Effect of Subjective and Objective Workload on Asthenopia at VDU Workplaces

An ergophthalmological tool has been developed to investigate effects of subjective and objective workload on work-related visual complaints (asthenopia). In field studies on different visual display unit (VDU) workplaces effects of objective and subjective workload, work intensity, and work breaks (5-9 min/hour) could be found. It could be shown that during the first hours of VDU work, asthenopic complaints have the tendency to follow effective workload. With increasing working time the effect of a general and visual fatigue overlaps other reported visual complaints in the majority of cases.     

Impact of rest-break interventions on the neck and shoulder posture of symptomatic VDU operators during prolonged computer work

There is limited research on the effects of different types of rest-break interventions for visual display unit (VDU) operators on neck and shoulder postures. This study examined the effect of rest-break interventions on the neck and shoulder postures of symptomatic VDU operators during prolonged computer work. Thirty subjects were randomly and equally assigned to breaks with stretching, breaks with dynamic movement and passive breaks. Subjects performed the typing task for 60 min and received 3-min breaks after 20 min of work. The craniovertebral and forward shoulder angles were obtained from a 3D motion analysis system. Results showed that there were no significant differences in the craniovertebral and forward shoulder angles among any types of rest breaks. It can be concluded that the three types of rest-break interventions had positive effects on neck and shoulder posture during prolonged computer terminal work.     

Will Musculoskeletal,Visual and Psychosocial Stress Change for Visual Display Unit (VDU) Operators When Moving From a Single-Occupancy Office to an Office Landscape?

This study investigated the effect of moving from single-occupancy offices to a landscape environment. Thirty-two visual display unit (VDU) operators reported no significant change in visual discomfort. Lighting conditions and glare reported subjectively showed no significant correlation with visual discomfort. Experience of pain was found to reduce subjectively rated work capacity during VDU tasks. The correlation between visual discomfort and reduced work capacity for single-occupancy offices was r_s = .88 (p = .000) and for office landscape r_s = .82 (p = .000). Eye blink rate during habitual VDU work was recorded for 12 operators randomly selected from the 32 participants in the office landscape. A marked drop in eye blink rate during VDU work was found compared to eye blink rate during easy conversation. There were no significant changes in pain intensity in the neck, shoulder, forearm, wrist/hand, back or headache (.24 < p < .67). Pain levels in different body areas were significantly correlated with reduced work capacity, .77 < r_s < .99 (p = .000).     

Stress reactions in computerized administrative work

Ninety-five white-collar workers employed by an insurance company using visual display units (VDU) connected by telecommunication to a central computer filled in a questionnaire concerning psychosocial stressors in connection with work at the VDU. Eleven persons with extensive and ten with no work at VDUs were also studied during regular work, during breakdown of machinery, and in their leisure time. Self-reports on mood and alertness were recorded along with blood pressure, heart rate, and excretion of adrenaline and noradrenaline. Results indicate that (1) stress and mental strain occurred in association with delayed response times in the computer system and unpredicted interruptions of system operation, (2) such a temporary interruption caused an increase of blood pressure and adrenaline excretion, (3) complaints of stress and strain were repotted mainly by data-entry staff, (4) data-entry groups displayed a higher level of physiological arousal during post-work hours than a control group, and (5) that a majority of those who worked continuously at a VOU reported physical discomfort within 1.5 hours. It is concluded that stress and strain in computerized work may be counteracted at the technological and the organizational level: by reducing the duration and frequency of breakdowns, by reducing response times in the system, and by eliminating pure data-entry tasks.     

Effects of Ergorest® Arm Supports on Muscle Strain and Wrist Positions During the Use of the Mouse and Keyboard in Work With Visual Display Units: A Work Site Intervention

The effects of Ergorest^® arm supports on wrist angles and musculoskeletal strain in the neck-shoulder-arm region and electrical activity in the shoulder and arm muscles were studied during typing or the use of the mouse in work with a visual display unit (VDU). Twenty-one women were randomized into 3 groups (1 arm support, 2 arm supports, and control). Measurements were carried out before and after the 6-week intervention. The wrist extension of the mouse hand, the muscle activity of the trapezius muscle, and the subjective discomfort ratings indicated that 2 arm supports were better than 1 in work with a mouse. The Ergorest^® arm support alleviates muscle and joint strain in VDU work when used for both arms.     

Effect of Different Types of Rest-Break Interventions on Neck and Shoulder Muscle Activity,Perceived Discomfort and Productivity in Symptomatic VDU Operators: A Randomized Controlled Trial

Objective. This study evaluated the effect of different types of activities during rest-break interventions on neck and shoulder muscle activity, muscle discomfort and productivity among symptomatic video display unit (VDU) operators performing prolonged computer terminal work. Study design and setting. Randomized controlled trial was used. Thirty symptomatic VDU operators were randomly assigned to 2 active break groups (stretching and dynamic movement) and a reference group. The subjects performed the same typing task for 60 min and received 3-min breaks after each 20 min of work. Root mean square and median frequency were calculated for neck and shoulder muscle activity. Muscle discomfort was measured with Borg’s CR-10 scale. Productivity was measured by counting words. Results. There were no significant differences between the types of activities during breaks on neck and shoulder muscle activity, muscle discomfort or productivity. However, there was a significant difference in the level of muscle discomfort over time. Conclusions. Three types of activity during breaks showed a favourable effect on neck and shoulder muscle activity and productivity, and a positive effect on muscle discomfort in symptomatic VDU operators.     

Sitting Posture,Postural Discomfort,and Visual Performance: A Critical View on the Interdependence of Cognitive and Anthropometric Factors in the VDU Workplace

The study focuses on individual and standard visual display unit (VDU) workplaces with respect to performance and muscular load. Three different work settings were realized: The workplace was either adjusted to individual preferences or to the European standard. The third condition mirrored exactly the individual setting, however participants were told that it was set according to another standard. Dependent variables were visual performance in a search task, the rated muscular load, and individual preferences. Results show that both individual work settings yielded a superior performance as compared to the standard. However, performance and muscular comfort improved when participants knew they had adjusted the workplace. Apparently, VDU users follow a intuitive rationale adjusting their work setting minimizing muscular load and optimizing performance.     

Dimensions of Job Control in Computerized and Traditional Office Work and Its Health Effects

This study investigates whether a consistent relationship exists between computerization and job control. It also examines the role of job control as a predictor of stress symptoms typical for data entry and word processing (VDU) work. Two groups of VDU users and two comparable non-VDU-user groups took part in this study. A special questionnaire made it possible to assess global job control and four indexes of control related to specific aspects of work (control over choice of tasks and methods, control over time frame, control related to one’s skill, and control related to participation in the decision-making process). Results did not show an unequivocal relation between computerization and the latitude of control. The latitude of control depends on the task performed and the aspect of control we are considering. Regression analyses showed that global control is a good predictor of job satisfaction, some mood disturbances, and visual complaints. The other aspects of control are related in a variety of ways to stress symptoms. The role of a Type A behavior pattern in the relationship between job control and stress symptoms varies depending on which aspect of control is being considered. It was concluded that because of the high functional differences between various aspects of control, it is better to avoid using the concept of global control and, when possible, apply specific indexes of control.     

Operators’ signal-detection performance in video display unit monitoring tasks of the main control room

This study evaluated the operators’ signal-detection performance in video display unit (VDU) monitoring tasks of the main control room (MCR). So far the study of the relationship between VDU design strategy and human errors has been superficial. To validate the effect of VDUs design strategies on operating errors in the MCR, this present research adopted a within subject experimental design to develop different experimental treatments based on two types of display modes included consistent mode and mixed mode. A total of 13 undergraduate and graduate students were recruited as participants in the experiment. Dependent variables included situation awareness, reaction time, error frequency, and subjective performance. Some research support was found for the representation principles. The conclusions of this study could not only be implemented by the human-system interface (HSI) designers of a MCR in the advanced nuclear power plant (NPP) but also could be generalized to the extent that other digital workstation similar to the MCR.     

Work-related injuries of educational support staff in schools

This study aims to describe the characteristics of occupational injuries to educational support staff (service worker) in schools. In this research, 803 injured workers registered in 2015 were analyzed in terms of their gender, age, work experience, school type, work type, accident type, agency of accident, nature of injury and injured part of the body for each occupation. The workers were classified into after-school instructor, custodian and cooking staff. Accidents occurred mainly due to slips (35.6%) on floor/stair or contact with high temperature (18.1%). Also, the workers mostly fractured (41.2%) or had burns (19.3%) on their leg/foot (37.1%) or arm/hand/finger (29.8%). The results showed the difference in characteristics and injury pattern of injured persons for each occupation type, addressing the need for customized preventative measures for each situation. The results of this study can be a baseline in devising policies and guidelines for preventing accidents of service workers in schools.     

视屏作业人员慢性肌肉骨骼损伤的调查研究

２３２名微机操作人员的慢性肌肉骨骼损伤表现为肩、颈、下背的酸痛和肩疲劳，与对照组比差异显著。手、腕及上肢的慢性损伤虽较对照组高，但无统计学意义。这与他们的击键次数相对较少（每日１００００次左右），但需长期间保持低头及向前弯腰的坐位姿势及工作台面太高等因素有关     

Age and lost working days as a result of an occupational accident: A study in a shiftwork rotation system

The present work analyzed the relationship of age and tenure with occupational accident severity of 156 male shiftworkers at an industrial plant. Based on past research, negative binomial regression analyses were performed to examine the association of age and tenure with the lost working days due to medically certified occupational accidents (LWDI). The main effects of age and tenure and the contribution of age by tenure interaction and age squared terms were examined. Regression results indicated a significant association of age by tenure interaction with LWDI. However, this relationship was non-significant when considering an age squared term in the regression equation, suggesting a non-linear association of age with LWDI. The findings are discussed in regard to the specific preventative measures of occupational accidents in shiftwork systems that could be addressed to different age groups.     

"两硬"条件高瓦斯放顶煤工作面瓦斯防治技术探讨

放顶煤综采工作面由于其工艺的特殊性,瓦斯防治工作一直是安全开采的难题之一,大同矿区特有的“两硬”条件（坚硬顶板、坚硬煤层）作开采时其顶板、顶煤难以冒落,给瓦斯治理带来了更多的困难.经过近几年的攻关研究,同煤集团已经形成了一整套行之有效的方法,保证了矿井的安全生产.本文对“两硬”条件下的高瓦斯放顶煤工作面的瓦斯防治方法做一简单的介绍.     

Experimental research on explosibility at high initial pressures of combustible dusts

In recent years some explosibility experiments were carried out by LOM (Spain) to look into the behaviour of the combustible dusts at hyperbaric pressures. In this way, different aspects were studied, such as the effect of initial pressure on the explosion development, the influence of the effective present turbulence or preventative existing techniques such as inertization.This paper contains a summary of the different tests performed, which covered a range of initial pressure from 1 to 15 bar. Several fuels were used within the works, and their main features are described to facilitate understanding the results.     

贝叶斯网络在CFIT风险评价中的应用

针对事故树分析法(FTA)在风险评价中的局限性,在可控飞行撞地(CFIT)事故树的基础上,建立贝叶斯网络(BN).运用推理运算对贝叶斯网络进行定量分析,通过分析计算数据,寻找主要事故致因,并提出对应的改进措施.再将改进措施引入到贝叶斯网络中,评价相关措施的有效性.结果表明,改进措施后,高度设置错误的后验概率最大,将成为预防CFIT的工作重点.最后指出贝叶斯网络方法是对传统的基于故障树分析的风险评价方法的有益改进.     

Early warning signals noticed,but management doesn't act adequately or not at all: a brief analysis and direction of possible improvement

History has taught us that quite disastrous events with much human loss, injuries and asset damage could have been prevented or at least mitigated, if top management had recognized early warning signals in some form as urgent and had decided to take timely preventative measures. It turns out to be a rather common phenomenon in various sectors of life and some process industry examples are presented. The problem is further analyzed from a leadership point of view, from organizational structure and culture aspect, and what modern technology developments can help to improve the situation. Research in the latter directions is encouraged.     

Managers’ attitudes towards safety measures in the commercial road transport sector

Safety measures and related costs and benefits have been widely discussed and analysed in academic circles and by the authorities and industrial sectors. The study reported in this paper addresses these aspects from a cognitive based perspective. Risk management is about dealing with the conflict between production and safety. Enterprises which spend too much on safety will meet bankruptcy, and those not concerned with safety measures will meet with severe accidents and related damage. Inspired by James Reason’s theoretical framework, managers (n = 106) of commercial transport enterprises were asked about their attitudes towards safety management, what factors have contributed and their belief that further effort and investments in health, environment and safety (HES) measures will pay off. One half of the managers perceive HES work as too expensive and approximately one quarter assess mandatory HES work as compromising their competitiveness. One third of the managers do not find further safety measures than those already implemented necessary or remunerative. They claim that there are no other alternative ways of doing their activities and that there are no technical measures available that could meet outstanding safety challenges. Managers do acknowledge HES work as important for the reputation of the enterprise. The factor analysis gave five HES attitude factors: (I) concerned with formalities, (II) HES work improves health, environment and safety, (III) HES work is ineffective, (IV) HES regulation is appropriate, and (V) HES work can be improved.     

An algorithm for the implementation of safety improvement programs

In production system workplace environments, the achievement of safety objectives depends essentially on the risk assessment process and on the adequacy of measures to eliminate or reduce risk. The main goal of the planning phase is to define in advance the effective management of resources (financial, human and technical) involved in the completion of the overall safety improvement program. Indeed, whereas the results of the risk assessment process depend only on the correct evaluation of the work system with respect to human safety, the planning phase of safety improvement program is subject to economic, technical and organisational constraints and has to be integrated with other company objectives. Within this context, the plan definition should include additional objectives other than risk reduction, such as the clustering of measures with homogenous or compatible characteristics and the minimisation of production system disturbance (inefficiency) over the program time span. However, no safety improvement program can really be implemented if operational constraints (i.e. finite availability of resources, incompatibility in the execution of measures and limited acceptance of inefficiency) are overlooked. The present paper proposes a quantitative view of these objectives and constraints in order to develop an algorithm for the scheduling of measures within a safety improvement program. By means of the evaluation of a priority index, this algorithm provides a plan with the higher rate of risk reduction possible that maximises the objectives in function of their relative importance, obeying the imposed constraints. The definition of the safety improvement program for a textile factory shows how the algorithm can produce a plan with higher rate of risk reduction in comparison with plans based only on risk priority.     

Characteristics of worker accidents on NYSDOT construction projects

INTRODUCTION: This paper aims at providing cost-effective safety measures to protect construction workers in highway work zones, based on real data. Two types of accidents that occur in work zones were: (a) construction work area accidents, and (b) traffic accidents involving construction worker(s). METHODOLOGY/RESULTS: A detailed analysis of work zone accidents involving 36 fatalities and 3,055 severe injuries to construction workers on New York State Department of Transportation (NYSDOT) construction projects from 1990 to 2001 established that five accident types: (a) Struck/Pinned by Large Equipment, (b) Trip or Fall (elevated), (c) Contact w/Electrical or Gas Utility, (d) Struck-by Moving/Falling Load, and (e) Crane/Lift Device Failure accounted for nearly 96% of the fatal accidents, nearly 63% of the hospital-level injury accidents, and nearly 91% of the total costs. These construction work area accidents had a total cost of $133.8 million. Traffic accidents that involve contractors' employees were also examined. Statistical analyses of the traffic accidents established that five traffic accident types: (a) Work Space Intrusion, (b) Worker Struck-by Vehicle Inside Work Space, (c) Flagger Struck-by Vehicle, (d) Worker Struck-by Vehicle Entering/Exiting Work Space, and (e) Construction Equipment Struck-by Vehicle Inside Work Space accounted for nearly 86% of the fatal, nearly 70% of the hospital-level injury and minor injury traffic accidents, and $45.4 million (79.4%) of the total traffic accident costs. CONCLUSIONS: The results of this paper provide real statistics on construction worker related accidents reported on construction work zones. Potential preventions based on real statistics have also been suggested. IMPACT ON INDUSTRY: The ranking of accident types, both within the work area as well as in traffic, will guide the heavy highway contractor and owner agencies in identifying the most cost effective safety preventions.     

Occupational deaths and injuries by the types of street cleaning process

This study aims to obtain an overall picture of occupational injuries by the types of street cleaning process. Three hundred and fifty-four injured persons were analyzed in terms of the company size and details of the injured persons and accidents. Results show that ‘roadway cleaning’ was the most common type of cleaning process for injuries, followed by ‘sidewalk cleaning,’ ‘going/returning to work by bike’ and ‘lifting/carrying.’ The findings also show that most accidents which occur when ‘going/returning to work by bike’ are in the form of traffic accidents, while in other processes they happen most often in the form of slips. Most of the accidents related to ‘lifting/carrying’ affected workers in their 50s or younger while other processes had a large portion of injured persons in their 50s or older. The findings of this study can be used as baseline data for preventative policies.