دو ماهنامه سلامت کار ایران
سال سیزدهم شماره 6 (بهمن و اسفند 1395)

Toluene is a toxic volatile organic compound that needs to be removed from contaminated air. Photocatalytic degradation is one of the techniqe available for removeing of compound. This study was performed to determine the efficiency of ZnO-SnO2/AC catalyst on the photocatalytic removal of toluene vapors.
In this experimental study, the characteristics of the produced catalyst were evaluated by determining the specific surface area using the BET method and examining the images obtained from scanning electron microscopy (SEM). The efficiency of toluene degradation was examined using the ZnO-SnO2 / AC catalyst under UV radiation. The effect of initial concentration of toluene and intensity of UV radiation on the degradation of toluene was studied as well.
The results of specific surface area measurements and SEM images indicate that a proportion of the Zno-Sno2 nano-coupled oxides agglomerate on the AC, also entering into the pores. Also, the combination of AC with ZnO-SnO2 nano-coupled oxides had a synergetic effect on the photocatalytic degradation of toluene. The results showed that the system efficiency decreases with increasing the initial concentration of toluene input. Furthermore, the removal efficiency of toluene positively associated with the intensity of ultraviolet radiation.
The study demonstrated that the ZnO-SnO2 / AC catalyst may be a practical and promising way to degrade the toluene under UV irradiation.

Performance assessment of the HSE-MS in the contractors is a key step in the contractor’s management process and it forms the basis of continuous improvement. Therefore, the present study aims to develop a practical model for the performance assessment of Health, Safety and Environment Management System (HSE-MS) of construction contractors.
In this analytical-practical study, after determining the main factors and indicators related to each of them, the questionnaire was built and then, the process of its validity and reliability were conducted. The importance of the main factors and their indicators were identified by using the questionnaire along with a poll of three groups of HSE experts in a holding company. Afterward, the results of the expert opinions were investigated and the corresponding formulas were used for calculating of the relative importance of main factors and their indicators. The performance indicators score in order to build the model was calculated. At the end, in order to validate the presented model, HSE performance of three large construction contractors in a holding company was evaluated.
developed model was composed of seven main factor and 123 indicators. Total score of contractor performance assessment in the project level can be a range between 80 (very poor performance) and 400 (very good performance) from the perspective of the HSE. The result of performance assessment in project level of three contractors shows that the HSE performance of first contractor was good and both second and third contractors were moderate.
The proposed model can be used by employers of the large organizations to assess their HSE performance of contractors in level project. In addition, with regards to the output of assessing the contractors’ performance, the contractors can be graded according to their HSE performance and was used as an input in the selection of contractors for the future project.

The present study tests a model of the relationship between safety management practices with unsafe behaviors and with of mediation of safety motivation.
Research design was correlation through structural equation modeling (SEM) and the sample consisted of 265 employees of an industrial company who were selected by stratified random sampling method. Participants of this study completed safety management practices Scale, safety motivation scale and unsafe behaviors questionnaire. Reliability and validity all of questionnaires were accepted. Structural equation modeling (SEM) through AMOS-21 and SPSS-19 software packages was used for data analysis. In addition, Preacher and Hayes’ SPSS Macro program was used for testing mediation.
The results showed that the proposed model fit the data properly. Safety management practices have direct effect on unsafe behaviors and safety motivation (p Therefore, organizations can by increasing the safety management practices and also training to employees and supervisors to reinforce the safety motivation, reduce unsafe behaviors and followed to reduce occupational accidents.

Survay of the particulates, biological molecules and other harmful materials which enter into Earth's atmosphere as airborn agents is one of research intrest of health sciences. Animal housing laboratories for producing malodor especially near residential, educational and official areas can cause neighbors complainant. In order to overcome this challenge qualitative and quantitative evaluation of airborn contaminants of Iran university of medical scienses animal housing had been done.
In order to sampling and evaluation of the airborne contaminants in the animal housing the ASTM D3686-95 (for VOCs), ASTM D 4490-90 (for NH3, CO2 and, H2S) and, NIOSH 0500 (for total dusts) standard methods had been used. According to the survey goals apparatus and equipment were prepared and calibrated.
According to the results, the unspesified mixed dusts need controling measures and, also showed the presence of the toxic substances like xylene and ethyl benzene, 1, 2, 3-trimethyl Benzene. However the analyses of these show trace concentration of mixture exposure in the air. High number of animals in the small areas and large animal such as rabbits are responsible for more ammonia production.
More frequently passing through the salons and geographical condition of the building and also natural ventilation of the laboratory all are good methods reducing the concentration of pollutions. In the other hand long times presence of employees in the laboratory could cause reduce sensitively. Nevertheless in order to increase employees and researcher welfare the implementation of general ventilation is recommended

Metro driving is one of the newest jobs in Iran. Therefore, there are few studies were conducted on the tasks and hazards of metro drivers. The objective of this study was task and hazard analysis of metro drivers to recommend control measures.
This qualitative study was conducted in Metro organization in Tehran during 2012-2013. In this mixed method study, data generation was made through field observations, document reviews, individual interviews, focus group interviews and focus group discussions. Many models and techniques include Task Analysis, Organizational Accident Model, Energy Model, Human Factor Analysis and Classification, Failure Mode and Effect Analysis, Fault Tree Analysis, Event Tree Analysis, Management Oversight and Risk Tree, Risk Priority Number, and Lower and Upper Control Levels were used to data analysis.
Metro driving has both many tasks and hazards. Most hazards were under upper control level while Automatic Train Protection (ATP) was active. In contrast, when ATP was inactive, most hazards were over upper control level.
Commitment to customer over commitment to safety was root cause of all of systematic failures and hazards in metro driving job and operation. Establishment of permit-to-work system can control many of hazards while ATP is inactive.

Mindfulness is a technique that is used to reduce stress and promote psychological well-being. The present study was conducted to determine the Effectiveness of training the mindfulness skills on professional stress and psychological well-being of female teachers in Qazvin.
This study is a semi-experimental one with pretest-posttest and a control group, which its population consisted of all female high school teachers in city of Qazvin. The sample size was 30 individuals that were selected by voluntarily sampling method. Osipow’s Professional Stress Questionnaire and Ryff’s Psychological Well-being Questionnaire (short form) were used as the instruments of measurement. At first, all 30 participants completed the questionnaires (pre-test). Then the participants were divided into experimental and control groups (15 individuals in each group). The experimental group received 8 sessions of training mindfulness skills, but the control group did not receive any training and was on the waiting list. Next, both groups completed the questionnaires (post-test).
The mean score of pre-test in professional stress in experimental group was 27.34±133.93 and in control group was 22.55±127.33, and the mean score of post-test in experimental group was 19.73±100.86 and in control group was 17.86±128.46). The mean score of pre-test in psychological well-being in experimental group was 7.46±88.06, and in control group was 11.02±85.86 and the mean score of post-test in psychological well-being in experimental group was 5.15±97.13 and in control group was 9.17±85.60. The results of analysis of covariance showed that professional stress of teachers in the experimental group compared to control group after the intervention has significantly reduced, and the components of professional stress and psychological well-being increased in the experimental group compared to those of the control group (P Training the mindfulness skills was effective in reducing professional stress and enhancing psychological well-being of female teachers in Qazvin. Therefore, we can take steps to increase psychological well-being and reduce teacher's professional stress by holding the mindfulness skill training through in-service trainings.

Nowadays, the basic role of human resources in the socio-economic activities has made it the most important element of each society; which takes a vital place in promoting productivity. One of the most important factors affecting human productivity is the amount of fit between worker and his/her work. The aim of this study is to evaluate bankers work ability and to investigate its relationship with their productivity.
117 bankers were volunteered to participate into this study. Data was collected by means of questionnaire. Demographic and job related information such as age, seniority, education was asked. The Work Ability Index was used to assess work ability and the Quantity-Quality questionnaire was applied to measure productivity. Data was analyzed with SPSS software using Pearson correlation methods.
According to our results, the mean WAI was 40.43± 4.9. In the case of presenteeism, productivity of bankers reduced by 4.2 ± 2.1, as compared to the normal condition. WAI has a significant relationship with productivity (p = 0.011; r = -0.3).
Since there is a positive correlation between reduced productivity and reduced working ability, appropriate strategies should be taken into account in order to stabilize acceptable working capacity. In addition to reduce costs, such interventions, through increasing staff motivation and satisfaction, could facilitate the path to promote productivity.

Job stress is a major problem in the modern world and a main concern for organizations. Rescue workers, including firefighters constantly exposed to toxins, high emotional shock and stress resulted from physical injuries while performing their duty. Development of job stress in firefighters decreases occupational motivation and ultimately leads to productivity reduction. There is no problem even if the work is inherently stressful, but when a person loses a sense of control, higher stress takes over him. People who are better educated have broader solutions to cope with stress.
This study aimed at investigating the effect of stress management education on stress of Rasht firefighters.
This study was a randomized controlled trial. 128 firefighters who completed the first phase of HSE Job Stress Questionnaire and showing higher stress were divided randomly into experimental and control groups. The experimental group participated in two class sessions of three hours on stress management. Two weeks after the end of the educational session, a questionnaire was distributed and completed for both groups. In the follow-up study after one month, the questionnaire was distributed in the experimental group and the results were evaluated.
The mean score of stress in the experimental and control group changed slightly before and after the intervention. It was observed that the mean increased slightly in the experimental group and decreased slightly in the control group, and this difference was not statistically significant. Of the stress areas, there were statistically significant differences in the relationship and change. In the area of relationship, it was observed statistically significant difference before, two weeks and a month after the intervention (p=0.05). In the area of change, there was a significant decrease in the score of the control group (p=0.03). This reduction was not observed in the experimental group.
Stress management education was effective in improving the area of relationship in the experimental group. It seemed that decline in the area of change in the control group and lack of decrease in the same area in the experimental group was due to remarkable changes and movement at workplace, and the experimental group could adjusted themselves because of receiving stress management education. Based on the results of this study, stress management education was effective in keeping the stress score constant in the experimental group and prevented stress condition worsening. According to the findings of the study and the impact of stress management education to prevent firefighters stress condition worsening, it is suggested that the educational program implemented as a permanent educational plan at the fire stations.

For prevention of accidents in chemical processes, the use of multiple layers of protection is essential. In this regard, the analysis of adequacy and use of protective layer resistance is a necessity. In this study the level of protection layers security of Cephalexin Crystals production unit of one the pharmaceutical companies is examined.
In this descriptive study the existing hazards in Cephalexin Crystals production unit of one the pharmaceutical companies assessed LOPA technique. Therefore, with visiting and inspecting the Cephalexin Crystals production unit which Cephalexin Crystals production occurs in four reactors, using HAZOP technique the risks were identified. Then, using LOPA technique that is an analysis and risk assessment technique, protective layers were analyzed and finally the risk number calculated.
Using this method the 104 scenarios were identified. Of the 104 Scenarios the 102 Scenarios were at acceptable levels and only two scenarios needed to management's judgment to determine whether further reductions are needed or not.
LOPA technique is a useful method for assessing the adequacy of the independent protective layers in the Cephalexin Crystals production unit of the pharmaceutical company. The results showed that calculation of the some initiating event frequency using specific tables is not possible. Therefore, expert judgment and the exchange of experiences are emphasized. Because of the direct involvement of experts in risk assessment, the skill of the team in determining the authenticity and accuracy of the results is very important and hence calibration and evaluation procedures are also important.

Evaluation of physical pressure during different working conditions is one of the important and applicable aspects of human factors engineering at industrial and construction environments. accurate calculation of physical pressure helps to improve working condition and status of workers. On of the challenges that experts faced with is the optimal assignment of human resources to the diverse tasks with respect to physical features of them.
In this study, we chose 9 casual construction works to clarify our subject. Then we measure the pressure on lumbar area for all person during different position. In order to measuring the pressure, we assume average time that each person be in the different position in a single shift. After that we calculate work risks by means of Chaffin and Doisis model. At the next step in order to assign work to workers we use a linear programming model at which the cost of assignments is equal to work risks and the objective function is to minimize total work risk. Finally, by solving the model, best assignment is achieved.
Since we choose 5th percentiles to 95th percentiles anthropometric features, we find out that by increasing height and weight, the risk of all works increases too. However, by means of proposed method, we can make a decision that minimizes person’s work risk.
Persons that has higher anthropometric features are not suitable for these kind of construction works and their risk increases up to 20% with respect to other ones. Also using mentioned method for decreasing total work risk among people is made benefits.