International Journal of Occupational Hygiene <strong><em>I</em></strong><strong><em>nternational Journal of Occupational Hygiene (IJOH) </em></strong><span>is a quarterly Journal published by Iranian Occupational Health Association (IOHA). This Journal covers multidisciplinary researches concerning factors influencing quality of life in any environment and workplaces. IJOH publishes original research, field and case reports, review articles, short communications and letters to the Editor NOT previously published or submitted for publication elsewhere including national and international Journals.</span> Tehran University of Medical Sciences en-US International Journal of Occupational Hygiene 2008-5109 Quantitative model of safety working behaviors management staff on construction projects based on the theory of planned behavior : The case of study twin towers telecommunication of company of Tehran <p><span style="font-family: Times New Roman;"><span style="font-size: medium;">Construction projects are one of the most important economic sectors in the world; incidents in these projects are commonplace in all countries of the world, as well as the high incidence of incidents in this industry. The rate of incidents in construction projects in the world is higher than the average rate of incidents in other industries. The method of this research is descriptive correlational survey and the statistical population of the research is the employees of the construction workshop of the Central </span><span style="font-size: medium;">twin towers telecommunication of company of Tehran</span><span style="font-size: medium;">. The data gathering tool was a researcher made questionnaire that was analyzed using LISREL and SPSS23 software. In order to determine the validity of the confirmatory factor analysis, a Cronbach's alpha was used to assess the reliability, and a structural equation model was used to test the research hypotheses.</span></span></p><p><span style="font-family: Times New Roman; font-size: medium;">The results showed that the effect of attitude with the intensity of 0.49 and subjective norm with an intensity of 0.46 on behavioral intention was more than perceived behavioral control with a coefficient of intensity of 0.19. According to the findings of this research, to improve the safe behavior of work and health of staff, it is necessary to take corrective measures to improve the attitudes and mental norms of employees on the agenda.</span></p> MAHDI MALEKIANIFARD AZADEH NEKOOEI ESFAHANI FARZAD VEYSANLU ##submission.copyrightStatement## 2018-08-14 2018-08-14 10 2 Evaluating the status of occupational stress and identifying the related risk factors in nurses in Babol: A cross-sectional study <p><strong>Background</strong>: The health of people is of great importance and stress is one of the factors affecting the health. Stress affects humans under different conditions and appears to be responsible for a significant number of illnesses and absence from work in the personnel of the health care centers.</p><p><strong>Purpose:</strong> The present study was performed to evaluate the status of occupational stress in nurses working in the public hospitals in the city of Babol and identify the associated risk factors.</p><p><strong>Methods</strong>: This was cross-sectional study of descriptive-analytical type, which was performed from October 2016 to April 2017 in hospitals affiliated with the Babol University of Medical Sciences (6 hospitals). 406 nurses working in hospitals were selected for study by simple random sampling method. occupational Stress Questionnaire-HSE was used to survey the stress of nurses along with other demographic information that was completed on the questionnaire.</p><p><strong>Results</strong>: According to the results of analyzing the dimensions of the HSE questionnaire, the lowest and highest scores were related to the communication dimension (9.8 ± 3.3) was demand (23.1 ± 5.1), respectively. Based on the regression model, among the independent variables of the present study, only the variables of gender, weekly working hours, employment status, shift work system and education level able to predict the occupational stress of the nurses.</p><p><strong>Conclusion</strong>: Since healthy and motivated nurses are vital for any health care system and also due to the inevitability of some stressors in the nursing profession, it seems necessary and crucial to use effective controlling and educational measures to improve the status of occupational stress and the quality of life of nurses by the relevant and responsible administrators.</p> SEYED EHSAN SAMAEI OMRAN AHMADI SEYED SEDIGHEH SOLEIMANIAN MANDANA KALAMTAR NADALI AKBARIAN MAHMOUD SADEGHI MINA GALESHI ##submission.copyrightStatement## 2018-07-24 2018-07-24 10 2 P-HAZOP: A New Extended HAZOP (Hazard and operability study) for Pipelines Risk Analysis <p>Due to high potential consequences of pipeline accidents, it is necessary to manage the inherited risks in the pipeline sectors. Several techniques are available to identify hazardous situations; however, it is crucial that the selected tool be fitted for the proposed scope. HAZOP study is one of the most accepted techniques by experts to identify hazards. Despite of the wide application of HAZOP in the process industries, this method is not suitable for pipelines. In this study, a new extension of HAZOP (P-HAZOP) is introduced through integrating the classic HAZOP and the Kent’s method. This research focuses on producing the new sort of deviation for pipelines. A previously conducted HAZOP study for a network of pipelines was repeated by using P-HAZOP. A large number of new generated deviations demonstrate more coverage of the P-HAZOP for pipeline scope. Finally, it is recommended to improve the traditional HAZOP for pipeline applications.</p> OMID KALATPOUR ##submission.copyrightStatement## 2018-07-24 2018-07-24 10 2 Characteristics, Pressure Drop and Capture Efficiency of Heavily Loaded New and Repeatedly Washed HEPA Filters <p class="15"><span dir="LTR">The particulate loading effect on pressure drop as well as the capture efficiency of new custom fabricated high-efficiency particulate air (HEPA) filters were determined and the findings were compared with those of the same filters after being wet cleaned and reused multiple times. A set of five samples from three different types of HEPA rated filtration media, made of </span><span dir="LTR">polypropylene </span><span dir="LTR">(Puritrate®), Teflon and </span><span dir="LTR">glass fiber </span><span dir="LTR">filters, were fabricated in cylindrical shape. Each filter was mounted in a specially designed filter testing unit and gradually loaded with airborne particles of cadmium telluride (CdTe) in 10-gram increments up to a total of 100 grams. During the loading, the face velocity of each filter was kept constant at 17. 8 m/s (3500 ft/min). Four filters (two Puritrate</span><span dir="LTR"><sup>®</sup></span><span dir="LTR"> and two Teflon) were fully loaded 4-10 times and each time they were wet cleaned in dilute (&lt; 4%) nitric acid soaked for 24 hours, rinsed with deionized water and gradually dried at ambient temperature under a laboratory hood until the filter gained its original weight.  The </span><span dir="LTR">glass fiber </span><span dir="LTR">was used as a reference medium; it was loaded and tested only once and was not wet cleaned or reused. The pressure drop across all filters (new or reused) increased by cubic model expression as the filters were gradually loaded. Baseline pressure drop on new (unused) filters ranged from 45 Pa (Puritrate</span><span dir="LTR"><sup>®</sup></span><span dir="LTR">) to 115 </span><span dir="LTR">Pa (Teflon).  A</span><span dir="LTR">s the filter-loading </span><span dir="LTR">progressed, the pressure drop ranged from 146 Pa (</span><span dir="LTR">Puritrate</span><span dir="LTR"><sup>®</sup></span><span dir="LTR">) to 306 Pa (Teflon).  </span><span dir="LTR">After each wet cleaning and drying cycle, the filters' pressure drop returned almost to their original baselines. All filters, new or reused, performed well, with particulate capture efficiencies exceeding 99.97% at 0.3 µm. The results suggested that certain custom fabricated HEPA filters can be effectively wet cleaned and reused. </span></p> KEN SMIGIELSKI FARHANG AKBAR-KHANZADEH ##submission.copyrightStatement## 2018-07-24 2018-07-24 10 2 Quality of spirometry tests in periodic examination of workers <strong>Background</strong>: Spirometry is a tool for screening and early diagnosis of harms caused by occupational respiratory exposures. Since spirometry results largely depend on spirometry method, their credibility and acceptability may vary. <strong>Objectives:</strong> Accordingly, the quality of spirometry procedures and test reports were studied in periodic examinations of workers of an industry. <strong>Materials and Methods</strong>: In a cross-sectional study, the recorded results of 506 spirometry tests performed in periodic examinations of 190 workers of an industry between 2005 and 2015 were evaluated. Each test was assessed in terms of ATS standards and quality of reporting, and the results obtained were compared with the results of spirometry conducted by the research team. <strong>Results</strong>: The most common error in performing these tests was failure to allow for the 6-second exhalation (in 70% of cases). After matching for the elapsed time, reported FVC and FEV1 in these tests were different from the standard spirometry performed by the research team by 5% in more than half of the cases and by more than 10% in a quarter of the cases. <strong>Conclusion</strong>: The results obtained revealed poor quality of spirometry tests performed in worker’s periodic examinations. It is therefore recommended that spirometry operators be trained and quality of spirometry tests in occupational examinations be more vigorously monitored. MARYAM SARAEI RAMIN MEHRDAD EHSAN HEYDARBEYGI GHOLAMREZA POURYAGHOUB ##submission.copyrightStatement## 2018-07-24 2018-07-24 10 2 The Impact of Ergonomic Interventions on Human Whole-body Vibration of Heavy Machinery Drivers of Sarcheshmeh Copper Complex <p><strong>Introduction: </strong>There are mechanical vibrations in the vehicle and around industrial machinery and their operators are exposed constantly, which increases the risk of musculoskeletal disorders and ultimately affects their overall health, negatively. So, the aim of this study was to investigate the effects of ergonomic interventions on human whole body vibration of heavy machinery drivers in the Sarcheshmeh copper complex.</p><p><strong>Materials and Methods</strong>: In order to evaluate drivers' exposure to whole-body vibration total 25 drivers were investigated out of 45. The measurement was done before and after intervention, using the Brike &amp; Kjær 4447 model in the three axes (X, Y, Z) for each operator according to ISO 2632-1 (1997). Also obtained values were compared with occupational exposure limits recommended by the Iranian Ministry of Health. Data analysis was done using independent t-test by SPSS software version 19.</p><p><strong>Results</strong>: Before the intervention, the maximum exposure to whole-body vibration in the z-axis was the main axis of vibration to the drivers’ body. Comparing the results with equivalent standards was determined that the equivalent acceleration in all vehicles were higher than permissible limits (0.65 m.s<sup>-2</sup>). The mean and maximum exposure before and after the intervention were 0.66, 0.56, 0.88 and 0.63 m.s<sup>-2</sup>, respectively, which were significantly different (P&lt;0.001).</p><p><strong>Conclusion</strong>: Applying engineering and administrative interventions such as seat replacement and modification of the suspension system, work pace control and training operators to control vehicle suitably, can play a meaningful role in reducing exposure to vibration is heavy mining machinery.</p> SAEED GHANEH YASER SHAHRNAVARD MASOUMEH KARAMI ZOHREH KARAMI ##submission.copyrightStatement## 2018-07-24 2018-07-24 10 2 Proposing a customized model of safety culture and behavior in a car manufacturing company <p><strong>Background</strong>: Work-related accidents and illnesses are a great concern in developed countries. This study was designed to develop a customized model of the safety culture and identifying effective factors in a car manufacturing company.</p><p><strong>Methods</strong>: The present descriptive analytical study was conducted based on retrospective and field studies in a car manufacturing company. In order to present a new customized model of safety culture questionnaire, the study was designed in three phases: 1) offering a customized model 2) providing a customized questionnaire 3) field study.</p><p><strong>Results</strong>: A total number of 619 cases completed the questionnaire 321 damaged and 298 undamaged people). The Cronbach's alpha for the questionnaire was 0.855. With the exception of the safety rules and conditions, the damaged population markedly acquired more points for the whole questionnaire in comparison with their undamaged colleagues, though, this difference was statistically significant (P&lt;0.05) only in 7 questions. Moreover, the correlation of safety culture components in damaged personals and undamaged one or combination of both showed that approximately all components present positive correlations (P&lt;0.05 or P&lt;0.001).</p><p><strong>Conclusions</strong>: The use of the customized model and questionnaire in car manufacturing industry is the marked feature of the present study. The result of the mentioned factors demonstrated that the safety culture of the damaged population is higher than undamaged one. Thus, it might be stated that the occupational accident is the milestone to evaluate the safety culture. </p> ADEL MAZLOUMI GHASEM TOORI EHSAN GAROSI ##submission.copyrightStatement## 2018-07-24 2018-07-24 10 2 Analysis of Construction Safety Risk in House Power of a Power Plant Based on Bow-Tie Technique <p><strong>Introduction:</strong> Large construction projects are always at high risk. Safety in these projects is vulnerable position. Analysis of risk resources and its safety risk is one of the important activities to prioritize existing risks as well as managing them in the process of building a power plant as one of the most dangerous industries in terms of safety risks. The purpose of this study was to analyze the safety risks existing in the construction phase in a power plant based on the Bow-tie technique.</p><p><strong>Method:</strong> This is a cross-sectional analytical study that was carried out at house power of a combined cycle power plant in 2017. Safety analysis of risks in this study was performed based on the Bow-tie technique using the Bow Tie Pro<sup>TM</sup> software. For the more effectiveness of this study, two phases of system descriptions and identifying risk sources have been designed and implemented before the risk analysis steps, and the identification of the path of each branch of the Bow-tie chart (consequence to event occurrence).</p><p><strong>Results:</strong> The results of analysis of the relationship between the elements of each activity and its threats and its consequences showed that the highest level of threats has related to pressured cylinders, welding and cutting (8 threats including mechanical damage, heat, transportation, unsafe connections, cylinders storage, oil and grease, leakage and flame retardation); the most significant consequences have related to heavy loading (3 consequences including human injury, damage to cranes and damage to facilities and equipment), and pressured cylinders, welding and cutting (3 consequences of human injury, fire and explosion and damage to facilities and equipment).</p><p><strong>Conclusion:</strong> The findings of the study indicated that the use of Bow Tie Pro<sup>TM</sup> software is a suitable method for analyzing the safety risks of large projects such as the construction of a power plant that can lead to provide preventive and limiting safety measures in order to prevent and reduce threats as well as to control the safety implications of construction activities.</p> MOHAMMAD DANESHVAR AHMAD SOLTANZADEH HEIDAR MOHAMMADI ALIAKBAR SOLTANZADEH NASRIN AHMADIYAN ##submission.copyrightStatement## 2018-07-30 2018-07-30 10 2