International Journal of Occupational Hygiene
Volume:11 Issue: 2, Aug 2019

Accident statistics indicate that the majority of accidents at four categories of human, environment, equipment, and reputation of a community have mainly occurred in the process industries. Amongst them, the Oil and Gas industries have a significant portion, as these industries handle large quantities of flammable, toxic chemicals, and exposure to the high potential of serious accidents. Having considered these issues, it is essential to execute an in place safe system of work in such industries. Permit to work system (PTWS) is one of the most important and effective key of HSE-MS sub-systems, which has a significant role in identifying, predicting, controlling, and eliminating hazards of activities and probable accidents at workplaces. As a question for this research, it is being used in the oil and gas industry. Currently used PTWS method at gas refineries in Pars Special Economic Energy Zone (PSEEZ) is a paper-based management system document, based on the statistical results obtained using the experiences of trustees and experts, which intrinsically contains some defects and deficiencies; consequently it could not provide sufficient and effective barriers. These inherent PTWS errors and faults as the data-based permit to work system (D.B.P.T.W) are leading the operating system to different types of accidents, and finally system failures and catastrophic disasters. Therefore, in this study Bayesian theory was applied for the conditional probability of fault creator cases (FCCs) of PTWS assessment. Fault creator cases analysis in permit to work system with changes in the current PTWS were used (Current Permit to Work, C.P.T.W) in gas refineries by logical management. So that the use of this new method based on historical and interconnected and multi-faceted fault factors communication and also disconformity/capability for immediate and simultaneous informing and discovering on the relevant system components and also according to a Bayesian analysis on seven important and critical variables for both CPTWS and DPTW.S for pessimist and optimist statuses may improve the protection safety layers and it is possible to decease and finally eliminate accidents as low as reasonably practicable (ALARP) level at gas refinery plants.

Opinions about the occupational trauma causes are significantly different, which have a great impact on the nature of interventions and may improve health and safety (H&S) performance. Locus of control can be one of the most important determinants of the H&S performance. Because of the importance of this variable in relation to the prevention of occupational trauma in work environments, this study was aimed to investigate the relationship between safety locus of control and occupational trauma. This cross-sectional study was conducted on 346 employees of a cosmetic industry. The instruments included a demographic questionnaire, safety locus of control questionnaire, and self-reported occupational trauma questionnaire. Data were analyzed using descriptive and analytical statistical tests in IBM SPSS software version 22.0. Of the total number of participants in the study, 22.5% (76 people) were reported that they had experienced an occupational trauma in the last year and 77.5% (262) did not have occupational trauma. Four subjects did not respond to the occupational trauma-related questions. The mean score of safety locus of control in the study group was 38.87±5.8 and was higher than the mean value of the questionnaire (36.0). The results showed that the safety locus of control had a significant relationship with occupational trauma (p<0.01). These findings confirmed the results of previous studies, which had been carried out mostly in non-industrial areas. The results have indicated that the place of safety locus of control had a significant effect on occupational trauma in industrial areas, so it can be considered as a predictor of occupational trauma occurrence.

Noise-Induced Hearing Loss (NIHL) is one of the most common occupational disorders. Different characteristics of environmental or occupational exposure as well as individual differences trigger NIHL. This study was aimed to evaluate the effect of blood groups, Rhesus (Rh) antigen, and serum cholesterol, triglyceride, and glucose level as risk factors of NIHL. A total number of 1900 drivers who attended the occupational medicine clinic of Baharloo Hospital for the annual health-test of drivers were entered to the study. Pure tone audiometry test was performed for all subjects, blood group, serum cholesterol, triglyceride, and glucose levels were measured. Coles, Lutman, and Buffin’s (2000) algorithm were used to identify notched audiograms. A total number of 752 out of 1900 drivers (39.6%) were identified with notched audiograms. No significant difference was observed in serum glucose, cholesterol, and triglyceride between the two groups according to the presence of high-frequency notches. The distribution of blood groups in the study group was as follows: O (36.7%), A (34.1%), B (22.7%), AB (6.5%). There was no significant relationship between blood groups and hearing thresholds or between Rh antigens and high-frequency notch. The results of this study was proved the relationship between age and hearing loss, but did not demonstrate any association between blood groups, Rh antigen, serum cholesterol, triglyceride, glucose levels, and NIHL.

The strategic advantages of sparsely populated towns near major cities make them suitable for the industrial activities. This study was aimed to identify and rank the industrial estate development environmental factors in order to minimize negative environmental effects. In this study, the criteria for industrial development were first determined; then, the weight of each criterion was obtained through the technique known as Analytical Network Process (ANP). These indices were entered into Geographic Information Systems based on 13 defined layers, then compiled and standardized using the fuzzy method. Afterward, selected options were ranked via the VIKOR technique and the final site for industrial development was determined in a fuzzy GIS. According to the results, the most important industrial estate development suitability criteria assessments were environmental, social, and economic, respectively. The results also showed that the sub-criterion of distance from city was the most important environmental pollution factor. The environmental pollution was considered a sub-criterion of social criteria in this study. Generally, environmental criteria to develop an industrial estate were significantly important and should be duly considered in the development of industrial towns. Additionally, the main cause of environmental problems in industrial towns was their proximity to a city zone. This methodology may provide useful information in the development of industrial settlements and may also reduce environmental pollution.

The measure of volumetric flow rate is utilized to calculate sampling volume and airborne concentration in integrated air sampling. Consequently, calibration of the sampling train to verify volumetric flow rate is critical. The relation between sampler pressure drop and volumetric flow rate was studied in support of using the former rather than the latter for the calibration of sampling trains. Four types of respirable cyclones, two filter brands with membrane samples of the same and different lots of production, and two personal pump types were considered as components of the sampling trains under consideration.  Volumetric flow rate and pressure drop were measured under controlled conditions in a cylindrical jar designed for these determinations. For all the configurations considered, the relation between sampler pressure drop and standard volumetric flow rate was linear.  Intra-sample selection of cyclones of the same type and pump type did not create significant differences in sampler pressure drop.  Filter selection, regardless of brand or production lot, did create linear response functions that had statistically different slopes and intercepts. When grouped by cyclone type and filter brand, the sampler pressure drop at the flow rate recommended by the cyclone’s manufacturers showed variability that was not normally distributed. The recommended central tendency estimate of pressure drop is the median value, with point estimates that should be specific to a cyclone type / filter brand combination.

Prevalent use of mobile phones has led to increasing worries about the effect of radiofrequency waves on the physiology of human body. This study was aimed to determine the mobile phones radiofrequency waves’ impact on different brain tissue depth and brain tissue temperature. In this empirical research, a cow’s brain tissue was placed in a compartment and the effects of radiofrequency waves of the mobile phone were analyzed during and after radiation, in three different brain tissue depths of 2, 12, and 22 mm, in 4 mm and 4 cm distances of the tissue to a mobile phone, for 15 min. Lutron thermometer was used to measure the tissue temperatures. Data were analyzed using Lutron software. The rate of temperature increasing in 22 mm depth was higher than 2 and 12mm depths. The results also showed that during radiation of the brain tissue in 4 mm distance by the mobile phone, the tissue temperatures in 2, 12, and 22 mm depths were increased 0.29 ˚C, 0.31 ˚C, and 0.37 ˚C, respectively, relative to the base temperature (tissue temperature before radiation). Moreover, the brain tissue temperature in 4 cm distance was more sensitive than other depths. There was also a direct relationship between brain tissue depth and tissue temperature increase after mobile phone radiofrequency waves’ radiation. The temperature in 22 mm depth increased with higher speed. Not only radiofrequency waves of mobile phones increased the tissue temperature in all depths of the brain tissue, but also the higher temperature was observed in the 22 mm tissue depth. In fact, the radiofrequency wave’s thermal affect was higher in higher depths.

The fumes and gases releasing from welding processes may seriously affect welders’ health compared to other hazardous agents arising from welding like, noise, and ultraviolet radiation. The present study was aimed to measure the exposure levels of welders to fumes and gases at seven of arc welding processes in a melting company. This descriptive-cross sectional study was carried out on several types of arc welding including TIG, GMAW, PAW ،SAW, and MMAW in a melting industry. In order to measure the concentrations of welding fumes, NIOSH 7300 method was applied. Direct reading instruments were used for sampling of welding gases. The median concentration of all studied metals among different types of welding process were significantly different (P<0.02). The median concentration of some released gases among different types of welding process were not significantly different (P >0.05). The average exposure levels for metals of Cu (from TIG), Fe (from PAW and MMAW processes), Mn (from GMAW, MMAW processes), and Cr (from PAW and MMAW processes) were higher than Occupational Exposure Limit-Time Weighted Average. The finding showed that the nitrogen dioxide average concentrations and ozone gases were higher than the other gases. The welder’s exposure levels to toxic metals and gases in some stations exceeded from recommended levels; so, it is necessary to apply the appropriate preventive methods like engineering control measures to effectively protect welders’ health.

Pushing/pulling activities are known as usual and high frequent tasks in industrial sectors, especially in developing countries. Nearly, half of all manual material handling tasks is comprised of push/pull exertions, so it is essential to determine the maximum value of push/pull force exertions by Iranian workers to design the workplace optimally. A total number of 31 volunteer students (19 males and 12 females) were participated in a one-handed maximum push/pull force measurement test in standing posture. The results were measured using the Isometric Push-Pull Dynamometer. Height and weight were also recorded through interviews. Data analysis showed that the pull/push forces of women were 72% and 52% of men, but the data variation for men was higher than women. Using linear regression and Pearson correlation coefficient, it was found that there were only two strong correlations between the push force of women with body mass index (R-Sq = 75.55%) and weight (R-Sq = 74.8%) and men’s pull strength was almost independent of individual characteristics. The results of maximum push/pull can be used for improvement in workstations and push/pull tools’ design in production and services industries, in which occupational health promotion will be achieved.