دو ماهنامه سلامت کار ایران
سال سیزدهم شماره 1 (فروردین و اردیبهشت 1395)

X-band with 8-12.5 frequencies range has various applications such as air control traffic, navy communication and etc. Uncontrolled exposure with microwave can lead to adverse effect on workers. Application of the shielding is superior control for prevention of microwave exposure, now. This study investigated the effect of dispersion on shielding effectiveness improvement about a novel nanocomposit shiled.
Nanocomposites prepared by epoxy resin and nano nickel oxide (7wt %) with 2, 4 and 6 mm thicknesses. In order to investigate the effect of dispersion , 10 and 66 minutes was considered as mixing time . Nanoparticles characterized by X-ray Diffraction and Field Emission Scanning Electron Microscope. Shielding effectiveness measured with vector network analyzer.
Dispersion of nanoparticles in group 2-nanocomposites was better than group 1- nanocomposites. Average of percentage attenuation in group 2-nanocomposites was better than group 1- nanocomposites. The Average of shielding effectiveness for three thicknesses in group 1 was 46.5, 69.03 , 70.83 and for group 2 was 52.02%, 78.48% and 84.14 %dB, respectively. Maximum attenuation obtained by the 6mm thickness in group 2- nanocomposites at 8.8 GHz frequency (91.12%). The Average of shielding effectiveness increased with increasing the thickness.
with increasing the mixing time, the dispersion and shielding effectiveness be improved. These nanocomposites could be used as appropriate shielding for exposure control of X-band frequency in workplace and nanocomposite with 4mm thickness is appropriate shield in this study. Both 4mm and 6mm thicknesses in group2 are useful in specific frequency such as 8.8 and 12.5 GHz .the average of percentage attenuation for above thicknesses is more than 87%.

Since assessment of crisis management has important role in planning for training and increase awareness and preparation hospitals, therefore the usage of new Resilience Engineering approach can help to increase efficiency of crisis management and empowerment hospitals to encounter with crises. The aim of this study was to evaluate of validity and reliability of the questionnaire to assess crisis management based on seven principles of Resilience Engineering approach in hospitals.
In this descriptive study, eight hospitals in Ahvaz in 1392 were examined. The Self -designed questionnaire completed by personnel of nursing and management sections. Data were analysed using SPSS software. Reliability was assessed by internal consistency and for proving validity was used of exploratory and confirmatory factor analyses.
Reliability evaluation showed high internal consistency and good reliability. The Cronbach’s alpha coefficient was 0.977 and intraclass correlation coefficient (ICC) was 0.97. The results of exploratory factor analysis (EFA) showed seven factors for the questionnaire that jointly explained 75.3% of variance. Confirmatory factor analysis showed KMO=0.885, BT=6.41, df =946 (p The findings from this study suggested that the designed questionnaire to assess crisis management based on seven principles of resilience engineering approach in hospitals was suitable and practical. It will be useful to assess crisis management in hospital and recognize its weak points and strengthen of its strong points.

The Organizational factors affecting safety performance while impact on the overall performance of their organizations, also have a causal relations with each other, so the intensity or weakness of a factor in the organization can be effective on the other factors that enhance or weakness of the factor. Accordingly, the aim of the current study is assess causal relations between organizational factors affecting industries safety performance.
This study due to the aim of applied research and is based on descriptive-causal methods. In this paper, initially the organizational factors affecting the industries safety performance has been elicited. And in order to assess causal relations, a field study has been used. The statistical population of this research includes safety experts of small and medium basic metals industries in the east Azerbaijan province. Also, in order to collect data used DEMATEL questionnaire. As regards DEMATEL method is types of decision-making procedures based on paired comparison; so to design of the questionnaire, a paired matrix composed and provided to professors and experts familiar with the issue and face validity is confirmed. Also, questionnaire reliability obtained based on 0.81 retest.
The research findings indicates that among organizational factors affecting safety performance, Management's commitment to safety, the most effective factor and the continuous improvement of safety is the most important factor. That located in the category of impressionable factors and caused other effective organizational factors. Also safety behavior of employees is considered the most impact factor.
In order to improve safety performance, the managers of industries can focus on the influential or causal factors and proceed to improve and better them. Improvement and betterment of the causal factors group will lead to the improvement of the affected factors and the general improvement and betterment of the industrial safety performance system.

Occurrence of crashes and forward collisions, one of the most frequent types of roads and highways incidents, is mostly resulted by drivers’ distraction. Forward collision warning systems (FCWS) are of the technologies which may improve driver’s situational awareness, and consequently driving performance. The present study has aimed to design an intelligent forward collision warning system (IFCWS), and evaluate its effect on driving performance.
Driving performance variables including initial reaction time (IRT), movement time (MT), brake reaction time (BRT), frequency if errors (ER) and distance between two vehicles (D), were measured through four various tests (without and with a cognitive secondary in-vehicle task, off/on warning system).
The results indicate a significant effect of the secondary task on drivers’ reaction time, frequency of errors, and distance between the two vehicles. Moreover, the IFCW system led to a decreased frequency of errors and reaction time. However, the warning system had no significant effect on drivers’ movement time.
The IFCW system improved driving performance. Further naturalistic studies, with more participants are required to validate the results of the study.

The effective human resources are the main factor for realization, resuming and success of organizational purposes.In the organization milieu, human exposure to different kinds of mental and psychological stress and pressure. In fact, stress associates with many physical and mental diseases, or has a role on making, development and mutation of them and it decreases general health of staffs, innovation and creativity abilities and also staff's efforts. For this reason, stress studying is important regarding both personnel health and psychological hygiene; and investigation of personnel performance. Therefore, main purpose of this study is to investigation the effect of job stress on general health and job performance on Air Traffic Controllers (ATC).
This study is a cross-sectional, descriptive- correlation study. Statistical research community included all workers of ATC in Tehran, and then 103 individuals were selected as sample using stratified random sampling method. Flip L.R. (1992) questionnaire used for gathering of data’s in job stress section and to collect data for General Health section, used Goldberg & Hillier questionnaire and Paterson questionnaire used for gathering data in job performance section. The software SPSS19 with multi regression and simultaneously Baron and Kenny (1986) quadruplet process used for data analyzing.
The results show that there is a negative and meaningful relationship between the stress which is produced in workplace and job performance. This means that increased job stress reduces job performance. Also general health has a mediating role between workplace stress and job performance.
Based on the results of research that confirms the negative impact of stress on job performance and considering the mediating role of general health between stress and job performance in ATC. Regarding to get better the personal performance, it is an essential thing to design and to implement a comprehensive program in order to manage staff's stress, to improve general health, as well as to handle the promotion and occupational safety and to accrete their participation necessities in decision-making, and these should be a priority.

Low Back Pain is the most common type of musculoskeletal disorders among nurses. The high prevalence of low back pain in nurses is a result of activities such as patient handling, improper postures, sudden movements, bending, turning and lifting the load.
The aim of this study was Comparison of risk assessment methods related to the patient's transfer and its relationship with prevalence of low back pain among hospital nursing personnel Kerman University of Medical Sciences.
The present analytic study was done on 243 nursing personnel in 3 hospitals under the supervision of Kerman University of Medical Sciences in 2014.the data was gathered by Nordic Musculoskeletal Questionnaire (NMQ) related to low back region, a questionnaire containing individuals’ demographic information, and MAPO and PTAI check lists. The data was analyzed by SPSS.22 software and Analytical statistics of Pearson's and Chi-square analyses.
prevalence of low back pain in subjects was 69.5 percent. Based on chi-square test, a significant correlation was observed between the prevalence of Low Back Pain and levels of risk by MAPO and PTAI (p MAPO and PTAI risk assessment methods are considered as efficient tools for risk level classification and identification of effective factors on low back pain incidence in nursing personnel involved in patient transfer. In this regards, for ergonomic intervention to reduce incidence of low back pain in this occupational group we can mention the modification of improper factors identified in this two methods such as the increases of lifting and aid device in wards.

Leakage of toxic and hazardous substances in the chemical and process industries always had been one of the factors threatening the workers and residents of the industries. The purpose of this study is modeling of hexane emissions planning emergency response program.
In this study we describes the factors affecting discharging release of material and ALOHA software used as one of the best software for modeling emissions from storage tank 579 thousand gallons of hexane, in a petrochemical. And based on modeling results emergency response plan in sudden devastation of hexane tank prepared and presented.
The results of modeling toxic vapor cloud formation caused by the release of hexane and form liquid pools around tank (scenario 1) showed that the diameter of pool formed was 200 m. And about 140 meters around tank concentration of hexane is 8600 PPm (range AGEL-3) that there is risk of death and life-threatening in people that are in the area. Distances up to 160 meters of tank, concentration of hexane is 7200 ppm that is about 60% of the Lower explosive limit (LEL) in gas-hexane. To 526 meters of hexane tank, concentration of hexane is 1200 ppm that is about 10% of the Lower explosive limit (LEL) of hexane gas. In explosion of toxic vapor cloud up to 133 meters away from the tank area is 8 psi, and to a distance of about 196 meters of tank, the blast wave pressure is 3 Psi. In the event of scenario 2 (hexane emissions from tank associated with the burning) thermal radiation from a distance of 353 meters of the tank is 10KW / sqm and to 491 meters of away from tank thermal radiation is 5 KW / sqm. BELEVI and tank explosive occurring (scenario 3) leads to the formation of a fireball with 640 meters diameter in 31 seconds time, and the amount of thermal radiation to 1.3 km from tank is 10KW / sqm.
Hexane toxicity is the most serious consequences of danger that threatening the personnel. Therefore preparation of emergency response plan will have an important role in limiting the harmful effects in release of toxic and hazardous substances.

Skin cancer is the most common cancers. Repeated exposure to sunlight causes high levels of cancer and climate change including changes in the ozone layer along with changes in personal and social habits. Given the importance of farmer's health and increase their skin cancer, the study aimed to determine the factors preventing skin cancer in farmers city Tuyserkan on protection motivation theory was done in 2014.
In this cross-sectional study, 200 peasant farmers from 18 to 60 years, Tuyserkan city where the sun had Using a cluster of four health centers and rural health houses Were selected. Using a questionnaire, which was based on protection motivation theory, Collected through interviews with farmers and were analyzed using SPSS 21.
Farmers who use sunscreen, hats, gloves and clothing worn used Respectively, 31.5, 53.5, 3, and 65%. and 81% of farmers do not use eyeglasses. Among Agricultural work experience and average score reward structures and perceived severity a significant correlation was found. Also Between preventive behaviors and the mean score of the fear structure, intensity and reward and motivation, perceived protection there was a significant correlation.
With regard to the theory solidarity structures associated with the use of means of protection against the sun's rays, Education and health promotion programs designed to increase the incentives for farmers to use the theory of protection is emphasized.

Neck disorders among office workers are one of the main causes of the increase in the job absence, Jobs turnover and health care costs. Different factors are attributed to the occurrence of neck disorders. This study was carried out to investigate the association of psychosocial factors associated with the incidence of neck disorders in office workers of Shiraz University of Medical Sciences (SUMS).
In this cross-sectional study, 224 office workers of SUMS participated. Nordic Musculoskeletal Disorders Questionnaire (NMQ) and Job Content Questionnaire (JCQ) were used as data collection tools. Statistical analysis were performed using SPSS (ver. 19).
71.7% of office workers experienced neck symptoms during the last 12 months. Statistical analysis revealed that perceived psychological demands (lack of enough time to do the tasks and job tenure) were significantly associated with musculoskeletal symptoms in neck region.
Neck disorders had high prevalence among office workers of SUMS. Lack of time and job tenure was found to be associated with neck symptoms. Interventional programs to prevent neck symptoms should be focused on the psychological demands and job tenure.

Protection the hospitals against fire is very important due to presence of disable persons, lack of awareness and expensive devices and equipments in the hospitals. This study aimed to assess fire risk in the selected hospitals of Shiraz University of Medical Sciences.
This cross-sectional descriptive study was conducted in 8 hospitals (16 buildings) affiliated by Shiraz University of Medical Sciences. Assessment checklists were extracted from NFPA101 standard completed through field observation. In the next stage, gathered information was analyzed using “Computerized Fire Safety Evaluation System” (CFSES) software.
From all studied buildings 87.5% in the aspect of fire control, 6.25% in the aspect of egress and 56.25% in the aspect of general fire safety were acceptable. In total, the fire risk level was acceptable only in 1 (6.25%) of the studied buildings, from all three aspects.
To improve the level of fire risk in hospitals, required measures especially in the area of egress including buildings design for better access to exits and increasing the number and standardization of emergency exits.