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New information technologies are being introduced in all industrial sectors, albeit to varying extents. In some cases, the costs of computerizing production processes may constitute an impediment to innovation, particularly in small and medium-sized companies and in developing countries. Computers make possible the rapid collection, storage, processing and dissemination of large quantities of information. Their utility is further enhanced by their integration into computer networks, which allow resources to be shared (Young 1993).

Computerization exerts significant effects on the nature of employment and on working conditions. Beginning about the mid-1980s, it was recognized that workplace computerization may lead to changes in task structure and work organization, and by extension to work requirements, career planning and stress suffered by production and management personnel. Computerization may exert positive or negative effects on occupational health and safety. In some cases, the introduction of computers has rendered work more interesting and resulted in improvements in the work environment and reductions of workload. In others, however, the result of technological innovation has been an increase in the repetitive nature and intensity of tasks, a reduction of the margin for individual initiative and the isolation of the worker. Furthermore, several companies have been reported to increase the number of work shifts in an attempt to extract the largest possible economic benefit from their financial investment (ILO 1984).

As far as we have been able to determine, as of 1994 statistics on the worldwide use of computers are available from one source only—The Computer Industry Almanac (Juliussen and Petska-Juliussen 1994). In addition to statistics on the current international distribution of computer use, this publication also reports the results of retrospective and prospective analyses. The figures reported in the latest edition indicate that the number of computers is increasing exponentially, with the increase becoming particularly marked at the beginning of the 1980s, the point at which personal computers began to attain great popularity. Since 1987, total computer processing power, measured in terms of the number of million instructions per second executed (MIPS) has increased 14-fold, thanks to the development of new microprocessors (transistor components of microcomputers which perform arithmetical and logical calculations). By the end of 1993, total computing power attained 357 million MIPS.

Unfortunately, available statistics do not differentiate between computers used for work and personal purposes, and statistics are unavailable for some industrial sectors. These knowledge gaps are most likely due to methodological problems related to the collection of valid and reliable data. However, reports of the International Labour Organization’s tripartite sectoral committees contain relevant and comprehensive information on the nature and extent of the penetration of new technologies in various industrial sectors.

In 1986, 66 million computers were in use throughout the world. Three years later, there were more than 100 million, and by 1997, it is estimated that 275–300 million computers will be in use, with this number reaching 400 million by 2000. These predictions assume the widespread adoption of multimedia, information highway, voice recognition and virtual reality technologies. The Almanac’s authors consider that most televisions will be equipped with personal computers within ten years of publication, in order to simplify access to the information highway.

According to the Almanac, in 1993 the overall computer: population ratio in 43 countries in 5 continents was 3.1 per 100. It should however be noted that South Africa was the only African country reporting and that Mexico was the only Central American country reporting. As the statistics indicate, there is a very wide international variation in the extent of computerization, the computer:population ratio ranging from 0.07 per 100 to 28.7 per 100.

The computer:population ratio of less than 1 per 100 in developing countries reflects the generally low level of computerization prevailing there (table 1) (Juliussen and Petska-Juliussen 1994). Not only do these countries produce few computers and little software, but lack of financial resources may in some cases prevent them from importing these products. Moreover, their often rudimentary telephone and electrical utilities are often barriers to more widespread computer use. Finally, little linguistically and culturally appropriate software is available, and training in computer-related fields is often problematic (Young 1993).


Table 1. Distribution of computers in various regions of the world







   United States


















































   United Kingdom




   Czech Republic






   Russian Federation








   New Zealand




   South Africa














   Korea, Republic of




   Saudi Arabia










Less than 1

1 - 5   6 - 10   11 - 15   16-20   21 - 30

Source: Juliussen and Petska-Juliussen 1994.


Computerization has significantly increased in the countries of the former Soviet Union since the end of the Cold War. The Russian Federation, for example, is estimated to have increased its stock of computers from 0.3 million in 1989 to 1.2 million in 1993.

The largest concentration of computers is found in the industrialized countries, especially in North America, Australia, Scandinavia and Great Britain (Juliussen and Petska-Juliussen 1994). It was principally in these countries that the first reports of visual display unit (VDU) operators’ fears regarding health risks appeared and the initial research aimed at determining the prevalence of health effects and identifying risk factors undertaken. The health problems studied fall into the following categories: visual and ocular problems, musculoskeletal problems, skin problems, reproductive problems, and stress.

It soon became evident that the health effects observed among VDU operators were dependent not only on screen characteristics and workstation layout, but also on the nature and structure of tasks, organization of work and manner in which the technology was introduced (ILO 1989). Several studies have reported a higher prevalence of symptoms among female VDU operators than among male operators. According to recent studies, this difference is more reflective of the fact that female operators typically have less control over their work than do their male counterparts than of true biological differences. This lack of control is thought to result in higher stress levels, which in turn result in increased symptom prevalence in female VDU operators.

VDUs were first introduced on a widespread basis in the tertiary sector, where they were used essentially for office work, more specifically data entry and word processing. We should not therefore be surprised that most studies of VDUs have focused on office workers. In industrialized countries, however, computerization has spread to the primary and secondary sectors. In addition, although VDUs were used almost exclusively by production workers, they have now penetrated to all organizational levels. In recent years, researchers have therefore begun to study a wider range of VDU users, in an attempt to overcome the lack of adequate scientific information on these situations.

Most computerized workstations are equipped with a VDU and a keyboard or mouse with which to transmit information and instructions to the computer. Software mediates information exchange between the operator and the computer and defines the format with which information is displayed on the screen. In order to establish the potential hazards associated with VDU use, it is first necessary to understand not only the characteristics of the VDU but also those of the other components of the work environment. In 1979, Çakir, Hart and Stewart published the first comprehensive analysis in this field.

It is useful to visualize the hardware used by VDU operators as nested components that interact with each other (IRSST 1984). These components include the terminal itself, the workstation (including work tools and furniture), the room in which the work is carried out, and the lighting. The second article in this chapter reviews the main characteristics of workstations and their lighting. Several recommendations aimed at optimizing working conditions while taking into account individual variations and variations in tasks and work organization are offered. Appropriate emphasis is placed on the importance of choosing equipment and furniture which allow flexible layouts. This flexibility is extremely important in light of international competition and rapidly evolving technological development that are constantly driving companies to introduce innovations and while simultaneously forcing them to adapt to the changes these innovations bring.

The next six articles discuss health problems studied in response to fears expressed by VDU operators. The relevant scientific literature is reviewed and the value and limitations of research results highlighted. Research in this field draws upon numerous disciplines, including epidemiology, ergonomics, medicine, engineering, psychology, physics and sociology. Given the complexity of the problems and more specifically their multifactorial nature, the necessary research has often been conducted by multidisciplinary research teams. Since the 1980s, these research efforts have been complemented by regularly organized international congresses such as Human-Computer Interaction and Work with Display Units, which provide an opportunity to disseminate research results and promote the exchange of information between researchers, VDU designers, VDU producers and VDU users.

The eighth article discusses human-computer interaction specifically. The principles and methods underlying the development and evaluation of interface tools are presented. This article will prove useful not only to production personnel but also those interested in the criteria used to select interface tools.

Finally, the ninth article reviews international ergonomic standards as of 1995, related to the design and layout of computerized workstations. These standards have been produced in order to eliminate the hazards to which VDU operators can be exposed in the course of their work. The standards provide guidelines to companies producing VDU components, employers responsible for the purchase and layout of workstations, and employees with decision-making responsibilities. They may also prove useful as tools with which to evaluate existing workstations and identify modifications required in order to optimize operators’ working conditions.



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" DISCLAIMER: The ILO does not take responsibility for content presented on this web portal that is presented in any language other than English, which is the language used for the initial production and peer-review of original content. Certain statistics have not been updated since the production of the 4th edition of the Encyclopaedia (1998)."


Part I. The Body
Part II. Health Care
Part III. Management & Policy
Part IV. Tools and Approaches
Part V. Psychosocial and Organizational Factors
Part VI. General Hazards
Barometric Pressure Increased
Barometric Pressure Reduced
Biological Hazards
Disasters, Natural and Technological
Heat and Cold
Hours of Work
Indoor Air Quality
Indoor Environmental Control
Radiation: Ionizing
Radiation: Non-Ionizing
Visual Display Units
Part VII. The Environment
Part VIII. Accidents and Safety Management
Part IX. Chemicals
Part X. Industries Based on Biological Resources
Part XI. Industries Based on Natural Resources
Part XII. Chemical Industries
Part XIII. Manufacturing Industries
Part XIV. Textile and Apparel Industries
Part XV. Transport Industries
Part XVI. Construction
Part XVII. Services and Trade
Part XVIII. Guides

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