JOURNAL OF OCCUPATIONAL HYGIENE ENGINEERING
Year:2017 | Volume:4 | Issue:3 |Papers Count:8

Background and Objective: The determination of the compounds and some metabolites in exhaled air is a practical method for biological monitoring, especially when the workplace air monitoring is not sufficient to determine the exposure level. Regarding this, the aim of the present study was to determine the relationship of tetrachlorethylene concentration in exhaled air with personal exposure levels among the dry cleaning workers.Materials and Methods: This descriptive, cross-sectional study was performed in 2017. For the purpose of the study, the samples of exhaled air and personal exposure of 12 workers were collected. Additionally, the ambient air samples of dry cleaning workplace were simultaneously studied.The measurement of tetrachlorethylene in the exhaled air was performed using gas chromatograph equipped with flame ionization detector (GC-FID) through the incorporation of 1003 and 3704 NIOSH methods and optimization of the analysis parameters.Results: According to the results, the personal exposure levels were above the recommended national occupational exposure limits. Furthermore, tetrachlorethylene concentration in the exhaled air of the workers was higher than the biological exposure index. There was a significant relationship between the concentration of tetrachlorethylene in exhaled air and personal exposure levels (r=0.66, P=0.046). Additionally, the concentration of ambient air showed a significant relationship with exhaled air concentration (r=0.59, P=0.003) and personal exposure levels (r=0.91, P<0.001).Conclusion: As the findings indicated, the measurement of tetrachlorethylene in the exhaled air was a valid non-invasive biomarker for the assessment of occupational exposure in the dry cleanings. The measurement of tetrachlorethylene concentration in exhaled air can be accomplished with high sensitivity through the optimization of analytical conditions in GC-FID system and integration of 1003 and 3704 NIOSH methods.

Background and Objective: Cleanroom is a tightly enclosed environment where airborne particles are under control and is a necessary environment in pharmaceutical industries to produce quality products. Hence, we sought to assess and simulate particle dispersion and track particles in a cleanroom by computational fluid dynamics (CFD) method in a pharmaceutical industry.Materials and Methods: This experimental study was conducted in 2015 in a pharmaceutical industry. We evaluated particle concentration and number in the cleanroom according to ISO 14644- 3 standard. In addition, air flow pattern and particle dispersion in the cleanroom with cleanliness class of C was simulated based on CFD.Results: The results showed that the path of particle movement and distribution and dispersion of particles in the cleanroom are completely dependent on flow shape and the pattern of air flow in the cleanroom. Furthermore, the simulation results showed that wall return had efficiency of higher than 70% for particle sizes of 0.5 and 5 microns.Conclusion: Equipment and tools existing in the cleanroom affect the air flow pattern, and in turn, particle removal efficiency. Moreover, particle dispersion simulation in the cleanroom illustrated that air flow pattern exerts the highest impact on particle removal in cleanrooms.

Background and Objective: Nowadays, observational methods based on video recording of work processes and its analysis by using computer software are widely used. Therefore, we attempted to assess welders’ posture and its biomechanical analysis by using computer aided three-dimensional interactive application (CATIA) software.Materials and Methods: This study was performed among welders of Iranian Gas Transmission Company. The evaluated postures, which included three postures, were determined from photos and videos, which were recorded during the welding process. After determining the target postures, digital human models were simulated in the CATIA software. Then, rapid upper limb assessment (RULA) method and biomechanical analysis of forces were performed on the human digital models.Results: The analytical results were directly extracted from the CATIA software. The final scores of the three postures evaluated using RULA method indicated that for two postures, immediate corrective action is required, and for one posture, corrective action should be taken in the near future. In addition, biomechanical analysis of forces in one of those postures revealed forces higher than the recommended limit by the National Institute for Occupational Safety and Health.Conclusion: CATIA software provides a better assessment of workers’ conditions in workplaces. Analysis using RULA method is a significant measure in evaluation and redesign of workstations.

Background and Objective: Since human resources and employees are among the most important assets of any organization, identification of the factors affecting their performance and occupational stress is becoming increasingly important. In this study, we examined the relationship between occupational stress and the performance of different health care units.Materials and Methods: This cross-sectional study was performed among all the health care workers (n=150) of urban and rural health centers of Hamadan, Iran. The data collection instruments included a stress questionnaire designed by Elliot (1994) and an annual checklist provided by the Ministry of Health of Iran. To analyze the data, Pearson correlation coefficient and independent t-test were run in SPSS, version 16.Results: The total mean scores of occupational stress and performance were 55.16 and 79.64, respectively. These scores were respectively 55.14 and 78.21 in the family health unit, 57.06 and 76.87 in the disease control unit, and 54.03, 83.31 in the occupational and environmental health unit. The results showed a significant negative relationship between occupational stress and performance of the units (P=0.001). Further, age had a significant positive association with performance (P<0.001) and a significant negative relationship with stress (P<0.001).Conclusion: Regarding the confirmation of the relationship between stress level and staff performance and the fact that human resources are key to determining the quality, accessibility, and cost of health care services, we recommend authorities to take effective actions for reducing stress and promoting efficiency.

Background and Objective: Formaldehyde used in the pathology and histology laboratories as a tissue fixation. This compound 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 air concentrations and personal exposure (TWA and ceiling) of formaldehyde in the pathology departments.Materials and Methods: This descriptive analytical study was performed in the second half of year 1395 at four teaching hospitals in Hamadan university of Medical Sciences. For that purpose 17 environmental, 28 TWA samples (by a census method) 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.Results: 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).Conclusion: According to the exist challenges about the evaluation of occupational exposure to formaldehyde, this study emphasizes on the assessment of the health and carcinogenicity risks in the staffs exposed to formaldehyde in the pathology departments, in order to assurance effectiveness of control measures.

Background and Objective: Controlling noise pollution in indoor environments has always been faced with administrative and financial constraints, and scientific prioritizing is a useful approach in dealing with this issue. In the current study, we sought to determine the noise control prioritizing index (NCPI) in various units of a tire manufacturing company.Materials and Methods: The evaluation of environmental noise for determining the sound pressure levels in various units was performed in accordance with ISO 9612 standard. An index was defined by using the three parameters of the number of people exposed, exposure time, and weighting factor corresponding to the sound pressure level. Further, a formula was devised to calculate this index. The distribution of noise level in each unit with noise control as the top priority was depicted using Surfer ver.10.Results: According to the environmental measurements, 22.9% of the investigated stations had a noise level within the danger zone and the others were in the caution zone (77.1%). No station was in the safe zone. The sound pressure level ranged between 69.9 and 104.7 dB (A). Among the 11 investigated units, the curing unit with 20 employees had the highest noise control priority index (NCPI=1.369).Conclusion: The use of a combination of various parameters affecting noise pollution provides a reliable method for prioritizing noise control in various units of an industrial company. The results of the present study are applicable to all similar industrial settings.

Background and Objective: Organizations, manufacturing and nonmanufacturing companies, as well as development units are always associated with incidents and the need for proper risk assessment. The subway construction project is one of the operations, which often entails accidents given its nature and requires special attention. As indicated in the risk definition, risk is always associated with uncertainty. Accordingly, it should be noted that the implementation of risk assessment calculations should be consistent with the principles that could cover this uncertainty. One of the most prominent methods in risk calculation is the use of fuzzy logic that can provide an appropriate response, if accompanied by expert opinions, to estimate the probable risk of accidents.Materials and Methods: In this study, first, the existing occupational hazards in the subway construction projects were identified. Then, the prioritization and ranking of the identified hazards were performed based on their degree of importance using the fuzzy hierarchical analysis. Finally, the ranking of the safety risks of the subway construction was accomplished by means of the fuzzy hierarchical analysis.Results: Accrding to the results, the main risk factors of the underground operations included collapse during drilling, collision of machinery with manpower, shotcrete hazards, and leakage of surface water and groundwater.Conclusion: The present study is the first attempt focusing on the development of a new model to calculate the probability of event incidence. Effective measures can be taken to reduce the risk of a project by eliminating the high risk factors.

Background and Objective: Knowledge management is the optimal use of knowledge to achieve intended purposes. Given the type of activity of health care systems and their high health and safety risks, knowledge of health and safety executive (HSE) principles not only contributes to patient safety and health, but also enhances the health and safety of employees through raising awareness and using others' experiences.Materials and Methods: In this study, a questionnaire with 11 key questions was developed. Then, to evaluate the validity and reliability of the primarily questionnaire, inter-method reliability and Cronbach’s αcoefficient were used. To analyze the data, binominal test was run in SPSS, version 22.Results: The validity of Relevancy, clarity, and Cronbach’s alpha coefficient of the questionnaire were 92.72%, 91.18%, and 0.7, respectively. The results of binominal test showed that all the questions were accepted (above 75% for each) by the experts.Conclusion: Although knowledge management is a niche area in Iran, it is important to apply new patterns in various aspects of the relevant activities such as HSE. It can be concluded that the introduced questionnaire is a valid and reliable tool that can be used in vocational processes.