Prioritizing the noise control methods by using the Analytical Hierarchy Process (AHP) method in an Iranian tire factory.

BACKGROUND: Noise is a common harmful physical factor in the work environment. OBJECTIVE: This study sought to prioritize noise control methods using the analytical hierarchy process (AHP) in a tire factory. METHODS: The study, which adopted a cross-sectional, descriptive, analytical design, was conducted in the baking hall of an Iranian tire manufacturing factory in 2018. 4 criteria (namely implementation and maintenance cost, method applicability, method effectiveness and efficiency, and intervention in the process) and 8 alternatives (including reducing individuals' noise exposure time, designing and installing sound isolation chamber for operators, using of earmuffs and earplug simultaneously, changing processes or operational procedures in machinery with excessive noise generation, forming noise control engineering teams, requiring people in charge to quickly fix the leaks and change baking press washers on time, using acoustic panels in the ceiling and walls, and designing and manufacturing silencer and nuzzle for the steam and compressed air outlet of baking press machinery) were selected. Then, to prioritize noise control methods based on objectives, criteria, and alternatives, an AHP questionnaire was developed and completed by domain experts and noise control specialists. Data analysis was performed using Expert Choice V. 11 and Excel. RESULTS: The results showed that the inconsistency rate in all cases was less than 10%, hence the consistency of responses was approved. Based on experts' opinion about the selected criteria, "implementation and maintenance cost" had the highest weight (0.481), while "method effectiveness and efficiency" recorded the lowest one (0.046). With regard to the alternatives, "change in the process" registered the greatest weight (0.193), whereas "individuals' noise exposure time" had the lowest weight (0.046). CONCLUSIONS: Based on the final weights, the most appropriate noise control methods in this industry are changing processes in machinery with excessive noise generation, forming noise control engineering team, and manufacturing silencer and nuzzle for the steam and compressed air outlet of baking press machinery. Furthermore, AHP is a suitable approach for prioritizing decisions related to noise control.

The association between wet-bulb globe temperature and other thermal indices (DI, MDI, PMV, PPD, PHS, PSI and PSIhr): a field study.

The current study aimed at comparing the correlation coefficients between wet-bulb globe temperature (WBGT) and a number of parameters, including the discomfort index (DI), modified discomfort index (MDI), predicted mean vote (PMV), predicted percentage of dissatisfaction (PPD), predicted heat strain (PHS), physiological strain index (PSI) and physiological strain index heart rate (PSIhr). In total, 30 workers of a pelletizing factory participated in this study. Environmental parameters and workers' physiological parameters were measured in 10 working stations. The results showed that effective WBGT (WBGTeff) strongly correlates with DI, MDI, PMV, PPD, PHS, PSI and PSIhr. WBGTeff had the highest correlation coefficients with PMV, MDI, PHS and PSIhr. Based on the obtained results, it was concluded that heat stress exceeded the standard limit for a number of indices in some of the working stations. Thus, some controlling measures should be taken to reduce heat stress in these stations.

Using the Analytic Network Process Method for Prioritizing and Weighing Shift Work Disorders Among the Personnel of Hospitals of Kerman University of Medical Sciences.

INTRODUCTION: Increasing population, the need for services, and industrialization of societies have led to a growing demand for shift work. Shiftwork causes several disorders, and determining the weight of each disorders is important for their prevention and treatment. Therefore, the purpose of the present study was to use Analytic Network Process (ANP) to prioritize and weigh shift work disorders among the personnel of hospitals of Kerman University of Medical Sciences. METHODS: This cross-sectional, descriptive-analytical study was conducted in 2017 among 300 shift work personnel of 10 public hospitals affiliated with Kerman University of Medical Sciences. ANP was used to prioritize and weigh shift work disorders. To this end, the criteria, sub-criteria, and alternatives were initially identified. Then, shift work disorders were categorized into 7 general criteria, 20 sub-criteria, and 3 alternatives. After designing the ANP and determining the effect of each criterion on the sub-criteria, the ANP questionnaire was developed and administered among the shift work personnel, who filled it out based on ANP. Super Decisions was subsequently used to weigh and prioritize shift work disorders. RESULTS: The results indicated that shift work disorders among the nurses included sleep disorders (0.297), psychological disorders (0.275), digestive disorders (0.137), personal life disorders (0.122), etc., in that order of weighing. With respect to the support staff, the major shift work disorders involved sleep disorders (0.252), digestive disorders (0.198), personal life disorders (0.168), and psychological disorders (0.164). Considering security personnel, the top four shift work disorders were sleep disorders (0.201), digestive disorders (0.186), psychological disorders (0.174), and personal life disorders (0.145). CONCLUSION: According to the findings, sleep disorders had the highest weight in the three studied groups. Moreover, the night shift had the most profound effect on shift work disorders among the personnel in the three groups. It was followed by the evening shift. Morning shift had the lowest influence on shift work disorders. Therefore, the schedules should be taken to prevent these complications in the shift workers. It is suggested that work shift complications be included in the periodic examination program and, in case of discovery of any rhythmic disorder in each shift workers, the person should not remain in the shiftwork group for some time.