دو ماهنامه سلامت کار ایران
سال یازدهم شماره 4 (مهر و آبان 1393)

since some jobs induce more job burn out and increase physical and mental problems and decrease productivity, the aim of this study was to examine job burnout, somatic symptoms, alexithymia and religion orientation in Tehran and related towns wards and compare with other jobs as control group. in this cross-sectional study, 427people (200 people were award and 227 people in other jobs) was selected by available sampling. Data collected by Allport religion orientation, Toronto alexithymia scale, somatic symptoms scale, Maslach burnout inventory and demographic questionnaire and analyzed by independent t-test, Pearson correlation and variance analyses. there was significant differences between job burnout and somatic symptoms and alexithymia in awards and other jobs (p=0/002).but significant differences were not observed for internal and external religion orientation in two groups. On the other hand, there was significant relation between job burn out and alexithymia (p=0.018). Due to importance of alexithymia and somatic symptoms in job burn out, it will be useful to improve interventions which consider these issues.

although industrial progresses are one of the most factors in increasing society wellbeing, also it can be led to hazard accidents and subsequently disordering to parts of economic, social and psychological of human communities. Studies show that promotion of HSE culture with the purpose of work place safety is very important for accident reduction. For improvement of HSE culture, identification of current state in work place is necessary. Therefore, a tool with suitable validity and reliability is essential. In this cross-sectional analytical study after literature review and identification of dimensions of HSE culture, variables or questions were designed in this field‌. For study of validity in the primary questioner, appearance and content validity in form of quantity and quality was used, that is, method of variable effect, content validity rate (CVR) and content validity index (CVI) and then for study of tool reliability, Cronbach's alpha coefficient method by SPSS18 was used. 9 variables were defined as dimensions of HSE culture. Obtained results shown that 39 items from 89 items existed in initial questioner were eliminated and its reason was low score of these variables in validity stages (CVR<0.62, CVI<0.70, SCORE<1.5). In this study Cronbach's alpha coefficient was counted to be 0.86. in the end by doing essential modifications, the questioner of HSE culture with suitable validity and acceptable reliability was prepared that it could be used as a reliable and acceptable tool for the study of HSE culture in the mentioned manufacturing company.

Nano-fibrous mats are one of the unique nonwoven materials that have been recently carried out in nanofiltration industry. The aim of this study was to synthesize nano-fibrous path mats using electrospining method following by determination of their efficiency for nanoaerosols removal. The efficiency and pressure drop of nano-fibrous mats was measured using nano-scale sucrose aerosols with the particle size range of 70 -700 nm at different flow rates of 1.58 - 5 m.s -1. Cylindrical test system in a form of stainless steel with a filtration surface of 130 cm2 was built. Desired particles were generated using Electro spray 3480 model particle generator. Condensation particle counter PMS Models Micro LPS DAS of Boulder Company was used to measure the particle number concentration both before and after the filtration and then to determine the performance. Obtained results showed that the fibers diameter and pore size of synthesized nanofibers provide uniformity with the fiber diameter ranging from 20 to 70 nm. Our results revealed that the maximum permeability of nano-fibrous pads was related to 100 nm particles that were selected as MPPS in this medium. Considering the test particles size distribution it was found that with increasing the velocity the permeability and the pressure drops were increased and the quality factor was decreased. this study shows that electrospinning is a promising technology for the synthesis of high performance nanoparticle filters.

Toluene effects on the nervous system and causes numbness, lack of control in voluntary muscles and seizures. Ethyl benzene can also cause irritation of the eyes and throat and at higher concentrations it can damage the nervous system. Exposure with toluene and ethyl benzene may occur in different environments such as vehicle cabindue to possible emissions of vehicle interior decoration. The aim of this study was to estimate the concentrations of toluene and ethyl benzene with the internal source in the cabin of Logan (L90) cars. In this study, 44 vehicles were sampled. Samples were collected using personal sampling pumps and sorbent activated carbon. The samples were analyzed using gas chromatography equipped with mass detecto r. A check list was used to collect the other required information. The mean concentrations of toluene and ethyl benzene in vehicles were respectively 42.2 and 17.44 µg/m3. Toluene and ethyl benzene concentrations were significantly higher in the new cars. T he natural ventilation significantly reduced the concentrations of toluene and e thyl benzene inside the cars., However, fuel type and smoking inside the car did not significantly contribute to the concentrations of these two compounds.

Nature of the work in control rooms is such that it can be classified as sophisticated with high-cognitive load jobs and, therefore, the prevention of human error seems to be necessary. A nalysis of cognitive tasks is the first and important step for designing preventive programs. This study was conducted to identify, quantify and compare the cognitive requirements of different occupations in the control rooms of a petrochemical industry. In this cross-sectional and descriptive-analytical study, Cognitive Task Analysis (CTA) and Fleishman Job Analysis Survey (FJAS) methods were used. The samples were 20 expert control room operators from leaders, board operators and site operators with 40.9 ± 6.98 years of old and 17.05 ± 6.25 years of work experience, which voluntary participated in this study. The One-Way ANOVA and Tukey HSD tests were used for Statistical data analysis via SPSS version 17. Based on the results of HTA –as the first CTA phase- 8 subtasks in leadership, board operator and site operator tasks were recognized. In addition, 12 cognitive requirements were defined for studied tasks via CTA. The FJAS scores indicated that 70% of recognized requirements in CTA are in moderate to high levels (the FJAS mean score higher than 4) which obligates a relatively high cognitive ability to operators. The Tukey HSD test results revealed no significant difference in cognitive requirements level of leadership and board operator tasks, as well as board operators and site operators. However, it was significantly different between leadership and site operator tasks (P value <0.05). This study indicated numerous and relatively, high level cognitive requirements of tasks in petrochemical control rooms, especially, among board operators. Moreover, due to the ability of scaling and analyzing various parameters, FJAS can be considered not only as a complementary but also as an alternative for CTA.

Among different types of occupational accidents in the construction industry, falls and falling objects accidents (group I) account for 44% of construction accidents. Hit by vehicle, electric shock, collapse in the excavation and fire or explosion accidents (group II), while are only 7% frequent, make up about 26% of all fatalities and total disabling accidents. The aim of this study is to investigate these two groups of accidents and to discuss the obtained results in order to identify the potential hazards of construction industry. Data mining methods are employed to analyze data in this research. Hence, 21864 data records which were provided by Social Security Organization (SSO) and were related to construction accidents of the whole country between 2007 and 2011 were analyzed using decision tree and association rule methods. In the first group of accidents, the frequency of accidents at night shift is less than the others, and injury to the head, back, spine and lower extremities are more prevalent. The final result is similar to other accidents. In the second group, the frequency of accidents among married and older workers is more than single and young workers. There was a higher frequency in the evening and especially night shifts as well as during the weekends. The injuries to the head, face and neck are greater than the other accidents in this group. The results of this study confirm the results of the past research. Hence, utilizing data mining methods has been successful. Policy makers, managers of construction industry and managers of insurance companies can propose preventive actions against accidents using such patterns.

Workload can be defined as the operator's required capacity to meet a special level of performance while performing a task. Optimized workload is a point at which any increase or decrease could have negative effects on operator's performance. Therefore, the aim of this study was to assess the workload using subjective and objective methodologies in the assembly lines of a car manufacturing company. This is a cross-sectional and descriptive-analytical study. In the first phase, among assembly line workers of one of the car manufacturing industries, operators with heavy and very heavy jobs where selected by using the Borg scale. In the next phase, the workload of selected workers was assessed by Subjective (NASA-TLX) and Objective (SI, REBA) workload assessment tools. Data were analyzed by SPSS version 11/5. Results of NASA-TLX showed that performance and physical demands with mean scores of 89/23 and 86/92 were respectively the most important and mental workload with mean score of 49/23 was the least important dimensions. Furthermore, working stations with high workload have obtained high scores by observational tools as well. Adaptive Weighted Workload (AWWL) was positively associated with strain index score for right hand, which means that any increase of workload can result to an increase of strain index score of right hand. It was revealed that workload was high in assembly lines. This result was also confirmed by observational evaluation. Based on our results, workload management programs should be focused on omitting or reducing improper working postures.

the Car manufacturing workers due to direct exposure to machinery and wide range of ergonomic problems have high prevalence of musculoskeletal disorders rather than other industries workers. The purpose of this study was to investigate relation between pains with sick leave in an Iranian car manufacturing company. This case-control study was conducted at assembly plant Irankhodro Car Company. In this study 528 workers (234 case group and 294 control group) were randomly selected. Data were collected by body map and personal information questionnaire. Statistical analyses such as Mann–Whitney and χ2 test have been used for data analysis. results shown that there was no significant relationship between sick leave and pain in bodies (p<0.05). There was significant relationship between Low back pain and sick leave (p<0.001). In case group, the maximum and minimum pain relate to leg and left knee (94%) and elbow and Right forearm (3.2%) respectively. also there was maximum pain intensity in back (63.95±15.78) and minimum pain intensity in elbow and left forearm (44.88±15.55). based on this study effecting factor on sick leave requires ergonomic considerations. Also preventive and modifying actions is essential for the improvement of the ergonomic working conditions of assembly workers and their lifestyle.

Fatigue has a high prevalence in working population and associated with psychological stress in work environment, strongly. Occupational fatigue has negative effects on human errors and performance. Self report fatigue and hormonal change are fatigue assessment tools. This study aimed to evaluate acute fatigue and Urinary Free Cortisol level of carpet weavers in working and non-working day. This cross-sectional study conducted for 12 carpet weavers in 2013. Three Urine sample and 3 fatigue rating are collected in working and non-working days. Urinary free Cortisol measured by ELISA method and occupational fatigue level determined by valid and self-report scale (VAS-fatigue index). Data were analyzed by STATA 11 software. Cortisol level in working day (176.77) was higher than Cortisol level in non-working day (133.80). Important cause of significant difference in Cortisol level between working day and non-working day (p=0.001) is awaking Cortisol level. Fatigue changes in working day were significant (p=0.001), but were insignificant in non-working day. Cortisol level and fatigue in working days have a weak reverse correlation, but in non-working days wasn’t observed significant correlation. The study reported significant differences between morning Cortisol secretion and fatigue level in working and non-working days; that indicate work-related stress have substantial impacts on workers. Acute fatigue hasn’t strong and effective factor on Cortisol level and application of Cortisol change for fatigue assessments is not recommended.

Today, nanosilver have a wide range of applications in personal care products, food processing and medical fields because of its antimicrobial properties. Recent studies have revealed that nanoparticles are able to transfer from mothers to their offspring via the placenta and maternal milk and accumulate into various organs, including brain. Since oxidative stress is a key mechanism for nanoparticles toxicity and the developing brain is highly vulnerable to oxidative stress, in this study, we evaluated the potential of nanosilver to induce oxidative stress in the rat offspring brain. The lactating mothers were divided into the treated and control groups that were treated orally with nanosilver (25 mg/kg BW) and deionized water (from 1th to 12th days of lactation), respectively. The offspring's brains were collected on postnatal day 13. For histopathological studies, some of the brains were sliced and stained with hematoxylin and eosin. The levels of Malondialdehyde, Glutathione, Glutathione peroxidase activity and silver accumulation in offspring's brains were determined using spectrophotometric assay and ICP-MS analysis, respectively. The high numbers of microvacuolar structures, significant increase in silver content and Malondialdehyde level (p<0.001) and significant decrease in Glutathione peroxidase activity and Glutathione level (p<0.05) was observed in the offspring brain of the treated group compared with those in the control group. The results showed that accumulation of silver in the brain might cause oxidative stress via reduction of the capacity of the antioxidant defense mechanism. However, further experiments should be carried out to clarify these events in details.