Iranian Journal of health, safety andenvironment

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.

5

Authors: Fatemeh Bahadori, Khadijeh Mirza, Alireza Behroozsarand, Sima Rezvantalab

Furnaces are the devices for providing heat to the industrial systems like boilers, gas turbines and etc. The main challenge of furnaces is emission of huge air pollutants. However, porous burners produce less contaminant compared to others. The quality of the combustion process in the porous burners depends on the length of flame in the porous medium. In this paper, the computational fluid dynamic (CFD) is used to investigate the porosity effects on the flame length of the combustion process in porous burner. The simulation results demonstrate that increasing the porosity increases the flame length and the combustion zone extends forward. So, combustion quality increases and production of carbon monoxide decrease. It is possible to conclude that temperature distribution in low porosity burner is lower and more uniform than high porosity one. Therefore, by increasing the porosity of the burner, the production of nitrogen oxides increases. So, using an intermediate porosity in the burner appears to be reasonable.

6

Authors: Narmin Hassanzadeh- Rangi, Yahya Khosravi, Ali Asghar Farshad, Hamed Jalilian, Fatemen Falaki, Rezvan Abedinlo, Hassan Sharafkhaneh, Sepideh Majdabadi

Urbanization is growing rapidly in recent centuries. This phenomenon can cause many changes in various aspects of human life including the economy, education and public health This study was conducted to assess the Health, Safety and Environment (HSE) problems in Tehran neighborhoods. A new instrument was developed based on the results of a literature review and formulated during a pilot study. Through cluster sampling, 10 neighborhoods were selected based from 374 neighborhoods of Tehran. Six observers completed observational items during the field studies. Secondary data were used to obtain non-observation characteristics. Standard descriptive statistics were used to compare the HSE characteristics in sampled neighborhoods. Furthermore, control chart was used to as a decision rule to identify specific variation among sampled neighborhoods. Niavaran neighborhood had the best HSE status (52.80%±25.03) whereas Khak Sefid neighborhood had the worst one (20.09%±27.51). Standard deviations of HSE characteristics were high in different parts of a neighborhood. Statistical analysis indicated that significant differences in HSE characteristics exist among sampled neighborhoods. HSE status was in warning situation in both rich and poor neighborhoods. Community-based interventions were suggested as health promotion programs to involve and empower people in neighborhoods.

8

Authors: I. Alimohammadi, Fatemeh Danesh

Generally, no industry can be found to be safe in terms of noise pollution. Noise is the wide- spread form of environmental stressor in the industrialized urban areas. Aim: the purpose of this paper is to evaluate the combined effect of workplace noise and smoking on some hematological parameters on employing work in a food manufacturing plant. This is a retrospective study before and after for five years since starting of the work. In this study, 50 male subjects participated: smokers (n=11) and nonsmokers (n=39), for further individual information and certain specific points, a developed standard questionnaire, were filled out by participants. For the past 4-year’s details, blood tests and medical records of persons since initially hired, were used. The details of the fifth year were measured by the presenters. Using the ISO protocol 1999 and 9612, workplace noise was measured and the noise map was drawn using arc-view GIS software. Statistical analysis SPSS software version 18 was investigated. Due to the nature of the study, the significance level was set at a P value ≤0.1. Statistical findings and laboratory data showed that the effect of noise and smoking on red blood cells and white blood cells of smokers and nonsmokers was significant (p<0.1), so that the amount of red blood cells in smokers who are exposed to noise exceeding 88.83 dB, is higher than nonsmokers, and the white blood cells are lower in nonsmokers in compared with smokers. Our findings showed that combined of workplace noise and smoking has severe adverse effects on hematological parameters, and these alterations might be associated with a greater risk for more diseases. It is notable that results are from a research effort of its researchers and it is not completely certain so further investigation will be needed.

6

Authors: Gholamreza Goudarzi, Sahar Geravandi, Mehdi Vosoughi, Mohammad javad Mohammadi, Abdolkazem neisi, Sepideh sadat Taghavirad

Carbon monoxide is an odorless, colorless and toxic gas that emitted from combustion. Carbon monoxide can cause harmful health effects by reducing oxygen delivery to the body's organs (like the heart and brain), tissues, fibrinolysis effects, abortion and death at extremely high levels. The aim of this study was to assess health- effects of carbon monoxide exposure in Ahvaz city. Data were collected through Ahvaz Meteorological Organization and Department of Environment. Raw data processing by Excel software includes (instruction set correction of averaging, coding and filtering) and after the impact of meteorological parameters was converted as input file to the Air Q model. Finally, health-effects of carbon monoxide exposure were calculated. The results showed that the concentration of carbon monoxide was 7.41 mg/m3 in Ahvaz as annual average. Sum of total numbers of deaths attributed to carbon monoxide was 16 cases within a year. Approximately 4.3% of total Cardiovascular deaths happened when the carbon monoxide concentrations was more than 20 mg/m3. This could be due to higher fuel consumption gasoline in vehicles, Oil industry, steel and Heavy industries in Ahwaz. Mortality and Morbidity risks were detected at current ambient concentrations of air pollutants.

6

Authors: Homa Kheiri, Hossein Moshfegh, Hossein Hatani, M Ranjbarian

Musculoskeletal disorders may be observed in all industries and professions and most of these disorders are related to the back, upper and lower extremities of the body organs. In Pharmaceutical industry, almost lack of standard ergonomic conditions and sometimes can cause outbreaks of diseases and musculoskeletal disorders in various parts of the body. The aim of this study was to determine the relationship between musculoskeletal disorders and working on the packaging section of the pharmaceutical industry. The Nordic questionnaire and Rula method were used for collection of data and 392 workers were selected as the subjects of study. Based on the results of this study, (28.5%) of workers working in Packaging Unit complained of severe pain and discomfort in their neck, (23.7%) in their shoulder, (27.9%) in their hand and wrist and (33.2%) complained of severe pain in their back. The results indicate that workers in this industry could show musculoskeletal disorders based on age, education, gender and working conductions.

9

Authors: Mohammad Malakootian, Hossein Jafari Mansoorian, Ahmad Reza Yari

Dyes are an important class of pollutants and disposal of them in precious water resources must be avoided. Among various methods adsorption occupies a prominent place in dye removal. The aim of this study is to evaluate adsorption of dye Reactive Red 198 and Blue 19 (RR-198 & RB-19 (on to Aloe Vera plant ash from aqueous solutions. In this research Aloe Vera ash was prepared at laboratory conditions and then after shredding, screened by ASTM standard sieve with 60 -200 mesh sizes and the effects of pH (3-12), adsorbent dose (0.1-1 g/L), contact time (10-60 min), initial dye concentration (10-160 mg/L) and temperature were investigated in the experiment. In different samples Dye concentration was measured by spectrophotometer at 592 nm and 520 nm wavelength for RR198 and RB19 respectively. Also the Langmuir and Freundlich adsorption isotherms were determined in order to describe the relations between the colored solutions and the adsorbent. The results of this study showed that acidic conditions were more conducive to enhance the hydrolysis rate than basic ones as the decomposition was optimum at pH 3. The adsorption rate of RR-198 and RB-19 dyes was increased by increasing of initial dye concentration, increasing of adsorbent dose in 0.1 to 0.4 mg/L. Dye solution was decolorized in a relatively short time (20 min). The efficiencies for RR-198 and RB- 19 reactive dyes were 82.68% and 90.42% respectively. The maximum adsorption capacity (qmax) has been found to be 80.152 mg/g for RR-198 reactive dye and 88.452 mg/g for Blue 19 reactive dye. Adsorption isotherms were examined by Freundlich and Langmuir isotherm that finally showed the Freundlich multilayer isotherm has better accordance with dates. The results indicate that Aloe Vera ash plant as a natural and inexpensive adsorbent is a suitable adsorbent for the adsorption of textile dyes.

59-66

Authors: Ahmad Jonidi Jafari, malek hassanpour, Mitra Gholam, Mehdi Farzadkia

Acidic sludge is a by-product from used motor oil reprocessing industries, which thousand tons of this sludge are disposed into the environment as a hazardous waste material daily. The acidic sludge contains unsaturated compounds that are polar and asphaltene. The bitumen under certain conditions is produced from mixing of bentonite, polymer styrene – butadiene – styrene (SBS), and acidic sludge. Context and purpose: The objective of this study was the recovery of acidic sludge to bitumen using additives such as bentonite and SBS. Also, the effect of additives with different weight percentages (wt%(on the performance parameters of bitumen was evaluated. At first, spilled oil was separated from the acidic sludge by a centrifugal concentrator. Then, concentrated acidic sludge and additives were mixed in together. Finally, the performance tests were carried out to compare the quality of acidic sludge with the obtained products.The results indicated that performance parameters such as softening point (SP), weight loss, penetration degree, PI, Frass breaking point, and temperature susceptibility (TS) were promoted from 37°C, 1.3%, 230 dmm, -0.07854, -5°C and 0.0451 to 54°C, 1%, 130 dmm, 2.7094, -11°C , 0.02721, respectively. According to the paired sample t-test analysis, a significant difference was found between the bentonite dosage and the improved performance parameters from concentrated acidic sludge and obtained products (pvalue ≤.001). The bentonite and SBS with 2 and 4 wt%, respectively were determined as the suitable additives in the recovery of acidic sludge to bitumen.

74-82

Authors: I mohammadfam, A. Shafkhani, A Soltanian

Accident analysis shows that one of the main reasons for accidents is non-integration of maintenance units with safety. Merging these two processes through an integrated system can reduce and or eliminate accidents, diseases, and environmental pollution. These issues lead to improvement in organizational performance, as well. The aim of this study is to design and establish an integrated system for obtaining the aforementioned goal. Integration was carried out at Nirou Moharreke Machine Tools Company via Structured System Analysis & Design Method (SSADM). In order to measure the effectiveness of the system, selected indexes were compared using statistical methods prior and after system establishment. Results show that the accident severity index reduced from 135.46 in 2010, to 43.85 in 2012. Moreover, system effectiveness improved equipment reliability and availability (e.g. reliability of the Pfeiffer Milling machine (P (t>50)) increased from 0.89 in 2010, to 0.9 in 2012. This system by forecasting various failures, and planning and designing the required operations for preventing occurrence of these failures, plays an important role in improving safety conditions of equipment, and increasing organizational performance, and is capable of presenting an excellent accident prevention program.

89-94

Authors: Iraj Alimohammadi, Dr.Javad Adl

Developing technology and using equipment in Iranian industries caused that maintenance system would be more important to use. Using proper management techniques not only increase the performance of production system but also reduce the failures and costs. The aim of this study was to determine the quality of maintenance system and the effects of its components on failures of kilns in two gypsum production companies using Failure Modes and Effects Analysis (FMEA). Furthermore the costs of failures were studied. After the study of gypsum production steps in the factories, FMEA was conducted by the determination of analysis insight, information gathering, making list of kilns’ component and filling up the FMEA’s tables. The effects of failures on production, how to fail, failure rate, failure severity, and control measures were studied. The evaluation of maintenance system was studied by a check list including questions related to system components. The costs of failures were determined by refer in accounting notebooks and interview with the head of accounting department. It was found the total qualities of maintenance system in NO.1 was more than NO.2 but because of lower quality of NO.1’s kiln design, number of failures and their costs were more. In addition it was determined that repair costs in NO.2’s kiln were about one third of NO.1’s. The low severity failures caused the most costs in comparison to the moderate and low ones. The technical characteristics of kilns were appeared to be the most important factors in reducing of failures and costs.