مجله مهندسی بهداشت حرفه ای
سال چهارم شماره 2 (تابستان 1396)

Given that the satisfaction from educational facilities and feel comfort and relax in classroom can affect on learning, focus and increase productivity, so the necessity for a questionnaire with appropriate validity and reliability to determine student's satisfaction from training chairs has been felt. therefor the aim of this study was to design and validate of student's satisfaction questionnaire from training chairs.
this descriptive study was performed in two phases of designing and considering the validity and reliability of satisfaction questionnaire and determining its cut point in 2016. to determine the content validity of questionnaire, CVR and CVI indices were used and to determine the external and internal reliability, test-retest method and cronbach's alpha were used. also ROC curve was used to assess the sensitivity, specificity and cut point.
content validity index was calculated 0.798 that is an acceptable nmber for questionnaire. cronbach's alpha was 0.799 and correlation between the questions in first and second series was in a acceptable significant level (r=0.825, p-value=0.000). in ROC diagnostic test, cut point was reported 35.5 with sensitivity and specificity 80.9% and 46.2% respectively and sub curve area in this cut point was 0.65.
according to this study's results, in investigating the validity and reliability indices of questoinnaire developed by the researcher was noted that this questionnaire have a proper validity and reliability to assess student's satisfaction from training chairs and can be used to assess any office and student chairs.

Continuous exposure to cold air is considered to be a hazardous agent in the workplace in cold seasons. This study aimed to determine the level of cold stress and relation with physiological responses in auto mechanic employees.
This cross-sectional study was conducted in the winter of 1395 on auto mechanic employees in Hamadan city. Physiological responses during daily activity were measured in accordance with ISO 9886 standard method. Environmental air measures like air temperature and air velocity were measured simultaneously and cold stress indexes were also determined. Data was analyzed using SPSS 21 software.
The result showed that mean wind chill index, equivalent chill temperature and required clothing insulation were 489.97±47.679 kcal/m2.h, 13.78± 1.869 0c and 2.04 ± 0.246 clo, respectively. According to the results of cold stress indexes, the studied employees are exposed to cold stress. Pearson correlation test showed that there are significant relationship between cold stress indexes with physiological responses (p The result confirmed that IREQ min index has high validity for estimation of cold stress among auto mechanic employees. Moreover, the increase of body fat percentage leads to an increase of cold tolerance power of employees.

Grip and pinch strength assess the function of hand and is considered as a sign of general health. Considering the high prevalence of related-work musculoskeletal disorders (WMSDs) due to the incongruity of work with the workers and preventability of diseases that are caused by such incongruity, we decided to study the relationship between maximum oxygen consumption (Vo2max) and with grip and pinch strength and endurance.
This cross-sectional study was performed among 120 men assembly workers by means of simple random sampling. To assess the Vo2max, grip and pinch strength and endurance, the Step Test, dynamometer and pinch gauge were respectively used. Participant’s grip endurance was specified through determining the maximum time (in seconds) that he could continue applying one third of the maximum voluntary contraction. Data analysis was carried out by using SPSS version 20 and Pearson correlation coefficient It is noteworthy to mention that P value The findings of the study indicate that there is a direct relationship between the Vo2max and grip strength and endurance, pinch strength and endurance P value In jobs that require high grip and pinch strength and endurance it is necessary to employed those with high Vo2max so that WMSDs would be prevented and increased efficiency.

long term work, nonstandard and improper tools, and inadequate lighting in the workplaces are important factors which resulted in awkward postures in hairdressers. The present study was performed to assess general and local lighting and investigate its relationship with postural status assessed by Rapid Entire Body Assessment (REBA) method in Hamadan’ hair salons.
Material and in this descriptive analytical study, 100 hairdressers who worked in 50 hair salons were studied. The local and general lighting was measured using a Hanger ESI photometer. The hairdressers’ postures were assessed using REBA method. Data were analysed using version 21.0 of the SPSS/PC statistical package.
in 97 and 72% of the studied hair salons, local and general illuminance levels were lower than the occupational exposure limit, respectively. REBA assessment indicates that 26 and 12.5% of the studied subjects fell in to high and very high risk levels, respectively. ANOVA test showed significant relationship between general illuminance and the REBA scores in face and eyebrow makeup tasks (p in most of the hair salons, local and general illuminance was lower than the Iranian occupational exposure limit and it had not a suitable condition in term of quality and quantity. According to the obtained risk levels, the modification of lighting systems of the hair salons and training of the hairdressers are recommended to prevent ergonomic disorders in hairdressers.

Introdaction: Musculoskeletal disorders MSDs is one of the most common causes of occupational injuries and disability in industrialized nations and developing countries. Musculoskeletal disorders have a high economic losses. . Musculoskeletal disorders not only impact on individuals, but also on organizations and community.
This interventional study was conducted in the Tundish and Slide gate workstations of a steel company. To assess workers’ postures, the REBA and ManTRA technique were applied before and after the intervention. After data analysis, corrective engineering measures implemented in two mentioned workstations.
The findings showed a 63% and 64% reduction in risk level at Tandish and Slide Gate stations using the REBA method and a 47% and 56% reduction in ManTRA cumulative risk score at the Tandish and Slide Gate stations. Also data analysis showed that mean intensity of risk level score in the Tandish and Slide Gate stations using the REBA and ManTRA technique before and after the intervention were significant.
The simultaneous use of the ManTRA and REBA methods is beneficial for occupations which the entire body is involved and more activity is manual as well as Occupations that work duration is important and limitation each method will be minimized using another method.

Probabilistic risk assessment using fault tree analysis is an effective tool to assess occurrence probability of hazardous events in chemical process industries. Unfortunately, the failure occurrence probability of the basic events are often not available in process industries. The aim of this study is how calculate basic events failure occurrence probability when basic events do not have precise failure data.
In this study, the proposed risk assessment framework was based on five-scale and six-scale fuzzy-based approaches. Firstly, the fault tree diagram was constructed using the risk identification methods. Then, by applying the two types of failure possibility distributions, failure occurrence probability of the basic events were calculated. Finally, using the importance measure analysis, critical minimal cut sets were ranked.
Results show that the failure occurrence probabilities calculated by the five-scale and six-scale approaches for the 32 basic events were closed to each other. The occurrence probability of the top event calculated using the five-scale and six scale approaches were 3.64E-04 and 4.76E-04 at year, respectively. After ranking of the MCSs based on their calculated importance measures, the process failures have been determined as the critical causes of the TE.
The results show that the fuzzy-based approach seems to be a good alternative for conventional approach of the FTA to deal with basic events which do not have failure rate data to obtain their failure occurrence probabilities. This study has validated the consistency of fuzzy-based approach, to assess basic events failure occurrence probabilities.

Increasing women’s participation in the labor market is one of the most important social phenomena in the world. Currently, the number of pregnant mothers working in industries in the developing countries is significant; therefore, there are always issues related to occupational hazards and pregnancy health. This study has analyzed articles that examined the complications of occupational noise exposure among women.
To collect required data, available resources and electronic databases were used. To do so, keywords of occupational exposure, women, noise effects and pregnancy during1980 to 2016 were searched in international databases such as Science Direct, Scopus, ISI, Pubmed, and in internal databases, including Iranmedex, Magiran, and SID.
Studies have shown that there are differences in hearing loss as well as the description of tinnitus between men and women. Some studies have shown that the effect of sound in women, as a risk factor for the incidence of ischemic heart disease and changes in plasma cortisol levels, is significantly higher than that of men. Also, exposure to sound during pregnancy can lead to reduced fetal growth by altering the mother's endocrine system. And may also cause hearing loss in the baby after birth. Increased blood pressure, painful menstruation, hormonal disorders, and reduced fertility are other complications of exposure to women by voice.
The present review article showed that the women’s exposure to occupational noise has specific effects in addition to hearing loss and physiological effects which for women in all circumstances, and especially during pregnancy, can have more consequences than men. Therefore, it is essential to pay attention to the physiological and even psychological characteristics of women, especially pregnant women, in the occupational health monitoring program and periodic medical examinations.

Low frequency sound is one of the most important sources of sound in the environment. Some individual differences such as extraversion, neuroticism, and sound sensitivity are factors that influence the effect of sound on cognitive functions. The purpose of this study was to investigate the effect of personality type (introversion/extraversion) on cognitive Performances in the presence of low frequency noise.
This is an interventional study. The study population was Hamadan University of Medical Sciences students. 120 of them were selected through purposeful sampling (60 extraversion and 60 introverted) and entered the study. By simulating the real environment of each person, they were exposed to 50, 60 and 70 dB for 40 minutes. During the encounter, the cognitive Performances of the subjects were examined using the integrated visual auditory continuous performance test. Data were analyzed using SPSS20 software, independent t-test and ANOVA.
The results showed that low frequency noise negatively affects the components of cognitive Performances and decreases from 50 to 70 dB with increasing noise pressure (p The results of this study showed that the noise pressure level of the low frequency noise has different effects on the parameters of the cognitive Performances of extrovert and introverted individuals, and this negative effect on introverts is lower than the low frequency noise.