Journal of Health and Safety at Work

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Introduction: The purpose of this study was prioritizing the noise control methods using Analytic Hierarchy Process (AHP) technique in Hamadan glass industry.

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Material and Method: This is a cross-sectional – descriptive - analytical study. According to a survey of experts by questionnaire and Delphi method four criteria were selected including cost, efficiency, executive capability and not to interfere in the process and eleven alternatives for control options. Prioritizing of the items was conducted based on the study criteria as well as the importance ranking determined in this study.

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Result: The results showed all that consistently Ratios were less than 10 % and compatibility of answers has been confirmed. According to expert’s views, the criteria of executive capability (0.277) and using the barrier between the two main sections (0.111) have achieved the highest priority among the criteria and control methods, respectively.

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Conclusion: In this study a pattern of decision-making structure was introduced based on Analytic Hierarchy Process for determining the method noise control. This method can improve the decision making process and prioritizing noise control methods as an efficient and effective approach.

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Introduction: One of the most important threats for employees working in chemical industries is exposing to the chemical materials. Lack of precaution and control regulations during working with chemicals can have irreparable consequences. So, in order to achieve an effective control program, it is necessary to have an appropriate assessment of the procedures involving exposure to the chemicals. William-fine method can provide an acceptable insight into hazard risk rate.

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Material and Method: In this study, a combination of AHP and William-fine adopted to achieve a model for chemicals exposure risk assessment in oil and gas industry. The numbers were extracted from questionnaire, and then, they weighted entered to assessment the model. Finally, they were presented quantitatively with protection layer.

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Result and Conclusion: The results revealed that the quantitative amount of consequence, probability and exposure was 83.2, 8.45, and 2.2, respectively. Generally, the chemical exposure risk number was 1546 which shows that reforming plans are in highly priorities from an economical point of view. William-fine method has the benefit of an accurate chemical exposure by combination of effect severity, exposure probability and detriment rate, and also minimization of personal judgments during the assessment.

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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: Resilience engineering (RE), as a new approach in the system safety domain, is intended to preserve the performance of socio-technical systems in various conditions; and accentuates the positive activities instead of the failure modes. The aim of this study was to develop a new framework for safety assessment on the basis of RE, using the Fuzzy Analytical Hierarchy Process (AHP) method.  

Material and Method: Current study is an analytical cross-sectional survey performed in a petrochemical industry. Initially, six RE indicators were selected, including top management commitment, just culture, learning culture, awareness, flexibility and emergency preparedness and accordingly an assessment framework was established. Then, the selected RE indicators were evaluated and validated by experts in a specialized panel. Following, an indicator was proposed named “resilience early warning indicator”. Finally, the RE indicator score of the total process was determined using the fuzzy evaluating vector.   

Result: Findings revealed that top management commitment and learning indicators have the most and the least effects on the RE level of the process, respectively. Besides, the flexibility (C3) indicator was located in orange early warning zone (OEWZ) while other indicators were positioned in the no early warning zone (NEWZ). Furthermore, the overall resilience level of the process was evaluated as level III (NEWZ).

Conclusion: Management commitment and emergency preparedness are two main indicators of RE and can carry out the most important effect for remaining the RE in the NEWZ level.

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Introduction: Human error is considered as a crucial challenge in occupational settings. Health care system is amongst occupational environments with high rate of human errors. Numerous preceding studies noted that more than 2/3 of medical errors are preventable. Accordingly, different methods are suggested to evaluate human errors, especially in nuclear industries. The aim of this study was to evaluate the application and accuracy of HEART technique in medical health system.

Material and Method:  This qualitative study was conducted in surgical intensive care units of a hospital in Shiraz city. All nurses recorded errors were categorized regarding the given tasks and then all tasks were ranked based on the number of errors. The probability of nurses’ tasks error was estimated through AHP-HEART method and the resultant ranking was compared with the recorded errors. Additionally, the prioritization of contributing factors to errors, determined by AHP and AHP-HEART methods, was compared employing Pearson statistical test.

Results: Based on the results, there was a concordance in the rate of nurses’ error determined by HEART method and the recorded errors. However, no significant correlation was between errors contributing factors determined by AHP and AHP-HEART methods.

Conclusion: This study suggested that although HEART technique was successful to rank the tasks considering the magnitude of error probability, but the coefficients of error producing conditions should be customized for nurses’ tasks in order to provide appropriate control measures.

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Introduction: Heat stress is one of the harmful risks in casting and die casting industries, which can not only cause work-related diseases but also can impair the performance and safety of workers. Since the indicators that are used to evaluate heat stress are very different, it is very difficult to choose a suitable index. The aim of this study was to determine the optimum heat stress index in foundry, die-cast, and road construction industries using FAHP and Topsis methods.

Material and Method: In order to determine optimum heat stress index in foundry, die-cast, and road construction industries, first, the prioritization criteria were defined by experts (including ease of measurement, measurement accuracy, comprehensiveness, time, cost, and correlation). Then, considering these criteria, the best heat stress index was determined based on experts’ opinions and using FAHP and Topsis methods.

Result: The results of this study suggest that given the current conditions and criteria, WBGT and P4SR is the best indices for foundry, die casting and construction.

Conclusion: The results showed that according to comprehensiveness, accuracy and correlation criteria, the WBGT index is considered as the best indicator of heat stress assessment in foundry, die-cast and road construction industries. Moreover, the HSI ranked in the last place due to the complexity and cost of its calculation.

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Introduction: To evaluate heat stress in the workplace different indices are used. But, none of these measures have been widely accepted. The aim of this study was to determine effective criteria in selecting a heat stress index and weighting of these criteria.

Material and Method:  This study is a qualitative study that was designed and conducted within 10 stages. In the current study, effective criteria for choosing a heat stress index was determined by using Delphi technique and expert’s opinions (30 people), and then the fuzzy analytic hierarchy process was used for weighting and prioritization of these criteria.

Results: Analyzing the completed questionnaires by the experts and according to the percentage of respondents, 11 criteria were finally selected. “Simplicity” criteria by %76.6 had the highest percentage of response. But, the relative weight of this criteria was 0.041, and had the lowest weight after the “low cost” criteria.  The criteria relating to the “Standard” item was 0.141as the highest relative weight.

Conclusion: It can be concluded that the first step to have a reliable and accurate measurement is to choose a proper and correct index. Based on specialists and expert’s opinions, standardization of the index is the most important selection criteria. Other criteria that must be considered were accuracy, reliability and good correlation with the physiological strain indices.

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Introduction: FMEA method is one of the most used techniques in risk assessment and prioritization. But, due to several reasons, its application has been limited to the real-world settings. The aim of this study was to deal with these restrictions using the combined fuzzy (in terms of the Z-numbers) and grey (in terms of the grey relational analysis) theories.

Material and Method: The current study is an analytical cross-sectional survey that was performed to prioritize the failure modes of the overhead cranes. Initially, an FMEA team including 4 specialists was established. Then, the opinions of the team members were gathered in terms of the Z-numbers and the weights of the risk factors (O، S, and D) were determined using the fuzzy AHP method. Finally, the failure modes were prioritized using the GRP method.

Result: From 13 cases of the identified failure modes, the conventional FMEA was assigned equal priority to the 7 cases and as a result 9 risk priorities were determined. But, in the proposed method, because of the elimination of the restrictions of conventional FMEA, 13 risk priorities were assigned to the failure modes.

Conclusion: Relying upon the fuzzy AHP, Z-numbers and GRP method, the proposed method dealt with the equal weights of the risk factors, fuzziness of the data (expert’s judgments) and the prioritization of the failure modes. The proposed method has more capabilities in relation to the conventional FMEA for prioritization of the failure modes.

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Introduction: Skin disease caused by exposure to the chemicals is one of the major health-related problems in the workplaces. This study has done to prioritize the strategies for skin exposure with chemical in a painting company.
Material and Method: In this analytical cross-sectional study 7 criteria and 8 selection control methods were initially chosen by surveying the existing records and through the assessments of expert panel and checking the result of previous studies. Subsequently, control strategies were prioritized according to the criteria using Fuzzy Analytical Hierarchy process & Topsis.
Result: Results of the paired comparison showed that the safety of the control strategy (w=0.298) and it’s up to date (w=0.0138) were the most and least important criteria for skin control strategies. Among skin control strategies for chemical exposure, the highest and lowest importance were for training (w=0.817) and work-rest schedule (w=0.233), respectively.
Conclusion: In this study, training was determined as the best control strategies for skin chemical exposure in the studied painting company according to the investigated criteria. This decision-making process could be applied for promotion of the skin health among workers.

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Introduction: Evaluating environmental risks in the oil and gas industry is essential to prevent irreparable damage to the environment. Using classical methods for prioritizing environmental risks does not achieve high-reliable results. Therefore, the aim of this study is to minimize the limitations of classical methods in a typical oil and gas production zone, by using fuzzy logic and Multi Attribute Decision Making (MADM) approach.  
Material and Methods: After forming an identification and assessment team including experienced experts from different organizational units in a region of exploitation of oil and gas, values of each risk factor (likelihood of occurrence, severity and detectability) related to identified environmental risks are determined according to their qualitative opinions represented by linguistic variables. Relative weights of the risk factors are calculated by applying the group Analytic Hierarchy Process (AHP) in a fuzzy environment on expert opinions. Then, fuzzy aggregation in the linear form by considering the weight of the risk factors and a method that is developed based on the center of gravity are employed in evaluation and ranking of the risks.
Results: In this study, the severity factor has the most important contribution in risk assessment compared to the other risk factors, since it has the highest relative weight. Raw sewage aspect resulted from absence of appropriate treatment system has the highest priority and spilling over of acid that is caused by chiller cleaning stands at the second position in the identified environmental risks.
Conclusion: The results demonstrate that although the proposed methodology requires greater time than classical methods, it is able to determine the risk ranking more practically because of minimizing the limitations of classical methods: high sensitivity to judgmental errors, considering some risks in the same index group and ignoring uncertainty in experts’ opinions. Proposed method is a proper alternative for classical environmental risk assessment technique, and capable of prioritization and evaluation risks in terms of safety and health.