29 research outputs found
Comparing of Four Ergonomic Risk Assessment Methods of HAL-TLV, Strain Index, OCRA Checklist, and ART for Repetitive Work Tasks
This study is aimed to compare the results obtained from four risk assessment methods, videlicet HAL-TLV, Strain index, OCRA checklist, and ART. These musculoskeletal disorders assessment tools are generally used in the studies as well as in the field of occupational health. In this study, the data was collected via assessments of 30 tasks by 9 raters in poultry slaughter, assembly, and container production industries using four methods of upper limb musculoskeletal disorder risk assessment. In order to determine the level of agreement between the risk assessment methods, the Spearman's rank correlation coefficient and Cohen's weighted kappa were used, according to which the highest agreement and correlation were found between ART and OCRA checklist methods, while the HAL-TLV and OCRA checklist exhibited the lowest agreement and correlation. The difference between the risk classification results of the studied methods could be due to the difference of definitions of the risk variables; therefore, selecting the assessment tools for assessing the task risks in the working environment must be in accordance with the assessment objectives and complexity of the work tasks
A fuzzy analytic hierarchy process-TOPSIS framework for prioritizing emergency in a petrochemical industry
Background: Petrochemical industry has experienced a variety of accidents and the number of emergency situation in this industry is high. Therefore, prioritizing these situations is important. The aim of this study was to determine the effective criteria for the selection of emergency scenario and prioritize them for corrective actions. Subjects and Methods: Delphi technique was used to determine and prioritize the appropriate criteria for the selection of high-risk emergency scenarios. Then, the weights of selected criteria were obtained using fuzzy hierarchical analysis and finally, using the fuzzy TOPSIS technique, the criteria for emergency scenarios were prioritized for corrective actions. Results: The most important criteria for the selection of dangerous emergencies included the amount of loss, damage, and probability. According to the weight of these criteria, emergency situations were prioritized. The most important emergencies included fire in the chemical storage, hydrogen leakage at the cylinder fitting in the Alfin unit, and extreme gas leakage in one of the power plant turbines. Conclusions: Using this approach, high-priority emergencies can be identified, and it is suggested that planning for controlling these situations and preventing crises should be prioritized by managers
The relationship between Work Engagement and Job Stress among Emergency Technicians of Markazi Province, Iran, in 2015
Several factors influence the efficiency and effectiveness of organizations, one of them is work engagement.
Nowadays job stress has become one of the most costly and a common problem in the workplace. United Nations introduced job stress as wentieth-century disease. Emergency unit in hospitals is stressful environments with high working pressure. This study is a cross-sectional study to determine the most common stress factors and assess work
engagement among emergency center technicians in Markazi Province in 2015. Data were collected by using three questionnaires containing demographic questionnaire, job stressors questionnaire and job engagement questionnaire
(UWES-9 Scale. SPSS version 19 software was used to analyze the data. The results showed that the patient care stressor had the maximum mean stress score (3.63±0.59) and physical stressors had the lowest mean stress score (3.26± 0.77). A significant relationship was observed between individual stressors and all aspects of work engagement
and interpersonal stressors and vigour (P≤0.05). The results of this study showed that work engagement can have aneffect on job stress or job pressure. There was a negative association between work engagement and job stress
Non-Image Forming Effects of Light on Brainwaves, Autonomic Nervous Activity, Fatigue, and Performance
Fatigue and sleepiness are one of the main causes of human errors and accidents in the workplace. The empirical evidence has approved that, in addition to stimulating the visual system, light elicits brain responses, which affect physiological and neurobehavioral human functions, known as the non-image forming (NIF) effects of light. As recent evidences have shown the positive effects of red or low correlated color temperature white light on alertness and performance, we investigated whether exposure to 2564 K light could improve subjective and objective measures of alertness and performance compared with 7343 K, 3730 K, and dim light (DL) conditions during the daytime. Twenty two healthy participants were exposed to the light while they were performing a sustained attention task and their electroencephalogram (EEG) and electrocardiogram (ECG) were recorded. Both 2564 K and 7343 K conditions significantly reduced EEG alpha-power compared with the DL and 3730 K conditions. Moreover, the 2564 K, 7343 K, and 3730 K conditions significantly reduced subjective fatigue, sleepiness and increased heart rate and performance compared with the DL condition. Furthermore, the effects of light conditions on alertness and performance varied over the day so that more effective responses were observed during the afternoon hours. These findings suggest that light interventions can be applied to improve daytime performance
Ergonomic evaluation of pressurized irrigation equipment factotry operators using an easy posture assessment
introduction: One of the most common causes of occupational injuries in industrialized and developing countries is musculoskeletal disorders Determining the risk factors of musculoskeletal disorders can be helpful choosing the right method for interventions and detailed studies. This study aimed to evaluate the ergonomic risk factors in operators of pressurized irrigation equipment factory.
Materials and Methods: This cross-sectional study was conducted in a pressurized irrigation equipment manufacturing company. In this study, a new method based on observation was used to evaluate the ergonomic aspects of operator's activity. In order to assign tasks and sub-tasks, direct observation and video recording equipment were used. Ergonomic assessment was carried out on all sub-tasks identified. then, the criticality of the task determined.
Results: Among the tasks identified 53 very critical posture 61 critical and 82 low critical posture was determined. Ergonomic point in the ball valve production line was 0.6 and 0.68 respectively for tow operator. For drop valve and automatic valve production line's ergonomic point was 0.52 and 0.67 respectively.
Conclusion: According to the results, posture analysis method used in this study is easy and accurate. The advantage of this method is 14 ergonomic domaines that covered whole body and time fragment of each task. Findings of previous studies showed good correlation between results from this method and OCRA method.
In this study, The most critical posture was related to operator's wrist, so it is recommended that control measures on wrist posture correction should be considered
Evaluation of the workers exposure to heat and presenting intervention to control heat stress in profile factory
Background & Objectives : Exposure to heat is a significant problem in the Industries. The present study aimed at the evaluation of thermal risk, measurement of heat stress index, and proposing a plan for heat control in cutting and welding units in profile factory .
Methods : The data of study was analyzed through the measurement of physical parameters with digital WBGT device and silvered Kata thermometer. Workers’ thermal comfort was calculated based on predicted mean voted (PMV) and predicted percentage of dissatisfied (PPD) with regard to the computed parameters. In order to control heat stress, an aluminum-insulated wall was used and airflow velocity was increased in cutting and welding units.
Results : The results of the WBGT index before and after the intervention using the shield were 30.8° C and 23.2° C, and by increasing airflow velocity were 30° C and 29.5° C respectively. In addition, the obtained results for PMV and PPD by using the shield were 1.38 and %44, and by increasing airflow velocity they were %90 and 2.56 respectively. The results confirmed by using the shield the measured WBGT index was lower than the occupational exposure limit (28 ◦ c).
Conclusion : The results showed that by appropriate designing and using control methods, such as insulation shield and increased airflow velocity, optimal thermal comfort based on national heat exposure limits could be reached
The Impact of Ergonomically Designed Workstations on Shoulder EMG Activity during Carpet Weaving
Background: The present study aimed to evaluate the biomechanical exposure
to the trapezius muscle activity in female weavers for a prolonged period in the
workstation A (suggested by previous studies) and workstation B (proposed by
the present study).
Methods: Electromyography data were collected from nine females during four
hours for each ergonomically designed workstation at the Ergonomics Laboratory,
Hamadan, Iran. The design criteria for ergonomically designed
workstations were: 1) weaving height (20 and 3 cm above elbow height for
workstations A and B, respectively), and 2) seat type (10° and 0° forwardsloping
seat for workstations A and B, respectively).
Results: The amplitude probability distribution function (APDF) analysis
showed that the left and right upper trapezius muscle activity was almost similar
at each workstation. Trapezius muscle activity in the workstation A was significantly
greater than workstations B (P<0.001).
Conclusion: In general, use of workstation B leads to significantly reduced
muscle activity levels in the upper trapezius as compared to workstation A in
weavers. Despite the positive impact of workstation B in reducing trapezius
muscle activity, it seems that constrained postures of the upper arm during
weaving may be associated with musculoskeletal symptoms
Assessment of Interior General and Local Lighting in Carpet Weaving Workshops in Bijar City
Background & Objectives : The comfort lighting in the workplace provides employees visual health which can improve safety, visual comfort and enhance performance and product quality. The present study was conducted to evaluate general and local lighting in carpet weaving workshops in Bijar city .
Methods : In this descriptive analytical study, 101 carpet weaving workshops were randomly selected. The illuminance were measured based on the models and formulas presented in Illuminating Engineering Society (IES) using luxmeter model Hagner EC1 in height 76 cm from the ground surface. The local illuminances were measured in horizontal and vertical weaving level. Data were analyzed by SPSS software (version 16).
Results : Research findings revealed the average of total and artificial illuminance level were 484.5±458.9 and 80.0±49.9 Lx respectively. Mean total, natural and artificial illuminance 39.6, 57.4 and 100 percent were lower the recommended 300 Lx levels. The average of minimum of local illuminance was less than 500 Lx in all workshops.
Conclusion : About 60% of workrooms had the acceptable general illuminance levels in middle day. However, due to the insufficient lighting sources in workshops, the artificial illuminance levels are unsuitable. Therefore, it is necessary to improve general illuminance levels by reform and repair artificial lighting systems or redesign them in carpet weaving workrooms
Investigating Intra-Rater and Inter-Rater Reliability of Three Upper-Limb Risk Assessment Methods
There are several methods for assessing the risk of upper-limb disorders in occupational health studies. The goal of present study is to determine the intra-rater and inter-rater reliability of three risk assessment methods of SI, OCRA Checklist and ART in repetitive tasks and exposure to upper-limb risk factors. First, 9 raters used SI, OCRA Checklist and ART to assess the physical exposure level of the upper limb in workers 30 tasks with different levels of profession for two assessment periods. In the results of inter-rater reliability using ICC, the risk classifications were ρ = 0.54, ρ = 0.74 and ρ = 0.77 for SI, OCRA Checklist and ART, respectively. And the intra-rater reliability for the final score of the OCRA Checklist, SI and ART methods was κ = 0.59, κ = 0.66 and κ = 0.67, respectively. The inter-rater reliability for risk classification and final score of ART, OCRA Checklist and SI methods using ICC) obtained as moderate to good. However, the overall results showed that the reliability of ART method was higher than two other methods. The findings demonstrated that all three methods are appropriate for assessment in workplaces. These methods should be used based on assessment objectives, rater experience and required time for assessing the tasks
Evaluation of Artificial Lighting and its Relationship with Body postures During Work in Hamadan Women\'s Hairdressers
Background and objective: 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 methods: 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.
Results: 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<0.05).
Conclusions: 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.