JOURNAL OF OCCUPATIONAL HYGIENE ENGINEERING
Year:2019 | Volume:6 | Issue:3 |Papers Count:8

Background and Objective: Road transportation is the most common way to ship hazardous materials (HazMat) in many countries, including Iran. Therefore, it seems necessary to assess the consequences of road HazMat accidents during transportation. The present study aimed to develop a method for the assessment of HazMat accidents during transportation. Materials and Methods: In the current study, a fuzzy inference system (FIS) was developed for evaluating the risk of road HazMat transportation. The FIS consisted of three input variables, including "the concentration of released HazMat", "the vulnerability of the exposed population", and" toxicological characteristics of HazMat". The output of the FIS was also indicative of exposure severity coefficient (ESC) which in turn suggests the irreversible effect of exposure to chemical substances. It is worthy to note that a case study was performed on the release of Cl to test the method. Results: Base on the results of the study, the area around the release point was divided into two regions of low hazard area (with a diameter of 187 m) and a safe area (diameter more than 187). The highest ESCs were obtained for vulnerable groups (i. e., children, the elderly, and those with underlying diseases) with an ESC of 0. 92 and teenagers and adolescents with an ESC of 0. 767. Conclusion: The results of the present study indicated that it is necessary to assess the consequences of chemical incidents in designing and locating roads where hazardous chemicals are to be transported.

Background and Objective: It is of utmost importance to analyze the causes of accidents to control and prevent their recurrences. This study aimed at analyzing the causes of amputation-leading accidents in a dam construction project using a Tripod beta and SCAT Combined Method. Materials and Methods: This study analyzed the data related to amputation-leading accidents using a Tripod beta and SCAT Combined Method. Initially, the interface and root causes were obtained by the Tripod beta Method and were subsequently placed in SCAT cause and effect table along with the suggested control provisions. In addition, the data were collected using questionnaires, and the effect of the causes of accidents and their ranks were evaluated using the Chi-Square and Friedman tests, respectively. Accordingly, appropriate control measures and necessary suggestions were provided in this study. Results: According to the results, the underlying causes were classified into 6 categories. Maintenance management (25%) and training (20%) obtained the first and second ranks. On the other hand, the executive instructions (5%) obtained the lowest rank. Moreover, 13 preconditions were determined in this study. The most important indirect and root causes were "inappropriate machine lifting (rank: 2. 69)" and "the erosion and excessive deterioration of the mechanical excavator (rank: 4. 55)", respectively. Furthermore, the most important control measure was "the inspection and control of the operation (the mean rank: 5. 05)". There was also a significant relationship between indirect and root causes. A P-value less than 0. 001 was considered statistically significant. Conclusion: The combined method presented in this study has met the needs of different organizations in many cases and is currently one of the most important methods to analyze the accident causes. Therefore, it is suggested to combine the SCAT with other methods to analyze the causes of accidents in dam and construction projects.

Background and Objective: It is a widely held belief that the physical workplace environment exerts a profound effect on the health and performance of office employees. The assessment of administrative working environment can pave the way for the enhancement of ergonomic conditions of workplace environment. With this background in mind, the present study aimed to design a valid and psychometrically evaluated questionnaire for the assessment of administrative work environment. Materials and Methods: Based on the theoretical foundations of ergonomics and the assessment of administrative work environment, a 22-item questionnaire for the evaluation of administrative workplace environment was designed. The face validity was evaluated by four experts and the content validity of the questionnaire (queries on necessity, relevance, clarity, and simplicity) was evaluated by 20 experts using the quantitative method (CVR and CVI). Thereafter, the questionnaire was administered to a total number of 203 employees of Iranian Gas Engineering and Development Company. Structural validity and reliability of the questionnaire were assessed by Cronbach's alpha coefficient using SPSSsoftware (version 24), and confirmatory factor analysis was performed in AMOS software (version 24) evaluating AVE and CR indices. Results: Based on the results of content validity, 21 questions were approved and 1 question was rejected. The mean content validity ratio and the mean content validity index were reported as 0. 73 and 0. 94, respectively. In addition, the results of the structural validity and reliability of the questionnaire demonstrated that confirmatory factor analysis fit indices were acceptable; moreover, Cronbach's alpha coefficient for the whole questionnaire was measured at 0. 882 and AVE and CR indices were estimated at 0. 57 and 0. 96, respectively. Conclusion: As evidenced by the obtained results, the newly developed 21-item questionnaire for administrative workplace environment assessment enjoys an appropriate validity and reliability to evaluate the conditions of the administrative workplace environment concerning ergonomy (engineering psychology dimension), and can be administered as an effective tool in related research.

Background and Objective: Pipeline inspection gauge operation which is called “ pigging operation” is a practical online monitoring method for maintaining the pipeline in a healthy and safe condition. This operation requires high man-machine interactions. Therefore, it is sensitive to human error which can lead to catastrophic consequences, including human mortality. Materials and Methods: This descriptive study was carried out to assess the probability of human error in pigging operation in a gas transmission plant in Iran. Initially, hierarchical task analysis was conducted via walking through the pigging operation, observing the pigging operation tasks, and doing interviews with operators working in the operation. Subsequently, the Standardized Plant Analysis Risk-Human Reliability Analysis (SPAR-H) was utilized to assess the human error probability. Results: In this study, SPAR-H method was implemented on “ pigging operation” . The mean value of human error probability (HEP) was estimated at 0. 218. It should be noted that the mean value of HEP was regarded as a subtask of “ opening bypass valve for decreasing pressure” , as well as a subtask with the highest probability of human error (0. 841). Conclusion: The SPAR-H method is a useful tool for practitioners to assess HEP. According to the obtained results, some of the preventive actions to reduce HEP include the utilization of more clarified instructions for performing operations as well as the automation of the launching and receiving pigging cups.

Background and Objective: One of the most common problems of firefighters is performance degradation while using protective gloves. Regarding the existence of various types of firefighting gloves in Iran, this study aimed to investigate and compare the effect of these gloves on hand dexterity. Materials and Methods: Two types of the most widely used firefighting gloves were selected for the purpose of this study. The dexterity was evaluated using four standard tests, including Bennett, Minnesota, Pegboard, and modified Pegboard, for each pair of gloves on 40 male students. The Spearman's correlation coefficient, Wilcoxon test, and Friedman test were used to compare dexterity and its effective factors. Results: Based on the obtained results, the type of gloves had a significant effect on hand dexterity (P<0. 001). The findings showed that the modified Pegboard test had high sensitivity in measuring finger dexterity. However, the Pegboard test due to its low sensitivity and severe reduction in scores was not suitable for measuring dexterity. The Bennett and Minnesota tests due to their similar trends can be used to measure hand dexterity. In addition, since Minnesota test was less tiresome and solved some problems, it can be used instead of the Bennett test. Conclusion: Various firefighting gloves available in the market have different effects on the dexterity of the hands and fingers. Therefore, this should be considered by firefighting organizations. It is recommended to evaluate dexterity while using firefighting gloves with the help of the modified Pegboard and Minnesota tests.

Background and Objective: Job stress is one of the factors affecting workers' health and occupational productivity. In recent years, stress has been considered as a factor in the loss of productivity and efficiency induced by stress. This study aimed to investigate the effect of job stress on workers' productivity in one of the Oil and Gas Companies in Southwest Iran. Materials and Methods: In this study, two separate questionnaires, namely Health and Safety Executive and productivity questionnaire (by Saatchi) were used to assess the job stress and workers' productivity. The validity and reliability of these questionnaires have been reviewed in previous studies. The data were analyzed in SPSS software (version 24). Moreover, a P-value less than 0. 05 was considered statistically significant. Results: According to the results, the mean score of workers' job stress was 3. 68 ± 0. 43. The results showed that 36. 4% and 63. 6% of the workers had low and no stress, respectively. In addition, there was a reverse correlation between productivity and job stress with dimensions, such as role, relationship, support of authorities and coworkers, as well as demands (P<0. 05). On the other hand, a significant relationship was observed between productivity and variables, such as age, work experience, and education level (P<0. 05). Conclusion: Given the reverse correlation between occupational stress and productivity, it can be concluded that the ability to control the amount of job stress and the influencing factors in the workplace is one of the strategies to increase productivity.

Background and Objective: Heat stress is one of the major safety and health concern in the oil and gas industry. The main purpose of this study was to compare the heat stress of oil terminals in northern and southern Iran. In addition, two physiological parameters were utilized in order to validate these indices. Materials and Methods: This descriptive-analytical study was performed on 130 employees working at two oil terminals in Iran (i. e., Kharg and Neka). Initially, heat stress indices including Hang Seng Index (HIS), Allow Exposure Time (AET), WetBulb Globe Temperature (WBGT), and Predicted Four Hour Sweat Rate (P4SR) were measured in this study. Subsequently, the oral and tympanic temperature of the participants were taken in order to validate the mentioned indices using Pearson correlation test. The data were analyzed in SPSS software (version 22). Results: The results showed a significant correlation between the heat stress indices of the indoor workplace in Kharg, Iran, and physiological parameters (P<0. 05). Moreover, a positive correlation was observed between the indices and the parameters, except for HSI. Regarding the oil terminal in Neka, the oral parameter was also correlated significantly with AET, WBGT, P4SR. However, there was no significant correlation between the tympanic temperature and the aforementioned indices (P> 0. 05). Conclusion: According to the results, WBGT and AET are valid indices to assess heat stress in oil terminals. In addition, it was revealed that the heat stress in indoor workplace in Kharg oil terminal was higher than that in Neka oil terminal.