Iranian Journal of health, safety andenvironment

5

Authors: Ahmad Reza Yazdanbakhsh, Hasti Daraei, Masomeh Davoodabadi

Phenol is one of the serious pollutants from the chemical and petrochemical industries. This pollutant due to its convoluted structure is resistant to biodegradation. One of the methods that are useful to remove this pollutant is advanced oxidation (AOP). A laboratory scale study was done on a synthetic wastewater containing phenol. All experiments were done in batch conditions and effect of variables pH, amount of hydrogen peroxide, iron dosage, contact time and an initial concentration on the phenol removal were tested. The remaining phenol concentration was evaluated using the DR-5000 device. In order to effect of these parameters, the experiment was performance at pH 2 to 6, 5 to 45 ml/ml of peroxide, and time of 5 to 60 minutes with 2 to 15 g/ml iron (Fe˚). The optimum pH, the ratio of hydrogen, Fe˚and time were 3, 15 ml, 8g and 5 minutes respectively. Chemical oxygen demand (COD) index was chosen as the parameter for evaluation in this study. Result showed that mineralization of phenol was not complete. The COD removal efficiency was obtained 71%. According to the results of this study, Fenton-like process can be used for conversion organic resistant compounds to other compounds with lower toxicity

5

Authors: Ghorbanali Mohammadi

Although Musculoskeletal Disorders (MSDs) represents a common occupational problem, few epidemiological studies have investigated MSDs among industrial workers. MSDs are a common industrial health problem throughout the world and a serious cause of disability among the industrial workers.The goal of the study was to investigate the prevalence of musculoskeletal symptoms (ache, pain, or discomfort) among rubber workers in Iran, using the standard Cornell Musculoskeletal Discomfort Questionnaire (CMDQ). The study population consisted of 100 males with mean age 31.73. Out of every 10 workers, in the last work week, seven reported complaints in the lower legs. The results are also indicated age and experience were significantly associated with musculoskeletal symptoms in the different body regions.

8

Authors: Mohsen Janghorbani, Masoumeh Faraji, Javad Ramazanpour, Reza Fadaei

The objective of this study was to assess the relative efficacy and tolerability of topical MJ1 compared to routine care in the treatment of histologically proven CL. A total of 150 patients with 297 lesions were randomly allocated to receive either topical MJ1 agent as a paste to applied to the lesions without cover three times a day for 20 days or routine care (intramuscular injection of meglumine antimonate 20 mg/kg/day for 2 weeks or intralesional 0.5-1CC for a total of four injection with one week interval). The primary end point of this study was the clinical cure of the lesion. Response to treatment was assessed at 1, 2, 3 and 8 weeks after start of therapy. Of the 132 lesions treated with MJ1, the mean size of lesions decreased from 423.9 to 30.4 mm2, 111 (84.1%) were reduced in size and 21 (15.9%) not responded. Correspondingly, in the 165 lesions treated with routine care, the mean size of lesions slightly increased from 295.8 to 330.5 mm2, 82 (49.7%) were reduced in size and 83 (50.3%) not responded. The differences were statistically significant (P<0.001). No sever adverse effect occurred. The findings highlight that topical treatment with MJ1 agent was much more effective than routine care and is safe and well tolerated.

348-354

Authors: Abooalfazl Azhdarpoor, Zahra Mohammadi, Mansoureh Dehghani

Wastewater sludge typically contains large amounts of water and organic materials; therefore, its stabilization and dewatering is of particular importance. In this study, Fenton oxidation process is used for stabilization and dewatering of sludge in the output of a wastewater treatment plant. To evaluate the sludge stabilization and dewatering, specific resistance to filtration (SRF), volatile organic compounds (VSS), total suspended solids (TSS), soluble chemical oxygen demand (SCOD) and heterotrophic bacteria were measured. During the experiment, the optimal values of various parameters such as pH (2-9), hydrogen peroxide (0.015- 0.18mol/L), Fe2+ (0.008- 0.1mol/L) and time (5 - 60 minutes) for optimum sludge dewatering and stabilization were investigated. The results showed that the highest percentages of SRF reduction and removal rates of SCOD, VSS and TSS were 99.48, 61, 42, and 41 percent respectively. These results were obtained in optimum pH 5, 0.05 mol/l Fe2+, 0.12 mol/l hydrogen peroxide, and the retention time of 15 minutes. The removal rate of heterotrophic bacteria increased with increasing dose of hydrogen peroxide, so that a removal rate of 84 percent was observed at a dose of 0.18 mol/l. In general, Fenton process can reduce volatile organic materials and chemical oxygen demand of the sludge resulting in its significant stabilization and dewatering. In general, Fenton process can reduce volatile organic materials and chemical oxygen demand of the sludge resulting in its significant stabilization and dewatering.

366-373

Authors: Malek Hassanpour

Numerous small recycling units of plastic wastes have been currently constructed heedless to study of economic indices in Iran. Pay attention to the prominent performance of the industrial sector for economic development and its priority for fortifying other sectors to implement job opportunities, survey of the economic indices beckon the stakeholders and industries owners. The main objective of this study was a survey of economic indices in small recycling unit of plastic wastes. Therefore, the practice of computing the economic indices was performed using empirical equations, professional experiences and observations in site of the industry in terms of sustainability performance. Current study had shown the indices values such as value-added percent, profit, annual income, breakeven point, value-added, output value, data value, variable cost of good unit and production costs were found 62%, $ 366558, $ 364292.6, $ 100.34, $ 423451.25, $ 255335.75, $ 678787, $ 389.65 and $ 314494.4 respectively. The breakeven point about 15.93%, the time of return on investment about 1.12 (13.7 months) were represented that this industry slightly needs long time to afford the employed capital and starts making a profit.

380-384

Authors: Ayoub Ghanbary sartang, Ehsanollah Habibi, Arezou Abbaspoor Darbandy

Work-related musculoskeletal disorders are the most prevalent work-related disorders and injuries and being the main cause of disability. This study was conducted to assessment of the prevalence of musculoskeletal disorders in worker company household appliances production. Posture analysis was evaluated by OWAS method and prevalence of musculoskeletal disorders by Nordic questionnaire. With evaluating musculoskeletal disorders among company household appliances production can intervention action to reduce musculoskeletal disorders was carried out. This cross-sectional study was performed on 100 workers of the appliance manufacturing industry. These Individuals were included 15 persons from foam injection workshop, 17 persons from molding workshop, 17 operators of presses, 17 persons from packaging, 17 person from cutting unit and 17 operators of rivet. The Nordic questionnaire was completed by Individuals for the organs of arm, back, leg and wrist and Posture analysis was performed by OWAS method. The data were analyzed using Spss software version 18 and descriptive statistics and Anova test. Nordic questionnaire results revealed that highest disorders were observed in the arm (25%), back (22%) and leg (21%). Also Anova test showed that was observed a significant correlation respectively between age and work experience with the prevalence of musculoskeletal disorders (p<0.02) (p<0.01). The results showed based on the level of risk OWAS for each job respectively, the highest level of risk associated with foam injection unit, packaging and cutting unit (risk level 4) and the lowest level of risk associated with molding workshop unit (risk level 2).The results of this study showed that household appliances Manufacturing workers due to the nature of their jobs are at risk of musculoskeletal disorders and Ergonomic interventions to do such as workstation redesign, reduced working hours, cycle of rest-work development.

6

Authors: Ehsanollah Habibi , Hassan Rajabi , Mohsen Arbabi

ABSTRACT In most sensitive occupations such as nuclear, military and chemical industries closed circuit systems and visual display terminals (VDTs) are used to carefully control and assess sensitive processes. Visual fatigue is one of the factors decreasing accuracy and concentration in operators causing faulty perception. This study aimed to find out a relationship between visual fatigue symptoms (VFS) of Flicker value variations in video display terminal (VDT) operators. This cross-sectional study, conducted in 2011, aimed to examine visual fatigue and determine the relationship between its symptoms and visual flicker value changes in 248 operators of VDTs in several occupations. The materials used in this study were a visual fatigue questionnaire of VDTs and a VFM-90.1 device. Visual fatigue was measured in two stages (prior to beginning to work and 60 min later). The data were analyzed by SPSS11.5, using descriptive statistics, paired t-test, simple and multiple linear regressions, correlation and recognition coefficients. Then regression equations of changes in flicker value depending on the changes in the main domains and the changes in final score before the questionnaire were obtained. Paired t-test indicated significant differences in the mean score of visual fatigue symptoms and the mean score of flicker value between the two stages, respectively (P ≤ 0.001). Simple and multiple regressions of flicker value variations, for the last visual fatigue changes in questionnaire score and the four main domains of the questionnaire were obtained R2 = 0.851 and R2 = 0.853, respectively. Correlation coefficient in the above tests indicated reverse and significant relationships among flicker value changes with changes in questionnaire score and visual fatigue symptoms. Diagnosing the first symptoms of visual fatigue could be an appropriate warning for VDTs operators in sensitive occupations to react suitably, in behavior and management, to control or treat visual fatigue and prevent errors efficiently.

6

Authors: Sedigheh Atrkar Roshan, Somayeh Daneshvar

ABSTRACT Subway system is one of the critical infrastructures in a society. In economic optimizations of risk control measures, valuing the loss of life and other financial losses in terms of money on the other hand, could influence the optimal investments in safety. The purpose is to contribute to the implementation of HSE in the transportation system. In this research, a fire risk assessment along with its economic loss estimation in the Direct Current (DC) trains and rectifier substation (RS) of Tehran subway is implemented. The number of fatalities, the extent of damage on the train equipment, etc., is then calculated in monetary unit. By using Event Tree Analysis (herein ETA), after identification of initiating events through observation, interviews, and evaluation of documents, event tree was constructed for each of them and the probability of multiple scenarios were computed. The scenario with the highest probability of fire in RS, including increased heats in the RTU panels generate a loss of at least 730 Million Rials. Accordingly, the minimum and maximum economic loss caused by fire on DC trains is minimum 510 and 1230 Million Rials, respectively. Conclusion: Given the findings of this study, the financial and human life risks, along with all tangible and intangible losses, which is considerable, the relevant managers must compare investments in safety, with the decrease of calculated economic risks as a result of fire accident in Tehran subway.

8

Authors: Ramazan Mirzaei 1, Hamed Biglari 2, Mohammad Hosein Beheshti 3, Mohammad Javad Fani 3, Keykaous Azrah *3

ABSTRACT Workers in wood industry are exposed to vibration and its damages. The purpose of this study was to evaluate exposure to hand-arm and whole body vibration in the wood industry. In this study, the parameters of whole body and hand-arm vibrations such as effective acceleration, overall equivalent acceleration, Vibration Dose Value and crest factor were studied on two Thicknessing planes, two sliding panel saw machines, two orbital sander, and three operators of perforate procedure. Assessments were done by the use of an oscillator and an analyzer of Svantak Co. Evaluating Hand-arm and whole body vibrations were conducted based on ISO 5349-1, ISO 5349-2 and ISO 2631-1 standards, respectively, and the findings/ the evaluated data were analyzed. The mean amount of daily exposure to hand-arm vibration (RMS) in Thicknessing plane, Orbital Sander and Sliding panel saw machine operators are respectively 5.56, 5.49 and 3.37 m/s2 . In addition, the average crest factor of the 3 jobs is higher than 6. Mean of daily Exposure to whole body vibration in 3 machine operators of Thicknessing plane, perforate procedure and Sliding panel saw is respectively, 0.28, 0.24 and 0.17 meters per square second. The crest factor for all the exposures was to be less than 6 and the mean of the calculated daily vibration dose equaled 5.83 with the standard deviation of 0.87( m)⁄s^1.75 . In further measured situations, exposure to hand-arm vibration is more than the standard level, so engineering and management measures are required to reduce the amount of exposure and support the health of the operators and the equipment.