Journal of Occupational Hygiene Engineering
Year:2015 | Volume:2 | Issue:3|Papers Count:8

Background & objective: Desirable and ergonomic lighting in workplaces has a significant effect on the visual complications, improving the efficiency and productivity of employees. This study aimed to evaluate the lighting system and feasibility of improving the artificial lighting system for comfort lighting in the workshop of the Fourth South Pars Gas Refinery.Methods: In this descriptive-analytical study, the environmental conditions of the studied workshop were evaluated and the illuminance was measured in both day and night at 216 points. Based on lighting measurements, a site map was provided. Further, based on the current conditions of the workshop, illuminance was estimated using DIALux 4.12 lighting calculations software. By considering the national recommended limits for industrial lighting and the current luminaires, the different practical, accessible and low cost solutions were presented. Using the mentioned software, the share of each proposed solutions for improving workshop lighting were estimated.Results: The results showed that the workshop illuminance in day and night were 197±71.5lx and 160±50.6 lx, respectively. The same results were also obtained by software calculations. According to the results, lighting system was considered as undesirable lighting system that and needs to modifications. According to the software predictions, the use of proposed solutions can increase the light intensity from 260 to 405 lx.Conclusion: The results confirmed that the low cost and simple solutions can significantly improve the ergonomic and comfort lighting in the workplace. The use of the specialized tools, which were calculated by experts and designers can also facilitate the reliable conducting feasibility.

Background & objective: In Economic and competitive world today, cost-benefit analysis is one of the most important parameters for any intervention. The purpose of this study was the cost-benefit analysis of ergonomic intervention effects in Boiler and Equipment Engineering and Manufacturing Company.Methods: At first all workstations of the company were assessed using QEC. Then those earned more than 70% in QEC assessed by OWAS. By analyzing the results of these two methods, the “Haarp welding” workstation selected as the critical one. After presentation of possible solutions in specialized committee, the final solution selected and cost-benefit analysis was carried out by CyberManS tool. Finally, after implementing the intervention workstation was reassessed.Results: The results of the survey showed that the final score of assessment using QEC, OWAS and NASA-TLX before the intervention was 84.7%, 3 and 75.4, respectively and after the intervention was 47.5%, 1 and 42.7Also, the result of cost-benefit analysis by CyberManS showed that by spending 110 million rials after 1.5 years the investment returned and profitability initiated.Conclusion: In addition to reducing the risk of musculoskeletal disorders, ergonomic interventions have financial benefits by increasing the productivity and production, reducing the compensation and decreasing the lost work days can also cause financial benefits.

Background & objective: Physical and mental health of workers is one of the important factors affecting their job performance. The number of fatal occupational accidents in our country is high. This study aimed to investigate the relationship between mental health and safety behaviors, occupational accidents and demographic variables in a publishing industry in one of the central provinces of Iran, 2014.Methods: In this cross-sectional study all operational employees (98 persons) were included. Researchers developed a demographics questionnaire, Goldberg general health-28, safety behavior checklist and self-reported accidents were tools to gather the required data. Statistical analysis such as independent T-test, ANOVA and Pearson correlation were used for data evaluation by SPSS V20.Results: All workers were men and Mean of age was 41.79 also its standard deviation was 6.77. Studied personnel have been experienced occupational accident in a range of 0-5 cases. As well as, 80.75% of total observed behaviors (800) were safe. The mean score of GHQ test equals to 50.38±10.39 that was over the cut point (23). There was no significant relationship between mental health with safety behaviors (p>0.05). Also, significant level of its correlation with occupational accident was calculated as 0.08.Conclusion: Workers mental health status was unacceptable. Although, work condition based on the occupational accident and safety behavior has not showed caution situation, but the ABC model (Activators- Behaviors-Consequences) can help to promote personnel behaviors and control accidents.

Background & objective: Oil storage tanks are major industrial facilities which always pose risks of toxic substance release, fires and explosions. Fire has been recognized as the most common risk associated with such facilities, while explosion is the most important one in terms of ability to claim human lives and damage property. The current study aimed at investigating and modeling the effects of fires occurring in a gas condensate tank farm, according to which the level of possible emergencies were specified using the guidelines provided by the Center for Chemical Process Safety. Lastly, control measures were recommended.Methods: In the present study, the release and leakage of gas condensate from floating roof tanks were assessed using HAZOP method. Then, using PHAST software, the amount of radiation intensity received by the surrounding environment was determined, safe boundaries were computed, and according to the CCPS standard the emergency levels were determined.Results: modeling was performed based on the maximum capacity of tanks for both cold and hot seasons. The results revealed that safe distance for a maximum amount of irradiation density (4 KW/m2) related to a sudden release were 60 and 140 meters, respectively.Conclusion: according to the current condition of the plants and storage tanks, a plan was recommended for emergency management and practical suggestions were provided to improve the reliability and consistency.

Background & objective: Human error is one of the main causes of accidents. Due to the unreliability of the human element and the high-risk nature of demining operations, this study aimed to assess and manage human errors likely to occur in such operations.Methods: This study was performed at a demining site in war zones located in the West of Iran. After acquiring an initial familiarity with the operations, methods, and tools of clearing minefields, job task related to clearing landmines were specified. Next, these tasks were studied using HTA and related possible errors were assessed using ATHEANA.Results: de-mining task was composed of four main operations, including primary detection, technical identification, investigation, and neutralization. There were found four main reasons for accidents occurring in such operations; walking on the mines, leaving mines with no action, error in neutralizing operation and environmental explosion. The possibility of human error in mine clearance operations was calculated as 0.010.Conclusion: The main causes of human error in de-mining operations can be attributed to various factors such as poor weather and operating conditions like outdoor work, inappropriate personal protective equipment, personality characteristics, insufficient accuracy in the work, and insufficient time available. To reduce the probability of human error in de-mining operations, the aforementioned factors should be managed properly.

Background & objective: High workload may lead to increase human errors, compromise quality and safety of care, and reduce the nurses’ quality of working life. The aim of this study is to determine the task-induced workload in nursing.Methods: This is a descriptive analytical study. All of 214 nurses of one of the educational hospital took part in. After obtaining informed consent from participants, data were collected based on NASA-TLX questionnaire and the desired level assumed less than 50%. Analysis of data was performed by descriptive statistics and Anova in SPSS software (version 11.0) at significant level of 0.05.Results: The results showed that perceived mental pressure for nurses is more than other NASA-TLX subscales (P<.001). Also, the mean perceived workload was more than 50%. However, mean workload score of NASA-TLX showed significant correlation with age (P<.001), work experience (P<.001), shift work (P<.02), and department (P<.001).Conclusion: The results show that effective programs will be required to reduce the work load, and to enhance nurses' performance.

Background & objective: Due to the features such as intuitive graphical appearance, ease of perception and straightforward applicability, risk matrix has become as one of the most used risk assessment tools. On the other hand, features such as the lack of precision in the classification of risk index, as well as subjective computational process, has limited its use. In order to solve this problem, in the current study we used fuzzy logic inference systems and mathematical operators (interval numbers and mapping operator).Methods: In this study, first 10 risk scenarios in the excavation and piping process were selected, then the outcome of the risk assessment were studied using four types of matrix including traditional (ORM), displaced cells (RCM), extended (ERM) and fuzzy (FRM) risk matrixes.Results: The results showed that the use of FRM and ERM matrix have prority, due to the high level of "Risk Tie Density" (RTD) and "Risk Level Density" (RLD) in the ORM and RCM matrix, as well as more accurate results presented in FRM and ERM, in risk assessment. While, FRM matrix provides more reliable results due to the application of fuzzy membership functions.Conclusion: Using new mathematical issues such as fuzzy sets and arithmetic and mapping operators for risk assessment could improve the accuracy of risk matrix and increase the reliability of the risk assessment results, when the accurate data are not available, or its data are avaliable in a limit range.

Background & objective: Occupational accidents may occur in any types of activities. Carrying out daily activities such as repairing and maintaining are one of the work phases that have high risck. Despite the issuance of work permits or work license systems for controling the risks of non-routine activities, the high rate of accidents during activity indicates the inadequacy of such systems. A main portion of this lacking is attributed to the human errors. Then, it is necessary to identify and control the probable human errors during issuing permits.Methods: In the present study, the probable errors for four categories of working permits were identified using SHERPA method. Then, an expert team analyzed 25500 issued permits during a period of approximately one year. Most of frequent human errors and their types were determined.Results: The “Excavation” and “Entry to confined space” permit possess the most errors. Approximately, 28.5 present of all errors were related to the excavation permits. The implementation error was recognized as the most frequent error for all types of error taxonomy. For every category of permits, about 40% of all errors were attributed to the implementation errors.Conclusion: The results may indicate the weakness points in the practical training of the licensing system. The human error identification methods can be used to predict and decrease the human errors.