دو ماهنامه سلامت کار ایران
سال چهاردهم شماره 1 (فروردین و اردیبهشت 1396)

With a widespread regard to the human error issue and recognize the importance of human as an active processor of information The necessity for an effective framework to analyze different mental processes interact with the system to carry out job duties will be obvious. So the aim of this study was to analyze human errors by SHERPA and human information processing model.
This study is a cross-sectional study in 2014 carried out in the control room of the petrochemical industry. Subjects included 62 employees in four post shift supervisor control, head control, board man and outside operator in 4 sites which were working 8-hour shifts. To analyze the errors, SHERPA technique was used, then to classify human information processing Wickens model and to identify the factors those affecting the performance Kirwan classifier was used. In addition to gathering data observation, interview and documentation study methods were used.
with Analysis of SHERPA worksheet, 246 human errors were identified. Most errors (143) related to the understanding of human information processing. Both work instructions and training and experience, collectively became the most important factors affecting the processing of data in data processing.
The results of this study, with identification of possible errors in data processing and find those factors that affect on them, distinguish the system weaknesses.

Usability is the extent to which a system, product or service can be used by specified users to achieve specified goals with effectiveness, efficiency and satisfaction in a specified context of use. Increased public awareness of the usability issues has caused that usability plays an important role in production. Brooke’s SUS is one of the most used tool for measuring usability. Yet, the Persian translation of this tool has not been available to Iranian researchers, and therefore this study has been conducted in order to provide the Persian translation of it and measure its psychometric validation in assessing usability of traffic signs.
Modified version of SUS by Annie(2011) was translated using Backward-Forward method of translation. For measuring validity of the questionnaire the opinions of 10 experts in related field were used. Content Validity Ratio (CVR) was measured based on Lawshi method and Content Validity Index (CVI) was measured based on Waltz and Basel method. The questionnaire content validity index was also calculated.There is 10 items in SUS for assessing usability of each traffic sign, therefore for assessing usability of 20 selected traffic signs, a 200 items questionnaire was developed. Questionnaires were distributed among 50 staff of Iran University of Medical Sciences. Cronbach’s α was used was used to measure the reliability of the questionnaire. Stability of questionnaire was calculated by using test – retest and intra-cluster correlation index.
All the items in SUS showed a high level of CVR and all items were accepted. CVI of all items were above the acceptable level of 0.79 . Content validity index was equal to 0.927. Cronbach’s α was equal to 0.965, and inter-cluster correlation index was equal to 0.993.
The Persian version of SUS is a reliable tool for measuring usability level and showed a high level of validity and reliability and can be used for future researches in the field of usability.

Recently, occupational health and safety management systems performance has been discussed. Performance evaluation of occupational health and safety management systems provides useful information on the development, implementation and results of systems. The aim of this study is development of a framework for evaluating the performance of occupational health and safety management systems and identifying influential factors in their success.
5 main elements and 43 criteria were determined based on occupational health and safety management systems models and guidelines. Analytical network process and technique for order preference by similarity to ideal solution were used to calculate criteria weights and rank performance indicators data.
Policy and checking elements had highest and lowest weights respectively. Management commitment in policy element, announcement of occupational health and safety programs in planning element, workers involvement in occupational health and safety activities in implementation element , measuring and monitoring safety and health performance indicators in checking element and available occupational safety and health activities results in management review element were determined as critical factors.
Occupational health and safety management systems actions and activities could be systematically reviewed by developed method. Criteria and indicators evaluation can identify significant factors in success or deficiency of occupational health and safety management systems.

Needle trap micro-sampler, with all advantages of microextraction techniques such as solid phase microextraction, owing to the ease of use and becoming a powerful method for air pollution monitoring. In this study, the performance of needle trap micro-sampler device with silica composite of carbon nanotubes, prepared using sol-gel technique, was investigated for health monitoring of perchloroethylene in air.
After preparation of proposed sorbent, 1.5 cm length of a 21-gauge needle (10 cm length and 0.52 mm I.D.) packed and the experimental parameters adjusted and the performance of micro-extraction sampler assessed in the sampling, storage and desorption stages for micro-sampling and determination of perchloroethylene. Finally the sampler was used for air monitoring of perchloroethylene in the dry cleaning and compared with NIOSH relevant method.
The results demonstrated that breakthrough volumes were more than 1300 and 1100 ml for needle trap packed with CNTs/silica composite and CAR/PDMS, respectively. Increasing the sampling temperature and relative humidity reduced the sampling efficiency and the needle trap devices with both sorbents showed less than 4% for analyte losses after seven days. In the field sampling, needle trap with nano-structured sorbent showed better response comparing to the NIOSH 1003 method.
Needle trap device packed with silica composite of carbon nanotubes showed good performance for sampling of perchloroethylene in air and recommended for health monitoring of occupational and environmental pollutant.

In the tailoring occupation, the tailors take different posture for performing the activities such as sewing and repair of clothes. In this job, several factors such as physical, individual and mental factors can be affected on the awkward postures of the persons during the work. Therefore they are exposed to the risk the musculoskeletal disorders. The present study aimed to evaluate muscle fatigue and to determine some of the risk factors of musculoskeletal disorders.
This cross-sectional study was conducted on 165 tailors randomly selected in Shiraz. The required data were collected by using demographic characteristics, Nordic and general health questionnaires, and Muscle Fatigue Assessment (MFA) method. Then, the data were entered into the SPSS statistical software, version 21 and were analyzed using logistic regression and chi-square test .
Most of the study participants were male (79.4%) and married (75.2%). The highest prevalence of the musculoskeletal disorders symptoms were reported in the lower back (57%). Also, the highest percentage of the individuals placed in the action level 3 (high) based on the MFA method, was related to the lower back. In this study 63.6% of individuals had general health.
Marital status, posture, mental health, and working experience were the most important variables remained in the logistic regression model with an odds ratio were of greater than 1.21 in Tailors.

Risk assessment is one of the most important issues in making safety industrial environments. Motor vehicle industries are one of the most unsafe industries that have many annual accident. One of the most problems in the process of risk assessment is judgment about the effect of parameters of risk. The aim of the study is, safety risk assessment in motor vehicle industries by william fine and ANP-DEMATEL.
in this study, safety risk of the one of the bigest motor vehicle industries was assessed by william fine. Then, the weight of parameter of risk was determined by ANP-DEMATEL. Then, the result was combined by william fine. In the final stage the industrial was assessed with the obtain pattern again.
The results was showed, that by using William Fine method, The highest priority risks was the iron bath-cleaning unit (312) and steel structure (300). The results of combined william fine and ANP-DEMATEL pattern, the highest priority risk was the iron bath- cleaning unit ( 94.11) and steel structure (90.49).
Resent study shows that in Motor- vehicle industries, the application of the William-Fine model combined with the ANP-DEMATEL technique is an effective method to assess the safety risk levels in actual level.

The development of nanotechnology has result in the creation of new job opportunities and economic growth. But the lack of sufficient information about the toxicity and occupational exposure limits to nanomaterials on the toxicity and occupational exposure limits established nanomaterials always has created concerns. In this study design and providing of a simple software package based on Control Banding recommended by NIOSH (National Institute for Occupational Safety and Health), for assessing the risk of occupational exposure to nanomaterials.
In this experimental study, C # 2010 software was utilized in order to design the software package. first, the general principles of Control Banding risk assessment method recommended by the National Institute of Occupational Health and Safety (NIOSH) analyzed carefully. Then, all primary and secondary factors with their relative importance (weight) and influence on the risk level were considered exactly in the design software. Finally, the proposed package was used to assess the individual exposure to nanomaterials in several research laboratories.
From these results, the average (RL2) and acceptable (RL1) risk levels obtained at work stations that manipulated multi-wall nanotubes (MWNT) and titanium dioxide nanoparticles (TiO2) respectively.
The proposed package could be used as a simple, reliable, fast, and easy tool to assess the risk of occupational exposure to nanomaterials. It also will able to provide appropriate solutions to improve working conditions for employees if implement control measures are needed.

The power plants, including important industry of the country in which a large number of noise sources which workers are exposed with harmful levels occupational noise. The aim of this study was designing enclosures to noise control in the feed water pumps in a power plant.
This cross-sectional study and their Interventional plants were done on the ground floor of the turbine unit of a thermal power plant on 2014. The feed water pumps in the preliminary stage of study, in the ground floor was determined the major noise sources. The Sound power level of the main sources were estimated according to the ISO 3746. To determine the distribution of the sound pressure level measuring and frequency analysis on the vertical axis for the study sources we used the SLM model TES 1358 and the measuring technique was small scale mesh networking and using the SURFER software for interpolation calculation and noise map drawing. Eventually, in order to control the noise we designed a multilayer enclosure for this pump and the effectiveness of this layer was estimated.
The results of the noise analysis of this pumps showed that the dominant frequency of the noise were 2000 Hz. The results of the noise separation in the vertical axis of the sources confirms that the main pump and gearbox has the largest share in the noise distribution. The results also showed that the sound power level of the main pump is 107dB and of the gearbox is 108 dB. The design of the enclosure contains a primary layer made of steel and the inner layer made of rubber foam.In this design, including a percentage of noise leakage, the sound pressure level of the main parts of the pump will be reduced by 20 dB.
Enclosing technique can be reduced of noise levels for boiler feed water pumps. This result could protect the workers against harmful noise to the permissible limits.

Occupational accidents and review them in the field of industrial safety are the most important issues. If these accidents are investigated and analyzed, there will be the possibility of reducing their occurrence. This review aims to provide valuable information for researchers and reviewers of occupational accident.
In this study Persian-language academic journals were studied systematically. The aim was finding, classifying and analyzing the articles were published in these journals since the beginning of 1380 until the end of 1393 on occupational accidents. At the first list of scientific journals (59 journals) and then, the articles related to occupational accidents (Article 106) were selected. A criterion for the selection of the journals was existence at least one article in the field of occupational accidents published in them. Articles were analyzed according to publication year, journal and field survey.
The results showed that most studies were about healthcare (19.80%), manufacturing (16.98%) and epidemiology (11.32%) respectively. Also in the first six years of study, only 12 articles (11.32%) have published in the field of occupational accidents while in the six years at the end of study, 73 articles (68.86%) were published. 42 journals published only one article and 17 journals published more than one article in the field of occupational accidents. The Journal of Occupational Medicine and Iran Occupational Health were assigned of 19.80% of the articles.
This study can be used as a scientific resource for researchers and specialists in occupational health and safety field and help to Improving researches in the field of occupational accidents in Iran.

Just culture is conceptualized as a rational approach to human error and its fallibility. A good evaluation of just culture in an organization is needed to effectively design and implement of preventive measures to reduce the events and injuries. This study aimed to evaluate the psychometric features of the Persian language version of just culture questionnaire (JCQ).
JC questionnaire contains 27 questions in six dimensions of JC. The Persian version of JC questionnaire was prepared by the standard method, forward-backward translation. In order to evaluate the content validity, the questionnaire was sent to 28 ergonomists and the content validity index (CVI) and content validity ratio (CVR) were calculated. The reliability of questionnaire was determined when 221 questionnaires were fulfilled by hospital nurseries.
the initial evaluations by experts partial revisions in some subscales to approve the CVR. By revisions, the validity of all subscales and consequently the JCQ were confirmed. The Cronbach's alpha coefficient for JCQ dimensions was ranged from 0.65 to 0.89. The total coefficient for the JCQ showed that the questionnaire has high internal consistency in all dimensions measured (α = 0.894).
This study showed that the validity and reliability of the Persian version of JCQ are acceptable and it is applicable for assessment of just culture in Iranian organizations and workplaces.

Prioritizing research fields prevents wastage of budgets and increase efficacy of research. Paying attention to health of employees and workers is necessary for promoting health and sustainable development in the country. Therefore this study was conducted in order to determine the research priorities in the field of occupational health in Iran.
In order to determine the research priorities in the field of occupational health the COHRED model was used. Data collection was done by review of literature, obtaining the views of experts (by interview and Delphi technique) and collecting statistics from relevant officials. Priority setting was done in two stages and based on Delphi technique. In this research out of 70 identified research centers, 22 participated in the study. Descriptive statistics including mean (SD) and frequency (percentage) was used to analysis the data.
Results of this study showed that musculoskeletal disorders and injuries had the highest research priority in Iran. The occupation of workers in mine and industries had the highest research priority. Also three indicators of equity in service provision, work security and healthy life style had the highest research priority among the social determinants of health for workers.
In summary in this research it was attempted that research priorities be defined in different areas of research which can be used as a tool for decision makers in distribution of resources in the field of occupational health.

Using X-ray for diagnostic test, is one of the most important exposure to radiation sources for general population and in particular for radiation workers. Therefore, holding down the pollution at the lowest possible level is very important for protection against the internal exposure. The objective of this study is to survey the scattered X-ray rate and received dose by staff of angiography department in a military hospital.
Present cross – sectional study was conducted in a military hospital. The scattered x-ray produced from different angiography modes (pulse high-dose and continuous fluoroscopy) was measured in one and two meters distance of angiography set and in outside of the angiography room by using SmartION Model 2100 S. The staff received dose in 2 months, 1 year and 5 years periods, was obtained through staffs film badge results.
The results showed the scattered X-ray rate in one and two meters distance from patient table for pulse mode fluoroscopy was 47 and 7.9 µSVh-1 and for continuous fluoroscopy was 8.9 and 4 µSVh-1 respectively. The obtained results from the personnel film badge for a period of one and five years were respectively 8.08 and 22,85 mSV per year for physician's staff, 1,44 and 2,12 mSv per year for radiologists staff and 1 and 2.55mSv per year for nurses, respectively. The dose received by all employees was less than the permissible limits (20 mSv per year).
The various modes of angiography, experience and expertise of the physicians and other factors can play an important role in received effective dose by staff. The staff training, optimized radiation protection practice and staff dose monitoring can be kept well below the annual received dose limit.

Monitoring worker's work ability, planning to maintain and improve the work ability, and identifying and controlling its related risk factors are of the most important issues in the field of occupational health. The object of this study was to investigate the influence of factors related to work ability among farmers.
The subjects consisted of 213 male farmers. This research examined the influence of demographic characterization, work-related factors and diseases on farmers’ work ability. Work ability was assessed using the Work Ability Index (WAI) and work-related factors were measure by Job Content Questionnaire (JCQ). Spearman correlation coefficient was used to employ to examine the relationship between WAI and its affecting factors.
Mean WAI score was 34.6 (SD±10.59) and it had a statistically significant relationship with age, BMI, diseases and work-related factors. The strongest correlation was found for diseases and physical work-related factors such as physical exertion (r=0.309), physical isometric loads (r=0.263), physical demands at work (r=0.322), while psychological factors showed a poorer correlation.
According to findings, development of preventive approaches aimed at controlling diseases, eliminating awkward postures, reducing physical isometric loads, physical exertion and physical demands at work, as well as improving psychological work environment have an important role in promotion of the farmers’ work ability.

Quality of working life is a critical concept with great importance in the life of an employee which shows an appropriate balance between work and personal life, ensuring organizational productivity and employee’s job satisfaction. This study aimed to determine the effectiveness of relationship enhancement program on quality of work life (QWL) among Karaj Municipality staff.
The sample of the study included 30 employees who were randomly selected from among the applicants to participate in this program, and they were random assigned into experiment and control groups (15 subjects per group). The data collection tool was the 27-item Walton quality of work life questionnaire (1973), which was performed on both groups in the pre-test and post-test stages. Relationship enhancement program was implemented in 7 sessions with 90 minutes duration with step by step method for the experiment group, while the control group did not receive any intervention. The Data were analyzed through Univariate and multivariate analysis of covariance by using the software SPSS 18.
The results suggested that there is a difference between experimental and control groups after performing the intervention. In other words, the use of relationship enhancement program has enhanced quality of life among the employees in the post-test (p Quality of wok life is an important issue in the Workplace. Organizations can use training such as Relationship enhancement program in order to improve this components and increase Organization productivity and employees satisfaction, as well.

In the present study, the performance of Semnan Industry Park’s MBR/RO advanced treatment system for industrial effluent reusing was investigated.
To determine the performance efficiency of full-scale membrane bioreactor (MBR) with submerged polyether sulfone flat sheet modules (MA04-150, pore size of 0.05 &mum) into an aeration tank, the potential removal of nitrogen, phosphorous, BOD ,COD and TSS for industrial effluent reuse were investigated by seasonal sampling from MBR influent and effluent.
The results showed that the obtained removal efficiency of system for BOD, COD and TSS were more than 98 %, which increased in Summer. Furthermore, MBR reactor efficiency for the removal of nitrate, ammonia and TKN were 35%, more than 90% and 79% percent, respectively. The MBR removal efficiency for phosphorus was determined by an average of 52% . Low efficiency is due to low levels of phosphorous in the reactor.
According to the results and to compare it with existing standards , it can be stated that the Semnan Industrial Park advanced treatment system meets its founding objectives and namely can be used agricultural and industrial operation.