دو ماهنامه سلامت کار ایران
سال دهم شماره 6 (بهمن و اسفند 1392)

Repetitive tasks are common in assembly industries and the prevalence of musculoskeletal disorders is very high. Ergonomic survey should be applied to identify, assess and control related problems. There are several methods for risk assessment of repetitive tasks. This study aimed to assess the risk of repetitive tasks among assemblers in an electric industry using Assessment Repetitive Tasks (ART) tool. This tool was developed by the Health, Safety and Executive (HSE), UK in 2009. In this current study all workstations (20 workstations) were selected based on census method, after that, Hierarchical Task Analysis (HTA) method was used for task analysis and job was degraded to tasks, actions and movements. Then, ART method was implemented to identify common risk factors in repetitive tasks that can contribute to develop musculoskeletal disorders of upper limbs. In total, 20 ART worksheets were completed in 2 assembly lines. Results showed that 15% of tasks were at low level of risk, 55% of tasks were at medium level of risk and 35% of tasks were at high level of risk. The most important risk factors were hand grip and breaks that were high risk in all tasks. Monotonous of work was also the most important psychosocial factors in all tasks. the results of current study shown that the musculoskeletal disorders due to repetitive tasks are approximately high and ergonomics interventions is needed to reduce risk levels. Using ART method shown that it is a usable, easy and suitable method for assessing repetitive tasks that is recommended for ergonomics interventions and redesigns.

Traditionally in any event, the judgment was usually based on human error and accidents and according to the latest statistics published in Iran the main cause of accidents is unsafe acts and recklessness. The aim of this study was to investigate the factors influencing safety culture in detergents and cleansers units and its role in the incidence of accidents. In this study aimed to determine the safety culture in detergents and cleaners companies, the standard safety culture questionnaire was extracted and its reliability was determined in selected population as 0.86. After collecting the questionnaires and investigation of the related clinical files the data analysis was performed using SPSS17 software. Data analysis showed that in both selected companies the mean age of personnel, work experience and any incidents occurring during the period of their working in the company were 34.2 ± 6.67, 10.4 ± 5.842 and 0.92 ± 1.957 respectively. While in the first company the safety culture score was180.51, in the second company it was 200.45 that is statistically significantly different (p <0.001). There was a significant inverse relationship between safety culture and the prevalence of accidents in two companies.

The most important factors that influence human performance are; accuracy, speed and ability to perform the skills by individuals. Given the importance of human productivity in improving the production and quality, This study examines the impact of noise on error rate, speed and ability to perform the manual skills. This experimental study was conducted on 96 students. Sampling was conducted with a Randomized block design. Controlling exposure factors of sound intensity and duration of exposure, the accuracy and speed of performance of the test subjects were evaluated using Two-hand coordination test. Data was analyzed by SPSS18 software using descriptive and analytical statistical methods by ANCOVA repeated measure. The results showed that the increasing of sound level pressure from 65 dBA to 95 dBA increased the work speed significantly (P<0.05). Increasing the exposure time (zero to 40 minutes) and gender (men and woman), did not show a statistically significant difference in the performance rate (P<0.05). The error rate was statistically significant with increasing the sound intensity (P<0.05). Results indicate that with increasing the sound level pressure,performance rate and human error were increased and following exposure to sound levels less than 85 db performance was initially decreased then with low incline was increased.

One of the most essential and important steps for improving safety level in existing or designing units is consequence evaluation of hazards such as fire, explosion and dispersion of hazardous chemical substances. Due to severe operational conditions, high explosive and flammable gases such as methane and hydrogen, hydrogen production process is causing major industrial accidents of the view life and financial losses. Therefore safety is main concern of hydrogen producers. First, all hazards and potential scenarios of hydrogen production were identified by applying HAZID Technique, and after collecting the required data, consequence modeling was done by means of professional software PHAST6.54. Death probability of people by means of valid equations of probit was calculated and ultimately, the severity of the consequences was estimated using conventional criteria. The results revealed that, jet fire caused by a full bore rupture in Desulphurization reactor has the highest fatality (26person). The harm effect distance, maximum radiations of this incident were 250 m, 370 kW/m2 respectively. A full bore rupture in Reformer can lead to the most dangerous flash fire. So that people at distance up 130 m from placing leakage and affected area 1505m2 were exposed to concentration of 61120 ppm and all people would be killed. The most dangerous vapor cloud explosion caused by hydrogen purification absorbers, so that distances up to 60m from absorbers location all people would be killed and all process equipments and buildings will be completely destroyed. The safe distance of hydrogen production unit equals to 746 m from its boundary limit. Consequence evaluation is a quantitative and comprehensive method for estimation and evaluation of potential incidents severity of industrial hazardous units. The occurrence of incidents such as fires and explosions has the great life and financial losses in the hydrogen production process, Thus safety of industries nearby hydrogen production and consume must be specifically considered.

Today, it was revealed that Socio-technical systems did not have a bimodal nature and interactions in these systems are complex and non-linear. Consequently, since risks can be emerged as non-linear combinations of performance variability, so traditional methods of risk assessment are not able to capture these combinations. The present paper is aimed at identifying the emergent risks by means of the Functional Resonance Analysis Method in a process unit of an oil refinery. To identify the emergent risks in the functions, first the essential system functions including twenty five functions of human and four functions of organization were identified in an oil process unit. Then, potential variability (emergent risks) was characterized among the mentioned functions using a technical checklist. After then, resonance phenomenon was evaluated among the functions with regard to possible dependencies/couplings among functions and their effect on each other. Finally, mechanisms and barriers such as physical, symbolic, functional, etc., which were utilized to damp the variability, were identified. The results showed that the possibility of the high variability in fourteen human functions is likely, but the analysis of different scenarios revealed that five human functions contain the emergent risks, and should be controlled. These risks go beyond component failures and malfunctions. with regard to the results of this research and the conducted researches in the world, this model is so applicable to understand dynamics and nonlinearity of functional resonance in socio-technical systems in order to avoid accidents.

Accidents and injuries are a cause for concern for all countries in the world. Cognitive failures can be defined as cognitive-based errors on simple tasks that a person should normally be able to complete without fault; these mistakes include problems with memory, attention or action. The present study was designed to investigation of relationships between occupational cognitive failures and safety performance among bus drivers.

In this descriptive analytical study, 129 bus drivers completed an occupational cognitive failure questionnaire (OCFQ) and the DBQ as well as answered questions on accident involvements. Correlation and regression analysis were used for data processing.

Occupational cognitive failures have a significant direct positive effect on all driving unsafe behaviors including intended and unintended violations, slips and mistakes.

For assessment of safety performance in occupational driving jobs, we must use a valid instrument. The cognitive failures can predict bus drivers’ engagement in safe or unsafe behaviors.

Author(s): Microorganisms are one of the most important sources of contamination in indoor air and occupational environments especially in hospitals. The aim of this study was to evaluate the adsorption characteristics of bone char to adsorb B. Subtilis in the air. In this study B.subtilis spores were used as a model of bacterial spores. Also bone char was used as an adsorbent in this study that was prepared by thermal method from waste bones and the characterization of prepared adsorbent was determined. Then the adsorption capacity of bone char for B.subtilis was evaluated. The Present study show that bone char as a mineral adsorbent has high efficiency in adsorption of bacterial spores. The adsorption capacity of this mineral was 3698 spores per gram. bone char has a high capacity for adsorption of bacterial spores. Mineral structure of bone char can delay the reproduction and biofilm formation of microorganism on its surface. The result of this study could be used in development of control equipment of biological air pollutant.

Shift work intolerance has symptoms that names shift work maladaption syndrome. The aim of this study is the comparison between frequency of symptoms of acute shift work maladaption syndrome in two groups of shift workers. A cross-sectional study has been implemented in two groups of shift workers (with and without night shift), data has been gathered by a questionnaire and then analyzed in SPSS 11.5 using t-test, chi – 2 and forward logistic regression considering p<0.05 as significantly difference. Following the comparison of the frequency of symptoms of acute shift work maladaption syndrome, it was revealed that night shift workers had more symptoms, however, it was not statistically significant. In night shift workers chronic diseases had no relationship with symptoms (p=0.666), in spite of the other group (p= 0.037). While the frequency of symptoms showed to have a relationship with smoking in night shift workers (p=0.000), there was no such a relationship in other shift workers (p= 0.200). There was no significant difference between two groups in frequency of symptoms of acute shift work maladaption syndrome. Only smoking was a risk factor for symptoms.:

The construction industry is known as one of the most dangerous industries in terms of work-related mortality, injury rates and workers compensation payment. Therefore, safety risk assessment is a key step to be performed for management of major construction projects. Failure Mode and Effects Analysis (FMEA) is a risk assessment tool that mitigates potential failures in systems, processes, designs or services and is used in a wide range of industries. The purpose of this research is to employ the combination of fuzzy logic and FMEA, FTA, AHP-DEA methods for safety risk assessment of mass housing construction. In the case study section, for the purpose of safety risk assessment, two different types of mass housing projects are investigated. According to the results, the risks of falls from height in both projects are identified as the most significant risks. Hence, risk reduction strategies and actions for prevention and mitigation of hazards are presented. The ranking of the risks and the highest risks found in this research are consistent with the previous research and with the report of the Iranian Social Security Organization (ISSO). In addition, the root causes of the major risks match up with similar studies. Moreover, the validity of the research findings is approved by the risk assessment group. Hence, t his model (which is able to consider the current safety condition) can help safety professionals in construction sites to identify risks, explore their root causes and to develop accurate tools to control them.

The most effective way to overcome bottlenecks and crises caused by economic and social development process is proper utilization of human capital and benefiting from its intellectual and practical capacities. On the other hand in today’s competitive world, many companies have realized that HSE management should be an integral and essential part of their organizations and should be valued and focused on as much as other on management activities of their organizations. Simultaneous consideration of health, safety and environmental issues, in addition to elimination of parallel activities, will also, due to the technical and economic balance, facilitate increased productivity and sustainable development. The objective of this study was to determine the relationship between job satisfaction and HSE performance of employees in Iran Khodro Advanced Dies Company in the year 2011. The objective of this descriptive-survey research was to investigate the relationship between job satisfaction and HSE performance of the employees. The statistical population of this descriptive-survey research consisted of 275 employees of Iran Khodro advanced Dies Company out of which 70 people were selected as sample using Cochran formula and simple sampling technique. A questionnaire was the main tool of study and the validity of the questionnaire was approved by some of the faculty members and the reliability of the main scales of the questionnaire was approved by Cronbach alpha Coefficients (0.84 for HSE performance and 0.94 for job satisfaction). The questionnaire was in a Likert format, to convert the qualitative Likert options to quantitative options for entry into software, the triangular fuzzy numbers method was applied. The data were analyzed by SPSSver:18 software. Result of prioritizing job satisfaction indicated that, responsibility was in the highest rank and result of prioritizing HSE performance of employees indicated that, performance and implementation was in the highest rank. Further, findings revealed that, there were positive significant relationships between HSE performance of employees and job satisfaction at 0.05 percent level. The step-wise regression analysis indicated that seven variables (job satisfaction) explained 66.7 percent of variations of the HSE performance. According to the significant relationship between job satisfaction and HSE performance of the employees, it can be concluded that, paying more attention to job satisfaction indicators can lead to a better HSE performance of Employees.