Iranian Journal of health, Safety and environment
Volume:6 Issue: 3, Summer 2019

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%.

Low birth weight (LBW) of the babies was found to be associated with arsenic exposure through consuming arseniccontaminated water in Bangladesh. But the influences of maternal nutritional status and hemoglobin level remains to be dealt with. This study was conducted to assess the LBW of the babies in reference to arsenic exposure of mothers controlling the influences of the nutritional status (BMI) and hemoglobin level. This was a cross-sectional study carried out amongst the pregnant mothers who came to a district hospital for delivery. The mothers aged ≥18 years and had no complication were included in the study. A total of 101 mothers and their newborn babies were the study sample. Of the total 101 participant mothers, 41.5% were arsenic exposed. Comparatively, on an average, lower birth weight (2492± 477gr) was found among the babies born to arsenic exposed-mother. The exposed mother of LBW babies had significantly a higher urine arsenic concentration (381.38µg/L). The correlation analysis revealed that there was a negative relationship with the urine arsenic concentration (r=-.619; p=.000) and positive relationship with the hemoglobin level (r=.280; p=.092) and BMI (r=.204; p=195) of the exposed mother with the birth weight. After controlling the influence of hemoglobin level and BMI, an almost same association was found between LBW and urine arsenic. Mothers with arsenic exposure were at risk of giving birth to LBW babies, this could increase as evident by higher maternal urine arsenic concentration. And any positive effect of maternal nutritional status and hemoglobin level on birth weight of newborn could be offset by arsenic exposure.

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.

Dye industries and textile are among the most water-consuming industries, which severely disturb the aquatic life. Therefore, the aim of this study was to determine the feasibility of Fenton process in removing Direct Red 81 dye from aqueous solutions and the optimal conditions for maximum removal. This research was conducted in a laboratory-scale using a one-litre photochemical reactor. The effect of the influential parameters, including pH (3–9), Fe (II) concentration (10–150mg/L), H2O2 concentration (20–150mg/L), initial dye concentration (25–150mg/L), and reaction time (15–120min) on the dye removal was investigated and the optimal conditions were determined according to maximum dye removal efficiency The results showed that the dye removal rate increased as the pH and Fe(II) concentration decreased and as the initial dye concentration and time increased. The optimal condition was at pH=3, Fe (II)=10mg/L, H2O2=50mg/L, initial dye concentration=100mg/L, and reaction time= 45 minutes. Although the maximum removal efficiency (98.29%) was obtained at the reaction time of 120 minutes, 45 min was the appropriate reaction time considering the costeffectiveness. Our results suggest that the Fenton process is a reliable and efficient method with more than 95% efficiency for decolourization of DR-81 dye and many industrial wastewaters.

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.

Dental wastewater and solid waste are one of the most important sources of environmental pollution. The objective of the present study was to evaluate the quality of wastewater and solid waste produced in the general dentistry offices in the city of Arak, Iran. A total number of 30 samples of wastewater and 30 samples of solid waste were taken from 30 general dentistry offices. The samples of wastewater were analyzed for metals and other parameters such as BOD, COD, and TSS. The samples of solid wastes were manually separated into 66 components and 4 categories and then weighted. The mean concentrations of Zn, Cu, Hg, Fe, B, Ba, Sn, Ag, Pb, Al, Mn, Cr, and Co were 3950.09, 2578.59, 1247.28, 1060.21, 538.36, 493.21, 300.91, 156.56, 108.32, 107.37, 91.11, 66.00, and 6.48µg L-1, respectively. The mean generation of dental solid waste in each general dentistry office was 670.22g day-1. Potential infectious waste, domestic-type waste, chemical & pharmaceutical waste, and toxic waste constituted 51.52%, 35.30%, 11.11% and 2.07%, of the total waste generated, respectively. Due to the high levels of some metals in the samples, the wastewater should be treated before discharging into the public sewer.

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.

Mists of water-based metalworking fluids (MWFs) as a kind of lubricants mineral oil are reported as a respiratory irritant with having carcinogenic compounds such as formaldehyde. Due to the widespread exposure of Iranian metal machining workers to water-based MWFs and limitations of advanced analytical balance in Iran, which is required by the National Institute of Occupational Safety and Health (NIOSH) conventional method No5524, the purpose of this study was set to develop a new analytical method using Fourier-transform infrared (FTIR) spectrometry instead. In this study, the spiked standards in the range of 0.96 to 960 µg/sample were dried and extracted with carbon tetrachloride and scanned by FTIR in the range of 2700 to 3200cm-1 for the best absorption. FTIR and Gas chromatography analysis of formaldehyde as a toxic ingredient of MWFs was examined and its presence was confirmed. For establishing the validation, the merits of the analysis of the FTIR and NIOSH method No.5524, such as precision, accuracy, LOD, LOQ, and bias were obtained that were 1.49%, 103%, 0.0004, 0.0014 µg/sample, -3%, and 10.87%, 111%, 14.9, 49.1µg/sample and 11% respectively. Regression coefficients (r2) of the calibration line with the spiked standards (0.96-960µg/sample) were in the range of 0.997 to 0.999. Since the merits of the analysis of the FT-IR method for water-based MWFs were comparable to the respective NIOSH method, the developed method could be very useful in monitoring lathe workers, especially in developing countries. However, collaborative examination for full validation of the method is recommended.