Journal of Health and Safety at Work

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The safety of high risk jobs especially in oil refining activities is a major concern. In the present paper, the welding risks in Tehran oil refinery have been assessed using the Job Safety Analysis (JSA) and the effectiveness of the controlling methods have been investigated. A descriptive study was conducted on 33 risks of 10 welding tasks in Tehran oil refinery (north unit). After arranging the appropriate expertise team, tasks in the welding process were identified using two methods of viewing the process and interviewing with the welders. The risks of each task were then identified through viewing the process, interviewing the welders and completing safety checklists. Risk Priority Number (RPN) was used for risk assessment. RPN was estimated from Likelihood and Severity Numbers using Australia/New Zealand standard (AS/NZS 4360/2004). Risk assessment was conducted for existing and post-control conditions. The effectiveness of the controlling measures suggested by the expertise team was evaluated using appropriate statistical methods. The results revealed that in the existing condition, 27.3% of the studied risks have a RPN of 5 (with an extremely high hazard potential), 3% a RPN of 4 (with a high hazard potential) and 69.7% with a RPN of 3 (with a medium hazard potential). The results also revealed that with the application of control measures suggested by the expertise team, 21.2% of the studied risks will hold a RPN of 4 (with a high hazard potential), 6.1% will have a RPN of 3 (with a medium hazard potential), 48.5% with a RPN of 2 (with low hazard potential) and 18.2% will have a RPN of 1 (with a negligible hazard potential). Statistical tests revealed that the application of control measures, will reduce the average amount of likelihood, severity and risk priority numbers significantly (Pvalue<0.01).

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Introduction: ”Exposing to danger” or in other words, “risk” is a process which is led to an uncertain result in every field. Project risks are uncertain contingent events or situations that if they occur will have positive or negative effects on project’s objectives. Todays, research and educational process and more complicated and the professional risk management become much more difficult, as a result.

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Material and Method: In this research, the health and safety issues have been studied and analyzed using ISO 14121 and the environmental issues by EMEA to determine the risk level separately for research laboratories and to prioritize corrective measure in each field (school).

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Result: The finding in this study showed that from all the main risks within the rage of 38-86 percent have been decreased. Moreover average of the risk level for the health, safety and environment cases showed a significant decrease (Pvalue<0.0001) by implement controlling and protective countermeasures compariy to the priority state without any measures.

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Conclusion: The risk assessment with hazards control strategy based on ISO 14121 is a compatible method in laboratory site as universities and other reasearch sites.

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Introduction: In the steel industry,air blowers used to supply compressed air are considered as sources of annoying noise. This study aims to acoustics analysis of theairblower workroomand sound source characteristics in order to present noise controlmeasuresinthe steel industry.

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Material and Method: Measurement of noiselevel and its frequency analysis was performed usingsound levelmetermodelof CASELLA-Cell.450. Distribution of noise level in the investigated workroom in form of noise map was provided using Surfer software. In addition, acoustic analysis of workroom and control room was performed in view point of soundabsorption andinsulation. Redesignofdoor and window of controlroom and installation of soundabsorbing materialson theceiling of the workroom were proposed and the efficiency of these interventionswasestimated.

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Result: The totalsound pressurelevelin the blower workroom was 95.4 dB(L) and the dominant frequency was 2000Hz. Sound pressure level inside the room control was 80.1dB(A). The average absorption coefficient and reverberation time in the blower workroom was estimated equal to 0.082 Sab.m2 and 3.9 seconds respectively. These value in control room was 0.04 Sab.m2 and 3/4 seconds respectively. In control room, sound transmission loss between the two parts of the wall dividing was 13.7 dB(A). The average of noise dose in blower operators was 230%. With the installation of sound absorber on ceiling of workroom, average of absorption coefficient can increase to 0.33 Sab.m2 and sound transmission loss of the new designed door and window was estimated equal to 20dB.

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Conclusion: The main cause of noise leakage in the control room was insufficient insulation properties of door and windows. By replacing the door and window and installation of sound absorbing on ceiling of workroom, the noise dose can reduce to 49.6%. New Improved door and window of control room can reduce noise dose to 69.65% solely.

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Introduction: Although risk assessment and accident prevention program have been widely used in industries such as steel industry, there are still numerous accidents in these industries. Hence, applying an accident analysis method can identify the root causes and casual factors of accidents and causal factors. Human Factors Analysis and Classification System can identify human errors in the steel industry by using an analysis of past events. The aim of this study was to identify the human errors in the steel industry using the HFACS methodology.

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Material and Method: In this study first, incident reports of industries with high risk, such as Ahvaz steel and pipe industries existing in the department of work and social security was gathered. Then, an analysis of accident was done based on HFACS model. This model has 4 levels and 18 categories which are 1 - unsafe acts of operators (that includes four subtypes) 2 - pre-conditions for unsafe acts (with seven categories) 3 - unsafe supervision (includes four categories) and 4 - the effect of association (with three categories).

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Result: In this study, 158 reports of accident in Ahvaz steel industry were analyzed by HFACS technique. This analysis showed that most of the human errors were: in the first level was related to the skill-based errors, in the second to the physical environment, in the third level to the inadequate supervision and in the fourth level to the management of resources.

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Conclusion: Studying and analyzing of past events using the HFACS technique can identify the major and root causes of accidents and can be effective on prevent repetitions of such mishaps. Also, it can be used as a basis for developing strategies to prevent future events in steel industries.

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Introduction: Emergency situations are of the major challenges in industries. Understading the status of inter-team interaction is effective in improvement of emergency response team (ERT). The purpose of this study was to investigate the interaction space of ERP in a refinery, using the social network analysis (SNA).

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Methods and Materials: In the present case study, the density indicator was used to examine the interaction space in the ERT. The obtained data were analyzed, employing UCINET 6.0 social network analysis program.

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Results: The findings showed that the ERT has the relatively low concentration with the density of 0.2 overall, the result reflect a low level of interactions among response reams at emergency situations management.

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Conclusion: The presented approach provided an appropriate image of interactions network among the emergency response teams. The social network analysis can be used for assessing the interactions of the emergency response teams.

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Introduction: The purpose of this study was to compare MORT and Tripod Beta methods, using a hierarchical model, in order to choose the best technique to analyze an event in an organization.

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Material and Method: In this study, a critical event was selected and the causes of the event were identified, employing MORT and Tripod Beta capabilities. Following the identification of the event causes, the aforementioned techniques were weighted and compared considering selected criteria and AHP hierarchical method.

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Result: Relative weights of the selected criteria were calculated. The ability to identify the event causes with the weight of 0.315 had the greatest weight. The event analysis cost (0.24), required time to analyze the event (0.146), technical experts (0.125), training for implementation (0.24), and availability of the analytical software (0.07) had obtained the subsequent weights, respectively.

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Conclusion: Analytic hierarchy process is an efficient and practical method to prioritize the choices considering the study objectives and criteria. As scientific method, Analytic hierarchy process helps the experts in decision-making. Considering the selected criteria, findings in this study showed that Tripod Beta technique (with a weight of 0.563) is superior to MORT technique (with a weight of 0.437).

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Introduction: The weaknesses of traditional hazard analysis methods lead to their inefficiency to utilization for modern socio-technical systems. System Theoretic Process Analysis (STPA), which is in the category of systematic analysis methods, has a powerful logic to identify hazards in such systems,as a suitable alternative method. This study aimed to analyze hazards associated with extinguishing systems of steam unit of a power plant, using STPA method.

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Material and Method: The present research is a qualitative case study. The related hazards were defined using STPA method.Following, the safety control structure diagrams in different parts were plotted and inadequate control measures and its causal factors were identified.

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Result: For steam unit of power plant, the most tragic incidents wererelated to hazards and risks of turbine device (switch the turbine cycle). Then, according to the plotted diagram for structure of safety control extinguishing systems associated with switching the turbine cycle, PLC system was determined as the most important part of the control system and operator was identified as the strategic and effective part of a control system. Following, more than 54 causal factors were identified, considering the relevant details about the risks analysis of the turbine.

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Conclusion: Due to its systematic structure,STPA method can be effective for a more complete identification of risks and causal factors which causing hazards in the emergency extinguishing systems. Therefore, development of such tools for those operators involved in safety-critical systems will be useful in terms of safety.

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Introduction: Each year, many people suffer from numerous injuries and damages in construction industry. Determination of factors that cause the most problems in a process is the most important step to improve the situation. Pareto chart can be used to explore factors causing most of the problems. The aim of this study was to survey construction accidents in Qom city using Pareto chart.

Material and methods: In this descriptive-analytical study, all accidents related to construction industry registered during 2009-2012 in the social security organization of Qom city, were analyzed using Pareto chart and mini-tabs software.

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Results: According to the results, 73.3% of accidents are due to objects and workforce being fallen. About 73.3% of the events occurred among 20-40 years old people. Hands and feet injuries comprised 53.4% of the accidents. Approximately, 61.8 percent of accident occurred in the first six months of the year. Moreover, the highest percentage of accidents was happened on Wednesday (19.4), Saturday (18.8), while Friday (8.4) and Thursday (10.5) had the lowest percentage of incidents.

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Conclusions: Employing Pareto charts as a method for analyzing and identification of accident causes can have an effective role in the management of work-related accidents, proper allocation of funds and time.

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Introduction: Occupational accidents are of the main issues in industries. It is necessary to identify the main root causes of accidents for their control. Several models have been proposed for determining the accidents root causes. FTA is one of the most widely used models which could graphically establish the root causes of accidents. The non-linear function is one of the main challenges in FTA compliance and in order to obtain the exact number, the meta-heuristic algorithms can be used.

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Material and Method: The present research was done in power plant industries in construction phase. In this study, a pattern for the analysis of human error in work-related accidents was provided by combination of neural network algorithms and FTA analytical model. Finally, using this pattern, the potential rate of all causes was determined.

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Result: The results showed that training, age, and non-compliance with safety principals in the workplace were the most important factors influencing human error in the occupational accident.

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Conclusion: According to the obtained results, it can be concluded that human errors can be greatly reduced by training, right choice of workers with regard to the type of occupations, and provision of appropriate safety conditions in the work place.

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Introduction: By industrialization, work-related accidents emerged as one of the most threatening factors of human life therefore analyzing the causes of accidents and providing control measures to prevent reoccurrence of similar accidents are of crucial importance.
 

Method and Materials: This is an analytical-descriptive study in which the collected data were analyzed using Ishikawa and SCAT methods and results related to the relationships between variables were examined. In this sense, first, accidents leading to amputations associated with operating with press machines (stuck between two objects) were analyzed by Ishikawa method and the obtained causes were classified into three groups: direct causes, interface causes, and root causes. Then, the obtained causes and the control measures were placed in SCAT table. The effect of causes of accidents and their ranking were determined using Chi-Square Test and Friedman's test, respectively. Accordingly, appropriate control measures were provided based on the accidents causes.
 

Results: The most significant interface causes is hurry at work the most significant root causes is inappropriate and ineffective supervision and the most important control measures is establishing effective HSE management system in the organization.
 

Conclusion: According to results, the main interfce causes of accidents leading to amputation due to operating with press machines is hurry at work because of increased production volume particularly by contractor companies. Furthermore, non-dynamic HSE system accompanied by ineffective supervision of personnel’s unsafe acts by the first layers of management are recognized as the basic causes of such accidents.

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Introduction: Lead exposure is considered as a global health problem. The irreparable harmful effects of this heavy metal on human have been proven in various studies. Comparing to general population, workers in related industries are more exposed to lead. Several studies have investigated lead occupational exposure and its biological evaluation in Iran; however there is no overall estimate. Thus, the present study was conducted to determine the occupational exposure to lead and its biological evaluation in Iranian workers, using systematic review and meta-analysis.

Material and Method: This study was carried out based on information obtained from databases including Magiran, Iranmedex, SID, Medlib, Trials Register, Scopus, Pubmed, Science Direct, Cochran, Embase, Medline, Web of Science, Springer, Online Library Wiley, and Google Scholar from 1991 to 2016, using standard key words. All of the reviewed papers which met the inclusion criteria have been evaluated. Data combination was performed according to Random Effects Model using Stata software version 11.1.

Result: In the 34 qualified studies, the mean blood lead level (BLL) concentration in Iranian workers was estimated 42.8µg/dl (95% CI: 35.15-50.49). The minimum and maximum BLL were belonged to west (28.348µg/dl) and center (45.928µg/dl) regions of Iran, respectively. Considering different occupations, the lowest mean value was reported in textile industry workers (12.3 µg/dl), while the highest value was for zinc-lead mine workers (72.6 µg/dl). Mean breathing air lead level of Iranian workers reported in 4 studies was estimated 0.23 mg/m3 (95% CI: 0.14-0.33).

Conclusion: According to the high concentration of BLL and breathing air, it is recommended to increase protective measures and frequent screening. Scheduled clinical and paraclinical examination should also be performed for workers.

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Introduction: Metro driving is one of the newest jobs in Iran. There are few studies in this field. Therefore, the physical workload and their influencing factors have not been identified in metro driving. The objective of this study was task and physical workload analysis of metro driving to recommend control measures.  

Material and Method: In this mixed method study, task analysis and Quick Exposure Check (QEC) were used to assessment of physical workload in metro driving. Different methods and techniques including field investigation, document reviews, individual and focus group interviews, and focus group discussions were used to analysis physical workload to recommend control measures.   

Result: Whole body exposure with physical workload was assessed unacceptable in metro driving. Although the exposures in back, shoulder/arm and hand/wrist were under threshold 70%, neck exposure lead to over physical workload in the whole body. Many themes include unsupported body; non-sufficient view on the track and on displays; awkward posture and unsuitable layout were extracted as significant factors influencing on physical workload.

Conclusion: An intervention plan was recommended to a) support body by chair, platform and footplate; b) optimize a sufficient view on the track and on displays; c) maintain body postures in seating position with easy reaching distance and sufficient view; and d) design a suitable layout for driving panel regarding to controls, keys and displays.

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Introduction: Correspondence analysis method and preparation of accidents and occupational hazards pattern is able to predict and anticipate accidents and is automatically prioritize the risks and injuries. The aim of this study was to present accidents and occupational hazards pattern based on risk-injury groups, which use it to manage of occupational accidents.

Material and Method: The report of occupational accidents, registered in the social security organization was collected in a period of ten years from 2005 to 2015 (222,300 accidents). Types of risk and injuries to any of the accidents specified based on International Labor Organization criteria and risk of injury were classified in a matrix (18 × 18). Risk-injury groups were separately identified using correspondence analysis and collapse process, as patterns of accidents and occupational hazards. In the mentioned patterns, the relationship between risks and damage can be identified, as it facilitates decision-making in risk assessment in companies covered by the social security organization.

Result: According to the findings, three groups of occupational accidents were obtained and variables of these three groups extracted from the obtained patterns. The first group included six risks and seven injuries that the risks variables were: contact with hot materials, accidents caused by caustic  and corrosive substances, contact with chemicals, accidents caused by toxic substances, contact with electrical equipment, explosion and fire, and injuries were: burns, other injuries, multiple injuries, gas poisoning, suffocation, poisoning, environmental hazards. The second group included seven risks and six injuries that the risks variables were: accidents caused by displacement, projections of fragments or particles, accidents caused by machine tools, slipping, falling people, falling objects, other accidents and injuries were: twists and sprains, dipping the objects in the body, objects in the eyes, cuts and amputations, superficial wounds, deep wounds. Finally, the third group included five risks and five injuries that risks variables were: Falling under the rubble, accident with vehicle, accidents caused by displacement, colliding of persons against objects, projections of fragments or particles, accidents caused by manual tools, trapped between objects, accidents caused by machine tools and injuries were: fractures, dislocation, back pain, hitting, contusions and crushing. It should be noted that the study of these patterns can be used to identify and prioritize of occupational accidents.

Conclusion: The proposed groups make new opportunities for development of the applications to analyze, interpret and automate management of occupational accidents in order to minimize uncertainty and increase its objectivity. Its advantage over other similar analyses can be considering both the risks and injury and to obtain groups of two variables. Due to the frequency and distribution of mass of risk and injury variables in the groups, the risk and injury variables of group 3 are the most important, and the risk and injury variables of group 2 are less important and the risk and injury variables of group 1 have the least importance.

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Introduction: Despite the ongoing efforts to reduce human errors in various systems, errors and unsafe behavior are the main cause of accidents in the workplace. Many studies have been conducted to identify and improve human error in recent years. The number of studies about the human error with the variety of topics has made it an overall overview difficult for researchers. Therefore, a systematic review of previous studies can be the best way to share useful findings and make a trend for the future research in the field of human error.

Material and Method: After a systematic search of valid databases, the analysis was focused on the title, publication year, journal title / Congress, city/region, the level of organization, job search, type of organization and the methods used. And articles were evaluated based encryption.

Result: Three groups of human error studies were identified. The first group studies in safety management, safety assessment, and safety planning have investigated the human error. The second group has examined the influence of individual characteristics such as behavior, cognition, and education on human error. The third group has focused on data arise from the previous accident to improve behavior and reduce human error. To make a better orientation for next studies two essential aspects included chronological analysis and thematic analysis was considered.

Conclusion: This study made an attempt to identify the gaps in the studies related to human error and afford some appropriate strategies.

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Introduction: The Surgical Safety Checklist has been introduced by the World Health Organization (WHO) as a tool for reducing medical errors. Reviewing the results of the checklist application indicates significant reduction in mortality and complications in surgery. Thus, this study aimed to customize and validate surgical safety checklist in order to complying with the surgical protocol in Iran.
 

Material and Method: In this cross-sectional and descriptive study, the WHO Safety Surgery Checklist was first translated. Next, through interviews with specialists and direct observation of activities, those tasks that were susceptible to the incident, identified, prioritized and analyzed using Hierarchical Task Analysis (HTA) and the results presented in form of HTA charts. Then, using Tabulate Task Analysis (TTA) and based on the recommendation and modification commented by expert panel, some questions added to the checklist and a customized version of the Surgical Safety Checklist was provided.  Hence, the faced validity, content validity and reliability of the checklist have been evaluated.
 

Result: In the surgery, four major tasks identified for analyzing using the HTA chart. Accordingly, 41 subtasks obtained and analyzed by TTA. The Lavashe method was used to determine the content validity ratio (CVR) and the content validity index (CVI). The question from the checklist, in which, CVI was less than 0.79, modified and replaced with appropriate question. Also, the scores for 3 questions were less than 0.49, and they were removed from the checklist due to the low CVR score. In the reliability assessment, the intra-observer method is used, and the Kappa coefficient obtained was acceptable and it was higher than 0.6, which confirmed the validity of the checklist.
 

Conclusion: In this study, the surgical safety checklist customized in terms of content validity and reliability, in a field study. Considering the compliance of the checklist items with the surgical protocol in Iran, we hope to use it to improve the quality of teamwork and reduce the complications and mortality caused by surgical errors

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Introduction: Safety at workplaces is an important issue, and lack of effective and efficient safety management methods based on scientific studies could cost the construction industry. An effective accident investigation and root causes analysis could prevent the occurrence of incidents at minimum cost and time.
Material and Method: First, major accidents in road construction projects were identified by interview and literature reviewing techniques. Then, fault tree was drawn for each main risks. In the next step, in order to calculate occurrence probability and severity of each accident type, a questionnaire was designed and distributed among the participants. Fuzzy logic was employed in calculations, due to the existence of uncertainty in linguistic variables. Fuzzy Fault Tree Analysis (FFTA) was used for calculating the occurrence probability, and importance of each criterion was determined using Fuzzy Analytical Hierarchical Process (FAHP) to calculate the severity of each accident. Finally, risk factors for each accident type was calculated and the risks were ranked accordingly.
Result: Accidents related to crusher and asphalt plant, traffic accidents, heat exhaustion and lack of hygiene and hit by machinery were identified as the most important risks among the eleven investigated accident types.
Conclusion: The findings in this research and also implementing effective safety management techniques, could be helpful on reduction of the probability of accidents root causes and to mitigate related risks.

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Introduction: Noise is one of the most harmful industrial agents and there are different methods to control it. Fuzzy analytical hierarchy process is an appropriate technique for selecting the best choice among several control methods. Therefore, the aim of this study was the selection of the most suitable sound control method using fuzzy hierarchical analysis (FAHP) technique in a refinery plant.
Material and Method: The present study was a cross-sectional research in a refinery plant. After identifying the main sources of the noise in the studied palnt, five criteria and ten noise control methods were selected using a questionnaire and Delphi methods. Then, Fuzzy hierarchy analysis was applied for the selection of the best noise control alternative.
Result: The results showed that the performance with a final weight of 0.277 and the non-interference in the process with a final weight of 0.06 were most and least important criteria, respectively. Meanwhile, worker enclosure had highest score (0.207) of the control methods.
Conclusion: In general, the results showed that best criterion for selection of the suitable noise control method is performance. What’s more, based on the results, worker enclosure was selected as best noise control method in the refinery.

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Introduction: Todays, the improvement and optimization of the safety performance are essential and important for control and prevention of accidents in the industry. The purpose of this research was to assist a hybrid cycle power plant for identification and prioritization of the influencing factors in enhancing safety in order to reduce risks and to improve system performance.  
Material and Methods: In this descriptive-analytical study, influencing factors were classified within three main categories of human, equipment, and managment, and 14 sub-factors was screened and selected by experts using Fuzzy Delphi method. Then, fuzzy DEMATEL method was adopted to determine the relationships, the intensity of affecting and being affected factors, and the analytical network process method for weighting and prioritization the factors.
Results: The findings of the fuzzy DEMATEL method showed that “Managerial”, “equipment” and “human” factors are respectively influencing factors on the improvement of safety performance. “Managerial factors” is the most influencing and “Human factors” is the most influenced one. Based on the results of fuzzy analysis network process method, “human factors” is the first priority among the main factors, and “employee motivation”, “system of control and prevention”, “work team spirit”, “individual skills” and “Individual protection equipment” sub-factors are respectively the first to fifth priorities were according to their weight.
Conclusion: “Human factors” re the most influenced factor and the main problem of the organization, which can be improved by the most influencing “managerial” factor. The success or failure of the safety performance in the power plant depends on better management of the “human factors” and managers need to motivate employees to improve safety performance.

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Introduction: Work-related musculoskeletal disorders (WMSDs) are any disorders or injuries to the musculoskeletal system due to working procedure or conditions. WMSDs is one of the main causes of occupational injuries and disability in advanced and developing countries. The present study was conducted to evaluate the prevalence of musculoskeletal disorders in drivers in order to achieve complete results with high statistical power, using meta-analysis method.  
Material and Methods: This study is a systematic review and meta-analysis. In this study, the articles extracted from national and international databases, including Scientific Information Database (SID), Science Direct, PubMed (using the word MESH), Pre Quest, Scopus, Google Scholar, Iran Medix, SID, and MedLib. The main keywords for the search were Prevalence، Musculoskeletal and Drivers. The time for selecting articles was from 2000 to 2017. Data were analyzed using meta-analysis (random effect model). I2 and Q indexes were used to calculate heterogeneity. All statistical analysis was performed using STATA 14 software.
Results: In this study, 22 articles were entered into the meta-analysis process. The sample size was 7706 people with mean of 350 people in each study. The prevalence of musculoskeletal disorders in different organs of drivers was as follows: 26.19% (CI: 38-14.30), 18.07% (CI: 25.99-10.16), and 5.75% (CI: 8.27-3.22) in neck, shoulder, wrist / hand, and elbow respectively. The highest prevalence was related to low back pain 41.63% (confindence Interval (CI): 33.09-50.17), and the lowest prevalence was related to elbow disorder 7.45% with (CI: 95.46-9.43).  The significance level was set at 0.05.
Conclusion: The results of this study show that the prevalence of pains in the back, neck, and shoulder are high among drivers. Also, due to the high prevalence of predicting the incidence of impaired driving. in order to control and reduce these disorders, appropriate design of seats and equipment of vehicles, conducting periodic examinations of drivers,performing proper exercise, and considering adequate rest time in working hours are recommended. Ergonomics and occupational health education programs are also recommended to reduce the risk of developing musculoskeletal disorders associated with driving.

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