Journal of Health and Safety at Work

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Introduction: In the interaction between man and machine, the human behavior plays a key role in the accidents occurrence and the risks. Safety culture models can be a base to safety culture assessments and may lead scientists toward effective aspects of organization safety. The aim of present study was to develop and offer a specific questionnaire for safety culture assessment according to the customized model in an automotive industry.

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Material and Method: In this cross-sectional analytical study, a questionnaire including 16 items and 37 questions was developed based on management, individual, and organizational factors. Then, the reliability and validity of the developed questionnaire, it were studied among 30 employees of an automotive company.

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Result: Concerning the reliability of the questionnaire, the Cronbach’s alpha was 0.855. In the context of validity of the questionnaire, the simplicity and clarification of contents were investigated by means of Expert Analysis. Moreover, in terms of the integral components of culture, according to the factorial analysis, this evaluation regarded to have ten main components.

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Conclusion: So far, there was no exclusive tool for evaluating safety culture based on a customized model. The findings of the present study showed that evaluating safety culture using the administered questionnaire is valid and reliable in the understudied industry.

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Introduction: currently, stress is known as one the most important issue among societies which may have positive or negative results. Stress is caused when there is not a harmony between job demands, capabilities and desires of a person. Most of the behavioral, physical and mental disorders are results of job stress. The objective of this study was Validity and Reliability analysis of NIOSH Generic Job Stress Questionnaire (GJSQ), in order to have an appropriate tool for evaluation and analysis of job stress in Iran.

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Material and Method: In this study, 228 members of Tehran fire-fighting office were chosen according to categorical and clustering sampling, methodology and they completed NIOSH Generic Job Stress Questionnaire (GJSQ). For Validity and Reliability of questionnaire, 20 persons of the group were chosen for content validity analysis of the questionnaire. For Reliability analysis of the result, Cronbach alpha test and in-cluster correlation test were used. SPSS software version 18 was used for analysis of the data.

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Result: The mean age of the participants was 30.8 years (SD=4.9) and the average of job tenure in fire-fighting office was 7.4 years (SD=4.8). In order to reliability analyze the questionnaire, Cronbach alpha coefficient of all influential factors was obtained more than 0.7. In-cluster correlation coefficient of the questionnaire is calculated using retesting on all influential factors. With the exception of Physical Environment and Mental Demands which were about average, all other coefficients were over 0.7, which is a very appropriate result.

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Conclusion: Considering that Validity and Reliability factors of the questionnaire were be appropriate, it can be recommended that NIOSH Generic Job Stress Questionnaire (GJSQ) can be used as a Valid and Reliable questionnaire for job stress evaluation in Iran.

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Introduction: Heat stress is considered as a serious risk factor to the health and safety of workers in most working environments, especially in outdoor works and jobs that workers are exposed to heat due to the working process. This study aimed to evaluate heat stress among workers of brick-manufacturing units in Qom city based on WBGT index as well as the relationship between WBGT and physiological indicators.
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Material and Method: The present study was conducted in 40 brick-manufacturing units in Qom city. WBGT measurements were performed according to ISO7243 standard. Physiological responses of 184 workers (up to 5 people per unit) and also atmospheric parameters were measured. The physiological responses included oral temperature, skin temperature, and temperature for the carotid artery of the ear, heart rate, systolic and diastolic blood pressure. Statistical analysis was done using SPSS software version 16.
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Result: Mean WBGT index for various brick-manufacturing jobs including firing, manual material handling, working with conveyors, molding, and tempering were 30.8 °C, 26.74 °C 26.58 °C and 24.25 °C, respectively and the average WBGT was estimated 27.98 °C. WBGT levels measured in all units exceeded the level provided in ISO7243 standard. The highest mean WBGT was belonged to kiln section (30.8 °C). The mean WBGT at three heights of head, abdomen and legs were not statistically different (using t-test). The correlation coefficients between mean WBGT and mean oral, skin and ears temperatures were 0.203, 0.319, and 0.490, respectively, with the highest correlation belonged to the carotid arteries of ears. Moreover, WBGT showed no significant association with the mean heart rate, systolic, and diastolic blood pressure (P-value>0.05). Indoor and outdoor WBGT index was significantly different (P-value<0.05).

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Conclusion: The level of heat stress in all brick-manufacturing units was higher than the recommended limits, and the workers in kiln unit were more exposed to heat stress, in comparison with other units. Therefore, special countermeasures should be adopted to control heat stress for this occupational group.

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Introduction: Working in hot and inappropriate climate condition is one of the most common problems of occupational health which can lead to heat induced diseases and even death. Heat stress may impair the cognitive processes involved in decision-making and converting simple tasks to complex ones. The aim of present study was to assess selective attention and reaction time among workers in a casting unit of a car manufacturing industry and to investigate the effects of heat stress on mentioned variables.

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Material and Method: In this retrospective cohort study 70 workers from a hot industry were selected in two of exposed and control groups. First, demographic questionnaire was completed for each of the participants and noise and light were measured as the likely confounding factors. Stroop test 1, 2, and 3 were done before and during the work in order to determine the effects of heat on selective attention and reaction time. Besides,WBGT were measured at the ankle, waist, and head levels. Data were analyzed using SPSS software, version 18.

Result.: WBGT measurements showed that the mean WBGT were 33 and 16.7 for the exposed and not exposed groups, respectively. Moreover, no significant relationships were observed between test duration, reaction time, and number of errors in Stroop tests 1 and 2 and the level of heat (P-value<0.0001). However, the mentioned variables had a significant positive correlation with Stroop test 3. Additionally, for exposed group variables of test duration, reaction time, and number of errors in Stroop 3 were significantly higher than those of control group.

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Conclusion: According to the findings in present study, heat stress causes an increase in reaction time and a decrease in selective attention. Thus, heat can be assumed as a stressor in hot work environments and the heat should be taken into account while design of job and tasks which needed selective attention or reaction time.

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Introduction: Outdoor workers are exposed to heat from solar radiation and the atmospheric conditions, in addition to the heat from the working process, which is worse by global warming. The purpose of this study was to evaluate heat stress based on wet bulb globe temperature index and also to examine the relationship between WBGT and physiological indices among outdoor workers of Shabestar city.

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Material and Methods: This cross-sectional study was conducted in August 2014. WBGT measurements were taken according to ISO7243 standard in different hours. The physiological response of 53outdoor workers (including heart rate, systolic and diastolic blood pressure, oral temperature, and skin temperature) were measured among9occupationalgroups, including municipal workers, concrete makers, porters, construction and road making workers, stonemasons, farmers, traffic officers, and street vendors.

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Result: The mean WBGT index for all outdoor workers, except for municipal workers, street vendors, traffic officers and stonemason, was greater than threshold limit. The highest average WBGT index was for construction workers and the lowest was for municipal workers (respectively 27 and 26 °C). Moreover, a significant direct association was reported between the WBGT index and physiological parameters (P <0.0001), with the highest correlation coefficient belonged to heart rate (r=0.492).

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Conclusion: According to WBGT index, porters, Concrete makers, construction and road makers, and farmers had the highest exposure at all times of the day while the lowest level was related to municipal workers. What is more, heat stress showed a significant correlation with the study strains. Therefore, it is essential to conduct further research and in order to represent preventive countermeasures for the workers in this field.

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Introduction: Adherence to the design values and ventilation standards (VS) after installing and also maintaining continuous work of ventilation system with maximum performance throughout its life are amongst the reasons of ventilation systems monitoring. Therefore, the aim of this study was to evaluate performance of local exhaust ventilation system for control of dust by measuring the operating parameters and also to compare it with ventilation standards (VS) and design values.

Material and Method: The present research is a descriptive and cross-sectional study, conducted in three sections of measuring, monitoring and evaluating the operating parameters on hoods, channels and fan of ventilation system based on the current status of the system, documentation (design), and recommended standards (VS). Static pressure, velocity pressure, surface area, and flow rate were measured based on the recommendations of various sources and ACGIH industrial ventilation manual, and the data were compared with the design and recommended values, using the SPSS software version 16.  

Result: The results of paired sample t-test between flow rate and velocities of design and current status, showed significant differences in various parts. Accordingly, the results revealed a reduction of more than 50% in the design duct velocity compared to the current duct velocity, while design duct velocity is 1.3 more than the standard duct velocity of current status, and current duct velocity is about 65% of standard duct velocity.

Conclusion: The reduction and nonconformity of the results of measurements of operating parameters (after a minimum of two decades) with design and standard values are corroborant and sufficient reason for obstructions, abrasions, leaks, imbalance of system ducts and their inefficiency in some branches. Since there is no base line measurements for system (supposing that the system worked with maximum amounts of setup time), one of the reasons for these changes can be attributed to lack of schedule for regular and appropriate maintenance.

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Introduction: One of the important consequences of globalization and development, especially in developing countries, are occupational accidents. As, today the economic burden due to these accidents is remarkable on the country’s economy. The aim of this study was financial estimate of the productivity loss due to work-related deaths in Iran in 2013.

Material and Method: In this study, occupational accident data were used registered in the environmental and occupational health center, in Iranian Ministry of Health and Medical Education. A formula used by the Centers for Disease Control and Prevention America (CDC) was used to estimate the productivity loss. Finally, after replacing the necessary parameters amount of productivity loss was calculated.

Result: The total lost years of life were calculated 1293.15 years due to the deaths caused by occupational accidents. The total amount of monetary loss due to the productivity loss in the country, was estimated 730513.06 Rials. The greatest loss was in the 59-50 years old age group.

Conclusion: The negative rate of productivity, the large quantity of the discount rate, low life expectancy in the country as well as the low wages of the workers, are the likely reasons for minimal negative impact of the workforce deaths on the country’s productivity.

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Introduction: Work-Family Conflict can influence the physical and mental health of workers as a social parameter. The aim of this study is supposed to provide theoretical model of relationship between work-family conflict and occupational accidents, taking into account parameters such as job stress and general health of employees in a steel manufacturing industry.

Material and Method: Research population included workers of steel department of a steel manufacturing industry. This research was a cross-sectional study, and 270 individuals were selected in two groups, with an accident experience during lasts 5 years (case) and without (control). They responded to questionnaires including 4 parts, demographic, 18 questions of work-family conflict, 35 questions of job stress and, 28 questions of general health. Data were analyzed and introduced using AMOS software.

Result: Result showed that the model present an excellent goodness of fit and all of factors were significant between parameters (p<0.001). In addition, individual health and job stress with high coefficient could affect work-family conflict and work-family conflict was effective in the event of occupational accidents.

Conclusion: Reducing work-family conflict as a social parameter affecting stress can be effective in the reduction of occupational accidents. The organizational management system with optimization of this important factor can upgrade its level of occupational safety.

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Introduction: Nowadays, HEPA filters is used in hospitals, clean rooms, microbiology hoods, ventilation of surgery rooms, and Pharmacy for removing microorganisms and reduce health hazard. The aim of this study is to increase the efficiency of HEPA filters with UVC radiation to reduce the density of airborne microorganisms.

Material and Method:  The closed–loop chamber was made to evaluate Staphylococcus epidermidis, Bacillus subtilis bacteria and Aspergillus Niger, Penicillium fungi. The concentration of fungi and bacteria suspension Respectively was 106, 107 CFU/ml. After the suspension was prepared, it was sprayed into the closed loop chamber by nebulizer. Sampling was done with UVC radiation (1.8 mW/cm2 Illuminance) and no radiation (dark) that included time periods 60, 90 and 120 minutes. Microorganisms density was determined in term of CFU/m3.

Result: The result showed that there was a significant difference between UVC radiation and dark section for all the microorganisms (epidermidis, subtilis, Niger and Penicillium) at each time periods (P value< 0.05). This indicates that concentration of four microorganisms were decreased at all the time periods. UVC radiation could change the essential molecular substances for cellular factor. UVC can penetrate the cell walls of microorganisms. thus nucleic acids and other cellular vital material affected and will cause the destruction or inactivation of microorganisms.

Conclusion: UVC radiation is effectiveness to decrease concentration of four microorganisms. because UVC radiation could remove both bacteria and fungi. While the other studies in other countries, UVA radiation is only effective in reducing bacteria. Therefore, achieved greater efficiencies of HEPA filters, using HEPA filters with UVC will have a significant effect on reducing the density of microorganisms.

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Introduction: Efficiency of hoods for local exhaust ventilation system is influenced by hood geometry, its situation relative to the process and the air volume exhausted by it. The aim of this study was to present a simple and practical method based on the standards for assessment of potential problems of ventilation system in a steel making company.  

Material and Method: In this cross-sectional study, a checklist based on the ACGIH ventilation standards was developed for investigating potential problems related to the three types of hoods in an oxide screen process. This checklist has completed in order to feasibility study of corrective changes in evaluation of the hood hardware parameters. The differences between design and current status to the standards were considered as noncompliance. Finally, differences were analyzed statistically.   

Result: Based on statistical analysis, the average of current status of hoods, plans and design documents and standards were for variables of conveyors downstream enclosure (1.6, 2.38 and 2.41m), vertical distance from hoods to conveyors (0.39, 0.37 and 0.61m), conveyor longitudinal enclosing after hood (1.225, 1.288 and 0.296 m) and hood numbers (18, 17 and 31), respectively. Comparing the results between current status of hoods with plans and design documents showed no significant differences (0. P-value≤ 0.05). But, the results between current status of hoods and design documents with standards have significant difference (0. P-value≥ 0.05). A significant difference  (0. P-value≥ 0.05) revealed between the average of the current status of hoods, plans and design documents and the standards for variables of hood flow (813.3, 2276.9 & 3085.9 cfm) and duct velocity leading to the hoods (2289.3, 5083.5 & 3500 fpm), respectively.

Conclusion: This method can be applicable for the local ventilation systems with extensive pollution sources and hoods. One of the advantages of this method can be easily application of this system, as one of the requirements for delivering ventilation systems from contractors and the use of it for studying potential problems of the hoods that they have standards. Also, by comparing current status of hoods with the design specifications and standards, the mismatches/ unconformities in the lifetime and maintenance process of the system can be understood.

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Introduction: Nursing is one of professions that employees are at risk of fatigue and work related musculoskeletal disorders, because of high physical workload and high job stress. Connecting serum set to serum solution is one of the repetitive tasks for nurses in their working times and it may cause pain and discomfort in their hand. The aim of this study was to design and ergonomic evaluation of a tool for connecting serum set to serum solution.

Material and Method: This experimental- interventional study conducted on 12 nurses (6 men and 6 women) in 3 phases. First phase was assessment of manual connecting of serum set to the bag by nurses, second phase was design and manufacturing of serum set connector and third was ergonomic assessment of the manufactured tool. In first and third phases, amount of perceived exertion by nurses was assessed using the Burg scale (CR10), and electromyography assessment for hand muscles activity was conducted during connecting serum set. Data of first and third phases compared with statistical tests.

Result: Mean score of perceived effort during manual connection of serum set was 5±1/2 (of 10) and while mechanical connection with designed tool was 2.3±0/49. There was significant difference between activity in 5 muscles (Flexor Digit Comonis, Flexor Carpi Radial, Biceps, Triceps and Deltoid) in manually and mechanically connection mode (P-value<0.05).

Conclusion: Use of serum set connector reduced the perceived effort and activity of hand and wrist muscles. This device can be used as an ergonomic tool for nurses to easing the inserting the serum set to serum solution

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Background: Industrial incidents are one of the major problems of today's societies. Studies in this field show that the main and most important cause of error occurrence is human factor. Therefore, the aim of this study was to identify and evaluate the risk of human error in the activities related to the operation of electrical installations of the Tehran Province Electricity Distribution Company.
Methods: This study is a qualitative and cross-sectional research was conducted by direct observation of the activities and documents, interview. Tasks and subtasks were selected and analyzed using Hierarchical task Analysis, (HTA).The results were presented in the form of  HTA. Finally, according to the instructions of SHERPA, the relevant worksheet was completed.
Results: The analysis of SHERPA worksheets showed that a total of 3399 errors were detected for 759 tasks as 39.57% of them were action errors, 32.4% review type, 7.32% recovery type, 19.64% communication type and 1.80% were selective errors. According to the results of risk assessment, 12.47% of the errors were unacceptable risks level, 59.57% were undesirable, and 20.2% were acceptable risks but need to be revised and the rest, 7.33% acceptable with no need for revision or safe ones.
Conclusion: According to the results, the most common type of error was action errors and in order to reduce this type of errors, using necessary corrective measures such as proper selection of people for occupations, training, monitoring, using smart machines, using tag out systems and checking at the suitable time and updating the instructions would be useful and effective countermeasures.

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Introduction: Assessing health, safety, and environment (HSE) performance based on up-to-date analytical models like resilience engineering, especially in automobile manufacturing companies, affected by the trilogy of HSE factors and functions, is of crucial importance. Therefore, this study was to review the factors effectively involved in HSE management performance assessment based on resilience engineering in automobile manufacturing industries.
Material and Methods: To collect and classify the data, many relevant articles and procedures published in journals or presented at seminars were researched and cited. In this study, reliable online databases, including Google Scholar, Web of Science, Scopus, and PubMed were searched to meet this purpose. Other databases in Farsi such as Magiran, CIVILICA, and Scientific Information Database (SID) were also employed. Accordingly, a total number of 211 articles were extracted and filtered in terms of content and topic by a team of four HSE senior experts, whereby irrelevant studies were deleted, the full text of each relevant article was more closely considered, and finally 18 studies were selected and thoroughly examined.
Results: The findings from these 18 articles revealed that the HSE would be influenced in various industries by factors such as organizational culture, learning and training, political-economic variables, workforce qualifications and skills, strategic and large-scale programs of organization plus its assets and financial resources. In automobile manufacturing industries as well, circumstances might emerge because of some extra-organizational threats and intra-organizational weaknesses, whereby the appearance of deficiencies in various processes and even the functions of the HSE as a whole would be impaired. Of the many external factors, one could mention economic sanctions, large-scale socioeconomic problems, and lack of materials and production equipment. The internal problems would also range from production reduction and cuts in budgets earmarked for different management departments to a rise in the number of accidents and diseases, soaring medical treatment costs, as well as growing expectations in employees, which together impact the HSE management performance.
Conclusion: Regarding the studies conducted on various models presented so far in the area of resilience, it was concluded that the HSE performance of organizations intended to prevent and control risk factors were by no means distinct from other management factors and strategic decision-making in an organization. Rather, the HSE indicators could be impacted by many extra- and intra-organizational factors. Based on the models surveyed, it would be essential to consider the concept of resilience in HSE management. The reason for this is that the idea of the HSE would appear to be an issue of less virtue and importance in various stages and situations in the lifecycle of an organization, which is not consistent with the HSE management system and does not keep pace with the influencing factors.

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Introduction: Regarding the daily growth of Volatile Organic Compounds (VOCs) application in a vast variety of industries which also contributed to their adverse effects, different methods were used for controlling their emission. One of the most effective methods for this purpose, is a combination of cold plasma and catalyst or photo catalyst. In this study, the effectiveness of the HZSM-5/ Tio2 for Toluene treatment removal was investigated
Material and Methods: HZSM-5 zeolite, and Tio2 in 3 and 8 weight percent were used for photo catalyst preparation. The TiO2 particles were coated on the zeolite by impregnation method. X-Ray Diffraction, Scanning Electron Microscope and Brunauer Emmett Teller tests were used for the identification of photo catalyst structural properties. Toluene vapors with 58±2 PPM concentrations were produced in ambient condition including the room pressure and temperature by a dynamic system and introduced to a reactor included 1 gr of the photo catalyst. Vapors were passed from the reactor continuously with a rate of 0.5 liter per minute. Removal efficiency in three different states; plasma only, plasma /HZSM-5/TiO2 3%tw, and plasma/HZSM-5/TiO2 8% tw were assessed at the voltages of 4000 to 8000.
Results: In the current study, the removal efficiency of toluene vapors were 44.9, 75.36 and 66.68 percent for plasma, plasma /HZSM-5/TiO2 3%tw and plasma/HZSM-5/TiO2 8% tw, respectively. Photo catalyst with 3 weight percent showed the best removal efficiency. In all tests, the removal efficiency increased when the voltage increased and in 7000 volts it reached the maximum level. Therefore, adding photo catalyst to the plasma caused significant improvement in removal efficiency. Also, HZSM-5/TiO2 3% tw showed the best performance for toluene vapors removal.
Conclusion: According to the current study findings, using this combination in an industrial environment can be an effective way for Toluene vapors without the need for high temperatures. This combination can be proposed for other VOCs.

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Introduction: Nurses’ high workload may affect their ability to work, cause health problems, and reduce nurses’ quality of life. Considering the important role of nurses in society’s health, it is important to identify the factors affecting their physical and mental health. The current study investigates and correlates nurses’ workload, quality of life, workability, and contextual variables.
Material and Methods: In this descriptive-analytical and cross-sectional study, 142 subjects from the ICU, CCU, emergency department, and other departments of Qazvin educational-therapeutic hospital participated. Data collection tools included a demographic information questionnaire, NASA-TLX (Task Load Index), Short Form Health Survey (SF-36), and work ability index (WAI). Data were analyzed with an independent t-test, Pearson’s correlation coefficient, and a one-way ANOVA test.
Results: The mean and standard deviation of nurses’ age and work experience were 31.3±6.1 and 7.6±5.8, respectively. The mean and standard deviation of nurses’ workload score, quality of life, and workability were 80.4±13.4, 55.5±18.7, and 31.8±7.3, respectively. According to the results, nurses’ workload had a significant relationship with quality of life (P-value=0.001) and workability (P-value=0.000). Significant relationships were also observed between quality of life and workability (P-value=0.001). Quality of life had a significant negative correlation with age, work experience, and the number of nurses’ shifts per month (P-value<0.05). Nurses with higher education had lower workload and higher workability.
Conclusion: Nurses working in ICU and CCU units had a higher workload. Nurses with higher education levels had less workload and more ability to work. There was an inverse correlation between workload quality of life and nurses’ workability. It is possible to reduce nurses’ workload by reducing their tasks and working hours.

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Introduction: Obesity and overweight are major global health challenges. One of the bad effects of noise that has been recently expressed is the effect of noise on obesity. This study aimed to investigate the effect of high-frequency noise exposure on obesity, food intake, and abdominal visceral fat in adult male guinea pigs.
Material and Methods: The animals in this study were 24 adult male guinea pigs randomly divided into 3 groups (control and two case groups). Each case group was separately exposed to high- frequency white noise with sound pressure levels in 65 dB and 85 dB for 5 days per week in 30 days. The food intake was measured daily. The weight of animals was measured at the start and on days 6, 12, 18, 24, and at the end of exposure period. The abdominal visceral fat was extracted and weighted at the end of the study period. The data were assessed using SPSS V.22 software.
Results: ANOVA analysis showed that exposure to high-frequency noise at 65dB and 85dB had a significant effect on weight gain, food intake, and abdominal visceral fat weight (P-value< 0.05) which in the group exposed to the noise with 65 dB was more than other groups.
Conclusion: Based on this study, exposure to high-frequency noise may be an effective factor in obesity and increasing abdominal visceral fat. Further studies are needed to investigate the mechanism affecting weight status following noise exposure.
 

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Introduction: Despite the numerous studies on occupational noise-induced hearing loss, there is limited documentation on the vibration effects on the workers’ auditory system. Heavy equipment drivers are exposed to high levels of whole-body vibration (WBV) and noise. Therefore, this study aims to investigate the heavy equipment drivers’ auditory response to WBV exposure and combined exposure to noise and WBV.
Material and Methods: 30 male heavy equipment drivers with an average age of 32.40 ± 4.91 years participated in this study, which was designed based on the repeated measurements model. During 3 defined scenarios of exposure to WBV, combined exposure to noise and WBV, as well as the scenario without exposure, the drivers’ auditory response was measured using distortion product otoacoustic emissions (DPOAE). Statistical analyses were performed by IBM SPSS-25 software.
Results: The range of heavy equipment in-cabin noise was 84-89 dB. Also, the most exposure of drivers to WBV was obtained in the Z axis with an average acceleration of 1.29 m/s2. The DPOAE amplitude of the drivers in all three investigated scenarios showed significant changes (P<0.05); But in comparison between different scenarios, exposure to WBV and combined exposure to noise and WBV had a significant effect on the response of the auditory system of the participants in the study compared to the scenario without exposure (P<0.05). Also, there was a significant difference in the changes of the DPOAE amplitude in different frequencies; Thus, the most changes in the DPOAE amplitude were observed in the frequencies of around 4000 Hz.
Conclusion: The results of this study showed the damaging consequences of exposure to noise and WBV on the auditory response; In addition, the present study provided evidence of synergistic effects of combined exposure to noise and WBV on heavy equipment drivers.