مجله مهندسی بهداشت حرفه ای
سال چهارم شماره 3 (پاییز 1396)

When workplace air monitoring is not sufficient to determine the exposure levels, the determination of compounds and some metabolites in exhaled air and personal exposure levels is considered a practical method for biological monitoring. The aim of this study was to determine the relationship between the concentration of tetrachlorethylene in exhaled air and personal exposure levels in the dry cleaning workers
In this descriptive cross - sectional study was performed in 2017, in addition to the collecting samples of exhaled air and personal exposure of 12 workers, the ambient air samples of dry cleaning workplace were examined. Also the ambient air samples were studied simultaneously. Measurement of tetrachlorethylene in the exhaled air was performed using gas chromatograph equipped with flame ionization detector (FID) through an incorporation of 1003 and 3704 NIOSH methods and optimization of analysis parameters.
In this study, the personal exposure levels were above the recommended national occupational exposure limits (OEL-TWA), and tetrachlorethylene concentration in exhaled air of workers were above the biological exposure index (BEI) respectively. The results showed that there is a significant relationship between the concentration of tetrachlorethylene in exhaled air and personal exposure levels (r=0.66, P=0.046). Also, was obtained the significant relationship between the concentration of ambient air with exhaled air concentrations (r=0.59, P=0.003), and personal exposure levels (r=0.91, P The results indicated that tetrachlorethylene measuring in the exhaled air as a non-invasive biomarker is valid enough for assessing occupational exposure in the dry cleanings. And also tetrachlorethylene concentration in exhaled air can be measured with high sensitivity through optimizing of analytical conditions in GC-FID system and the integration of 1003 and 3704 NIOSH methods.

clean room is an environment fully enclosed where parameters such as airborne particles under control and is requirement in the pharmaceutical industries to produce quality products. The aim of this study was to assessment and simulation of airflow and particle of clean room by CFD method in a pharmaceutical industry.
This study used an experimental study that was conducted at 2015 in the pharmaceutical industry. The methodology used in this study was to evaluate the level and number of particles in the clean room according to the standard ISO 14644 – 3. Also, air flow and particle in cleanroom with cleanness of class C was simulated with Computational Fluid Dynamics.
The results showed that the path of particle movement and distribution of particles in the clean room completely depend on the shape of the flow and the pattern of air flow in the clean room. Furthermore, the results of the simulation showed that the particles in the clean room wall return particle removal efficiency of 70% at 0.5 and 5 microns.
There is equipment and a tool in a clean room effects on the airflow pattern. The results of simulation showed that the pattern of dispersion, air flow in the clean room is the most affected by the removal of particles.

Nowadays, observational methods based on video recording of work processes and its analysis by using computers software are widely used. Therefore, the aim of this study is the assessment of welder’s posture and its biomechanical analysis by using CATIA software.
This research has been done on welders Iranian Gas Transmission Company. Evaluated postures, which include three postures were determined from photos and videos, which were recorded during the welding process. After determining the target postures, digital modeling of person posture was simulated in CATIA software. Then assessments using RULA method and biomechanical analysis of forces to human digital modeling were done.
The analytical results are directly extracted by CATIA software. The final score of three postures evaluated using RULA method indicated that for two postures, we need immediate corrective action and for one posture, the corrective action should be taken in near future. Also, biomechanical analysis of forces in one of those postures revealed excessive force higher than recommended limit by NIOSH.
The results of this study show that we can provide a better assessment of workers conditions in workplaces using CATIA software. Analyzing according to RULA methods is a significant measure in evaluation and redesign of workstations.

Since human resources and employees are one of the most important assets of organization, identification of factors associated with these resources that can affect their performance and job stress is becoming increasingly important to study.The present study examined the relationship between job stress and the performance of different health units.
The present study is a cross-sectional study.All of the health care workers of urban and rural health centers in Hamadan city were included in this study.The study population included 150 people and all of them were examined.The questionnaires included the Stress Relief Elliot(1994)and an annual checklist provided by the Ministry of Health.The data analyzed in SPSS software with Pearson and independent –T test.
The mean of stress level and performance were55.16, 79.64 which respectively was 55.14, 78.21in family Health unit, 57.06 and 76.87 in Disease control unit and 54.03, 83.31in Occupational and Environmental Health unit respectively.The results showed that the significant and negative relationship between employees stress and performance of units (p=0.001).The results also showed that age had a significant positive correlation with service history and performance (p =0.001) and negative significant relation with stress (p =0.001).
Regarding the confirmation of relationship between stress level and staff performance that shown in this study, and the fact that human resources are the key factor in determining the quality, accessibility and cost of health care, it is recommended that managers take effective actions for reducing stress and increasing productivity planning.

Formaldehyde used in the pathology and histology laboratories as a tissue fixation. Formaldehyde classified in group A1 (human carcinogen) by the International Agency for Research on Cancer (IARC). The aim of this study was the evaluation of relationship between ambient concentrations and time-weighted average or ceiling exposures of formaldehyde the pathology departments.
This descriptive analytical study was performed in the second half of year 1395 at four teaching hospitals in Hamadan university of Medical Sciences. For those purpose 28 TWA samples (by a census method), 17 environmental and, 5 ceiling samples in the peak of pollution were collected simultaneously. The NIOSH 3500 method was used to sampling and analysis of air samples.
The mean ambient concentration of formaldehyde was 1.67±1.81 ppm. The mean personal exposure levels in both TWA and ceiling were obtained 0.31±0.40 ppm and 2.36±2.34 ppm respectively. TWA and ceiling levels were more than from NIOSH recommended exposure limits (REL) and Iran's national occupational exposure limit (OEL) respectively. In this study, there were a significant correlation between the personal concentrations with TWA (r= 0.82 , P=0.0001) and ceiling exposure levels (r=0.47 , P=0.01).
According to the exist challenges in the risk assessment of formaldehyde, this study in addition to measuring the ceiling exposure levels in the contaminant peak emphasized the simultaneously measure ambient concentrations and TWA exposure levels in order to informed of the staffs exposure levels to assurance effectiveness of control measures at the teaching hospitals.

Introduction; controlling noise pollution in an indoor environment has always been faced with administrative and financial constraints. Prioritizing in a scientific manner is a useful approach in dealing with such problems. The aim of the present study was to determine the noise control prioritizing index (NCPI) in various units from a tire manufacturing company.
Methods; the sound pressure levels in various units were determined in accordance with ISO 9612 standard. The index was a function of three parameters; the number of people exposed of the noise, exposure time, and a weighting factor corresponding to the sound pressure level. The distribution of noise levels on the unit with the highest priority was depicted using Surfer ver.10.
Results; according to the environmental measurements, 22.9% of the investigated stations had a noise level in the danger zone and other 77.1% was in the caution zone. No station was in the safe zone. The sound pressure level had a range between 69.9-104.7 dB(A). Among the investigated units, the curing unit with 20 employees had the highest priority of noise control (NCPI=1.369).
Conclusion; the results of the present study indicated that using an index resulted from a combination of various parameters affecting the noise pollution, we would be able to prioritize units for implementing noise pollution control confidently. The results of the present study are applicable to all similar industrial settings.

Organizations, manufacturing and non-manufacturing companies, and development units are always associated with incidents and the need for proper risk assessment. One of these is the process of constructing subwayways that, given its nature, require special attention and the occurrence of accidents is always there. But as risk definition is clear, risk is always associated with uncertainty. Accordingly, it should be noted that the performance of risk assessment calculations should be consistent with the principles that could cover this uncertainty. One of the most prominent methods in this field is the use of fuzzy logic fuzzy calculations that can provide an appropriate response, if accompanied by expert opinions, to estimate the probable risk of accidents.
In this paper, firstly, identification of the existing occupational hazards in the construction of subway projects was carried out. Then, prioritization and ranking of identified hazards were performed based on the degree of importance of the fuzzy hierarchy analysis method, and finally using the method of analysis and the fuzzy hierarchical analysis of ranking has been done on the safety risks of the subway construction.
The results show that the main risk factors of these operations are priorities, including depletion during drilling, the collision of machinery with manpower is associated with hazards associated with shotcrete and surface water and groundwater operations.
In the present article, a new model was developed to calculate the probability of occurrence of the event, which so far has not been addressed in other studies. Finally, effective measures can be taken to reduce the risk of a project by eliminating the high risk factors.

Knowledge management is the process of using knowledge to achieve intended purposes. Since there are extremely high health, safety and environmental risks in healthcare system, knowledge management not only helps the patient health, but also improves the health and safety of healthcare workers through using proper information and experiences.
In this study, a questionnaire with 11 key questions was developed, Then for the evaluation of validity and consistency of the primarily questionnaire, Inter Rate Agreement and Cronbach α coefficient were used. Finally based on information collected, data was done by the binominal test with SPSS-22 software.
The relevancy (92.7%) and clarity (91.8%) were found to be acceptable, the questionnaire was internally consistent (α=0.7) and the results of binominal test showed that all questions were accepted (up to 75% for each) by the experts.
Although knowledge management is a new area in our country, it is important applying new and beneficial patterns in various aspects of activities like HSE management. Based on obtained results, in can be concluded that the introduced questionnaire is a valid and reliable tool for using in workplace processes.