Iranian Journal of Ergonomics

Study of ergonomic conditions in use of visual monitors and its relation to subjective feeling of fatigue in master science students of Hamadan University of medical science

Mohsen Aliabadi

Background: The use of visual monitors especially in relation to computer can cause health effects which have negative impacts on mental and physical performance of users. This study aims to determine the relation between ergonomic conditions in use of visual monitors and subjective feeling of fatigue in master science students as permanent users. Methods: In this study, 40 students in the Hamadan University of Medical Scienceswere selected based onsimplerandomapproach. For determining subjective feeling of fatigue, the standard questionnaire with reliability coefficient equal to 0.8 was distributed and completed among students. This questionnaire has 30 questions which was covered three criteria included drowsiness, difficulty of concentration and physical impairment. The data about environmental and ergonomic conditions of the workstations was also recorded. Exposure to electromagnetic radiation in very low frequency was measured using instrument model HI 3603 front of the studied monitors. Data was analyzed with SPSS 16 software. Results: The results showed mean score of drowsiness, difficulty of concentration and physical impairment were 17.8±6.5, 18.7±4.4 and 11.9±6.9, respectively. Totally, mean score feeling of fatigue was 48.5±15.7. The relation between continuous work time and feeling of fatigue was significant (P<0.05).The relation between work day time and feeling of fatigue was not significant (P>0.05). The relation between type of used monitor and feeling of fatigue was significant (P<0.05). Moreover, the relation between environmental conditions of the workstations and feeling of fatigue was not significant (P>0.05). However, descriptive results showed growing trend of feeling of fatigue in unsuitable environmental and ergonomic conditions. Moreover, exposure to electromagnetic radiation between to type monitors was statistically difference (P<0.05). Conclusion: Criterion of difficulty of concentration was allocated the maximum score of feeling of fatigue which can cause negative impacts on educational performance. Compliance with the ergonomic principles especially reduction continuous work time and use of updated monitors and optimization of lighting and acoustic conditions of the workstations can reduce feeling of fatigue among students, considerably.

Investigation risk perception, safety attitude and safety performance in supervisors of construction sites Shiraz-Iran

Mehdi Jahangiri

Background Given the breadth and diversity of construction activities and their hazards, it is at the top of accident cause lists. According to the supervisor's role in safety and prevention of accidents at construction sites, this study was conducted to study the risk perception, safety attitude and safety performance in the supervisors of construction sites in Shiraz city. Methods This cross-sectional descriptive study was conducted on 200 supervisors who agreed to participate in the study. The study was by conducted using a structured questionnaire consist of questions regarding general information, risk perception, safety attitude and safety performance. The questionnaire was completed through self-statement. Results All studied supervisors had medium and high risk perception (35.5 and 64.5% respectively), medium and high safety attitude (78.6 and 21.4% respectively), medium and high safety performance (41.4 and 58.6% respectively). Among studied variables, size of construction site, had positive and significant effect on safety performance of supervisors. Conclusions The result of this study showed that there is a significant relationship between risk perception and safety attitude with safety performance among supervisors in construction sites. Somehow, by increasing safety attitude in supervisors, their safety performance were increased too.

Evaluation of noise pollution and acoustic comfort in the classrooms of Hamadan University of medical sciences in 2012

Masoud Shafie Motlagh

Introduction: Noise pollution cause mental fatigue, concentration disturbance and learning loss in students during the training activities. This study aims to evaluate Noise pollution and the level of acoustical comfort in typical classrooms, and present treatment methods for improving acoustic comfort. Method: In cross sectional study, twenty classrooms in the seven faculty of Hamadan University of medical sciences, were studied using questionnaire with reliability coefficient equal to 0.8 was completed among 413 students. Measurement of noise level was performed using sound level meter (model TES-1358) according ANSI S12.6 in classrooms. Result : The results showed the background noise level and outdoor noise level were equal 46.97 ± 3 dB(A), and 57.16 ± 4.8 dB(A) , respectively. The background noise was higher than the recommended limit equal to 45 dB(A) (P<0.01). The construction activities are most important annoying factor and concentration disturbance are most complication of noise. Signal to noise ratio within the classroom was 13.14±3.54 dB (A), which was inappropriate compared with the recommended limit 15 dB (A) (P<0.01). The difference in speech intelligibility at various levels of signal to noise ratio was significant (p<0.05). Conclusion: The results confirmed the studied classrooms haven’t acceptable acoustic conditions and background noise level was affected by outdoor noise. In regard to confirmation of the effects of noise on the student attention, the acoustic interventions is must be considered.

Risk assessment of cumulative trauma disorders in Quarry and Stone Industries workers Kermanshah in 1392

Mansour Ziaei

Background and aim: the workers in Quarry and Stone Industries done frequently some duties including lifting and carrying of heavy loads and they are exposed to high risk of cumulative trauma disorders. The aim of this study was to comparing the prevalence of musculoskeletal disorders and risk of work postures in Quarry and Stone Industries workers. Material and methods: this cross-sectional and analytical study was done on 63 workers of Stone Industries and 46 workers of Quarries in Kermanshah. Data were collected using by Nordic standard questionnaire, Body map chart and REBA method. The gathered data was been analyzed by Independent t-test, Mann-Whitney, Spearman and Pearson tests. P was 0.05. Results: The most prevalence of musculoskeletal disorders in both Stone and Quarry industries was related to low back that was 54% and 39% respectively. Mean and standard deviation of final scores of REBA in Stone and Quarry workers were 9.06±1.45 and 4.6±1.18 respectively. Results shows that a significantly correlation between age, work history and BMI with musculoskeletal disorders in Stone Industries and between age and work history with this disorders in Quarries (P<0.05). Conclusion: the results shows that the risk level of REBA and prevalence of musculoskeletal disorders of Stone Industries was more than Quarries in shoulder, wrist, hand, lumbar, femur, knee, leg and ankle.

Identifying individual and work-related risk factors of musculoskeletal disorders in an industrial organization

Ali-Asghar Farshad

Introduction: Musculoskeletal disorders (MSDs) are the main causes of work related injuries and disabilities in developed as well as developing countries. Few studies have considered different interactive effects of individual and work-related factors on MSDs, simultaneously. Methods and Materials: Data were gathered by Nordic questionnaire and Quick Exposure Check (QEC) method and were analyzed using logistic regression model in order to study the correlation between the prevalence and intensity of MSDs and individual and work-related factors. Results: More than half of all participants (61.6%) reported suffering from one form of MSDs during the past 6 months. Results showed that risk factors such as work stress, sleeping position, lifestyle and poor posture had an important role in the prevalence and intensity of MSDs. Discussion: The effect of a risk factor is constantly in interaction with other risk factors, and is modified by other factors. Participatory ergonomic intervention programs, work station intervention, ergo stress intervention and life-style interventions were suggested in order to decrease the prevalence and intensity of MSDs.

Effect of daylight on subjective general health factors in elderly

Rostam Golmohammadi

This before-after clinical trial investigated the effect of daylight on morning and night melatonin, subjective general health using GHQ questionnaire, sleepiness and alertness on elderly who lived in nursing houses. Nineteen nursing home residents participated voluntarily. They exposed to daylight from 9 to 10 A.M. and from 4 to 5 P.M. for 6 weeks. General health of all participants was evaluated using general health questionnaire (GHQ) as well. Also we used of KSS and VAS questionnaire foe assessment of sleepiness and alertness. Baseline morning and night melatonin levels were 25.39 (±19.75)pg/ml, and 40.3 (±21.55)pg/ml respectively. Daylight exposure significantly affected morning melatonin at 7:00 A.M. but had no significant effect on night melatonin at 8:00 P.M. Mean score of general health changed 36.31 to 29.89 (P=0.003). Karolinska sleepiness scale (KSS) and Visual Analogue Scale (VAS) showed increase sleepiness and decrease alertness from 3:00 to 7:00 A.M. Sleepiness decreased and alertness increased during 1:00 P.M and 20:00 P.M. Overall day light exposure may delay sleep phase and circadian rhythm problems in elderly people. Anxiety and insomnia could be improved with daylight exposure. Our findings suggest that elders should be exposed to scheduled daylight in morning and evening for prevention and improvement of mental disorders. Adequate light should be provided for elder’s homes and nursing house. We have proposed to further study with a larger sample size be done to assess effect of daylight on GHQ' subscales.

The Survey of Quality of Work Life and Determination of Its Related Factors in Shiraz University of Medical Sciences Staff

Hadi Daneshmandi

Introduction: Regarding to the competing and increasing competitions in organization and markets, paying attention to manpower and his quality of work life have progressively become important. This study was conducted with the objective of investigating of quality of working life and determination of its related factors in Shiraz University of Medical Sciences (SUMS) staff. Material and Methods: In this cross-sectional study, 218 employees of SUMS participated voluntarily. A questionnaire consisted of two parts was used as data collecting tool. In the first part, demographic and occupational characteristics, and in the second part questions about the quality of working life were included. Data were analyzed using statistical tests including Pearson Correlation, Kruskal-Wallis and Mann-Whitney U by SPSS software (Version 16.0). Results: Mean and standard deviation scores for the quality of working life of staff were 127.51±16.61. The results showed that there were associations between gender and income with quality of work life score (p<0.05), such that the quality of work life scores of women and high-income individuals were higher than those of men and lower- income staff. Age, job tenure, marital status, number of children, level of education, type of employment and job unit had no association with quality of work life score. Discussion: In this study, quality of work life had association with gender and income level of staff.

Investigating the Correlations of results of three methods OCRA Index, Strain Index, ACGIH HAL to evaluate the risk of upper extremity musculoskeletal disorders

Majid Motamedzade

Introduction: Three methods of OCRA Index, Strain Index and ACGIH HAL are proposed to assess risk factors of upper extremity musculoskeletal disorders. These methods are important in work environments to evaluate musculoskeletal disorders. Thus the aim of this study is to determine the correlation between the results of the above mentioned methods. Materials and Methods: In this cross - sectional study, a total of 150 job tasks studied in four industries . For each task, not only video taping was used to record the duration of a full cycle but also tasks were evaluated according to instructions. The correlation coefficient and the coefficient of agreement were analysed using SPSS16 and R software. Results: Correlation between the results of risk assessment methods OCRA and SI for right and left hand, were acceptable correlation (0.751) and (0.726) respectively. Also the result of agreement between the methods OCRA and HAL for right and left hands, were (0.526) and (0.595) respectively. Conclusion: This study showed that none of the two methods do not fully agree. One of the source of differences is the number and types of variables and their effects on the final score of the methods.