Showing 16 results for Hadi
A. Neissi, E. Hashemi Sheykhshaba, T. Rahimi Pordanjani, N. Arshadi, K. Beshlideh,
Volume 3, Issue 2 (8-2013)
Abstract
Introduction: previous studies have shown approximately 90% of accidents in the workplace are due to unsafe behavior and human errors. Identifying predictors of unsafe behaviors would be unsafe in accidents prevention. The purpose of this study was to investigate personality characteristics, cognitive and organizational variables of line workers in an industrial company in bojnurd.
.
Material and Method: The sample, in the main stage, consisted of 300 employees and in the validation stage 100 They were selected thought stratified random sampling. Firstly, participants were divided into two groups (safe and unsafe) using safety behavior scale. Next, each group was evaluated using the five-factor personality questionnaire, safety efficiency questionnaire, regulatory focus at work, safety climate, safety motivation and safety competency scales and also perceived work pressure questionnaire. In order to analyze the data, the discriminate analysis, the confirmatory factor analysis and the Pearson’s correlation coefficient were applied.
.
Result: According to the result of the present study, unsafe behaviors of employees can be predicted by neuroticism, extroversion, agreeableness, consciousness, safety efficiency, regulatory focus and its dimensions, safety climate and its dimensions, safety motivation, safety competency and role overload variables.
.
Conclusion: The results of this study showed the importance of safety competency, prevention focus, safety rules and procedures, safety efficiency and consciousness as predictors of unsafe work behaviors. Therefore, it is recommended to rely on these variables in the safety training courses and also in selecting people for high risk environments.
Mohammad Beiruti, Hadi Daneshmandi , Seyed Abolfazl Zakerian, Mohammad Fararooei, Zahra Zamanian,
Volume 6, Issue 4 (12-2016)
Abstract
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.
Hadi Asady, Adel Mazloumi, Morvarid Zarif-Yeganeh, Mostafa Hosseini, Mahin Haghshenas, Parisa Hajizadeh-Moghadam,
Volume 7, Issue 1 (4-2017)
Abstract
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.
Mehdi Jahangiri, Hossein Molaei Far, Marzieh Honarbaksh, Payam Farhadi, Behboud Khani, Fazal Rajabi,
Volume 8, Issue 4 (12-2018)
Abstract
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.
Mojtaba Zokaee, Mohsen Falahati, Hadi Asady, Masoud Rafee, Mohammad Najafi, Azam Biabani,
Volume 9, Issue 2 (6-2019)
Abstract
Introduction: Throughout the world, many efforts have been made to provide suitable tools for achieving sustainable urban development and the achievement of a sustainable city. Establishing a Health, Safety and Environment Management System (HSE-MS) is one of the tools for achieving sustainable urban development. Measuring the performance of an organization in the HSE area is a precondition for continuous improvement, which is the spirit of the new HSE management systems. Therefore, the main purpose of this research was to provide a practical model for quantitative ranking of different areas of Tehran municipality in terms of HSE performance with using of multi-criteria decision-making method.
Material and Methods: In this descriptive-applied study, after determining functional axis and performance evaluation indicators related to each of them (29 functional axis and 154 performance evaluation indicators), through designing a questionnaire and based on the views of the expert group, weight of functional axis and performance indicators were determined using a hierarchical process analysis technique.
Results: In this study, the weighted value for functional axis of the process based HSE in comparison to the result based HSE were higher. “Commitment and Leadership” and “HSE Certificate of Occupations” for the process based HSE, “Safety” and “Health” for the result based HSE, and “Economic Sustainability” and “Architecture and Urbanism” for urban management had the higher and lowest weighted values.
Conclusion: The results of assessment and validation of selected indicators and functional axis showed that in designing and determining the HSE performance assessment model of municipalities, in addition to the axises and indicators of the HSE domain, factors affecting urban management can have a significant impact on the performance of municipalities in the field of HSE.
Taleb Askaripoor, Majid Motamedzade, Rostam Golmohammadi, Mohammad Babamiri, Maryam Farhadian, Hamed Aghaei, Mohammad Ebrahim Ghaffari, Elahe Kazemi, Mehdi Samavati,
Volume 11, Issue 4 (12-2021)
Abstract
Introduction: Recent evidence indicates that lighting can affect physiological and neurobehavioral human functions, referred to as non-image forming (NIF) effects of lighteffects. This study aimed to determine the effects of illumination levels and correlated color temperature (CCT) on alertness and performance under NIF conditions.
Material and Methods: In this study, 22 participants were exposed to light at various levels of illumination, including very low illuminance (<5 lux, control) and light conditions with correlated color temperatures (CCT) of 4000 K, 8000 K, and 12000 K at 300 and 500 lux. The data collection process included recording the power of brainwaves (alpha, alpha-theta, beta, and theta), sleepiness and mood scales, and cognitive performance tests for sustained attention, psychomotor vigilance task (PVT), working memory, and inhibitory capacity.
Results: The results indicated that 500 lux light conditions at correlated color temperatures of 8000 and 12000K significantly reduced normalized alpha, alpha-theta power, subjective sleepiness, and performance compared to the dim light condition. Under illumination levels of 300 and 500 lux, there were no significant differences in the measured values of the variables.
Conclusion: Lighting interventions can be used as a supplement to other strategies for increasing alertness and performance in the workplace.
Vida Rezaei- Hachesu, Shadi Naderyan Fe’li, Khadije Maajani, Rajabali Hokmabadi, Farideh Golbabaei,
Volume 12, Issue 1 (3-2022)
Abstract
Introduction: Covid-19 pandemic has imposed a significant effect on mental health of the health care workers. The present systematic review and meta-analysis aimed at determining the pooled prevalence of anxiety and depression among Iranian health care workers during the Covid-19 pandemic.
Material and Methods: To conduct this systematic review and meta-analysis, Web of Science, Scopus, Medline (PubMed), Embase, SID, Magiran databases and Google Scholar search engine were investigated to find studies over the prevalence of anxiety and depression among health care workers during the Covid-19 pandemic from December 2019 to June 10, 2021. Quality of the primary studies was assessed using the Newcastle-Ottawa tool and the random effects model was applied to estimate the pooled prevalence. Furthermore, χ2 test and I2 index were used to evaluate the degree of heterogeneity among the studies. The pooled prevalence of anxiety and depression in different subgroups was reported based on the severity of anxiety and depression, assessment tools, and staff jobs.
Results: Of 488 articles obtained as a result of the initial search, 10 related studies were identified and entered into the systematic review and meta-analysis. The pooled prevalence of anxiety was 42% (95% CI: 25-75) and the pooled prevalence of depression was 35% (95% CI: 19-55). The pooled prevalence of anxiety was 54% (95% CI: 39-70) in the occupational group of nurses and 29% (95% CI: 17-44) among all health care workers. The pooled prevalence of depression was 46% (95% CI: 30 to 63) and 17% (95% CI: 10 to 26) among nurses and all health workers, respectively.
Conclusion: According to the findings, a high prevalence of anxiety and depression was observed among the health care workers of Iran during the Covid-19 epidemic. The authorities are required to plan for preventive and therapeutic interventions to reduce the psychological burden of the epidemic.
Asghar Hadi, Aligholi Niaei, Azam Seifi, Yahya Rasoulzadeh,
Volume 12, Issue 3 (9-2022)
Abstract
Introduction: Rapid population growth and industrialization have increased chemical pollutants. Some studies show that employee exposure to formaldehyde in industrial places, hospitals, and laboratory settings is more than the allowed limits. Therefore, it is necessary to implement a proper control system to reduce this exposure. This study aimed to synthesize Ag3PO4/TiO2 nanocomposite, determine its morphological and structural characteristics, and test the degradation efficiency of this photocatalyst on formaldehyde.
Material and Methods: Ag3PO4/TiO2 composites were synthesized via an in-situ precipitation method. The physicochemical, morphological, and optical properties of the synthesized sample were investigated by employing the BET method, X-ray diffraction (XRD), UV–visible absorption spectroscopy, and scanning electron microscopy (SEM). The photocatalyst degradation efficiency test was performed on gaseous formaldehyde in a 3.2-liter photoreactor under visible light radiation.
Results: The UV–Vis absorption spectrum of the Ag3PO4/TiO2 sample noticeably shifted to the visible light region compared to that of the TiO2. The bandgap energy of the nanocomposite was 2.3 eV. The SEM image demonstrated that the average particle size of the nanocomposite was about 102 nm. The result of the degradation efficiency tests revealed that 63% of the formaldehyde was removed under visible light irradiation after 90 minutes by the Ag3PO4/TiO2 photocatalyst.
Conclusion: The adopted synthesis method adopted was highly efficient and appropriate for the synthesis of Ag3PO4/TiO2 nanocomposite according to the analyses. The Ag3PO4/TiO2 photocatalyst performed well under visible light radiation and could be used in pollution control systems.
Soleiman Ramezanifar, Ehsan Ramezanifar, Elahe Khadiv, Ali Salehi Sahlabadi, Davoud Eskandari, Mahshid Namdari,
Volume 12, Issue 3 (9-2022)
Abstract
Introduction: Human error can occur in many work environments, especially in control rooms. Due to the vital role of the central railway traffic control room in guiding and controlling all types of trains along the railway network, any error in this control room can lead to a catastrophic accident. This study aims to identify and assess human error in the central control room of railway traffic using the HEART technique.
Material and Methods: This descriptive cross-sectional study was performed in 2021. In this research, tasks and sub-tasks were identified using the hierarchical task analysis (HTA) method. Then, the probability of human error was assessed using the HEART technique.
Results: Based on the results of the HTA method, 67 main tasks, and 149 sub-tasks were identified. The study results on the probability of human error using the HEART technique showed that the three main tasks of the traffic expert (distribution of types of diesel, establishing the freight priority, and planning the movement of trains) had the highest probability of error. In addition, the most critical factors influencing human error were “evidence of illness among employees”, “sleep disorder”, “inexperience”, “unfamiliarity”, and “stress”.
Conclusion: The results of this study indicated that the central railway traffic control room employees are prone to errors, and if these staff make errors, irreparable accidents will occur. To reduce the probability of error of these employees, measures should be considered, such as using regular and appropriate shifts, the use of skilled and competent people, and so on.
Asghar Hadi, Hananeh Haghighatnia, Arina Hesami, Yahya Rasoulzadeh,
Volume 13, Issue 1 (3-2023)
Abstract
Introduction: Computer vision syndrome (CVS) is one of the most common health concerns associated with the extensive use of computers, particularly in the working environment. Since recent studies have shown the high prevalence of CVS, it is necessary to have an appropriate tool for assessing this prevalence. The present research aims to translate the CVS questionnaire and analyze its validity and reliability and assess the incidence of this condition among the staff members at Tabriz University of Medical Sciences.
Material and Methods: The translation of the main questionnaire into the Persian version was carried out in three steps. Two coefficients including the content validity ratio (CVR) and the content validity index (CVI) were used to evaluate the content validity of the questionnaire. The reliability of the questionnaire was examined using two methods including internal consistency (Cronbach’s alpha) and test-retest. In total, 240 participants were asked to fulfill the questionnaire in order to investigate the prevalence rate of CVS among the staff members of Tabriz University of Medical Sciences. After removing the ineligible ones, 219 questionnaires were examined.
Results: The internal consistency coefficient and Cronbach’s alpha coefficient were 0.91 and 0.89, respectively. Out of a total of 102 women and 117 men, only 19 women and 21 men did not have CVS. Among the studied symptoms, eye redness (78.1%), burning (76.7%), and headache (74%) were the most prevalent in the statistical population. No significant relationship was observed between the final score of CVS and gender.
Conclusion: In terms of validity and reliability, the questionnaire was found to be satisfactory. The prevalence of CVS among the staff members of Tabriz University of Medical Sciences was high (81%). To determine the etiologies, further research is needed.
Nematullah Kurd, Abdulrahman Bahrami, Abbas Afkhami, Farshid Ghorbani Shahna, Mohammad Javad Assari, Maryam Farhadian,
Volume 13, Issue 3 (9-2023)
Abstract
Introduction: Toluene, benzene, xylene, and ethylbenzene (BTEX) belong to the class of monocyclic aromatic hydrocarbons and are identified as toxic volatile compounds due to their harmful properties. The reliable biomarkers for occupational exposure to these toxic compounds are hippuric acid (HA), trans,trans-muconic acid (tt-MA), mandelic acid (MA), and methylhippuric acid (MHA), which correlate with toluene, benzene, ethylbenzene, and xylene, respectively.
Material and Methods: A novel magnetized imine-linked covalent organic framework (Fe3O4@TFPA-Bd) was synthesized, marking its inaugural use as a sorbent in microextraction by packed sorbent (MEPS). The synthesis of Fe3O4@TFPA-Bd was executed in a straightforward and efficient manner, using Fe3O4 nanoparticles as the magnetic core and benzidine (Bd) and Tris (4-formyl phenyl) amine (TFPA) as the structural building blocks. This newly produced sorbent was tested for the microextraction of hippuric acid (HA), mandelic acid (MA), trans, trans-muconic acid (tt-MA), and m-methyl hippuric acid (m-MHA) from urine samples, which were then analyzed using high-performance liquid chromatography (HPLC). In order to optimize the extraction performance, parameters like sample volume, elution volume, extraction cycles, pH, and sample solution temperature were thoroughly adjusted. The synthesized adsorbent underwent thorough characterization via scanning and transmission electron microscopy (SEM and TEM), Fourier transforms infrared spectrometer (FTIR), and X-ray diffraction (XRD).
Results: The developed method showcased promising attributes: low detection limits (0.02 µg/ml for tt-MA, S/N=3), low quantification limits (0.06 µg/ml for tt-MA, S/N=10), a solid linear range (0.5-320 µg/ml for MA, R > 0.99), and commendable intra- and inter-day precision (2.4%-4.3% and 3.1%-7.8%, respectively) for volatile organic compound (VOC) biomarkers. Furthermore, the method demonstrated recoveries in the 81-87.5% range for spiked samples, indicating its practicality and effectiveness.
Conclusion: The developed procedure was suitable for the determination of BTEX biomarkers from urine samples and can be an alternative to previous methods.
Fatemeh Fasih-Ramandi, Farideh Golbabaei, Hadi Shakibian, Seyed Mohammad Asadzadeh, Mohammad Reza Monazzam-Esmaeelpour,
Volume 13, Issue 4 (12-2023)
Abstract
Introduction: To ensure employee safety and health, it is crucial to choose and use personal protective equipment correctly. An investigation of the respiratory and hearing protection equipment used in the industries of Tehran was conducted in the present study.
Material and Methods: This study was a descriptive-analytical study conducted in 2023 on 400 occupational health and safety experts in Tehran province. A researcher-made checklist and questionnaire (physical and online versions) were used to determine the criteria that are considered when selecting protective equipment. Statistical analysis and graphing were performed using SPSS-v21 and Excel-2016.
Results: Participants had an average age of 38.66 and an average work experience of 11.78 years. The participants reported 48.3% and 47.7% disapproval of the quality and 42.5% and 39.5% disapproval respectively of the quantity of respiratory and hearing protection equipment available in their industrial units. In addition, 56.3% of them admitted that they have no responsibility for providing or approving the equipment in their workplace. Overall, 27 and 29 criteria were mentioned by study participants pertaining to respiratory and hearing protection equipment, respectively. In the identified criteria, the frequency distribution ranged from 0.3% to 38%.
Conclusion: A high rate of expert dissatisfaction with protective equipment and a low frequency of most of the criteria mentioned indicates that industries aren’t paying much attention to the issue of choosing the right respiratory and hearing protection equipment. To improve the situation, more investigation is needed and practical and operational solutions will be provided. This study highlights the importance of proper selection and use of personal protective equipment in ensuring the safety and health of employees.
Reza Barzegar, Omid Kalatpour, Maryam Farhadian, Rashid Heidarimoghadam,
Volume 13, Issue 4 (12-2023)
Abstract
Introduction: Industrial firefighting (IFF) constitutes a high-risk occupation within the domain of process industries. Firefighting teams serve as the operational component of the incident command team. This study aims to assess the alignment of physical fitness assessments conducted in selected Iranian process industrial firefighting settings and to scrutinize the extent of compliance with The U.S. National Fire Protection Association (NFPA) requirements by analyzing the resultant percentages of similarity in test outcomes.
Material and Methods: A cross-sectional observational study was undertaken across 14 Iranian process companies, encompassing two refinery companies and 12 petrochemical companies, employing a census sampling approach. The study’s benchmark was NFPA1582-2018. Data analysis was performed utilizing SPSS 27 software. This investigation focused on assessing the percentage of essential parallels within five distinct groups, along with their corresponding sub-components, in alignment with the tests and elements stipulated in the NFPA standard.
Results: Most of the selected companies (58%) lacked a cohesive program or established standard to assess the fitness of their firefighting personnel. Among the subset of companies (42%) that did employ an evaluation standard, in the majority of instances, a minimal proportion (less than 20%) underwent individualized assessments in line with the components outlined in NFPA 1582-2018 for physical fitness evaluation tests.
Conclusion: Given that 58% of the surveyed process companies in this study lacked a cohesive fitness assessment program and 42% demonstrated limited compliance with NFPA 1582-2018 in the assessed components, this issue underscores the critical need to evaluate the components quality and conduct a technical needs assessment. Developing adaptable and suitable components aligned with the work conditions prevalent in the process industry becomes imperative. Additionally, there must be existed a legal mandate for the pertinent ministry to implement an integrated framework. This scenario necessitates that process companies reevaluate their approaches concerning the selection and oversight of their firefighting personnel.
Zahra Naghavi-Konjin, Vajiheh Keshavarz, Khadijah Gheysar Koushki, Afsaneh Yazdani Niko, Jamshid Yazdani Charati, Mohsen Gorgani Firouzjaei,
Volume 14, Issue 1 (3-2024)
Abstract
Introduction: People’s risk perception in an emergency situation affects how they behave. During the pandemic of a disease like COVID-19, the fear of the disease and its consequences causes people to deal with anxiety. The present study was conducted with the aim of determining the relationship between the perception of the risk of COVID-19 and the experience of anxiety caused by it among workers in manufacturing industries.
Material and Methods: The present descriptive-analytical study was conducted cross-sectionally in 2022 among 545 workers of manufacturing industries located in Tehran, Mazandaran and North-Khorasan provinces. In the study, data collection was conducted using three questionnaires: a demographic information questionnaire, the COVID-19 Disease Anxiety Scale (CDAS), and the COVID-19 Risk Perception and Psychological Predictors against COVID-19 questionnaire. Data analysis was done using descriptive (mean and standard deviation) and analytical statistics (Canonical Correlation Coefficients or CCC) in SPSS V25 software.
Results: The mean ± SD of the workers’ age was 35.98 ± 7.58 years, while the scores for risk perception and anxiety were 12.89 ± 3.31 and 4.51 ± 1.51, respectively. The Concordance Correlation Coefficient (CCC) between risk perception and anxiety caused by the COVID-19 disease in the first Canonical point was 0.734, and in the second Canonical point, it was 0.229. The corresponding p-value was found to be less than 0.01. Psychological symptoms (Canonical loading = -0.725) and physical symptoms (Canonical loading = -0.421) played a significant role in predicting the variability of the risk perception of COVID-19.
Conclusion: The perception of risk related to the COVID-19 disease resulted in a decrease in anxiety, having a more pronounced effect on psychological symptoms compared to physical symptoms. Therefore, in times of pandemic outbreaks similar to COVID-19, implementing measures that enhance workers’ awareness and understanding of the disease risks can prove effective in managing anxiety.
Zahra Khodabakhsh, Leila Omidi, Khadijeh Mostafaee Dolatabad, Matin Aleahmad, Hossein Joveini,
Volume 14, Issue 3 (10-2024)
Abstract
Introduction: Domino effects are a chain of low-probability and high-consequence accidents in which a primary event (fire or explosion) in one unit causes secondary events in adjacent units. Bayesian networks have been used to model the propagation patterns of domino effects and to estimate the probability of these effects at different levels. The unique modeling and flexible structure provided by Bayesian networks allow the analysis of domino effects through a probabilistic framework, taking synergistic effects into account.
Material and Methods: Firstly, collecting the basic information related to the location of the storage tanks and determining the scenario of the accidents were done. Furthermore, the values of the heat radiation as escalation vectors in case of a fire in one tank were determined using ALOHA software. The received heat flux values were compared with the heat radiation threshold of 15 kw/m2 and the escalation probability of the primary unit and the propagation of the initial scenario to nearby storage tanks were determined using Bayesian networks.
Results: The analysis of the heat flux values showed that among the 8 studied storage tanks, two storage tanks had the highest potential for spreading domino effects due to their location in a tank farm. Also, the implementation of Bayesian networks in GeNIe revealed that, compared to other storage tanks, the probability of domino effects propagating to other nodes is higher when a primary fire accident occurs in the two mentioned tanks, while considered as primary units.
Conclusion: Domino effect modeling and appropriate preventative measures can decrease the escalation probability in the process industries. Consideration of the synergistic effects of events at different levels by taking the escalation vectors into account leads to proper risk management and the determination of emergency response measures in storage tank farms.
Seyyed Mohammad Javad Golhosseini, Mohsen Aliabadi, Rostam Golmohammadi, Maryam Farhadian, Mehdi Akbari,
Volume 14, Issue 4 (12-2024)
Abstract
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.