mohsen yazdani aval

Background and purpose: Styrene, one of the most important compounds of VOCs, causes some health concern. In current study, the ability of ZSM5, TiO2/ZSM5, UV/ ZSM5, and UV/TiO2/ZSM5 methods was investigated in removing styrene from air synthetic current. In order to synthesize the zeolite and TiO2-coated zeolite, the sol-gel and saturation methods were employed, respectively. In this study, the effect of the type of removal process, saturation time and initial pollutant concentration were investigated on the removal of styrene in a photoreactor. Phocheck device with direct reading system was applied to determine the output concentration. Also, SEM, XRD, EDX, and BET analyses were used to characterize the chemical and physical properties of ZSM5, and TiO2/ZSM5. SEM analysis showed that zeolite has a crystal form, and TiO2 successfully covered the surface of this compound. In addition, the EDX analysis demonstrated that a great part of zeolite structural includes Al and Si constituents. The XRD pattern showed the presence of attached TiO2 in the zeolite structure. BET analysis revealed that the surface area of zeolite decreased when TiO2 was coated on its surface. The order of increase in removal efficiency was as follows: UV/TiO2/ZSM5 > ZSM5> TiO2/ZSM5. The saturation time of ZSM5 and TiO2/ZSM5 in the 300 ppm concentration was 370 and 280 min, respectively, while the outlet concentration in the UV/TiO2/ZSM5 method was fixed at 74% removal efficiency after elapsing 310 min. The increment of time exposure and initial styrene concentration also led to decrease in removal efficiency. In this study application of UV/TiO2/ZSM5 process provided a higher efficiency of the styrene removal than that of TiO2/ZSM or ZSM5 in the same time.

However, the increasing advances in technology have greatly reduced the physical presence of manpower in the workplace, but in many work environments, man is still the most important and, at the same time, the most critical element. A slightest human error due to unsafe actions in most of occupational environments, can lead to a disaster.
Material and The current qualitative case study was conducted to identify and evaluate human error in the entire mine's related tasks in 2016. In the first section of this study all the tasks were studied using HTA and then related possible errors were assessed using ATHEANA method. HTA technique proved that mining operations were composed of 9 main tasks and the explosion being analyzed as the main scenario.According to ATHEANA technique the possibility of human error for each of basic event was calculated as 0.001.Due to the fact that there were 13 base events and the occurrence probability of each of them was estimated at 0.001, finally the total possibility of human error in mining operations was calculated to be 0.013. The results of this study showed that the explosion in a mine has five sub-tasks that spark of cigarette wrappers, hand grasping and the inappropriateness of size and material, respectively, with the probability of defect of 0.004 and 0.003 were most probable errors. Therefore, it is recommended that managers and authorities take the necessary measures in order to protect the health of them and reduce the risk of human error and environmental conditions

Background & Aims of the Study: Identification of hazards is one of the first goals of risk analysis. Failure mode and effect analysis method (FMEA) is universally defined as efficient procedures for finding potential failures aimed to remove or decrease the risk which is related to them. This study aimed to investigate the effect of control measures on reduction of risk events in an edible oil factory in Tehran.
This cross-sectional study was conducted in an edible oil factory in Tehran, Iran. For this, a four-member team of safety engineer experts was formed. Some factory units were selected randomly. After that, in all units, probability, severity and detection probability of hazards in all processes and tasks were assessed based on FMEA method. Regarding to the RPN, some control measures were taken to reduce the risk of events. After 9 months, risk assessment was repeated; primary and secondary RPNs were compared with each other to investigate the effect of interventions.
The results showed that highest and lowest probability of hazard were related to installation and can production unit, respectively. The highest and lowest severity of hazard were related to tool and can production unit, respectively. There was a significant difference between the probability of hazard in can-making and filling units, before and after the interventions. There was a significant difference between the severity of hazard in can-making, filling and neutralization units, before and after the interventions. As well, total probability, severity and RPN had a significant difference in all parts of the factory before and after the interventions.
According to the results of this study and the overall risk reduction caused by interventional measures, it can be concluded that, FMEA is a successful method for identifying hazards and risk control measures.

The Failure Mode and Effects Analysis (FMEA), first of all, identifies dangerous modes in a process and, then, provides proper control measures that are required to reduce the level of risk. This study aims to investigate the risk level before and after the implementation of control measures in an edible oil factory.
This cross-sectional study was conducted in an edible oil factory in Tehran, Iran. The FMEA technique was used to identify failure modes related to equipment that existed in five units of this factory. After that, in all units, Risk Priority Numbers of all the processes were assessed on the basis of the FMEA method. With regard to the Risk Priority Number (RPN), some control measures were taken to reduce the risk of events. After nine months, risk assessment was repeated, and primary and secondary RPNs were compared with each other to investigate the effects of interventions.
The results showed that the highest probability of danger was related to the installation unit. The probability of danger in this unit before and after interventional actions was 4.5 and 3.25 respectively and the highest degree of severity was related to tool production. The marginal homogeneity test showed the positive effect of control measures on the risk level in the factory. There was a significant inference between before- and after-data in RPN in the unit tool production, neutralization unit, and installation unit. The Tests of Repeated Measure showed that there was a statistically significant inference between before- and after-data in the total average of RPN criterion (pvalue It can be concluded that the high risk level in the factory units was reduced after the application of interventional corrective measures. These actions have been useful. It can be mentioned that the FMEA has been successfully able to identify and control the level of risk in this factory.

Trees are one of the most commonly used bio-indicators and have been widely applied for heavy metals (HMs) monitoring in the ambient air because of their simple and efficient sampling and examination.
The main objective of this study was to evaluate local pine trees for their potential as a bio-indicator of HMs in urban areas. Besides, the distribution pattern of HMs in the study area, meteorological and land use factors affecting this pattern, and HMs source identification were investigated.
Forty-eight sampling locations were selected in the Yazd city, capital of Yazd province in Iran, and concentrations of five HMs- iron (Fe), copper (Cu), zinc (Zn), lead (Pb), and cadmium (Cd)- were measured in the leaves of the most abundantly local pine trees, Pinus eldarica, using the atomic absorption spectroscopy method. The obtained data were analyzed for source identification using Spearman’s rank correlation coefficient and principal component analysis (PCA). The ordinary Kriging method was used to obtain a spatial map of HMs distribution in the study area.
Iron had the highest concentration (345.0053 mg/kg) in leaves when compared with other HMs. The concentration of Zn, Cu, Pb and Cd were 26.1384, 5.5905, 2.9963 and 0.7383 mg/kg, respectively. Spatial mapping indicated that industrial districts and areas with heavy traffic had the highest HMs pollution. Wind direction was recognized to be the most important factor in HMs transportation. Anthropogenic sources were known as the main responsible factor for HMs emission..
Pine trees can be used as a worthy bio-indicator for HMs pollution monitoring in the ambient air in areas with extensive vegetation of pine trees.

Exposure to noise can result in hearing loss in many industrial workers. In many cases, hearing protective devices (HPDs) are considered as the main protective objects. As a large number of workers in the Iranian carpet weaving industry are usually exposed to noise levels exceeding the permissible exposure limits..
This study was conducted to evaluate the use of HPDs, quality of available equipment and possible reasons for lack of protective devices usage..
In a descriptive, cross-sectional study, 136 workers of Kashan carpet industries exposed to noise pressure levels greater than the action level defined in the Iranian legislation (85 dB (A) 8 h/d) were evaluated for HPDs use. The quality and HPDs suitability was defined according to the workers exposure to noise, available HPDs and their Noise Reduction Rate (NRR). The reasons for non-usage of HPDs were evaluated as well. Data were analyzed using the SPSS v. 18 software..
The mean age and work experience of workers were 31.39 ± 5.6 and 4.35 ± 2.5 years, respectively. Among the exposed-to-noise personnel, 7.35% used HPDs constantly; 75% used HPDs for only short periods of time (less than four hours) and 17.65% did not make use of them at all. Regarding the sound intensity and the level of noise reduction of HPDs, among the 112 workers who used such devices, 59.6% had HPDs with appropriate protection and 22.8% used inappropriate ones. There was a significant relationship between age, work experience, education and use of HPDs. Inappropriateness and difficulty in the use of the devices were also reported as the main reasons for not using them..
This study showed an unsatisfactory situation in the mentioned industries for HPDs usage; low percentage of usage, low preparation rate, the inappropriateness of some of the HPDs, and unawareness of some of the workers. A noise training and education program is recommended to be developed for workers in order to protect them from hazardous noises..

Heat stress is an important and serious threat at work and is a particular concern in outdoor occupational environments. This study aims at comparing heat stress and heat strain at different outdoor groups, examining the protective and adaptive actions which were done by workers and also provi services to them by government or employer to reduce heat load. This cross–sectional study was conducted in the hottest days of the summer 2015 in Shabestar, Iran and 53 healthy men in nine occupational groups including concrete makers, porters, construction, waste site and road making workers, stonemasons, farmers, traffic officers, and street vendors participated. A set of physiological parameters, like heart rate, blood pressure, skin temperature and etc., WBGT index details and some of the adaptive and protective parameters were measured and monitored simultaneously at different times of the day. The study finds that heat exposure in outdoor workplace is prevalent and WBGT TWA/TLVave is less than 1 in some groups like stonemasons, waste site workers, traffic officers and street vendors whereas in other studied occupations, it is more than 1.This matter is compounded by the fact that the provision of health services by employers or local government was limited, and almost all of the participants had poor or insufficient access levels to public health and welfare services. This study confirms the necessity of interventions by a range of factors, such as government plans, improvement of services in the prevention of heat stress, and planning training courses for outdoor workers to build their knowledge of heat stress.

Awkward posture during wok with computer is one of the most important risk factors which faced the computer users with risk of musculoskeletal disorders. The aim of the study was to assess effectiveness of an ergonomic training program on correction of awkward postures and reduction of other causes of musculoskeletal disorders among office workers in the National Iranian Gas Company. In this study, a total of 52 office workers were included. Training program was held two months and the Rapid Upper Limb Assessment (RULA) method was employed to assess risk of musculoskeletal disorders before and after of intervention phase. Statistical analysis was performed by using SPSS (ver 19.0). The results showed that the minimum and maximum of RULA scores were 3 and 7, respectively. After training intervention, these scores were reduced to 2 and 4, respectively. The significant association was observed between reduction of musculoskeletal risk factors before and after of intervention. Training program can effectively reduce risk of musculoskeletal disorders when held with the appropriate content and duration.