In designing a product or an industrial process, one focuses on the “average” and “healthy” worker. Information regarding human abilities in terms of muscular strength, bodily flexibility, length of reach, and many other characteristics is for the most part derived from empirical studies carried out by military recruitment agencies, and reflects measured values valid for the typical young male in his twenties. But working populations, to be sure, consist of people of both sexes and a broad range of ages, to say nothing of a variety of physical types and abilities, levels of fitness and health, and functional capacities. A classification of the varieties of functional limitation among people as outlined by the World Health Organization is given in the accompanying article "Case Study: The International Classifcation of Functional Limitation in People." At present, industrial design for the most part takes insufficient account of the general abilities (or inabilities, for that matter) of workers at large, and should take as its point of departure a broader human average as a basis for design. Clearly, a suitable physical load for a 20-year-old may exceed the capacity to manage of a 15-year-old or a 60-year-old. It is the business of the designer to consider such differences not only from the point of view of efficiency, but with a eye to the prevention of job-related injury and illness.

The progress of technology has brought about the state of affairs that, of all the workplaces in Europe and North America, 60% involve the seated position. The physical load in work situations is now on average far less than before, but many worksites, nonetheless, call for physical loads that cannot be sufficiently reduced to fit human physical capabilities; in some developing countries, the resources of current technology are simply not available to relieve the human physical burden to any appreciable extent. And in technologically advanced countries, it is still a common problem that a designer will adapt his or her approach to constraints imposed by product specifications or production processes, either slighting or leaving out human factors related to disability and the prevention of harm due to the workload. With respect to these aims, designers have to be educated to devote attention to all such human factors, expressing the results of their study in a product requirements document (PRD). The PRD contains the system of demands which the designer has to meet in order to achieve both the expected product quality level and the satisfaction of human capability needs in the production process. While it is unrealistic to demand a product that matches a PRD in every respect, given the need of unavoidable compromises, the design method suited to the closest approach to this goal is the system ergonomic design (SED) method, to be discussed following a consideration of two alternative design approaches.

Creative Design

This design approach is characteristic of artists and others involved in the production of work of a high order of originality. The essence of this design process is that a concept is worked out intuitively and through “inspiration”, allowing problems to be dealt with as they arise, without conscious deliberation beforehand. Sometimes, the outcome will not resemble the initial concept, but nonetheless represents what the creator regards as his or her authentic product. Not seldom, too, the design is a failure. Figure 1 illustrates the route of creative design.

Figure 1. Creative design

System Design

System design arose from the need to predetermine the steps in design in a logical order. As design becomes complex, it has to be subdivided into subtasks. Designers or subtask teams thus become interdependent, and design becomes the job of a design team rather than an individual designer. Complementary expertise is distributed through the team, and design assumes an interdisciplinary character.

System design is oriented to the optimal realization of complex and well-defined product functions through the selection of the most appropriate technology; it is costly, but the risks of failure are considerably reduced as compared with less organized approaches. The efficacy of the design is measured against the goals formulated in the PRD.

The way in which the specifications formulated in the PRD are of the first importance. Figure 2 illustrates the relationship between the PRD and other parts of the system design process.

Figure 2. System design

As this scheme shows, the input of the user is neglected. Only at the end of the design process can the user criticize the design. This is unhelpful to both producer and user, since one has to wait for the next design cycle (if there is one) before errors can be corrected and modifications made. Furthermore, user feedback is seldom systematized and imported into a new PRD as a design influence.

System ergonomic design (SED)

SED is a version of system design adapted to ensure that the human factor is accounted for in the design process. Figure 3 illustrates the flow of user input into the PRD.

Figure 3. System ergonomic design

In system ergonomic design, the human being is considered part of the system: design specification changes are, in fact, made in consideration of the worker’s abilities with respect to cognitive, physical and mental aspects, and the method lends itself as an efficient design approach for any technical system where human operators are employed.

For example, to examine the implications of the worker’s physical abilities, task-allocation in the design of the process will call for a careful selection of tasks to be performed by the human operator or by the machine, each task being studied for its aptness to machine or human treatment. Clearly, the human worker will be more effective at interpreting incomplete information; machines however calculate much more rapidly with prepared data; a machine is the choice for lifting heavy loads; and so forth. Furthermore, since the user-machine interface can be tested at the prototype phase, one can eliminate design errors that would otherwise untimely manifest                                                                                                                                         themselves at the phase of technical functioning.

Methods in User Research

No “best” method exists, nor any source of formulae and sure and certain guidelines, according to which design for disabled workers ought to be undertaken. It is a rather a common-sense business of making as exhaustive search of all obtainable knowledge relevant to the problem and of implementing it to its most evident best effect.

Information can be assembled from sources such as the following:

• The literature of research results.

• Direct observation of the disabled person at work and description of his or her particular work difficulties. Such observation should be made at a point in the worker’s schedule when he or she can be expected to be subject to fatigue—the end of a work shift, perhaps. The point is that any design solutions should be adapted to the most arduous phase of the work process, or else such phases may fail to be performed adequately (or at all) owing to the worker’s capacity having been physically exceeded.

• The interview. One has to be aware of the possibly subjective responses which the interview per se may have the effect of eliciting. It is a far better approach that the interview technique be combined with observation. Disabled persons sometimes hesitate to discuss their difficulties, but when workers are aware that the investigator is willing to exert special thoroughness on their behalf, their reticence will diminish. This technique is time-consuming, but quite worthwhile.

• Questionnaires. An advantage of the questionnaire is that it can be distributed to large groups of respondents and at the same time gather data of as specific a sort as one wishes to provide for. The questionnaire must, however, be constructed upon the basis of representative information pertaining to the group to which it will be administered. This means that the type of information to be sought must be obtained on the basis of interviews and observations carried out among a sample of workers and specialists that ought to be reasonably restricted as to size. In the case of disabled persons, it is sensible to include among such a sample the physicians and therapists who are involved with prescribing special aids for disabled persons and have examined them regarding their physical capabilities.

• Physical measurements. Measurements obtained from instruments in the field of bio-instrumentation (e.g., the activity level of muscles, or the amount of oxygen consumed in a given task) and by anthropometrical methods (e.g., the linear dimensions of body elements, the range of motion of limbs, muscular strength) are of indispensable value in human-oriented work designs.

The methods described above are some of the various ways of gathering data about people. Methods exist, too, to evaluate user-machine systems. One of these—simulation—is to construct a realistic physical copy. The development of a more or less abstract symbolic representation of a system is an example of modelling. Such expedients, of course, are both useful and necessary when the actual system or product is not in existence or not accessible to experimental manipulation. Simulation is more often used for training purposes and modelling for research. A mock-up is a full-size, three-dimensional copy of the designed workplace composed, where necessary, of improvised materials, and is of great use in testing design possibilities with the proposed disabled worker: in fact, the majority of design problems can be identified with the aid of such a device. Another advantage to this approach is that the motivation of the worker grows as he or she participates in the design of his or her own future workstation.

Analysis of Tasks

In the analysis of tasks, different aspects of a defined job are subject to analytical observation. These manifold aspects include posture, routing of work manipulations, interactions with other workers, handling tools and operating machines, the logical order of subtasks, the efficiency of operations, static conditions (a worker may have to perform tasks in the same posture over a long time or with high frequency), dynamic conditions (calling for numerous varying physical conditions), material environmental conditions (as in a cold slaughterhouse) or non-material conditions (as with stressful work surroundings or the organization of the work itself).

Work design for the disabled person has, then, to be founded on a thorough task analysis as well as a full examination of the functional abilities of the disabled person. The basic design approach is a crucial issue: it is more efficient to elaborate all possible solutions for the problem in hand without prejudice than to produce a single design concept or a limited number of concepts. In design terminology, this approach is called making a morphological overview. Given the multiplicity of original design concepts, one can proceed to an analysis of the pro and con features of each possibility with respect to material use, construction method, technical production features, ease of manipulation, and so on. It is not unprecedented that more than one solution reaches the prototype stage and that a final decision is made at a relatively late phase in the design process.

Although this may seem a time-consuming way to realize design projects, in fact the extra work it entails is compensated for in terms of fewer problems encountered in the developmental stage, to say nothing that the result—a new workstation or product—will have embodied a better balance between the needs of the disabled worker and the exigencies of the working environment. Unfortunately, the latter benefit rarely if ever reaches the designer in terms of feedback.

Product Requirements Document (PRD) and Disability

After all information relating to a product has been assembled, it should be transformed into a description not only of the product but of all those demands which may be made of it, regardless of source or nature. These demands may of course be divided along various lines. The PRD should include demands relating to user-operator data (physical measurements, range of motion, range of muscular strength, etc.), technical data (materials, construction, production technique, safety standards, etc.), and even conclusions arising out of market feasibility studies.

The PRD forms the designer’s framework, and some designers regard it as an unwelcome restriction of their creativity rather than as a salutary challenge. In view of the difficulties at times accompanying the execution of a PRD, it should always be borne steadily in mind that a design failure causes distress for the disabled person, who may relinquish his or her efforts to succeed in the employment arena (or else fall helpless victim to the progress of the disabling condition), and additional costs for redesign as well. To this end, technical designers should not operate alone in their design work for the disabled, but should cooperate with whatever disciplines are needed for securing the medical and functional information to set up an integrated PRD as a framework for the design.

Prototype Testing

When a prototype is built, it should be tested for errors. Error testing should be carried out not only from the point of view of the technical system and subsystems, but also with a view to its usability in combination with the user. When the user is a disabled person, extra precautions have to be taken. An error to which an unimpaired worker may successfully respond in safety may not afford the disabled worker the opportunity of avoiding harm.

Prototype testing should be carried out on a small number of disabled workers (except in the case of a unique design) according to a protocol matched to the PRD. Only by such empirical testing can the degree to which the design meets the demands of the PRD be adequately judged. Although results on small numbers of subjects may not be generalizable to all cases, they do supply valuable information for the designer’s use in either the final design or in future designs.

Evaluation

The evaluation of a technical system (a work situation, machine or tool) should be judged on its PRD, not by questioning the user or even by attempting comparisons of alternative designs with respect to physical performance. For instance, the designer of a specific knee brace, basing his or her design on research results that show unstable knee joints to exhibit a delayed hamstring reaction, will create a product that compensates for this delay. But another brace may have different design aims. Yet present evaluation methods show no insight as to when to prescribe what kind of knee brace to which patients under what conditions—precisely the sort of insight a health professional needs when prescribing technical aids in the treatment of disabilities.

Current research aims at making this sort of insight possible. A model used to obtain insight into those factors which actually determine whether or not a technical aid ought to be used, or whether or not a worksite is well designed and equipped for the disabled worker is the Rehabilitation Technology Useability Model (RTUM). The RTUM model offers a framework to use in evaluations of existing products, tools or machines, but can also be used in combination with the design process as shown in figure 4.

Figure 4. Rehabilitation Technology Useability Model (RTUM) in combination with the system ergonomic design approach

Evaluations of existing products reveal that as regards technical aids and worksites, the quality of PRDs is very poor. At some times, the product requirements are not recorded properly; at others they are not developed to a useful extent. Designers simply must learn to start documenting their product requirements, including those relevant to disabled users. Note that, as figure 4 shows, RTUM, in conjunction with SED, offers a framework that includes the requirements of disabled users. Agencies responsible for prescribing products for their users must request industry to evaluate those products before marketing them, a task in essence impossible in the absence of product requirement specifications; figure 4 also shows how provision can be made to ensure that the end result can be evaluated as it should (on a PRD) with the help of the disabled person or group for whom the product is intended. It is up to national health organizations to stimulate designers to abide by such design standards and to formulate appropriate regulations.

Back

Occupational disease and injury surveillance entails the systematic monitoring of health events in working populations in order to prevent and control occupational hazards and their associated diseases and injuries. Occupational disease and injury surveillance has four essential components (Baker, Melius and Millar 1988; Baker 1986).

1. Gather information on cases of occupational diseases and injuries.
2. Distil and analyse the data.
3. Disseminate organized data to necessary parties, including workers, unions, employers, governmental agencies and the public.
4. Intervene on the basis of data to alter the factors that produced these health events.

Surveillance in occupational health has been more concisely described as counting, evaluating and acting (Landrigan 1989).

Surveillance commonly refers to two broad sets of activities in occupational health. Public health surveillance refers to activities undertaken by federal, state or local governments within their respective jurisdictions to monitor and to follow up on occupational diseases and injuries. This type of surveillance is based on a population, that is, the working public. The recorded events are suspected or established diagnoses of occupational illness and injury. This article will examine these activities.

Medical surveillance refers to the application of medical tests and procedures to individual workers who may be at risk for occupational morbidity, to determine whether an occupational disorder may be present. Medical surveillance is generally broad in scope and represents the first step in ascertaining the presence of a work-related problem. If an individual or a population is exposed to a toxin with known effects, and if the tests and procedures are highly targeted to detect the likely presence of one or more effects in these persons, then this surveillance activity is more aptly described as medical screening (Halperin and Frazier 1985). A medical surveillance programme applies tests and procedures on a group of workers with common exposures for the purpose of identifying individuals who may have occupational illnesses and for the purpose of detecting patterns of illness which may be produced by occupational exposures among the programme participants. Such a programme is usually undertaken under the auspices of the individual’s employer or union.

Functions of Occupational Health Surveillance

Foremost among the purposes of occupational health surveillance is to identify the incidence and prevalence of known occupational diseases and injuries. Gathering descriptive epidemiological data on the incidence and prevalence of these diseases on an accurate and comprehensive basis is an essential prerequisite for establishing a rational approach to the control of occupational disease and injury. Assessment of the nature, magnitude and distribution of occupational disease and injury in any geographic area requires a sound epidemiological database. It is only through an epidemiological assessment of the dimensions of occupational disease that its importance relative to other public health problems, its claim for resources and the urgency of legal standard setting can be reasonably evaluated. Second, the collection of incidence and prevalence data allows analysis of trends of occupational disease and injury among different groups, at different places and during different time periods. Detecting such trends is useful for determining control and research priorities and strategies, and for evaluating the effectiveness of any interventions undertaken (Baker, Melius and Millar 1988).

A second broad function of occupational health surveillance is to identify individual cases of occupational disease and injury in order to find and evaluate other individuals from the same workplaces who may be at risk for similar disease and injury. Also, this process permits the initiation of control activities to ameliorate the hazardous conditions associated with causation of the index case (Baker, Melius and Millar 1988; Baker, Honchar and Fine 1989).An index case of occupational disease or injury is defined as the first ill or injured individual from a given workplace to receive medical care and thereby to draw attention to the existence of a workplace hazard and an additional workplace population at risk. A further purpose of case identification may be to assure that the affected individual receives appropriate clinical follow-up, an important consideration in view of the scarcity of clinical occupational medicine specialists (Markowitz et al. 1989; Castorino and Rosenstock 1992).

Finally, occupational health surveillance is an important means of discovering new associations between occupational agents and accompanying diseases, since the potential toxicity of most chemicals used in the workplace is not known. Discovery of rare diseases, patterns of common diseases or suspicious exposure-disease associations through surveillance activities in the workplace can provide vital leads for a more conclusive scientific evaluation of the problem and possible verification of new occupational diseases.

Obstacles to the Recognition of Occupational Diseases

Several important factors undermine the ability of occupational disease surveillance and reporting systems to fulfil the functions cited above. First, recognition of the underlying cause or causes of any illness is the sine qua non for recording and reporting occupational diseases. However, in a traditional medical model that emphasizes symptomatic and curative care, identifying and eliminating the underlying cause of illness may not be a priority. Furthermore, health care providers are often not adequately trained to suspect work as a cause of disease (Rosenstock 1981) and do not routinely obtain histories of occupational exposure from their patients (Institute of Medicine 1988). This should not be surprising, given that in the United States, the average medical student receives only six hours of training in occupational medicine during the four years of medical school (Burstein and Levy 1994).

Certain features characteristic of occupational disease exacerbate the difficulty of recognizing occupational diseases. With few exceptions—most notably, angiosarcoma of the liver, malignant mesothelioma and the pneumoconioses—most diseases that can be caused by occupational exposures also have non-occupational causes. This non-specificity renders difficult the determination of the occupational contribution to disease occurrence. Indeed, the interaction of occupational exposures with other risk factors may greatly increase the risk of disease, as occurs with asbestos exposure and cigarette smoking. For chronic occupational diseases such as cancer and chronic respiratory disease, there usually exists a long period of latency between onset of occupational exposure and presentation of clinical disease. For example, malignant mesothelioma typically has a latency of 35 years or more. A worker so affected may well have retired, further diminishing a physician’s suspicion of possible occupational aetiologies.

Another cause of the widespread under-recognition of occupational disease is that the majority of chemicals in commerce have never been evaluated with regard to their potential toxicity. A study by the National Research Council in the United States in the 1980s found no information available on the toxicity of approximately 80% of the 60,000 chemical substances in commercial use. Even for those groups of substances that are most closely regulated and about which the most information is available—drugs and food additives—reasonably complete information on possibly untoward effects is available for only a minority of agents (NRC 1984).

Workers may have a limited ability to provide an accurate report of their toxic exposures. Despite some improvement in countries such as the United States in the 1980s, many workers are not informed of the hazardous nature of the materials with which they work. Even when such information is provided, recalling the extent of exposure to multiple agents in a variety of jobs over a working career may be difficult. As a result, even health care providers who are motivated to obtain occupational information from their patients may not be able to do so.

Employers may be an excellent source of information regarding occupational exposures and the occurrence of work-related diseases. However, many employers do not have the expertise to assess the extent of exposure in the workplace or to determine whether an illness is work related. In addition, financial disincentives to finding that a disease is occupational in origin may discourage employers from using such information appropriately. The potential conflict of interest between the financial health of the employer and the physical and mental health of the worker represents a major obstacle to improving surveillance of occupational disease.

Registries and other Data Sources Specific for Occupational Diseases

International registries

International registries for occupational diseases are an exciting development in occupational health. The obvious benefit of these registries is the ability to conduct large studies, which would allow determination of the risk of rare diseases. Two such registries for occupational diseases were initiated during the 1980s.

The International Agency for Research on Cancer (IARC) established the International Register of Persons Exposed to Phenoxy Herbicides and Contaminants in 1984 (IARC 1990). As of 1990, it had enrolled 18,972 workers from 19 cohorts in ten countries. By definition all enrolees worked in industries involving phenoxy herbicides and/or chlorophenols, principally in manufacturing/formulating industries or as applicators. Exposure estimates have been made for participating cohorts (Kauppinen et al. 1993), but analyses of cancer incidence and mortality have not yet been published.

An international registry of cases of angiosarcoma of the liver (ASL) is being coordinated by Bennett of ICI Chemicals and Polymers Limited in England. Occupational exposure to vinyl chloride is the only known cause of angiosarcoma of the liver. Cases are reported by a voluntary group of scientists from companies producing vinyl chloride, governmental agencies and universities. As of 1990, 157 cases of ASL with dates of diagnosis between 1951 and 1990 were reported to the registry from 11 countries or regions. Table 1 also shows that most of the recorded cases were reported from countries where facilities started polyvinyl chloride manufacture before 1950. The registry has recorded six clusters of ten or more cases of ASL at facilities in North America and Europe (Bennett 1990).

Table 1. Number of cases of angiosarcoma of the liver in the world register by country and year of first production of vinyl chloride

Source: Bennett, B. World Register of Cases of Angiosarcoma of the Liver (ASL)
due to Vinyl Chloride Monomer, January 1, 1990.

Governmental surveys

Employers are sometimes legally required to record occupational injuries and illnesses that occur in their facilities. Like other workplace-based information, such as numbers of employees, wages and overtime, injury and illness data may be systematically collected by governmental agencies for the purpose of surveillance of work-related health outcomes.

In the United States, the Bureau of Labor Statistics (BLS) of the US Department of Labor has conducted the Annual Survey of Occupational Injuries and Illnesses (BLS Annual Survey) since 1972 as required by the Occupational Safety and Health Act (BLS 1993b). The goal of the survey is to obtain the numbers and the rates of illnesses and injuries recorded by private employers as being occupational in origin (BLS 1986). The BLS Annual Survey excludes employees of farms with fewer than 11 employees, the self-employed and employees of the federal, state and local governments. For the most recent year available, 1992, the survey reflects questionnaire data obtained from a stratified random sample of approximately 250,000 establishments in the private sector in the United States (BLS 1994).

The BLS survey questionnaire completed by the employer is derived from a written record of occupational injuries and illnesses which employers are required to maintain by the Occupational Safety and Health Administration (OSHA 200 Log). Although OSHA mandates that the employer keep the 200 Log for examination by an OSHA inspector upon request, it does not require that employers routinely report the log’s contents to OSHA, except for the sample of employers included in the BLS Annual Survey (BLS 1986).

Some well-recognized weaknesses severely limit the ability of the BLS survey to provide a full and accurate count of occupational illnesses in the United States (Pollack and Keimig 1987). Data are employer derived. Any illness that the employee does not report to the employer as being work related will not be reported by the employer on the annual survey. Among active workers, such a failure to report may be due to fear of consequences to the employee. Another major obstacle to reporting is the failure of the employee’s physician to diagnose illness as being work related, especially for chronic diseases. Occupational diseases occurring among retired workers are not subject to the BLS reporting requirement. Indeed, it is unlikely that the employer would be aware of the onset of a work-related illness in a retiree. Since many cases of chronic occupational illnesses with long latency, including cancer and lung disease, are likely to have their onset following retirement, a large proportion of such cases would not be included in the data collected by the BLS. These limitations were recognized by BLS in a recent report on its annual survey (BLS 1993a). In response to recommendations by the National Academy of Sciences, the BLS re-designed and implemented a new annual survey in 1992.

According to the 1992 BLS Annual Survey, there were 457,400 occupational illnesses in private industry in the United States (BLS 1994). This represented a 24% increase, or 89,100 cases, over the 368,300 illnesses recorded in the 1991 BLS Annual Survey. The incidence of new occupational illnesses was 60.0 per 10,000 workers in 1992.

Disorders associated with repeated trauma, such as carpal tunnel syndrome, tendonitis of the wrist and elbow and hearing loss, dominate the occupational illnesses recorded in the BLS Annual survey and have done so since 1987 (table 2). In 1992, they accounted for 62% of all illness cases recorded on the annual survey. Other important categories of disease were skin disorders, pulmonary diseases and disorders associated with physical trauma.

Table 2. Number of new cases of occupational illness by category of illness-US Bureau of Labor Statistics Annual Survey, 1986 versus 1992.

Sources: Occupational Injuries and Illnesses in the United States by Industry, 1991.
US Department of Labor, Bureau of Labor Statistics, May 1993. Unpublished data,
US Department of Labor, Bureau of Labor Statistics, December, 1994.

Although disorders associated with repeated trauma clearly account for the largest proportion of the increase in cases of occupational illness, there was also a 50% increase in the recorded incidence in occupational illnesses other than those due to repeated trauma in the six years between 1986 and 1992, during which employment in the United States rose by just 8.7%.

These increases in the numbers and rates of occupational diseases recorded by employers and reported to the BLS in recent years in the United States are remarkable. The rapid change in the recording of occupational illnesses in the United States is due to a change in the underlying occurrence of disease and to a change in the recognition and reporting of these conditions. By comparison, during the same time period, 1986 to 1991, the rate of occupational injuries per 100 full-time workers recorded by the BLS went from 7.7 in 1986 to 7.9 in 1991, a mere 2.6% increase. The number of recorded fatalities in the workplace has likewise not increased dramatically in the first half of the 1990s.

Employer-based surveillance

Apart from the BLS survey, many US employers conduct medical surveillance of their workforces and thereby generate a vast amount of medical information that is relevant to the surveillance of occupational diseases. These surveillance programmes are undertaken for numerous purposes: to comply with OSHA regulations; to maintain a healthy workforce through the detection and treatment of non-occupational disorders; to ensure that the employee is fit to perform the tasks of the job, including the need to wear a respirator; and to conduct epidemiological surveillance to uncover patterns of exposure and disease. These activities utilize considerable resources and could potentially make a major contribution to the public health surveillance of occupational diseases. However, since these data are non-uniform, of uncertain quality and largely inaccessible outside the companies in which they are collected, their exploitation in occupational health surveillance has been realized on only a limited basis (Baker, Melius and Millar 1988).

OSHA also requires that employers perform selected medical surveillance tests for workers exposed to a limited number of toxic agents. Additionally, for fourteen well-recognized bladder and lung carcinogens, OSHA requires a physical examination and occupational and medical histories. The data collected under these OSHA provisions are not routinely reported to governmental agencies or other centralized data banks and are not accessible for the purposes of occupational disease reporting systems.

Surveillance of public employees

Occupational disease reporting systems may differ for public versus private employees. For example, in the United States, the annual survey of occupational illnesses and injuries conducted by the federal Department of Labor (BLS Annual Survey) excludes public employees. Such workers are, however, an important part of the workforce, representing approximately 17% (18.4 million workers) of the total workforce in 1991. Over three-fourths of these workers are employed by state and local governments.

In the United States, data on occupational illnesses among federal employees are collected by the Federal Occupational Workers’ Compensation Program. In 1993, there were 15,500 occupational disease awards to federal workers, yielding a rate of 51.7 cases of occupational illnesses per 10,000 full-time workers (Slighter 1994). At the state and local levels, the rates and numbers of illnesses due to occupation are available for selected states. A recent study of state and local employees in New Jersey, a sizeable industrial state, documented 1,700 occupational illnesses among state and local employees in 1990, yielding an incidence of 50 per 10,000 public-sector workers (Roche 1993). Notably, the rates of occupational disease among federal and non-federal public workers are remarkably congruent with the rates of such illness among private sector workers as recorded in the BLS Annual Survey. The distribution of illness by type differs for public versus private workers, a consequence of the different type of work that each sector performs.

Workers’ compensation reports

Workers’ compensation systems provide an intuitively appealing surveillance tool in occupational health, because the determination of work-relatedness of disease in such cases has presumably undergone expert review. Health conditions that are acute and easily recognized in origin are frequently recorded by workers’ compensation systems. Examples include poisonings, acute inhalation of respiratory toxins and dermatitis.

Unfortunately, the use of workers’ compensation records as a credible source for surveillance data is subject to severe limitations, including lack of standardization of eligibility requirements, deficiency of standard case definitions, disincentives to workers and employers to file claims, the lack of physician recognition of chronic occupational diseases with long latent periods and the usual gap of several years between initial filing and resolution of a claim. The net effect of these limitations is that there is significant under-recording of occupational disease by workers’ compensation systems.

Thus, in a study by Selikoff in the early 1980s, less than one-third of US insulators who were disabled by asbestos-related diseases, including asbestosis and cancer, had even filed for workers’ compensation benefits, and many fewer were successful in their claims (Selikoff 1982). Similarly, a US Department of Labor study of workers who reported disability from occupational disease found that less than 5% of these workers received workers’ compensation benefits (USDOL 1980). A more recent study in the state of New York found that the number of people admitted to hospitals for pneumoconioses vastly outnumbered the people who were newly awarded workers’ compensation benefits during a similar time period (Markowitz et al. 1989). Since workers’ compensation systems record simple health events such as dermatitis and musculoskeletal injuries much more readily than complex diseases of long latency, use of such data leads to a skewed picture of the true incidence and distribution of occupational diseases.

Laboratory reports

Clinical laboratories can be an excellent source of information on excessive levels of selected toxins in body fluids. Advantages of this source are timely reporting, quality-control programmes already in place and the leverage for compliance provided by the licensing of such laboratories by governmental agencies. In the United States, numerous states require that clinical laboratories report the results of selected categories of specimens to the state health departments. Occupational agents subject to this reporting requirement are lead, arsenic, cadmium and mercury as well as substances reflecting pesticide exposure (Markowitz 1992).

In the United States, the National Institute for Occupational Safety and Health (NIOSH) began to assemble the results of adult blood lead testing into the Adult Blood Lead Epidemiology and Surveillance programme in 1992 (Chowdhury, Fowler and Mycroft 1994). By the end of 1993, 20 states, representing 60% of the US population, were reporting elevated blood lead levels to NIOSH, and an additional 10 states were developing the capacity to collect and report blood lead data. In 1993, there were 11,240 adults with blood lead levels that equalled or exceeded 25 micrograms per decilitre of blood in the 20 reporting states. The vast majority of these individuals with elevated blood lead levels (over 90%) were exposed to lead at the workplace. Over one-quarter (3,199) of these individuals had blood leads greater than or equal to 40 ug/dl, the threshold at which the US Occupational Safety and Health Administration requires actions to protect workers from occupational lead exposure.

Reporting of elevated levels of toxins to the state health department may be followed by a public health investigation. Confidential follow-up interviews with affected individuals allows timely identification of the workplaces where exposure occurred, categorization of the case by occupation and industry, estimation of the number of other workers at the workplace potentially exposed to lead and assurance of medical follow-up (Baser and Marion 1990). Worksite visits are followed by recommendations for voluntary actions to reduce exposure or may lead to reporting to authorities with legal enforcement powers.

Physicians’ reports

In an attempt to replicate the strategy successfully utilized for the monitoring and control of infectious diseases, an increasing number of states in the United States require physicians to report one or more occupational diseases (Freund, Seligman and Chorba 1989). As of 1988, 32 states required reporting of occupational diseases, though these included ten states where only one occupational disease is reportable, usually lead or pesticide poisoning. In other states, such as Alaska and Maryland, all occupational diseases are reportable. In most states, reported cases are used only to count the number of people in the state affected by the disease. In only one-third of the states with reportable disease requirements does a report of a case of occupational disease lead to follow-up activities, such as workplace inspection (Muldoon, Wintermeyer and Eure 1987).

Despite the evidence of increased recent interest, physician reporting of occupational diseases to appropriate state governmental authorities is widely acknowledged to be inadequate (Pollack and Keimig 1987; Wegman and Froines 1985). Even in California, where a system for physician reporting has been in place for a number of years (Doctor’s First Report of Occupational Illness and Injury) and recorded nearly 50,000 occupational illnesses in 1988, physician compliance with reporting is regarded as incomplete (BLS 1989).

A promising innovation in occupational health surveillance in the United States is the emergence of the concept of the sentinel provider, part of an initiative undertaken by NIOSH called Sentinel Event Notification System for Occupational Risks (SENSOR). A sentinel provider is a physician or other health care provider or facility that is likely to provide care for workers with occupational disorders due to the provider’s specialty or geographic location.

Since sentinel providers represent a small subset of all health care providers, health departments can feasibly organize an active occupational disease reporting system by performing outreach, offering education and providing timely feedback to sentinel providers. In a recent report from three states participating in the SENSOR programme, physician reports of occupational asthma increased sharply after the state health departments developed concerted educational and outreach programmes to identify and recruit sentinel providers (Matte, Hoffman and Rosenman 1990).

Specialized occupational health clinical facilities

A newly emergent resource for occupational health surveillance has been the development of occupational health clinical centres that are independent of the workplace and that specialize in the diagnosis and treatment of occupational disease. Several dozen such facilities currently exist in the United States. These clinical centres can play several roles in enhancing occupational health surveillance (Welch 1989). First, the clinics can play a primary role in case-finding—that is, identifying occupational sentinel health events—since they represent a unique organizational source of expertise in clinical occupational medicine. Second, the occupational health clinical centres can serve as a laboratory for the development and refinement of surveillance case definitions for occupational disease. Third, the occupational health clinics can serve as a primary clinical referral resource for the diagnosis and evaluation of workers who are employed at a worksite where an index case of occupational disease has been identified.

Occupational health clinics have become organized into a national association in the United States (the Association of Occupational and Environmental Clinics) to enhance their visibility and to collaborate on research and clinical investigations (Welch 1989). In some states, such as New York, a statewide network of clinical centres has been organized by the state health department and receives stable funding from a surcharge on workers’ compensation premiums (Markowitz et al. 1989). The clinical centres in New York State have collaborated in the development of information systems, clinical protocols and professional education and are beginning to generate substantial data on the numbers of cases of occupational disease in the state.

Use of Vital Statistics and Other General Health Data

Death certificates

The death certificate is a potentially very useful instrument for occupational disease surveillance in many countries in the world. Most countries have death registries. Uniformity and comparability is promoted by the common use of the International Classification of Diseases to identify cause of death. Furthermore, many jurisdictions include information on death certificates concerning the occupation and industry of the deceased. A major limitation in the use of death certificates for occupational disease surveillance is the lack of unique relationships between occupational exposures and specific causes of death.

The use of mortality data for occupational disease surveillance is most salient for diseases that are uniquely caused by occupational exposures. These include the pneumoconioses and one type of cancer, malignant mesothelioma of the pleura. Table 3 shows the numbers of deaths attributed to these diagnoses as the underlying cause of death and as one of multiple causes of death listed on the death certificate in the United States. The underlying cause of death is considered the principal cause for death, while the listing of multiple causes includes all conditions considered important in contributing to death.

Table 3. Deaths due to pneumoconiosis and malignant mesothelioma of the pleura. Underlying cause and multiple causes, United States, 1990 and 1991

Source: United States National Center for Health Statistics.

In 1991, there were 1,237 deaths due to the dust diseases of the lung as the underlying cause, including 693 deaths due to coal workers pneumoconioses and 269 deaths due to asbestosis. For malignant mesothelioma, there was a total of 452 deaths due to pleural mesothelioma. It is not possible to identify the number of deaths due to malignant mesothelioma of the peritoneum, also caused by occupational exposure to asbestos, since International Classification of Disease codes are not specific for malignant mesothelioma of this site.

Table 3 also shows the numbers of deaths in the United States in 1990 due to pneumoconioses and malignant mesothelioma of the pleura when they appear as one of multiple causes of death on the death certificate. For the pneumoconioses, the total where they appear as one of multiple causes is important, since the pneumoconioses often co-exist with other chronic lung diseases.

An important issue is the extent to which pneumoconioses may be under-diagnosed and, therefore, missing from death certificates. The most extensive analysis of the under-diagnosis of a pneumoconiosis has been performed among insulators in the United States and Canada by Selikoff and colleagues (Selikoff, Hammond and Seidman 1979; Selikoff and Seidman 1991). Between 1977 and 1986, there were 123 insulator deaths ascribed to asbestosis on the death certificates. When investigators reviewed medical records, chest radiographs and tissue pathology where available, they ascribed 259 of insulator deaths occurring in these years to asbestosis. Over one-half of pneumoconiosis deaths were, thus, missed in this group well-known to have heavy asbestos exposure. Unfortunately, there are not a sufficient number of other studies of the under-diagnosis of pneumoconioses on death certificates to allow a reliable correction of mortality statistics.

Deaths due to causes that are not specific to occupational exposures have also been used as part of occupational disease surveillance when occupation or industry of decedents is recorded on the death certificates. Analysis of these data in a specified geographical area during a selected time period can yield rates and ratios of disease by cause for different occupations and industries. The role of non-occupational factors in the deaths examined cannot be defined by this approach. However, differences in rates of disease in different occupations and industries suggest that occupational factors may be important and provide leads for more detailed studies. Other advantages of this approach include the ability to study occupations that are usually distributed among many workplaces (e.g., cooks or dry cleaner workers), the use of routinely collected data, a large sample size, relatively low expense and an important health outcome (Baker, Melius and Millar 1988; Dubrow, Sestito and Lalich 1987; Melius, Sestito and Seligman 1989).

Such occupational mortality studies have been published over the past several decades in Canada (Gallagher et al. 1989), Great Britain (Registrar General 1986), and the United States (Guralnick 1962, 1963a and 1963b). In recent years, Milham utilized this approach to examine the occupational distribution of all men who died between 1950 and 1979 in the state of Washington in the United States. He compared the proportion of all deaths due to any specific cause for one occupational group with the relevant proportion for all occupations. Proportional mortality ratios are thereby obtained (Milham 1983). As an example of the yield of this approach, Milham noted that 10 of 11 occupations with probable exposure to electrical and magnetic fields showed an elevation in the proportional mortality ratio for leukaemia (Milham 1982). This was one of the first studies of the relationship between occupational exposure to electro-magnetic radiation and cancer and has been followed by numerous studies that have corroborated the original finding (Pearce et al. 1985; McDowell 1983; Linet, Malker and McLaughlin 1988).

As a result of a cooperative effort between NIOSH, the National Cancer Institute, and the National Center for Health Statistics during the 1980s, analyses of the mortality patterns by occupation and industry between 1984 and 1988 in 24 states in the United States have recently been published (Robinson et al. 1995). These studies evaluated 1.7 million deaths. They confirmed several well-known exposure-disease relationships and reported new associations between selected occupations and specific causes of death. The authors emphasize that occupational mortality studies may be useful to develop new leads for further study, to evaluate results of other studies and to identify opportunities for health promotion.

More recently, Figgs and colleagues at the US National Cancer Institute used this 24-state occupational mortality database to examine occupational associations with non-Hodgkin’s lymphoma (NHL) (Figgs, Dosemeci and Blair 1995). A case-control analysis involving approximately 24,000 NHL deaths occurring between 1984 and 1989 confirmed previously demonstrated excess risks of NHL among farmers, mechanics, welders, repairmen, machine operators and a number of white-collar occupations.

Hospital discharge data

Diagnoses of hospitalized patients represent an excellent source of data for the surveillance of occupational diseases. Recent studies in several states in the United States show that hospital discharge data can be more sensitive than workers’ compensation records and vital statistics data in detecting cases of diseases that are specific to occupational settings, such as the pneumoconioses (Markowitz et al. 1989; Rosenman 1988). In New York State, for example, an annual average of 1,049 people were hospitalized for pneumoconioses in the mid-1980s, compared to 193 newly awarded workers’ compensation cases and 95 recorded deaths from these diseases each year during a similar time interval (Markowitz et al. 1989).

In addition to providing a more accurate count of the number of people ill with selected serious occupational diseases, hospital discharge data can be usefully followed up to detect and to alter workplace conditions that caused the disease. Thus, Rosenman evaluated workplaces in New Jersey where individuals who were hospitalized for silicosis had previously worked and found that the majority of these workplaces had never performed air sampling for silica, had never been inspected by the federal regulatory authority (OSHA) and did not perform medical surveillance for the detection of silicosis (Rosenman 1988).

Advantages of using hospital discharge data for the surveillance of occupational disease are their availability, low cost, relative sensitivity to serious illness and reasonable accuracy. Important disadvantages include the lack of information on occupation and industry and uncertain quality control (Melius, Sestito and Seligman 1989; Rosenman 1988). In addition, only individuals with disease sufficiently severe to require hospitalization will be included in the database and, therefore, cannot reflect the full spectrum of morbidity associated with occupational diseases. Nonetheless, it is likely that hospital discharge data will be increasingly used in occupational health surveillance in future years.

National surveys

Special surveillance surveys undertaken on a national or regional basis can be the source of information more detailed than can be obtained through use of routine vital records. In the United States, the National Center for Health Statistics (NCHS) conducts two periodic national health surveys relevant to occupational health surveillance: the National Health Interview Survey (NHIS) and the National Health and Nutrition Examination Survey (NHANES). The National Health Interview Survey is a national household survey designed to obtain estimates of the prevalence of health conditions from a representative sample of households reflecting the civilian non-institutionalized population of the United States (USDHHS 1980). A chief limitation of this survey is its reliance on self-reporting of health conditions. Occupational and industrial data on participating individuals have been used in the past decade for evaluating rates of disability by occupation and industry (USDHHS 1980), assessing the prevalence of cigarette smoking by occupation (Brackbill, Frazier and Shilling 1988) and recording workers’ views about the occupational risks that they face (Shilling and Brackbill 1987).

With the assistance of NIOSH, an Occupational Health Supplement (NHIS-OHS) was included in 1988 in order to obtain population-based estimates of the prevalence of selected conditions that may be associated with work (USDHHS 1993). Approximately 50,000 households were sampled in 1988, and 27,408 currently employed individuals were interviewed. Among the health conditions addressed by the NHIS-OHS are work-related injuries, dermatologic conditions, cumulative trauma disorders, eye, nose and throat irritation, hearing loss and low-back pain.

In the first completed analysis from the NHIS-OHS, Tanaka and colleagues from NIOSH estimated that the national prevalence of work-related carpal tunnel syndrome in 1988 was 356,000 cases (Tanaka et al. 1995). Of the estimated 675,000 people with prolonged hand pain and medically diagnosed carpal tunnel syndrome, over 50% reported that their health care provider had stated that their wrist condition was caused by workplace activities. This estimate does not include workers who had not worked in the 12 months prior to the survey and who may have been disabled due to work-related carpal tunnel syndrome.

In contrast to the NHIS, the NHANES directly assesses the health of a probability sample of 30,000 to 40,000 individuals in the United States by performing physical examinations and laboratory tests in addition to collecting questionnaire information. The NHANES was conducted twice in the 1970s and most recently in 1988. The NHANES II, which was conducted in the late 1970s, collected limited information on indicators of exposure to lead and selected pesticides. Initiated in 1988, the NHANES III collected additional data on occupational exposures and disease, especially concerning respiratory and neurologic disease of occupational origin (USDHHS 1994).

Summary

Occupational disease surveillance and reporting systems have significantly improved since the mid-1980s. Recording of illnesses is best for diseases unique or virtually unique to occupational causes, such as the pneumoconioses and malignant mesothelioma. Identification and reporting of other occupational diseases depends upon the ability to match occupational exposures with health outcomes. Many data sources enable occupational disease surveillance, though all have important shortcomings with regard to quality, comprehensiveness and accuracy. Important obstacles to improving occupational disease reporting include the lack of interest in prevention in health care, the inadequate training of health care practitioners in occupational health and the inherent conflicts between employers and workers in the recognition of work-related disease. Despite these factors, gains in occupational disease reporting and surveillance are likely to continue in the future.

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Culture and technology are interdependent. While culture is indeed an important aspect in technology design, development and utilization, the relationship between culture and technology is, however, extremely complex. It needs to be analysed from several perspectives in order to be considered in the design and application of technology. Based on his work in Zambia, Kingsley (1983) divides technological adaptation into changes and adjustments at three levels: that of the individual, of the social organization and of the cultural value system of the society. Each level possesses strong cultural dimensions which require special design considerations.

At the same time, technology itself is an inseparable part of culture. It is built, wholly or in part, around the cultural values of a particular society. And as part of culture, technology becomes an expression of that society’s way of life and thinking. Thus, in order for technology to be accepted, utilized and acknowledged by a society as its own, it must be congruent to the overall image of that society’s culture. Technology must complement culture, not antagonize it.

This article will deal with some of the intricacies concerning cultural considerations in technology designs, examining the current issues and problems, as well as the prevailing concepts and principles, and how they can be applied.

Definition of Culture

The definition of the term culture has been debated at length amongst sociologists and anthropologists for many decades. Culture can be defined in many terms. Kroeber and Kluckhohn (1952) reviewed over a hundred definitions of culture. Williams (1976) mentioned culture as one of the most complicated words in the English language. Culture has even been defined as the entire way of life of people. As such, it includes their technology and material artefacts—anything one would need to know to become a functioning member of the society (Geertz 1973). It may even be described as “publicly available symbolic forms through which people experience and express meaning” (Keesing 1974). Summing it up, Elzinga and Jamison (1981) put it aptly when they said that “the word culture has different meanings in different intellectual disciplines and systems of thought”.

Technology: Part and Product of Culture

Technology can be considered both as part of culture and its product. More than 60 years ago the noted sociologist Malinowsky included technology as part of the culture and gave the following definition: “culture comprises inherited artefacts, goods, technical processes, ideas, habits and values.” Later, Leach (1965) considered technology as a cultural product and mentioned “artefacts, goods and technical processes” as “products of culture”.

In the technological realm, “culture” as an important issue in the design, development and utilization of technical products or systems has been largely neglected by many suppliers as well as receivers of technology. One major reason for this neglect is the absence of basic information on cultural differences.

In the past, technological changes have led to significant changes in social life and organization and in people’s value systems. Industrialization has made deep and enduring changes in the traditional lifestyles of many previously agricultural societies since such lifestyles were largely regarded as incompatible with the way industrial work should be organized. In situations of large cultural diversity, this has led to various negative socio-economic outcomes (Shahnavaz 1991). It is now a well-established fact that simply to impose a technology on a society and believe that it will be absorbed and utilized through extensive training is wishful thinking (Martin et al. 1991).

It is the responsibility of the technology designer to consider the direct and indirect effects of the culture and to make the product compatible with the cultural value system of the user and with its intended operating environment.

The impact of technology for many “industrially developing countries” (IDCs) has been much more than improvement in efficiency. Industrialization was not just modernization of the production and service sectors, but to some extent Westernization of the society. Technology transfer is, thus, also cultural transfer.

Culture, in addition to religion, tradition and language, which are important parameters for technology design and utilization, encompasses other aspects, such as specific attitudes towards certain products and tasks, rules of appropriate behaviour, rules of etiquette, taboos, habits and customs. All these must be equally considered for optimum design.

It is said that people are also products of their distinctive cultures. Nevertheless, the fact remains that world cultures are very much interwoven due to human migration throughout history. It is small wonder that there exist more cultural than national variations in the world. Nevertheless, some very broad distinctions can be made regarding societal, organizational and professional culture-based differences that could influence design in general.

Constraining Influences of Culture

There is very little information on both theoretical and empirical analyses of the constraining influences of culture on technology and how this issue should be incorporated in the design of hardware and software technology. Even though the influence of culture on technology has been recognized (Shahnavaz 1991; Abeysekera, Shahnavaz and Chapman 1990; Alvares 1980; Baranson 1969), very little information is available on the theoretical analysis of cultural differences with regard to technology design and utilization. There are even fewer empirical studies that quantify the importance of cultural variations and provide recommendations on how cultural factors should be considered in the design of product or system (Kedia and Bhagat 1988). Nevertheless, culture and technology can still be studied with some degree of clarity when viewed from different sociological viewpoints.

Culture and Technology: Compatibility and Preference

Proper application of a technology depends, to a large extent, on the compatibility of the user’s culture with the design specifications. Compatibility must exist at all levels of culture—at the societal, organizational and professional levels. In turn, cultural compatibility can have strong influence on a people’s preferences and aptness to utilize a technology. This question involves preferences relating to a product or system; to concepts of productivity and relative efficiency; to change, achievement and authority; as well as to the manner of technology utilization. Cultural values can thus affect people’s willingness and ability to select, to use and to control technology. They have to be compatible in order to be preferred.

Societal culture

As all technologies are inevitably associated with sociocultural values, the cultural receptivity of the society is a very important issue for the proper functioning of a given technological design (Hosni 1988). National or societal culture, which contributes to the formation of a collective mental model of people, influences the entire process of technology design and application, which ranges from planning, goal setting and defining design specifications, to production, management and maintenance systems, training and evaluation. Technology design of both hardware and software should, therefore, reflect society-based cultural variations for maximum benefit. However, defining such society-based cultural factors for consideration in the design of technology is a very complicated task. Hofstede (1980) has proposed four dimensional framework variations of national-based culture.

1. Weak versus strong uncertainty avoidance. This concerns a people’s desire to avoid ambiguous situations and to what extent their society has developed formal means (such as rules and regulations) to serve this purpose. Hofstede (1980) gave, for example, high uncertainty avoidance scores to countries like Japan and Greece, and low scores to Hong Kong and Scandinavia.
2. Individualism versus collectivism. This pertains to the relationship between individuals and organizations in the society. In individualistic societies, the orientation is such that each person is expected to look after his or her own interests. In contrast, in a collectivist culture, social ties between people are very strong. Some examples of individualistic countries are the United States and Great Britain while Colombia and Venezuela can be considered as having collectivist cultures.
3. Small versus large power distance. A large “power distance” characterizes those cultures where the less powerful individuals accept the unequal distribution of power in a culture, as well as the hierarchies in the society and its organizations. Examples of large power distance countries are India and the Philippines. Small power distances are typical of countries like Sweden and Austria.
4. Masculinity versus femininity. Cultures that put more emphasis on material achievements are regarded as belonging to the former category. Those giving more value to quality of life and other less tangible outcomes belong to the latter.

Glenn and Glenn (1981) have also distinguished between “abstractive” and “associative” tendencies in a given national culture. It is argued that when people of an associative culture (like those from Asia) approach a cognitive problem, they put more emphasis on context, adapt a global thinking approach and try to utilize association among various events. Whereas in the Western societies, a more abstractive culture of rational thinking predominates. Based on these cultural dimensions, Kedia and Bhagat (1988) have developed a conceptual model for understanding cultural constraints on technology transfer. They have developed various descriptive “propositions” which provide information on different countries’ cultural variations and their receptivity with regard to technology. Certainly many cultures are moderately inclined to one or the other of these categories and contain some mixed features.

Consumers’ as well as producers’ perspectives upon technological design and utilization are directly influenced by the societal culture. Product safety standards for safeguarding consumers as well as work-environment regulations, inspection and enforcement systems for protecting the producers are to a large extent the reflection of the societal culture and value system.

Organizational culture

A company’s organization, its structure, value system, function, behaviour, and so on, are largely cultural products of the society in which it operates. This means that what happens within an organization is mostly a direct reflection of what is happening in the outside society (Hofstede 1983). The prevailing organizations of many companies operating in the IDCs are influenced both by the characteristics of the technology producer country as well as those of the technology recipient environment. However, the reflection of the societal culture in a given organization can vary. Organizations interpret the society in terms of their own culture, and their degree of control depends, among other factors, on the modes of technology transfer.

Given the changing nature of organization today, plus a multicultural, diverse workforce, adapting a proper organizational programme is more important than ever before to a successful operation (an example of a workforce diversity management programme is described in Solomon (1989)).

Professional culture

People belonging to a certain professional category may use a piece of technology in a specific fashion. Wikström et al. (1991), in a project aimed to develop hand tools, have noted that despite the designers’ assumption of how plate shares are to be held and used (i.e., with a forward holding grip and the tool moving away from one’s own body), the professional tinsmiths were holding and using the plate share in a reversed manner, as shown in figure 1. They concluded that tools should be studied in the actual field conditions of the user population itself in order to acquire relevant information on the tools characteristics.

Figure 1. The use of plate share tools by professional tinsmiths in practice (the reversed grip)

Using Cultural Features for Optimum Design

As implied by the foregoing considerations, culture provides identity and confidence. It forms opinions about the objectives and characteristics of a “human-technology system” and how it should operate in a given environment. And in any culture, there are always some features that are valuable with regard to technological progress. If these features are considered in the design of software and hardware technology, they can act as the driving force for technology absorption in the society. One good example is the culture of some southeast Asian countries largely influenced by Confucianism and Buddhism. The former emphasizes, among other things, learning and loyalty, and considers it a virtue to be able to absorb new concepts. The latter teaches the importance of harmony and respect for fellow human beings. It is said that these unique cultural features have contributed to the provision of the right environment for the absorption and implementation of advanced hardware and organizational technology furnished by the Japanese (Matthews 1982).

A clever strategy would thus make the best use of the positive features of a society’s culture in promoting ergonomic ideas and principles. According to McWhinney (1990) “the events, to be understood and thus used effectively in projection, must be embedded in stories. One must go to varying depths to unleash founding energy, to free society or organization from inhibiting traits, to find the paths along which it might naturally flow. . . . Neither planning nor change can be effective without embedding it consciously in a narrative.”

A good example of cultural appreciation in designing management strategy is the implementation of the “seven tools” technique for quality assurance in Japan. The “seven tools” are the minimum weapons a samurai warrior had to carry with him whenever he went out to fight. The pioneers of “quality control circles”, adapting their nine recommendations to a Japanese setting, reduced this number in order to take advantage of a familiar term—“the seven tools”—so as to encourage the involvement of all employees in their quality work strategy (Lillrank and Kano 1989).

However, other cultural features may not be beneficial to technological development. Discrimination against women, the strict observation of a caste system, racial or other prejudice, or considering some tasks as degrading, are a few examples that can have a negative influence on technology development. In some traditional cultures, men are expected to be the primary wage-earners. They become accustomed to regarding the role of women as equal employees, not to mention as supervisors, with insensitivity or even hostility. Withholding equal employment opportunity from women and questioning the legitimacy of women’s authority is not appropriate to the current needs of organizations, which require optimum utilization of human resources.

With regard to task design and job content, some cultures consider tasks like manual labour and service as degrading. This may be attributed to past experiences linked to colonial times regarding “master-slave relationships”. In some other cultures, strong biases exist against tasks or occupations associated with “dirty hands”. These attitudes are also reflected in lower-than-average pay scales for these occupations. In turn, these have contributed to shortages of technicians or inadequate maintenance resources (Sinaiko 1975).

Since it usually takes many generations to change cultural values with respect to a new technology, it would be more cost-effective to fit the technology to the technology recipient’s culture, taking cultural differences into consideration in the design of hardware and software.

Cultural Considerations in Product and System Designing

By now it is obvious that technology consists both of hardware and software. Hardware components include capital and intermediary goods, such as industrial products, machinery, equipment, buildings, workplaces and physical layouts, most of which chiefly concern the micro-ergonomics domain. Software pertains to programming and planning, management and organizational techniques, administration, maintenance, training and education, documentation and services. All these concerns fall under the heading of macro-ergonomics.

A few examples of cultural influences that require special design consideration from the micro- and macro-ergonomic point of view are given below.

Micro-ergonomic issues

Micro-ergonomics is concerned with the design of a product or system with the objective of creating a “usable” user-machine-environment interface. The major concept of product design is usability. This concept involves not only the functionality and reliability of the product, but issues of safety, comfort and enjoyment as well.

The user’s internal model (i.e., his or her cognitive or mental model) plays an important role in usability design. To operate or control a system efficiently and safely, the user must have an accurate representative cognitive model of the system in use. Wisner (1983) has stated that “industrialization would thus more or less require a new kind of mental model.” In this view, formal education and technical training, experience as well as culture are important factors in determining the formation of an adequate cognitive model.

Meshkati (1989), in studying the micro- and macro-ergonomic factors of the 1984 Union Carbide Bhopal accident, highlighted the importance of culture on the Indian operators’ inadequate mental model of the plant operation. He stated that part of the problem may have been due to “the performance of poorly trained Third World operators using advanced technological systems designed by other humans with much different educational backgrounds, as well as cultural and psychosocial attributes.” Indeed, many design usability aspects at the micro-interface level are influenced by the user’s culture. Careful analyses of the user’s perception, behaviour and preferences would lead to a better understanding of the user’s needs and requirements for designing a product or system that is both effective and acceptable.

Some of these culture-related micro-ergonomic aspects are the following:

1. Interface design. Human emotion is an essential element of product design. It is concerned in such factors as colour and shape (Kwon, Lee and Ahn 1993; Nagamachi 1992). Colour is regarded as the most important factor to do with human emotions with regard to product design. The product’s colour treatment reflects the psychological and sentimental dispositions of the users, which differ from country to country. The symbolism of colour may also differ. For example, the colour red, which indicates danger in Western countries, is an auspicious token in India (Sen 1984) and symbolizes joy or happiness in China. 
2. Pictorial signs and symbols that are used in many different applications for public accommodations are strongly culture related. Western pictorial information, for example, is difficult to interpret by non-Western people (Daftuar 1975; Fuglesang 1982).
3. Control/display compatibility. Compatibility is a measure of how well spatial movements of control, display behaviour or conceptual relationships meet human expectations (Staramler 1993). It refers to the user’s expectation of the stimulus-response relationship, which is a fundamental ergonomic issue for safe and efficient operation of a product or system. A compatible system is one which considers people’s common perceptual-motor behaviour (i.e., their population-stereotype). However, like other human behaviour, perceptual-motor behaviour may also be influenced by culture. Hsu and Peng (1993) compared American and Chinese subjects regarding control/burner relationships in a four-burner stove. Different population-stereotype patterns were observed. They conclude that population stereotypes regarding control/burner linkages were culturally different, probably as a result of differences in reading or scanning habits.
4. Workplace design. An industrial workstation design aims to eliminate harmful postures and improve user performance in relation to the user’s biological needs, preferences and task requirements. People from different cultures may prefer different types of sitting posture and work heights. In Western countries, work heights are set near the seated elbow height for maximum comfort and efficiency. However, in many parts of the world people sit on the floor. Indian workers, for example, prefer squatting or sitting cross-legged to standing or to sitting on a chair. In fact it has been observed that even when chairs are provided, the operators still prefer to squat or sit cross-legged on the seats. Daftuar (1975) and Sen (1984) have studied the merits and implications of the Indian sitting posture. After describing the various advantages of sitting on the floor, Sen stated that “as a large population of the world market covers societies where squatting or sitting on the ground predominate, it is unfortunate that up to now no modern machines have been designed to be used in this way.” Thus, variations in preferred posture should be considered in machine and workplace design in order to improve the operator’s efficiency and comfort.
5. Design of protective equipment. There exist both psychological and physical constraints with regard to wearing protective clothing. In some cultures, for example, jobs requiring the use of protective wear may be regarded as common labour, suitable only for unskilled workers. Consequently, protective equipment is usually not worn by engineers at workplaces in such settings. Regarding physical constraints, some religious groups, obliged by their religion to wear a head covering (like the turbans of Indian Sikhs or the head covers of Muslim women) find it difficult to wear, for example, protective helmets. Therefore, special designs of protective wear are needed to cope with such cultural variations in protecting people against work-environmental hazards.

Macro-ergonomic issues

The term macro-ergonomics refers to the design of software technology. It concerns the proper design of organizations and management systems. Evidence exists showing that because of differences in culture, sociopolitical conditions and educational levels, many successful managerial and organizational methods developed in industrialized countries cannot be successfully applied to developing countries (Negandhi 1975). In most IDCs, an organizational hierarchy characterized by a down-flow of authority structure within the organization is a common practice. It has little concern for Western values such as democracy or power sharing in decision-making, which are regarded as key issues in modern management, being essential for proper utilization of human resources as regards intelligence, creativity, problem solving potential and ingenuity.

The feudal system of social hierarchy and its value system are also widely practised in most industrial workplaces in the developing countries. These make a participatory management approach (which is essential for the new production mode of flexible specialization and the motivation of the workforce) a difficult endeavour. However, there are reports confirming the desirability of introducing autonomous work systems even in these cultures Ketchum 1984).

1. Participatory ergonomics. Participatory ergonomics is a useful macro-ergonomics approach for solving various work-related problems (Shahnavaz, Abeysekera and Johansson 1993; Noro and Imada 1991; Wilson 1991). This approach, mostly used in industrialized countries, has been applied in different forms depending on the organizational culture in which it has been implemented. In a study, Liker, Nagamachi and Lifshitz (1988) compared participatory ergonomics programmes in two US and two Japanese manufacturing plants which were aiming to reduce physical stress on workers. They concluded that an “effective participatory ergonomics programme can take many forms. The best programme for any plant in any culture may depend on its own unique history, structure and culture.”
2. Software systems. Societal and organizational culture-based differences should be considered in designing a new software system or introducing a change in the organization. With respect to information technology, De Lisi (1990) indicates that networking capabilities will not be realized unless the networks fit the existing organizational culture.
3. Work organization and management. In some cultures, the family is so important an institution that it plays a prominent role in work organization. For example, among some communities in India, a job is generally regarded as a family responsibility and is collectively performed by all family members (Chapanis 1975).
4. Maintenance system. Design of maintenance programmes (both preventive and regular) as well as housekeeping are other examples of areas in which work organization should be adapted to cultural constraints. The traditional culture among the sort of agricultural societies predominant in many IDCs is generally not compatible with the requirements of industrial work and how activities are organized. Traditional agricultural activity does not require, for example, formal maintenance programming and precision work. It is for the most part not carried out under time pressure. In the field, it is usually left to the recycling process of nature to take care of maintenance and housekeeping work. The design of maintenance programmes and housekeeping manuals for industrial activities should thus take these cultural constraints into account and provide for adequate training and supervision.

Zhang and Tyler (1990), in a case study related to the successful establishment of a modern telephone cable production facility in China supplied by a US firm (the Essex Company) stated that “both parties realize, however, that the direct application of American or Essex management practices was not always practical nor desirable due to cultural, philosophical, and political differences. Thus the information and instructions provided by Essex was often modified by the Chinese partner to be compatible with the conditions existing in China.” They also argued that the key to their success, despite cultural, economic and political differences, was both parties’ dedication and commitment to a common goal as well as the mutual respect, trust, and friendship which transcended any differences between them.

Design of shift and work schedules are other examples of work organization. In most IDCs there are certain sociocultural problems associated with shift work. These include poor general living and housing conditions, lack of support services, a noisy home environment and other factors, which require the design of special shift programmes. Furthermore, for female workers, a working day is usually much longer than eight hours; it consists of not only the actual time spent working, but also the time spent on travelling, working at home and taking care of children and elderly relatives. In view of the prevailing culture, shift and other work design requires special work-rest schedules for effective operation.

Flexibility in work schedules to allow cultural variances such as an after-lunch nap for Chinese workers and religious activities for Muslims are further cultural aspects of work organization. In the Islamic culture, people are required to break from work a few times a day to pray, and to fast for one month each year from sunrise to sunset. All these cultural constraints require special work organizational considerations.

Thus, many macro-ergonomic design features are closely influenced by culture. These features should be considered in the design of software systems for effective operation.

Conclusion: Cultural Differences in Design

Designing a usable product or system is not an easy task. There exists no absolute quality of suitability. It is the designer’s task to create an optimum and harmonic interaction between the four basic components of the human-technology system: the user, the task, the technological system and the operating environment. A system may be fully usable for one combination of user, task and environmental conditions but totally unsuitable for another. One design aspect which can greatly contribute to the design’s usability, whether it is a case of a single product or a complex system, is the consideration of cultural aspects which have a profound influence on both the user and the operating environment.

Even if a conscientious engineer designs a proper human-machine interface for use in a given environment, the designer is often unable to foresee the effects of a different culture on the product’s usability. It is difficult to prevent possible negative cultural effects when a product is used in an environment different from that for which it was designed. And since there exist almost no quantitative data regarding cultural constraints, the only way the engineer can make the design compatible with regard to cultural factors is to actively integrate the user population in the design process.

The best way to consider cultural aspects in design is for the designer to adapt a user-centred design approach. True enough, the design approach adapted by the designer is the essential factor that will instantly influence the usability of the designed system. The importance of this basic concept must be recognized and implemented by the product or system designer at the very beginning of the design life cycle. The basic principles of user-centred design can thus be summarized as follows (Gould and Lewis 1985; Shackel 1986; Gould et al. 1987; Gould 1988; Wang 1992):

1. Early and continual focus on user. The user should be an active member of the design team throughout the whole product development life cycle (i.e., predesign, detail design, production, verification and product improvement phase).
2. Integrated design. The system should be considered as a whole, ensuring a holistic design approach. This means that all aspects of the system’s usability should be evolved in parallel by the design team.
3. Early and continuous user testing. User reaction should be tested using prototypes or simulations while carrying out real work in the real environment from early development stage to the final product.
4. Iterative design. Designing, testing and redesigning are repeated in regular cycles until satisfactory usability results are achieved.

In the case of designing a product on a global scale, the designer has to consider the needs of consumers around the world. In such a case, access to all actual users and operating environments may not be possible for the purpose of adopting a user-centred design approach. The designer has to use a broad range of information, both formal and informal, such as literature reference material, standards, guidelines, and practical principles and experience in making an analytical evaluation of the design and has to provide sufficient adjustability and flexibility in the product in order to satisfy the needs of a wider user population.

Another point to consider is the fact that designers can never be all-knowing. They need input from not only the users but also other parties involved in the project, including managers, technicians, and repair and maintenance workers. In a participatory process, people involved should share their knowledge and experiences in developing a usable product or system and accept collective responsibility for its functionality and safety. After all, everyone involved has something at stake.

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Hazard surveillance is the process of assessing the distribution of, and the secular trends in, use and exposure levels of hazards responsible for disease and injury (Wegman 1992). In a public health context, hazard surveillance identifies work processes or individual workers exposed to high levels of specific hazards in particular industries and job categories. Since hazard surveillance is not directed at disease events, its use in guiding public health intervention generally requires that a clear exposure-outcome relationship has previously been established. Surveillance can then be justified on the assumption that reduction in the exposure will result in reduced disease. Proper use of hazard surveillance data enables timely intervention, permitting the prevention of occupational illness. Its most significant benefit is therefore the elimination of the need to wait for obvious illness or even death to occur before taking measures to protect workers.

There are at least five other advantages of hazard surveillance which complement those provided by disease surveillance. First, identifying hazard events is usually much easier than identifying occupational disease events, particularly for diseases such as cancer that have long latency periods. Second, a focus on hazards (rather than illnesses) has the advantage of directing attention to the exposures which ultimately are to be controlled. For example, surveillance of lung cancer might focus on rates in asbestos workers. However, a sizeable proportion of lung cancer in this population could be due to cigarette smoking, either independently of or interacting with the asbestos exposure, so that large numbers of workers might need to be studied to detect a small number of asbestos-related cancers. On the other hand, surveillance of asbestos exposure could provide information on the levels and patterns of exposure (jobs, processes or industries) where the poorest exposure control exists. Then, even without an actual count of lung cancer cases, efforts to reduce or eliminate exposure would be appropriately implemented.

Third, since not every exposure results in disease, hazard events occur with much higher frequency than disease events, resulting in the opportunity to observe an emerging pattern or change over time more easily than with disease surveillance. Related to this advantage is the opportunity to make greater use of sentinel events. A sentinel hazard can be simply the presence of an exposure (e.g., beryllium), as indicated via direct measurement in the workplace; the presence of an excessive exposure, as indicated via biomarker monitoring (e.g., elevated blood lead levels); or a report of an accident (e.g., a chemical spill).

A fourth advantage of the surveillance of hazards is that data collected for this purpose do not infringe on an individual’s privacy. Confidentiality of medical records is not at risk and the possibility of stigmatizing an individual with a disease label is avoided. This is particularly important in industrial settings where a person’s job may be in jeopardy or a potential compensation claim may affect a physician’s choice of diagnostic options.

Finally, hazard surveillance can take advantage of systems designed for other purposes. Examples of ongoing collection of hazard information which already exists include registries of toxic substance use or hazardous material discharges, registries for specific hazardous substances and information collected by regulatory agencies for use in compliance. In many respects, the practising industrial hygienist is already quite familiar with the surveillance uses of exposure data.

Hazard surveillance data can complement disease surveillance both for research to establish or confirm a hazard-disease association, as well as for public health applications, and the data collected in either instance can be used to determine the need for remediation. Different functions are served by national surveillance data (as might be developed using the US OSHA Integrated Management Information System data on industrial hygiene compliance sample results—see below) in contrast to those served by hazard surveillance data at a plant level, where much more detailed focus and analysis are possible.

National data may be extremely important in targeting inspections for compliance activity or for determining what is the probable distribution of risks that will result in specific demands on medical services for a region. Plant-level hazard surveillance, however, provides the necessary detail for close examination of trends over time. Sometimes a trend occurs independently of changes in controls but rather in response to product changes which would not be evident in regionally grouped data. Both national and plant-level approaches can be useful in determining whether there is a need for planned scientific studies or for worker and management educational programmes.

By combining hazard surveillance data from routine inspections in a wide range of seemingly unrelated industries, it is sometimes possible to identify groups of workers for whom heavy exposure might otherwise be overlooked. For example, analysis of airborne lead concentrations as determined in OSHA compliance inspections for 1979 to 1985 identified 52 industries in which the permissible exposure limit (PEL) was exceeded in more than one-third of inspections (Froines et al. 1990). These industries included primary and secondary smelting, battery manufacture, pigment manufacture and brass/bronze foundries. As these are all industries with historically high lead exposure, excessive exposures indicated poor control of known hazards. However some of these workplaces are quite small, such as secondary lead smelter operations, and individual plant managers or operators may be unlikely to undertake systematic exposure sampling and could thus be unaware of serious lead exposure problems in their own workplaces. In contrast to high levels of ambient lead exposures that might have been expected in these basic lead industries, it was also noted that over one-third of the plants in the survey in which the PELs were exceeded resulted from painting operations in a wide variety of general industry settings. Structural steel painters are known to be at risk for lead exposure, but little attention has been directed to industries that employ painters in small operations painting machinery or machinery parts. These workers are at risk of hazardous exposures, yet they often are not considered to be lead workers because they are in an industry which is not a lead-based industry. In a sense, this survey revealed evidence of a risk that was known but had been forgotten until it was identified by analysis of these surveillance data.

Objectives of Hazard Surveillance

Programmes of hazard surveillance can have a variety of objectives and structures. First, they permit focus on intervention actions and help to evaluate existing programmes and to plan new ones. Careful use of hazard surveillance information can lead to early detection of system failure and call attention to the need for improved controls or repairs before excess exposures or diseases are actually experienced. Data from such efforts can also provide evidence of need for new or revised regulation for a specific hazard. Second, surveillance data can be incorporated into projections of future disease to permit planning of both compliance and medical resource use. Third, using standardized exposure methodologies, workers at various organizational and governmental levels can produce data which permit focus on a nation, a city, an industry, a plant or even a job. With this flexibility, surveillance can be targeted, adjusted as needed, and refined as new information becomes available or as old problems are solved or new ones appear. Finally, hazard surveillance data should prove valuable in planning epidemiological studies by identifying areas where such studies would be most fruitful.

Examples of Hazard Surveillance

Carcinogen Registry—Finland. In 1979 Finland began to require national reporting of the use of 50 different carcinogens in industry. The trends over the first seven years of surveillance were reported in 1988 (Alho, Kauppinen and Sundquist 1988). Over two-thirds of workers exposed to carcinogens were working with only three types of carcinogens: chromates, nickel and inorganic compounds, or asbestos. Hazard surveillance revealed that a surprisingly small number of compounds accounted for most carcinogen exposures, thus greatly improving the focus for efforts at toxic use reduction as well as efforts at exposure controls.

Another important use of the registry was the evaluation of reasons that listings “exited” the system—that is, why use of a carcinogen was reported once but not on subsequent surveys. Twenty per cent of exits were due to continuing but unreported exposure. This led to education for, as well as feedback to, the reporting industries about the value of accurate reporting. Thirty-eight per cent exited because exposure had stopped, and among these over half exited due to substitution by a non-carcinogen. It is possible that the results of the surveillance system reports stimulated the substitution. Most of the remainder of the exits resulted from elimination of exposures by engineering controls, process changes or considerable decrease in use or exposure time. Only 5% of exits resulted from use of personal protective equipment. This example shows how an exposure registry can provide a rich resource for understanding the use of carcinogens and for tracking the change in use over time.

National Occupational Exposure Survey (NOES). The US NIOSH carried out two National Occupational Exposure Surveys (NOES) ten years apart to estimate the number of workers and workplaces potentially exposed to each of a wide variety of hazards. National and state maps were prepared that show the items surveyed, such as the pattern of workplace and worker exposures to formaldehyde (Frazier, Lalich and Pedersen 1983). Superimposing these maps on maps of mortality for specific causes (e.g., nasal sinus cancer) provides the opportunity for simple ecological examinations designed to generate hypotheses which can then be investigated by appropriate epidemiological study.

Changes between the two surveys have also been examined—for example, the proportions of facilities in which there were potential exposures to continuous noise without functioning controls (Seta and Sundin 1984). When examined by industry, little change was seen for general building contractors (92.5% to 88.4%), whereas a striking decrease was seen for chemicals and allied products (88.8% to 38.0%) and for miscellaneous repair services (81.1% to 21.2%). Possible explanations included passage of the Occupational Safety and Health Act, collective bargaining agreements, concerns with legal liability and increased employee awareness.

Inspection (Exposure) Measures (OSHA). The US OSHA has been inspecting workplaces to evaluate the adequacy of exposure controls for over twenty years. For most of that time, the data have been placed in a database, the Integrated Management Information System (OSHA/IMIS). Overall secular trends in selected cases have been examined for 1979 to 1987. For asbestos, there is good evidence for largely successful controls. In contrast, while the number of samples collected for exposures to silica and lead declined over those years, both substances continued to show a substantial number of overexposures. The data also showed that despite reduced numbers of inspections, the proportion of inspections in which exposure limits were exceeded remained essentially constant. Such data could be highly instructive to OSHA when planning compliance strategies for silica and lead.

Another use of the workplace inspection database has been a quantitative examination of silica exposure levels for nine industries and jobs within those industries (Froines, Wegman and Dellenbaugh 1986). Exposure limits were exceeded to various degrees, from 14% (aluminium foundries) to 73% (potteries). Within the potteries, specific jobs were examined and the proportion where exposure limits were exceeded ranged from 0% (labourers) to 69% (sliphouse workers). The degree to which samples exceeded the exposure limit varied by job. For sliphouse workers excess exposures were, on average, twice the exposure limit, while slip/glaze sprayers had average excess exposures of over eight times the limit. This level of detail should prove valuable to management and workers employed in potteries as well as to government agencies responsible for regulating occupational exposures.

Summary

This article has identified the purpose of hazard surveillance, described its benefits and some of its limitations and offered several examples in which it has provided useful public health information. However, hazard surveillance should not replace disease surveillance for noninfectious diseases. In 1977 a NIOSH task force emphasized the relative interdependence of the two major types of surveillance, stating:

The surveillance of hazards and diseases cannot proceed in isolation from each other. The successful characterization of the hazards associated with different industries or occupations, in conjunction with toxicological and medical information relating to the hazards, can suggest industries or occupational groups appropriate for epidemiological surveillance (Craft et al. 1977).

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