Video display terminals

System hardware consists of the central processor, the input devices (usually a keyboard), the output devices (probably both a video display terminal and a hardcopy printer), long-term storage devices, and perhaps communications components. In smaller systems, more than one of these components may be built in to one unit, while in larger systems there may be many units each of several components associated with the system. 

Work activities More time spent at photoduplication Carbonless copy paper More time at video display terminals Increasing amounts of time spent at workstation... 

Both allergic and irritant mechanisms have been proposed as explanations for eye symptoms. More rapid tear-film break-up time, a measure of tear film instability, is associated with increased levels of symptoms. Fat-foam thickness measurement and photography for documentation of ocular erythema have also been used. Some authors attribute eye symptoms at least in part to increased individual susceptibility based on those factors. In addition, office workers with ocular symptoms have been demonstrated to blink less frequently when working at video display terminals. Conjunctival staining with fluorescent dyes is a common clinical test for conjunctivitis sicca. 

Environmental criteria have been established for many of these, but the utility and applicability of such criteria for indoor environments is controversial for at least four reasons. Eor example, the goals of the threshold limit values often do not include preventing irritation, a primary concern in indoor environments with requirements for close eye work at video display terminals. For most of the pollutant categories, the problem of interactions, commonly termed the multiple contaminants problem , remains inadequately defined. Even for agents that are thought to affect the same receptor, such as aldehydes, alcohols, and ketones, no prediction models are well established. Finally, the definition of representative compounds for measurement is unclear. That is, pollutants must be measurable, but complex mixtures vary in their composition. It is unclear whether the chronic residual odor annoyance from environmental tobacco smoke correlates better with nicotine, particulates, carbon monoxide, or other pollutants. The measure total volatile organic compounds is meanwhile... 

The link between miscarriages and use of video display terminals (VDTs) became a public issue around 1980 with the reports of clusters of reproductive mishaps in women users ofVDTs. ... 

Now that we have the coefficients, we can return to the problem posed earlier how extraordinary are the reported clusters, or are they just what one might expect on the basis of pure chance, with or without video display terminals The statement in the above quote that the clusters were never adequately explained suggests that such an explanation is required, whereas pure chance neither requires nor has an explanation. 

Environmental Uncomfortable humidity and temperature cigarette smoke photocopiers and video display terminals handling carbonless paper chilled, humidified air from mechanical ventilation level of lighting odor complaints organic debris/volatile organic compounds... 

Acosta MC, Gallar J, Belmonte C. The inflnence of eye solutions on blinking and ocular comfort at rest and dnring work at video display terminals. Exp... 

National Institute for Occupational Safety and Health (NIOSH) (1981), Potential Health Hazards of Video Display Terminals, Cincinnati. 

Sauter, S. L., Gottlieb, H. S., Rohrer, K. N., and Dodson, V. N. (1983), The Well-Being of Video Display Terminal Users, Department of Preventive Medicine, University of Wisconsin-Madison, Madison, WI. 

VDT video display terminal WAD worst area difference... 

Lundberg, U., Melin, B., Evans, G. W, Holmberg, L. (1993). Physiological deactivation after two contrasting tasks at a video display terminal Learning vs. repetitive data entry. Ergonomics, 36, 601 -611. 

NIOSH S Publications on Video Display Terminals, 3RD. ED Author(s) No Author... 

For example, long hours at the video display terminal (VDT) can cause pains in the neck and back, eyestrain, and a general feeling of tension and irritability. Illness has increased among the office worker population. This may be attributed, in part, to the increased presence of environmental toxins within the office and to stress-producing factors associated with the automated office. Resulting illnesses may include respiratory problems, skin diseases, and stress-related conditions. 

Working safely with video display terminals, OSHA Pub 3092. 

Interventions—Video Display Terminal Workstation Design... 

Previously, all the stencils were prepared manually but, now, indirect photo-mechanical processing and photocomposition are widely used. The information is entered into a computer, which arranges it in an appropriate layout and exhibits it on a video display terminal from which it is photographed to make the stencils (Nethercott and Nosal 1986). 

OSHA has created the ergonomic assessment tool in Table 16.2 for video display terminal (VDT) workstations. This checklist is from the now-rescinded OSHA Ergonomics Safety Standard from 2000. Although the standard may not be currently in effect and enforced by OSHA, it still provides employers with a good... 

Video Display Terminal Volatile Organic Compound Voluntary Protection Program... 

Turville et al., 1998) To investigate the effects of two Video Display Terminals (VDT) on muscular activity VDT was positioned at a standard workplace design (15° below horizontal) and at 40° below horizontal. The results of the normalized EMG analysis showed significantly higher muscle activity in the 40° monitor condition... 

Ttirville, K.L., Psihogios, J.P., Uhner, TR. Mirka, G.A. (1998) The effects of video display terminal height on the operator a comparison of the 15 degree and 40 degree recommendations. Appl Ergon, 29,239-46. 

The first studies were described in occupational cervicobrachial disorder in cash register operators, driller s card and Japanese typists in Australia, described occupational overuse injury in typists and workers of the assembly line cases were subsequently referred to cumulative trauma disorders in workers exposed to cumulative trauma, including operators of video display terminals in the United States of America (McDermott, 1986, Kiesler and Finholt, 1988). 

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