental workload is one of the effective factors on the performance and efficiency of people working in an organization that put their health at risk. The aim of this study was to determine the mental workload of staffa working in a bank in Hamadan City of Iran by NASA-TLX method. Methods: In this cross-sectional study, 110 bank employees were surveyed. The data were collected using demographic and NASA-TLX questionnaires. Finally, collected data were analyzed using SPSS version 21 by running descriptive statistics and statistical tests. Results: According to the participants, the mean and standard deviation of effort and mental demand, as the most important dimensions were 81.04 ± 14.51 and 79.50 ± 18.05, respectively. The performance dimension was selected as the least important dimension with the mean and standard deviation of 64.37 ± 10.17. The results of statistical analysis showed no significant relationship between the participants' total score of mental workload and their demographic information such as age, gender, educational level, marital status, experience, and work overtime(P>0.05). The Pearson correlation coefficient showed that age (P

Background and aims: Lighting directly and indirectly affects employeeschr('39') mental health and their performance. Good lighting is required for good visibility of the environment and should provide a luminous environment that is human-friendly and appropriate for the visual task performed. Optimal lighting is one of the most important issues in providing the physical conditions of different places, especially the workplace. Lighting can provide comfortable working conditions, especially visual comfort. Life on Earth cannot be imagined without light. Defects in the qualitative and quantitative aspects of lighting in the workplace can cause visual discomfort and reduce the productivity and efficiency of an individual. Therefore, monitoring the intensity of brightness and color temperature of light is essential to maintain and enhance the health of employees. The quantity and quality of lighting can also affect onechr('39')s mental health. For example, one of the factors associated with depression is the defect in the quantity and quality of ambient lighting. Correlated color temperatures (CCT) of light play an important role in human psychological and physiological needs. In regards of human perception, two of the most important characteristics of lights are illumination and correlated color temperature (CCT). studies have proven that different CCT provided by different lighting are important in affecting human beings psychologically and physiologically, through their visual and non-visual processes.. According to European standard EN 12665, visual comfort is defined as a personchr('39')s mental well-being in the workplace. Studies on lighting in industrial environments have been conducted more frequently and public and office environments have received less attention. CCT is found to have effects on visual and mental fatigue. The right selection of CCT in an office environment will benefit its occupants in terms of visual comfort and reduction of daytime sleepiness. Studies have shown that insufficient and uncomfortable lightning conditions in office environments increase the risk of visual and ergonomic disorders in long term. The aim of this study was to evaluate the illumination and color temperature and its relationship with visual comfort in administrative staff in Hamadan city (west of Iran). Methods: This cross-sectional study was conducted in 50 rooms and among 70 staff of Hamadan University of Medical Sciences and random sampling. In this study, the intensity of illumination at the work surface and at the height of the individual eye The intensity of the local illumination at the work surface and at the level of the individual eye level was measured at the userchr('39')s point of view and the angles and distances were accurately observed and measured with the presence of the user in the presence of semiconductors or other factors. Also intensity of the general lighting based on the Illuminating Engineering Society of North America (IES) in terms of lux and color temperature of light source in terms of Kelvin at the work surface using new device Sekonic C-7000 SpectroMaster was measured. The device is capable of simultaneously measuring brightness intensity (Kendel / lux), color temperature, color expression index and wavelength. The device has an accuracy of over 1 nm. Visual comfort of visual display terminal users was assessed using visual fatigue questionnaire. Visual fatigue questionnaire with15 items and four components of eye stress, visual impairment, eye surface disorder and extra ocular problems was used for this purpose. This questionnaire is rated on a Likert scale ranging from 0 to 10 and none to very severe. Results: The results showed that the mean age of the staff was 42.18± 7.46 years with a minimum of 25 and a maximum of 62 years. In this study, the average general illumination intensity of the studied rooms was 437.57 ±116 and the average local illumination intensity was 341.16±109 and 307.13±195 respectively. Also, the intensity of illumination, general, local level at work and perpendicular were 30.6%, 33.9% and 38.4% lower than the national occupational health limits. The average color temperature during the working shift in 56% of the rooms was more than 4000 °K. The frequency of low and high visual fatigue score was 61.4% and 38.6% respectively. There was a statistically significant relationship between brightness intensity and visual fatigue of the staff during the study. The results of the study showed that people with room temperature below 4000 ° C had higher frequency of visual fatigue in these subjects. Chi-square test confirmed the relationship between the intensity of local illumination and visual fatigue of the subjects (p

Background and aims: Fatigue and sleepiness (decreased alertness), in addition to a negative impact on performance and quality of work, are considered as one of the leading causes of human error and accidents in work environments. There is much evidence indicating that physical factors in the workplace could affect fatigue, vitality, motivation, and productivity of individuals. A physical environment suitable for activity is formed by various factors, among which light is known as an essential element. Recent photobiological advances and recognition of intrinsically photosensitive retinal ganglion cells (ipRGCs) have shown that in addition to improving eyesight, light can affect the circadian and homeostatic regulations and melatonin suppression in human. Furthermore, light can have acute effects on the physiological, psychological, neurobehavioral, and neuroendocrine responses, such as improvement in the alertness and neurobehavioral performance, which are known as the non-visual or non-imaging forming effects (NIF) of light. However, the possible roles of these potential effects in the improvement of human safety and efficiency have not been thoroughly investigated. Some studies have shown that monochromatic blue light or blue-enriched white light (high correlated color temperature white light or high CCT) can enhance levels of alertness, and improve mood and cognitive function. Although recent evidence has indicated that monochromatic red light or red saturated white light (low correlated color temperature white light or low CCT) has also been able to induce such positive effects. There is still an open question left unanswered: “which of these lighting conditions (high CCT vs. low CCT) has a stronger effect on the alertness level and neurobehavioral function?” Therefore, the present study tested this hypothesis in a simulated office workplace environment with the recommended illumination level of 500 lx on the desk for daytime office work environments during the morning hours. Methods: In this study, 20 healthy paid volunteers (male; mean ± SD age, 27.6 ± 3.6 years) were selected and followed the experimental protocol. All participants were interviewed about the quality of sleep, lifestyle habits, and general health. The inclusion criteria were: not having any mental or physical health problem, having a good sleep quality according to the Persian version of Pittsburgh Sleep Quality Index (PSQI score

Background: Petrochemical industry has experienced a variety of accidents and the number of emergency situation in this industry is high. Therefore, prioritizing these situations is important. The aim of this study was to determine the effective criteria for the selection of emergency scenario and prioritize them for corrective actions. Subjects and Methods: Delphi technique was used to determine and prioritize the appropriate criteria for the selection of high-risk emergency scenarios. Then, the weights of selected criteria were obtained using fuzzy hierarchical analysis and finally, using the fuzzy TOPSIS technique, the criteria for emergency scenarios were prioritized for corrective actions. Results: The most important criteria for the selection of dangerous emergencies included the amount of loss, damage, and probability. According to the weight of these criteria, emergency situations were prioritized. The most important emergencies included fire in the chemical storage, hydrogen leakage at the cylinder fitting in the Alfin unit, and extreme gas leakage in one of the power plant turbines. Conclusions: Using this approach, high-priority emergencies can be identified, and it is suggested that planning for controlling these situations and preventing crises should be prioritized by managers.

Background and Aim: Noise is one of the most effective exogenous factors affecting the processing mechanisms of the human brain, which has a major role in the occurrence of human error and occupational accidents. Low frequency noise is usually produced by sources such as ventilation systems, pumps, compressors, diesel engines and gas turbines, and so on. For this reason, the sound is in addition to industrial environments such as control rooms, in residential, office, etc., and compared to high-frequency sounds, low frequency sound is less attention and the rules associated with its control Not satisfactory Low-frequency sound is one of the most important sources of sound-producing in the environment, and it is even annoying at low levels and affecting the cognitive function of individuals. These sounds are seen in both industrial and public environments. Because the levels of exposure to this sound are usually not very high, it does not attract much attention. Some of the individual differences, such as superiority, extroversion, neuroticism, and audible sensitivity, can reduce or increase the effect of sound on cognitive functions. The purpose of this study was to investigate the effect of handicapping on cognitive functions in the presence of low frequency noise. Materials and Methods: The present study is an interventional type. The research population was Hamedan University of Medical Sciences students. 120 of them were selected through purposeful sampling (40 right, 40 doubly capable and 40 lepers). All tests were carried out at the Faculty of Health of Hamedan University of Medical Sciences in a room with acoustic and physical control in March 2012. The conditions for entry to the study include: Being between the ages of 20 and 30 years, not taking any drug that reduces the level of consciousness during the test, no color blindness, hearing loss (hearing loss below 25 dB), lack of background Cardiovascular disease, respiratory problems, and sleep disorders. In order to eliminate the interfering factors, an audiometric test was conducted at the Faculty of Health and Ishihara Blind test. Individual information and medical records were collected by a questionnaire and, if they did not have the criteria for entering the study, were removed from the community under study. After the final selection of eligible individuals, all tests were fully explained to the subjects. It should be noted that all the subjects participating in this study were verbally and oral.Chapmanchr('39')s hand-breaking questionnaire was used to determine the supreme hand. By simulating the real environment of each subject, exposure to high-frequency audibility in the industry (45 and 65dB) was exposed for 40 minutes. The environmental conditions were maintained under thermal comfort conditions, with an equivalent temperature of 18 ° C and a relative humidity of 50%, without constant disturbance of air flow. Also, with 500 lux and fluorescent lamps, the brightness level of the surfaces was well maintained and maintained during all experiments. In this study, the recorded sound of the industrial air conditioning system was used in the work environment using the Cool Edit Program In the desired frequency band, it was edited. This program is a powerful software for producing sound at different frequencies, especially low-frequency noise. When playing sound, the level of sound pressure level was measured at the ears of the subjects tested and sitting. The benchmark used in the SVANTEK research is the 971-based Polish-American company, which operates according to the IEC 61672 standard, which has the ability to analyze 1.1 and one-third of the octave band. Spherical shaped speakers with a SWA-100 amplifier to amplify low-frequency noise that produces similar sound to the work environment. And during exposure to IVA PLUS CPT, the cognitive functions (reaction time, attention, balance, concentration, and processing speed) of the subjects were examined. The cognitive performance tests lasted 10 minutes, from the minute 30 to 40 people responded. After the implementation of each step, the groups changed to eliminate the effect of the exposure sequence, and the interval between each experiment was 24 hours in order to prevent cumulative fatigue at the second level. Data were analyzed using SPSS v.20 software, Kruskal-Wallis test and variance analysis. Results: The mean age of the subjects was 23.94 with a standard deviation of 3.35. The distribution of the tested subjects was only male, 85% of them were single and the rest were married. Most of the participants in the study were from health sciences and 80% of them were undergraduate. The results showed that there is a significant difference between cognitive functions of individuals with increasing voice level from 45 to 65 dB. Also, there is a significant difference between the components of cognitive function and hand holding (p

This study is aimed to compare the results obtained from four risk assessment methods, videlicet HAL-TLV, Strain index, OCRA checklist, and ART. These musculoskeletal disorders assessment tools are generally used in the studies as well as in the field of occupational health. In this study, the data was collected via assessments of 30 tasks by 9 raters in poultry slaughter, assembly, and container production industries using four methods of upper limb musculoskeletal disorder risk assessment. In order to determine the level of agreement between the risk assessment methods, the Spearman's rank correlation coefficient and Cohen's weighted kappa were used, according to which the highest agreement and correlation were found between ART and OCRA checklist methods, while the HAL-TLV and OCRA checklist exhibited the lowest agreement and correlation. The difference between the risk classification results of the studied methods could be due to the difference of definitions of the risk variables; therefore, selecting the assessment tools for assessing the task risks in the working environment must be in accordance with the assessment objectives and complexity of the work tasks.

Abstract Background: There is always an interaction between man and his environment that can be the cause of physical, physiological and psychological stress on people and also cause discomfort, annoyance, and have direct and indirect effects on their performance and productivity, health and safety. People in their workplace are exposed to many factors related to work activities and environmental factors, which can affect their health; So workplace disruptions such as noisy environments can cause safety problems, reduce employee morale and undesirable effects on performance, working memory, and attention; For these reasons, ergonomic designers must be capable of designing the physical environment because the design of the environment not only keep peoplechr('39')s performance high, but also provide a safe and healthy environment for improving employeeschr('39') health. Noise can also negatively affect communication between people. Banks are open plan offices and the financial services provided by bank staff that requires employeechr('39')s mental activity. Different sources of noise production can affect employees and negatively affect their comfortable, functional and communication aspects. Noise also effects on mental activities can cause employees to become tired early and increase their computational errors. In a bank environment where conversations between bank tellers and customers are necessary to conduct banking tasks, interfering with ambient noise, causing annoyance, human error, and ultimately failed to provide banking services. Because of high workload and the bankschr('39') competition to attract customers in order to provide better services, quiet workplace environments are essential for staff comfort and optimum performance; so right designing workplace can have a high impact on peoplechr('39')s comfort and productivity. Speech Interference Level is a simple way to predict or evaluate speech intelligibility where the conversation occurs directly in a noisy environment. At open plan offices, employee and customer communicate face-to-face and information exchange is done in that way. In recent years, many banks in our country have established their own workstations as sited customers and face-to-face with bank tellers, but so far no study has been conducted on the changed employeeschr('39') workstations and its effect on speech interference. A question now arises, is workstation redesign increase the Speech Interference Level and improve Intelligibility ratings for speech communications? Therefore, the purpose of this study was redesigned workstations and make environmental changes and its effect on SIL among bank tellers. Material and method: This study is a descriptive-analytic and Interventional study, this was carried out for one year in three branches of one of the governmental banks of Hamadan province (N= 12). Twelve workstations were redesigned and installed after measuring the sound and calculating Speech Interference Level, and calculating the distance between customer and employee. Bank tellers are those who have a direct relationship with customers and perform banking tasks. They had to sit long during the day and they spent all their time working on computers and they were getting things done and receiving customer financial requests. They used the workstations were constructed in the present study. The tools for data collection in this study were: 1) demographic and occupational questionnaire, 2) sound measuring and frequency analyzer CEL-450، 3) A questionnaire with a question “What noise sources in your workplace do you annoy?” to determine annoying sound sources and 4) ISO 9921-2003 standard to determine speech interference level of the noise at the listenerchr('39')s ear (LSIL), Speech level, Speech Interference Level (SIL) and Intelligibility ratings for speech communications. SIL is a simple way to predict or evaluate speech intelligibility, Speech intelligibility also increases with increasing SIL. speech intelligibility is divided into 5 rating (bad, poor, fair, good and excellent) based on SIL, also in sensitive situations where short messages are sent include important numbers, ability to understand at least "good" is recommended by increasing speech effort; the communication will be “fair” if the difference between LSIL and the speech level (LS, A, L) that both determined at the listener’s position is greater than 10. Measuring the sound within 1 meter of the speakerchr('39')s mouth, according to ISO 9921 (2003) for normal sound (60 dB) was considered. It was measured for 15 minutes at 10 a.m. to 13 p.m. every shift that they had the highest number of customers, and measuring was done twice for each workstation (total 24 times). To calculate LSIL, the sound pressure level was measured in four octave bands with the central frequencies 500 Hz, 1000 Hz, 2000 Hz and 4000 Hz at the listener position and during the normal communication period in time-weighting “slow”. the sound pressure level was measured for 15 minutes and the average of these pressure levels was calculated. After collecting the preliminary data, bank teller workstations were redesigned and built. Some actions were taken to reduce speech interference and improve communication between bank tellers and customers; For example, insert a glass between customer and bank teller and create 12 vents (diameter =2 cm) at a customerchr('39')s mouth height to improve communication, changing the workstation so that the operator and customer interact face-to-face and insert chair for customers to sit in, reduce customer gathering in front of the workstations, reducing the distance between the customers and the bank tellers by creating an arc at the table, Enhancing employee privacy by placing the glass between employees in beside workstations, increasing the glass height between the bank teller and the customer to prevent customer standing communicate with the bank teller. The mean distance between bank teller and customer prior to redesigning the workstations was 123 cm which was reduced to 103 cm in redesign; the mean distance between two employees was 95 cm, which increased to 115 cm after the redesign. Environmental interventions also include the installation of perforated acoustic tiles made of plaster as a false ceiling, so that, by installing them the distance between the main and false ceilings was 25 cm and there was an empty space between them which absorbs more sound. The walls of the branches were also covered with wall plugs that made of PVC and MDF, and the floor was improved. Data were collected before and after the interventions and they were compared. Data analysis was performed using SPSS software, version 16. Data were analyzed using descriptive statistics (mean and standard deviation) and analytical statistics. The Paired t-test was used to compare the mean results of the LSIL and SIL. Results: In the present study, all the bank tellers were male. Everyone was married, their mean age was 38.25 (5.62) and work experience was 15.25 (6.87) years. Each bank teller were doing 30-50 customerschr('39') finances task in one shift. All participants stated that their rest time was less than 30 minutes in a shift and they are working 7-8 hours in a sitting position; none of the participants had a history of hearing loss or other hearing problems. Results from annoying sources of noise showed that the most annoying sources of noise in all three branches were the noise of customers (42.85%) and the sound of money counting machine (33.3%); Printer noise was the lowest (4.76%). Before the interventions, mean speech interference level (LSIL) was 59.50 dB (4.07) that was then reduced to 54.98 (5.52) dB and this decrease was statistically significant (p

There are several methods for assessing the risk of upper-limb disorders in occupational health studies. The goal of present study is to determine the intra-rater and inter-rater reliability of three risk assessment methods of SI, OCRA Checklist and ART in repetitive tasks and exposure to upper-limb risk factors. First, 9 raters used SI, OCRA Checklist and ART to assess the physical exposure level of the upper limb in workers 30 tasks with different levels of profession for two assessment periods. In the results of inter-rater reliability using ICC, the risk classifications were ρ = 0.54, ρ = 0.74 and ρ = 0.77 for SI, OCRA Checklist and ART, respectively. And the intra-rater reliability for the final score of the OCRA Checklist, SI and ART methods was κ = 0.59, κ = 0.66 and κ = 0.67, respectively. The inter-rater reliability for risk classification and final score of ART, OCRA Checklist and SI methods using ICC) obtained as moderate to good. However, the overall results showed that the reliability of ART method was higher than two other methods. The findings demonstrated that all three methods are appropriate for assessment in workplaces. These methods should be used based on assessment objectives, rater experience and required time for assessing the tasks.

Several factors influence the efficiency and effectiveness of organizations, one of them is work engagement. Nowadays job stress has become one of the most costly and a common problem in the workplace. United Nations introduced job stress as wentieth-century disease. Emergency unit in hospitals is stressful environments with high working pressure. This study is a cross-sectional study to determine the most common stress factors and assess work engagement among emergency center technicians in Markazi Province in 2015. Data were collected by using three questionnaires containing demographic questionnaire, job stressors questionnaire and job engagement questionnaire (UWES-9 Scale. SPSS version 19 software was used to analyze the data. The results showed that the patient care stressor had the maximum mean stress score (3.63±0.59) and physical stressors had the lowest mean stress score (3.26± 0.77). A significant relationship was observed between individual stressors and all aspects of work engagement and interpersonal stressors and vigour (P≤0.05). The results of this study showed that work engagement can have aneffect on job stress or job pressure. There was a negative association between work engagement and job stress.

Introduction: Fatigue is the exhaustion of the body or spirit that can be caused by stress, excessive work, drug use, or physical or mental illness. Fatigue is a factor in reducing productivity and incidents. Therefore, measuring is important. The aim of this study was to determine the fatigue measurement measurements based on objective and objective indices. Materials and Methods: A cross-sectional study was performed on 120 male and female students. By simulating the real environment of each person in the 50 and 70dB pressure levels for 40 minutes, before and after exposure to noise, the amount of mental fatigue was measured using the subjective index Visual Analog Scale (VAS) and the objective index Continuous performance test (CPT) and its results were analyzed by paired t-test and Spearman correlation coefficient in SPSS20 software. Results: Measurement results with both self-declaration scale and continuous performance test showed that mental exhaustion increases significantly after exposure to the mentioned pressure level, but the results of the two methods are not consistent with each other. Conclusion: Considering that the VAS self-declaration scale is a subjective method, it seems that the mismatch of the two methods is more related to the ineffectiveness of this scale. Therefore, it is suggested that re-examination be done with more precise methods such as electroencephalogram.

Background and Objective: With respect to the importance of job stress in causing diseases and disorders among workers, the purpose of this study was to examine the staff's opinion on the level of implementation and prioritization of the most important stressors among Hamadan University of Medical Sciences (UMSHA) staff. Materials and Methods: The present study was quantitative and descriptive in design. The research population was UMSHA staff, that among whom 250 were selected by simple random sampling method. Research tool was ILO Stress prevention checkpoints. Data analysis was done by SPSS 18.0 software (SPSS, Chicago, IL, USA). Results: The results showed that staff opinion about the priority of intervention about the causes of stress are as follows: leadership and justice at work (32%), job security (32%), job control (29%), job demands (26%) and recognition (22%). Also staff opinion about the stressful factors that are not running are as follows: leadership and justice at work (52%), job demands (57%), job control (53%), social support (57%), physical environment (62%), work–life balance and working time (60%), recognition at work (58%), protection from offensive behavior (58%), Information and communication (59%). Conclusion: According to the results of this study, factors related to leadership and justice at work, job control, job demands, job security and recognition at work are main factors that managers should pay attention to them to reduce job stress.

Background: Night shift work is associated with many problems such as sleep deprivation, sleepiness, decreased cognitive performance, increased human errors, and fatigue. This study set out to measure cognitive performance, melatonin rhythms, and sleep after different consecutive night shifts (7 vs. 4) among control room operators (CORs). Methods: The participants included 60 CORs with a mean age of 30.2 years (standard deviation, 2.0) from a petrochemical complex located in Southern Iran. Cognitive performance was assessed using the n-back task and continuous performance test. To evaluate melatonin, saliva was collected and tested by enzyme-linked immunosorbent assay. To assess sleep and sleepiness, the Pittsburgh Sleep Quality Index and Karolinska Sleepiness Scale were used, respectively. Results: Individuals who worked 7 consecutive night shifts had a significantly better cognitive performance and sleep quality than those who worked 4 consecutive night shifts. However, salivary melatonin profile and sleepiness trend were not affected by shift type. Conclusion: The main duty of CORs working night shifts at the studied industry included managing safety-critical processes through complex displays; a responsibility that demands good cognitive performance and alertness. It is suggested that an appropriate number of consecutive night shifts in a rotating shift system should be planned with the ultimate aim of improving CROs performance/alertness and enhancing safety. Keywords: melatonin, night shifts, performance, sleepiness

Abstract Background and aims: Modern technology has imposed more cognitive demands than physical demands to operators in most workplaces. The increase of cognitive demands in real working conditions can have negative effect on the mental health and performance of operators. This study was coducted with the aim of subjective and objective evaluation of operators’ mental workload in a city traffic control room. Methods: In this study 16 opeartors of a traffic control center participated voluntarily. In setteled day at resting condition the physiological indices were measured for 5 minutes before the work started and after it was finished for each operator. Regarding to the city traffic density (low and high mental work conditions) the physiological indices were measured for 5 minuts in each condition. Also at the end of each condition the NASA-TLX questionaire was completed by each operator. The data were analysed using t-test and repaeated measure analysis of variance by SPSS.21 software. Results: The Results of our paired t-test showed a significant differences between the subjective responses of operators in all dimensions of NASA-TLX except for physical demand in low mental workload condition compared to high mental workload.The Findings of the repeated measures of ANOVA showed that there is a significant differences between the mean of heart rate, SDNN, RMSSD and LF/HF ratio features by increasing difficulty of mental work compared to before and after rests among operators. Conclusion: Our finding indicated that with increasing traffic density a lot of mental load imposed to operators maybe causing mental health problem and decreasing performance among operators in future. Therfore, in the traffic control room, organizing and managing human resources based on the workload in different working conditions is recommended. Keywords: Work load, Heart rates, NASA-Task load index, Traffic control center.

Background and Aim: Musculoskeletal disorders stand as the most common work-related problem in many developing and industrial countries. This study aimed to investigate the prevalence of musculoskeletal disorders and to assess ergonomic risk factors among traditional bread bakers. Materials and Methods: This descriptive-analytic, cross-sectional study was conducted on 129 traditional bread bakers in Hamadan in February 2017. The prevalence of musculoskeletal disorders was assessed using the Nordic questionnaire, body map, and Visual Analogue Scale. The ACGIH-HAL method was used to assess hand activity level and hand maximum acceptable strength. Analysis of data was performed in SPSS (version 20) using Chi-square and independent T tests. Results: The mean and standard deviation of tenure, height, weight, BMI, and age were, respectively, 4±6.82 (year), 1.6±0.08 (m), 60±12.76 (kg), 24.65±4.70 and 43.5±12.60 (year). The organs involved in baking consisted of the neck, shoulders, back, waist, elbow, arm, hand, thigh, knee, shin and ankle. The highest prevalence rates of pain in workers referred, respectively, to the middle back (n=38; %92.68), knees (n=33; %80.49), shoulders (n=13; %30.95), forearms (n=11; %26.19), and wrists (n=11; %26.19). The prevalence of musculoskeletal disorders correlated significantly with BMI and tenure (P

Background: The recent studies have shown that the rates of musculoskeletal injuries and disorders among workers in the construction industry are much higher than those working in other industries. The aim of this study was to investigate the physical risk factor among the workers in construction workshops using Workplace Ergonomic Risk Assessment (WERA) method. Methods: A total of 150 workers were randomly selected from five construction workshops. They were working in the wall plastering, bricklaying, and concreting tasks. During the site visit of five workshops, tasks were observed using WERA assessment. A structured interview with self-report charts (Body Discomfort Chart) was administered to participants for each task. Results: An analysis of the self-report charts revealed that 94%, 92%, and 83% of workers reported discomfort in their backs in concreting, wall plastering, and bricklaying tasks, respectively. The shoulder region was the second highest reported uncomfortable region by 86% and 84% of workers in concreting and wall plastering tasks, respectively. The wrist region was the second highest reported uncomfortable region reported by 80% of workers in bricklaying task. From the WERA assessment for wall plastering, bricklaying, and concreting tasks, the final scores were 36.57 (SD=8.62), 39.66 (SD=6.92), and 40.06 (SD=7.75), respectively. The highest and lowest scores were 5.87 (SD=1.14) and 2.21 (SD=1.28), respectively for neck and vibration in wall plastering. Conclusion: The results showed that workers have pain in their back, shoulder, wrist, elbow, neck, and leg regions during their work in wall plastering, bricklaying, and concreting tasks. The final score for concreting task was higher than wall plastering and bricklaying tasks.

Background and aims: taxi drivers are a large group of professional drivers, who spend so much time in driving. Considering traffic collisions as one of the Traffic Safety System in the country, modification of improper driving behaviors of this group can result in a significant decrease in accidents. Methods: This analytical-descriptive study was conducted on 245 taxi drivers in 2013. A questionnaire aimed into two sections: demographic information and reasons for lack of night use of the automotive lighting system was designed. The content validity of the questionnaire was confirmed by the experts and professors’ comments and its reliability was confirmed by Cronbachchr('39')s coefficient alpha (0.72). Results: It was found that 26.9% of the drivers do not turn on their automotive lighting system over nigh. Most in main squares of the city (46.2%). Forgetfulness in turning car’s light on (14.28%) and depreciation on car lights (13.06%) are the major reasons. Moreover, a significant relationship was observed among variables like working in taxi driving as the main occupation (P-Value= 0.0001), lack of receiving warning from passengers (P-Value= 0.0001), the level of education (P-Value= 0.012) and lack of using automotive lighting system. Conclusion: Considering that forgetfulness was the main reason for lack of using the lighting system and most of the drivers have not been received any warning or punishment from police because of lack of using lights overnight, it is essential to use appropriate training and exertion of regulations, as one of the ways to create correct culture of traffic and improve driver performance.

Background: Fire service workers often implement multiple duties in the emergency conditions, with such duties being mostly conducted in various ambient temperatures. Methods: The aim of the current study was to assess the firefighters' physiological responses, information processing, and working memory prior to and following simulated firefighting activities in three different hot environments. Seventeen healthy male firefighters performed simulated firefighting tasks in three separate conditions, namely (1) low heat (LH; 29â31°C, 55â60% relative humidity), (2) moderate heat (MH; 32â34°C, 55â60% relative humidity), and (3) severe heat (SH; 35â37°C, 55â60% relative humidity). It took about 45â50 minutes for each firefighter to finish all defined firefighting activities and the paced auditory serial addition test (PASAT). Results: At the end of all the three experimental conditions, heart rate (HR) and tympanic temperature (TT) increased, while PASAT scores as a measure of information processing performance decreased relative to baseline. HR and TT were significantly higher at the end of the experiment in the SH (159.41±4.25 beats/min; 38.22±0.10°C) compared with the MH (156.59±3.77 beats/min; 38.20±0.10°C) and LH (154.24±4.67 beats/min; 38.17±0.10°C) conditions (p0.05). Nonetheless, there was a measurable difference in PASAT scores between LH and SH (p

Introduction: Nowadays, observational methods based on video recording of work processes and its analysis by using computers software are widely used. Therefore, the aim of this study is the assessment of welder’s posture and its biomechanical analysis by using CATIA software. Methods: This research has been done on welders Iranian Gas Transmission Company. Evaluated postures, which include three postures were determined from photos and videos, which were recorded during the welding process. After determining the target postures, digital modeling of person posture was simulated in CATIA software. Then assessments using RULA method and biomechanical analysis of forces to human digital modeling were done. Results: The analytical results are directly extracted by CATIA software. The final score of three postures evaluated using RULA method indicated that for two postures, we need immediate corrective action and for one posture, the corrective action should be taken in near future. Also, biomechanical analysis of forces in one of those postures revealed excessive force higher than recommended limit by NIOSH. Conclusion: The results of this study show that we can provide a better assessment of workers conditions in workplaces using CATIA software. Analyzing according to RULA methods is a significant measure in evaluation and redesign of workstations.

Background and objective: long term work, nonstandard and improper tools, and inadequate lighting in the workplaces are important factors which resulted in awkward postures in hairdressers. The present study was performed to assess general and local lighting and investigate its relationship with postural status assessed by Rapid Entire Body Assessment (REBA) method in Hamadan’ hair salons. Material and methods: in this descriptive analytical study, 100 hairdressers who worked in 50 hair salons were studied. The local and general lighting was measured using a Hanger ESI photometer. The hairdressers’ postures were assessed using REBA method. Data were analysed using version 21.0 of the SPSS/PC statistical package. Results: in 97 and 72% of the studied hair salons, local and general illuminance levels were lower than the occupational exposure limit, respectively. REBA assessment indicates that 26 and 12.5% of the studied subjects fell in to high and very high risk levels, respectively. ANOVA test showed significant relationship between general illuminance and the REBA scores in face and eyebrow makeup tasks (p

Background: Firefighters often perform multiple emergency tasks during firefighting and life-saving operations under unknown and unpredictable conditions in hot and hostile environments. Therefore, this study examined the effect of cooling strategies on attenuating physiological and cognitive function response during simulated firefighting activities in a smoke-diving room. Methods: Each firefighter engaged in four conditions: namely (1) no cooling device; control (NC), (2) cooling gel containing menthol (CG), (3) cool vest (CV), and (4) cooling gel and cool vest (CG+CV). Cooling effects were evaluated by heart rate (HR), temporal temperature (TT), reaction time (RT), and the correct response (CR). Results: In the four experimental conditions, physiological response increased, reaction time improved, and correct response decreased after the activity relative to baseline. HR and TT were significantly lower at the end of the firefighting activity in the CG+CV (147.47 ± 4.8_bpm; 37.88 ± 0.20_○C) and CV (147.53 ± 4.67_bpm; 37.90 ± 0.22_○C) compared with the CG (153.67 ± 4.82_bpm; 38.10 ± 0.22_○C) and NC (154.4 ± 4.91_bpm; 38.11 ± 0.23_○C) conditions. RT and CR were significantly higher at the end of the activity in the CG+CV and CV compared with the CG and NC conditions. Conclusion: It is concluded that strenuous firefighting tasks have a detrimental effect on firefighters’ physiological responses and cognitive function. The findings also revealed that CV was more effective than the CG in attenuating physiological responses and cognitive function during firefighting operations. Furthermore, combining CV with CG provides no additional benefit. It is concluded that cooling the body by the use of CV offered physiological and psychological benefit for firefighters during simulated firefighting activities.

Introduction: Ergonomic problems and inadequate lighting are the causes of increased prevalence of musculoskeletal disorders in the workplace. The present study was conducted to evaluate lighting in carpet weaving workshops in Bijar and its association with musculoskeletal pain among female carpet weavers. Methods: In this descriptive cross-sectional study, 104 Carpet weaving workshops were randomly selected with 180 carpet weavers. Illuminance was measured based on the models presented in Illuminating Engineering Society (IES) using a Hagner luxmeter in 76 cm height from the ground. Local illuminance was measured in horizontal and vertical weaving level. By using body map and pain scale, site of pain and pain severity during the last three months were gathered. RULA method was used to evaluate weavers work posture. Data were analyzed by SPSS 16 and statistical analysis was performed applying linear and logistic regression models. Results: Results revealed that only daily working hours were associated with musculoskeletal pain severity in carpet weavers (P=0.023). The average of artificial and minimum of local illuminance in horizontal and vertical weaving level (‏P

Background: Musculoskeletal disorders (MSDs) are a common problem among carpet weavers. This study was undertaken to introduce affecting personal and occupational factors in developing the number of MSDs among carpet weavers. Methods: A cross-sectional study was performed among 862 weavers in seven towns with regard to workhouse location in urban or rural regions. Data were collected by using questionnaires that contain personal, workplace, and information tools and the modified Nordic MSDs questionnaire. Statistical analysis was performed by applying Poisson and negative binomial mixed models using a full Bayesian hierarchical approach. The deviance information criterion was used for comparison between models and model selection. Results: The majority of weavers (72%) were female and carpet weaving was the main job of 85.2% of workers. The negative binomial mixed model with lowest deviance information criterion was selected as the best model. The criteria showed the convergence of chains. Based on 95% Bayesian credible interval, the main job and weaving type variables statistically affected the number of MSDs, but variables age, sex, weaving comb, work experience, and carpet weaving looms were not significant. Conclusion: According to the results of this study, it can be concluded that occupational factors are associated with the number of MSDs developing among carpet weavers. Thus, using standard tools and decreasing hours of work per day can reduce frequency of MSDs among carpet weavers.

Introduction: Due to the large numbers of staff employed in health care services, the hospital should be seen as a big industry, with many workers mostly females. This fact along with the lack of sufficient manpower, and also frequent handling and transport of load (patient) in hospitals causes an increase of musculoskeletal disorders among personnel, so that most of the hospital personnel in the first few years, of employment suffer from Musculoskeletal disorders. Methods: The study was designed and implemented in four parts of the Nahavand Alimoradiyan hospital with aim of reducing musculoskeletal disorders resulting from handling and transport of patients. Data was collected using Nordic questionnaire and data analysis was performed by SPSS (ver. 16). The Questionnaires were completed for 46 personnel of the four parts of the hospital who complained a lot about musculoskeletal disorders, before and after the use of ergonomic stretcher designed and also the improvement of several rooms. Results: The main results of the initial investigations before the intervention, was a high prevalence of musculoskeletal disorders among personnel, especially disorders of lower back, shoulder and ankle, in which low back pain by %69.6 had the highest prevalence among personnel. The results of intervention by an ergonomic stretcher and improvement in layout of the hospital rooms significantly reduced the frequency and intensity of disorders. Conclusion: This study showed that the use of ergonomic equipment and proper layout of the rooms especially when the hospitals are designed, with proper training can significantly reduce musculoskeletal disorders resulting from patient handling.

Introduction: Protective clothes are among the basic needs of firefighters against their occupational risks. Combination of heat stress effects caused by muscle activation and protective clothing, result in a high level of strain in the regulating system of body temperature. The aim of this study was to evaluate the practical cooling method of hand and forearm immersion in water. Methods: In this study, fourteen professional firefighters were assessed. Each fire fighter wore protective clothing and heart rate, core body temprature and skin temprature were measured in sitting position. Then each subject walked on a treadmill in two 20-min bouts (5 km/h, 7.5% gradient) separated by a 15-min recovery period, during which firefighters were cooled (case) via application of hand and forearm water immersion and remained seated without cooling (control). During exercise and recovery time, firefighters, physiologic parameters (heart rate, core body temperature and mean skin temperature) were measured and recorded every five minutes. Results: The results of marginally modeling of longitudinal responses using generalized estimating equations method showed that paremeters of heart strain (core body temprature, skin temprature and heart rate) were significantly reduced after intervention (p

introduction: One of the most common causes of occupational injuries in industrialized and developing countries is musculoskeletal disorders Determining the risk factors of musculoskeletal disorders can be helpful choosing the right method for interventions and detailed studies. This study aimed to evaluate the ergonomic risk factors in operators of pressurized irrigation equipment factory. Materials and Methods: This cross-sectional study was conducted in a pressurized irrigation equipment manufacturing company. In this study, a new method based on observation was used to evaluate the ergonomic aspects of operator's activity. In order to assign tasks and sub-tasks, direct observation and video recording equipment were used. Ergonomic assessment was carried out on all sub-tasks identified. then, the criticality of the task determined. Results: Among the tasks identified 53 very critical posture 61 critical and 82 low critical posture was determined. Ergonomic point in the ball valve production line was 0.6 and 0.68 respectively for tow operator. For drop valve and automatic valve production line's ergonomic point was 0.52 and 0.67 respectively. Conclusion: According to the results, posture analysis method used in this study is easy and accurate. The advantage of this method is 14 ergonomic domaines that covered whole body and time fragment of each task. Findings of previous studies showed good correlation between results from this method and OCRA method. In this study, The most critical posture was related to operator's wrist, so it is recommended that control measures on wrist posture correction should be considered.

Introduction:Musculoskeletal Disorders (MSDs) are one of the most important factors occupational injuries and disabilities in workplaces. The aim of the persent study was ergonomics intervention to reducemusculoskeletal disorders. Methods: This interventional study was conduct on 126 preservation and maintenance workers in cement company by classfication sampling. The Nordic Musculoskeletal Disorders Questionnaire, QEC and Ergonomics Checkpoint methods were used to collected data before and after the interventions. The interventional program include practical and easy to implment solutions for improvement safety,health and work conditions, workers trainig, selective and corrective exer Data were analyzed by Mcnemar test using SPSS_22 software. Result: Data analysis showed significant differences(P_value

Introduction: Musculoskeletal disorders (MSDs) are one of the main problems in workplaces, which cause loss of working time, absenteeism, reduced workers’ efficiency and increased service and production costs. The present study was carried out to investigate the prevalence of musculoskeletal disorders and their associated risk among office workers. Methods: In this descriptive cross-sectional study one hundred and thirty three office workers of a huge construction company were involved. For collecting data related to musculoskeletal symptoms and to investigate the associated risk of these disorders the Nordic standard questionnaire and RULA method were used, respectively. Data were analyzed with chi-square test and multiple regressions by using SPSS software version 16. Results: About 50% of the workers reported MSDs’ symptoms, during the past 12 months, at least in one region of musculoskeletal system. The highest prevalence belonged to lower back (42.1%), neck (33.1%), wrist (18%), and shoulders (11.3%), respectively. The prevalence of symptoms in the neck and lower back of workers, with more than 10 working hours per day, was statistically significant (P>0.001). Additionally, a statistically higher prevalence of symptoms in the neck, wrist, and lower back of workers with job tenure higher than 5 years was noted (P>0.05). The risk assessment revealed that all workers’ postures were fall into action levels of 2 and 3. Conclusions: The findings revealed that MSDs symptoms have a high prevalence in office workers and the risk of these disorders is intermediate to high. Moreover, the main effective factors in the prevalence of MSDs symptoms were job tenure higher than 5 years and working hours more than 10 per day.

Background: The present study aimed to evaluate the operators’ mental workload (MW) of cement, city traffic control and power plant control centers using subjective and objective measures during system vital parameters monitoring. Methods: This cross-sectional study was conducted from June 2014 to February 2015 at the cement, city traffic control and power plant control centers. Electrocardiography and electroencephalography data were recorded from forty males during performing their daily working in resting, low mental workload (LMW), high mental workload (HMW) and recovery conditions (each block 5 minutes). The NASA-Task Load Index (TLX) was used to evaluate the subjective workload of the operators. Results: The results showed that increasing MW had a significant effect on the operators subjective responses in two conditions ([1,53] = 216.303, P < 0.001, η2 = 0.803). Also,the Task-MW interaction effect on operators subjective responses was significant (F [3, 53] = 12.628,P < 0.001, η2 = 0.417). Analysis of repeated measures analysis of variance (ANOVA) indicated that increasing mental demands had a significant effect on heart rate, low frequency/high frequency ratio, theta and alpha band activity. Conclusion: The results suggested that when operators’ mental demands especially in traffic control and power plant tasks increased, their mental fatigue and stress level increased and their mental health deteriorated. Therefore, it may be necessary to implement an ergonomic program or administrative control to manage mental probably health in these control centers.Furthermore, by evaluating MW, the control center director can organize the human resources for each MW condition to sustain the appropriate performance as well as improve system functions.

Introduction: This study aimed to investigate the effect of carpet weaving at a proposed workstation on Upper Trapezius (UTr) fatigue during a task cycle. Fatigue in the shoulder is one of the most important precursors for upper limb musculoskeletal disorders. One of the most prevalent musculoskeletal disorders between carpet weavers is disorder of the shoulder region. Methods: This cross-sectional study, included eight females and three males. During an 80-minute cycle of carpet weaving, Electromyography (EMG) signals of right and left UTr were recorded by the surface EMG, continuously. After raw signals were processed, MPF and RMS were considered as EMG amplitude and frequency parameters. Time series model and JASA methods were used to assess and classify the EMG parameter changes during the working time. Results: According to the JASA method, 58%, 16%, 8% and 8% of the participants experienced fatigue, force increase, force decrease and recovery, respectively in the right UTr. Also, 50%, 25%, 8% and 16% of the participants experienced fatigue, force increase, force decrease and recovery, respectively in the left UTr. Conclusions: For the major portion of the weavers, dominant status in Left and right UTr was fatigue, at the proposed workstation during a carpet weaving task cycle. The results of the study provide detailed information for optimal design of workstations. Further studies should focus on fatigue in various muscles and time periods for designing an appropriate and ergonomics carpet weaving workstation

A decrease in body temperature can impair manual performance leading to a lowered capacity to carry out a certain activity. This study was aimed to analyze the extent effects of extreme cold air exposure on workers’ manual performance. The study population was consisted of 50 outdoor auto mechanics that were participated in two experiments carried out in winter and spring. Following a standard method, air environmental factors in each workstation and the physiological responses of the participants were measured. Touch sensory test was conducted to determine the sensory function of the hand. The grip strength and manual dexterity tests were also performed to assess manual work disability. The hand grip and pinch grip strength of the auto mechanics were reduced by 10.3% and 10.1% in cold air, respectively, as compared with the neutral air. Manual dexterity of the auto mechanics was also decreased from 6.3% to 8.8 % in cold air, as compared with neutral air. The prevalence of finger sensation disorders in the auto mechanics was 62% in cold air, while it was only 4% in neutral air. There was also a significant correlation between finger skin temperature and manual dexterity (r=-0.80, p

Fatigue and sleepiness are one of the main causes of human errors and accidents in the workplace. The empirical evidence has approved that, in addition to stimulating the visual system, light elicits brain responses, which affect physiological and neurobehavioral human functions, known as the non-image forming (NIF) effects of light. As recent evidences have shown the positive effects of red or low correlated color temperature white light on alertness and performance, we investigated whether exposure to 2564 K light could improve subjective and objective measures of alertness and performance compared with 7343 K, 3730 K, and dim light (DL) conditions during the daytime. Twenty two healthy participants were exposed to the light while they were performing a sustained attention task and their electroencephalogram (EEG) and electrocardiogram (ECG) were recorded. Both 2564 K and 7343 K conditions significantly reduced EEG alpha-power compared with the DL and 3730 K conditions. Moreover, the 2564 K, 7343 K, and 3730 K conditions significantly reduced subjective fatigue, sleepiness and increased heart rate and performance compared with the DL condition. Furthermore, the effects of light conditions on alertness and performance varied over the day so that more effective responses were observed during the afternoon hours. These findings suggest that light interventions can be applied to improve daytime performance.

Background: Low-frequency noise is annoying even at lower levels and affects cognitive functions of individuals. Some individual differences, such as sensitivity, can reduce or increase the effects of noise on cognitive performance. Materials and Methods: This study investigated the effect of noise sensitivity on cognitive performance in the presence of low-frequency noise. In this experimental study, 120 fourth-year seniors in the field of health sciences year from Hamadan University of Medical Sciences, Iran were selected through purposive sampling (60 students with high sensitivity and 60 students with low sensitivity). All the participants were exposed for 40 min to the noise levels of 50, 60, and 70 dB at the frequencies of 125 and 250 Hz, during which, the cognitive performance of the subjects was examined using the Integrative Visual-Auditory Continuous Performance Test (IVA CPT). Data were analyzed by independent t-test, and ANOVA test in SPSS 20.0 software. Results: The low-frequency noise negatively affected the components of cognitive performance so that with increasing the sound pressure level (SPL) from 50 to 70 dB and from 125 to 250 Hz (P

Background & Objectives: Employee productivity depends on the individuals’ ability to work. As musculoskeletal disorders are considered one of the main causes of reduced work ability and disability, the present study was conducted to assess work ability among workers of Shomal Cement Co. and to determine the relationship between the Work Ability Index (WAI) and the severity of musculoskeletal disorders. Methods: The present analytical, descriptive, cross-sectional study was conducted on 175 workers of Shomal Cement Co. occupied in different job categories. The work ability of the employees was assessed using the WAI and the prevalence of musculoskeletal disorders among them was then assessed using the Nordic questionnaire. The data obtained were analyzed in SPSS-16 using statistical tests including the Pearson Correlation Coefficient and the Analysis of Variance. Results: The mean value and standard deviation of the WAI in the employees of Shomal Cement Co. was calculated as 38.37±5.80. The Pearson correlation coefficient obtained showed no significant correlations between the WAI and the variables of age and work experience (P-value=0.355 and 0.096). The ANOVA revealed a significant correlation between the WAI and the severity of musculoskeletal disorders (P-value

Background & Objectives : Currently, work-related musculoskeletal disorders are a major occupational health concern. This study tried to evaluate the risk factors of musculoskeletal disorders by the assessment of repetitive tasks (ART). It also sought to determine the effects of an ergonomic intervention on the mentioned risk in a manufacturing company . Methods: In this study, 60 production line workers were randomly selected. The data was collected by using a demographic questionnaire and the ART. The intervention was implemented for 39 cases. Data were analyzed in SPSS. Results: The initial evaluations suggested low, moderate, and high levels of risk in 21.7, 48.3, and 30.0 of the participants, respectively. Re-assessments after the intervention showed that the frequency of low-risk individuals increased from 30.70 before the intervention to 53.85 after the intervention. On the other hand, comparisons between the rates before and after the intervention revealed reductions in the frequency of moderate risk (64.10 vs. 43.59) and high risk (5.2 vs. 2.56). These changes were all significant. Conclusion: In most cases, the initial ergonomic risks were not at an acceptable level. In fact, most workers were at moderate level of risk. Since many workers in the assembling industry suffer from musculoskeletal disorders, low-cost eengineering and management measures can be taken to reduce the level of risk .

Background & Objectives : Along with the advances in many different levels of life, interest in measuring quality of life has increased. The aim of this study was to assess quality of life in hospitals of Hamadan University of Medical Sciences. Methods: This cross-sectional study was performed on 300 nurses in hospitals of Hamadan University of Medical Sciences during 2012-2013. To determine the quality of life, the WHO questionnaire (WHOQOL-BREF) was used. Data was analyzed using SPSS software version 16. Result: The mean cores on physical and mental health dimensions in men were more than women (Pvalue

Background: The present study aimed to evaluate the biomechanical exposure to the trapezius muscle activity in female weavers for a prolonged period in the workstation A (suggested by previous studies) and workstation B (proposed by the present study). Methods: Electromyography data were collected from nine females during four hours for each ergonomically designed workstation at the Ergonomics Laboratory, Hamadan, Iran. The design criteria for ergonomically designed workstations were: 1) weaving height (20 and 3 cm above elbow height for workstations A and B, respectively), and 2) seat type (10° and 0° forwardsloping seat for workstations A and B, respectively). Results: The amplitude probability distribution function (APDF) analysis showed that the left and right upper trapezius muscle activity was almost similar at each workstation. Trapezius muscle activity in the workstation A was significantly greater than workstations B (P

Background & Objectives : High prevalence of musculoskeletal pain in dentistry represents the importance of investigation of working conditions in this profession to reduce musculoskeletal disorders.The purpose of this study was to determine the postural load on the upper limb postural using macro LUBA technique and the prevalence of musculoskeletal disorders. Methods: This study was conducted on 30 post graduate dental students of Hamadan University of Medical Sciences . LUBA technique was used to evaluate the postural load. The Nordic questionnaire was used to assess the prevalence of musculoskeletal disorders . The results were analyzed using SPSS version 16 . Results: The prevalence of musculoskeletal disorders was as follows neck( 63.3%), back ( 43.3%), back ( 30%), knee ( 20%), shoulder( 13%), wrist ( 10%), legs (10 %), elbows( 6.7%) and thigh( 0%). The maximum postural load index was 23 for women and 21for men. In total, 50 % of dentists were in group 3 , 33 % of dentists in group 4 and 16.7 % in group 2 of the corrective measures . There was no significant association b etween demographic variables and presence of musculoskeletal disorders . Besides, there was no significant association between the presence of pain in upper limbs and the postural load index (Pvalue > 0.05). Conclusions: This study showed high levels of p ostural load index and musculoskeletal disorders among dental students of Hamadan University of Medical Sciences. High levels of p ostural load index indicate a high level of risk, which requires immediate corrective action and intervention.

Background & Objectives: Assessment of physical risk factors related to musculoskeletal disorders is performed by different methods including observational methods. Validity of these methods are important in workplaces. The purpose of this study was to investigate the reliability of the Washington States ergonomics checklist as an observational method. Methods: This descriptive-analytical study was performed on 50 workers and three tasks in a mattress manufacturing industry. The checklist completed by first group (non-specialists) and second group (ergonomic specialists) in the selected tasks. After assessment, the coefficient of agreement between observers with kappa value was analyzed using SPSS (version 16) software. Findings: The first group of observers disagreed about the risk factors of hand force related to caution zone jobs checklist and awkward posture related to hazard zone jobs checklist and kappa value were 0.349 , 0.360 and 0.847, respectively. In the second group of observers, kappa values were 0.847 and 0.719 respectively about awkward posture and hand force risk factors. Conclusion: Findings of this study showed that reliability of this method had been weak to good according to calculated kappa values between observers in the first group and good to excellent in the second group and there is possibility error in comparison between the two groups, which might be due to nonspecific nature of this tool and lack the necessary skills of the observers.

Background and aims: Human factors are significant factors causing car accident s . The driver when noticed by brake lights will pay attention to the danger and react appropriately. An appropriate reaction time can prevent car accidents. The aim of this study was to assess driver's reaction time to dynamic flashing and standard brake lights using a driving simulator. Methods: This experimental study was done on 46 volunteer drivers (10 female, 36 male). Participants drove for an hour under day and night conditions on a driving simulator system with standard brake lights and dynamic flashing brake lights. Results: Results showed that as the age of drivers increased one year , the brake reaction time was decreased 11.585 ms. Women had slower brake reaction time than men. There was no significant relationship between driving condition and brake reaction time. The time elapsed since taking driving license has not any significant effect on reaction time. Conclusion: In general, this research showed that using dynamic flashing brake light with a flashing frequency of 7 Hz reduced the brake reaction time significantly.

Introduction: Musculoskeletal disorders are a major part of occupational diseases in working environments. The aim of this study was evaluates the risk factors of musculoskeletal disorders by the assessment of Muscle Fatigue Assessment method (MFA). It also sought to determine the effects of an ergonomic intervention on the mentioned risk in an Assembly industry. Methods: This study conducted on 15 people working in the Assembly line. Medical records of Assembly line workers were reviewed and Nordic Musculoskeletal Questionnaires (NMQ) after one year of intervention was completed. Activities of these workers in Assembly line were evaluated by Muscle Fatigue Assessment method (MFA) and workers were given the necessary training. Data were analyzed in SPSS-16. Results: The initial evaluations showed that neck, back, leg and knee, respectively in 6.67, 20 and 13.33 percent were in the "very high" priority corrective measures. Re-assessments after the intervention showed that Percent of people with musculoskeletal disorders in the neck in the "very high" corrective actions changed to zero. The percent of organs at the level of "high" corrective actions before the intervention was greatly reduced. For example, around the waist from 60% to 33.33% and neck from 53% to 26.27% after intervention were reduced. A total of 30 cases of abnormalities detected before the intervention, after intervention, this number reduced to 11. Conclusion: According to MFA Score, risk of musculoskeletal disorders was reduced by intervention in this industry and According to Questionnaire, prevalence of musculoskeletal disorders also significantly reduced

Shift work is a common work schedule that has several inappropriate consequences, the most important of which is fatigue. The aim of this study was to invest gate the impact of the shift length on the occupatio al fatigue of operators in filling stations. This cross-sectional study was carried out on operators of the filling station in National Iranian Oil Products Distribution Company, Hamadan region, western Iran. Participants were chosen using the random sampling. In order to assess occupational fatigue, the Persian version of Swedish Occupational Fatigue Inventory (P-SOFI) was used in 8, 12 and 24-hour shift schedules. The total score of fatigue (P=0.05), functional fatigue (P=0.001) and conceptual fatigue (P=0.013) had significant difference in various shifts length, but physical dimension score had not significant differences. Among all aforementioned shift works, the 24-h shift had higher fatigue score in P-SOFI. It seems that shift length has a significant impact on occupational fatigue among filling tation workers. The result of the study can help to work scheduling and rest-work regime planning for health promotion of workers and accident risk reduction.

This study was conducted to determine the combined effects of noise and shift work on physiological parameters including body temperature, heart rate and blood pressure. This study was performed in a chemical industry in Tehran in 1993. The workers’ physiological parameters was recorded at the beginning and at the end of all work shifts. Groups under study included : day workers (n=115) , day workers with continuous noise exposure (n=44) , two-shift workers without noise exposure (n=180) , three-shift workers without noise exposure and three-shift workers with continous noise exposure (n=216). In workers with continuous noise exposure, noise dosimetry was performed using B & K noise dose meter type 4428. The results showed that noise and shift work hove more effects on systolic and diastolic blood pressure than body temperature. The statistical analysis showed that in 3-shift workers, combined effects of noise and shift work on systolic and diastolic blood pressure caused considerable differences between exposed and control group. In general, regarding research design of this study to determine probable combined effects of noise and shiftwork on physiological parameters, our findings confirmed the additive effects of noise and shiftwork on systolic and diastolic blood pressure in which the effect of noise was more significant. Our findings showed that combined exposure to shiftwork and noise may be regarded as a risk factor for cardiovascular diseases because it is responsible for increasing blood pressure in exposed workers.