Iranian Journal of health, safety andenvironment

1281-1288

Authors: Hamed Hassani, Neda Nazarpour, Gholamhossein Pourtaghi

Volatile organic compounds (VOCs) are one of the main group of air pollutants. Photocatalytic oxidation is one of the destructive methods for gaseous pollutants and has been received more attention in the past years. In this study investigated the comparison of the toluene removal efficiency by Photocatalytic Oxidation of Toluene by ZnO/SiO2 and TiO2/SiO2. In this study, the effect of parameters such as the amount of relative humidity, initial concentration of pollutant, the apparent speed of gas and the minimum speed of fluidizing of bed on the process of photocatalytic oxidation of Toluene is examined by comparison between TiO2/SiO2 and ZnO/SiO2 catalysts in a fluidized bed reactor. as it was explained, by absorption of water molecules on the surface of the catalyst and converting them to hydroxyl active radicals, these radicals act as a pushing factor in the reaction. The study also showed that an increase in the relative humidity in the 15–45% range would increase the efficacy of toluene oxidation. Conversion percentages between TiO2/SiO2 and ZnO/SiO2 catalysts were not significantly different (pv>0.05), while the reaction rate of ZnO/SiO2 catalyst was higher than TiO2/ SiO2 catalyst (pv<0.05). In the study of the interaction between the apparent velocity variables, initial concentration of toluene and loading of zinc oxide and titanium dioxide, only the interaction between two gas velocity variables and initial concentration of toluene was significant. The results showed that ZnO/SiO2 catalysts generally have a larger efficacy than TiO2/SiO2, presumably because ZnO/SiO2 has more active sites. Additionally, the ZnO/SiO2 catalysts offer better fluidity than TiO2/SiO2. The photo catalytic transformation rate of the pollutant is relatively low, as the optimum humidity level for appears to be 45%.

1291-1296

Authors: Zahra Ordudari, Ehsanollah Habibi

Grip and pinch strength are the most important factors affecting the hand’s performance. This study aimed to evaluate the relationship among maximum aerobic capacity (Vo2max) and ratings of perceived exertion (RPE) with grip and pinch strength and endurance and their impact on these factors. This cross-sectional study was performed among 83 male students and office workers by means of simple random sampling. To assess the Vo2max, RPE, grip and pinch strength and endurance the Step Test, Borg scale, dynamometer and pinch gauge were used, respectively. The findings of the study indicate that there is a direct relationship between the Vo2max with grip strength and endurance, pinch strength and endurance and BMI. On the other hand, there is an indirect relationship between RPE with grip and pinch strength and Vo2max. Moreover, there was no relationship between RPE with grip and pinch endurance. It was also found that there is a direct relationship between the BMI with grip and pinch strength, pinch endurance, and Vo2max. Finally, no relationship was observed between BMI and grip endurance. Moreover, the Vo2max was found to have no influence on the grip and pinch strength and pinch endurance, but it has an influence on the grip endurance. In jobs that require high grip and pinch strength and endurance employed those with high Vo2max so that work-related musculoskeletal disorders (WMSDs) would be prevented.

1303-1309

Authors: Majid Motamedzade, Mahdi Mohammadian, Javad Faradmal

This study is aimed to compare the results obtained from four risk assessment methods, videlicet HAL-TLV, Strain index, OCRA checklist, and ART. These musculoskeletal disorders assessment tools are generally used in the studies as well as in the field of occupational health. In this study, the data was collected via assessments of 30 tasks by 9 raters in poultry slaughter, assembly, and container production industries using four methods of upper limb musculoskeletal disorder risk assessment. In order to determine the level of agreement between the risk assessment methods, the Spearman's rank correlation coefficient and Cohen's weighted kappa were used, according to which the highest agreement and correlation were found between ART and OCRA checklist methods, while the HAL-TLV and OCRA checklist exhibited the lowest agreement and correlation. The difference between the risk classification results of the studied methods could be due to the difference of definitions of the risk variables; therefore, selecting the assessment tools for assessing the task risks in the working environment must be in accordance with the assessment objectives and complexity of the work tasks.

1318-1322

Authors: Behzad Fouladi Dehaghi, Abbas Mohammadi, Leila Ibrahimi Ghavamabadi, Ghasem Mardi, Amel Saki

Cigarette smoking had many adverse effects on health, also exposure to industrial noise is known as a health risk factor in the workplaces. The aim of this study was to investigate the relationship between industrial noise exposure and smoking on the hearing threshold levels in workers. In the study, 200 male workers in the two groups (100 smokers and 100 nonsmokers with noise exposure) were involved. To assess noise exposure used calibrated noise dosimeter. Demographic, smoking habits and health status information was obtained via questionnaire. The results showed a significant difference between noise-induced hearing loss (NIHL) in two ears and total NIHL in smokers and non-smokers with less than 10 years and more 10 years of noise exposure duration. From the outcome of this investigation it is possible to conclude a positive effect between cigarette smoking and noise exposure on hearing loss and it can be suggested that hearing protection programs should train workers about the increased risk of developing NIHL from smoking and exposure to high occupational noise levels.