Occupational health

Global strategy on occupational health for all: The way to health at work

Recommendation of the second meeting of the WHO Collaborating Centres in Occupational Health, 11-14 October 1994, Beijing, China

Situation analysis for health at work and development of the global working life

Trends of global economies

The ultimate result of the work input of the global workforce is a total global gross domestic product (GDP) of USD 21.6 trillion per year (USD 9 160 per worker). This GDP provides the economic and material re-sources by which all other activities, including health and social services, training and education, research and cultural services, are sustained. In addition to these material and tangible values human labour is also behind most intangible assets of society such as level of education and general knowledge.

In 1990, about 6.3% of global GDP was produced by agriculture, 36.3% by industry and 57.4% by services. The shares of different sectors varied widely, however, so that the respective proportions were 3.6%, 36.9% and 59.5% in the most industrialized countries and 48.4%, 15.5% and 36.1% in the least developed countries. In the industrialized world a major part of both the workforce and the GDP is bound to services, in developing countries the greatest part of the workforce is employed in agriculture. Due to variations in the productivity of different sectors and different countries, the average GNP per capita varies by a factor of 12 between the counties with the highest income and those with the lowest. This has a major impact on the workload and standard of living of workers in different parts of 9.the world. In recent years industry has been re-emphasized as the sector that produces the means to support other sectors such as services. Industrial productivity is often several times higher than productivity in agriculture.

The world is still economically very diverse. In spite of distinct progress made by the economies of many developing countries, the difference: between the least developed and the wealthiest countries of the world did not reduce but actually widened during the 1980s. There are many signs that this development will continue during the 1990s.

In spite of positive socio-economic trends in some developing countries. the future development of international economies speaks for further diversification in different parts of the world and on different areas of economic activity. Along with such development, working condition! and occupational health and safety standards are at risk of becoming polarized.

International economic and trade organizations predict further diversification of various economic sectors in different parts of the world in future. This will also have an impact on occupational structures and occupational health. The main recognized trends are growing internationalization, economic integration within the regions, such as North America, Europe and South-East Asia and growing competition between the regions. Slowing of economic growth is expected in the industrialized world, while 3.4-S% average annual growth is expected in the rapidly industrialising developing countries particularly in South-East Asia and China (8% growth in 1993). Also foreseen are increase of productivity of agriculture in developing countries, increase in the role of industry in the lower and upper middle-income countries, and decrease of the employment impact of industries and agriculture to the favour of the service sector in industrialised countries. However, among the least developed countries a clear regression is seen. The same is true in countries at war. Highly unstable and turbulent changes have been experienced in the recent past and are stil likely to be seen in the economies of the countries of Eastern Europe, with distinct consequences on health and safety at work.

There is a wide variation in economic structures, occupational structures conditions of work, quality of the work environment, and health status of workers in different regions of the world, different countries and different sectors of economies. There are also special occupational settings and types of enterprises, economic activities and undertakings in which world and workplace deviate substantially from the norm. Small-scale industrial and service enterprises often have few resources, heavy workloads and multiple tasks for one worker. Work takes place in an environment that does not always meet required standards. Family members of the workers and entrepreneurs, including children, pregnant women and elderly people, share the work in small-scale enterprises, home industries, small farms in all countries and cottage industries particularly in developing countries. In such situations most workplace exposures also affect family members and, since most of the time is spent in the combined home and work environment, the period of exposure also tends to be longer than the average. It has been estimated that two-thirds of the workers of the world still work in conditions that do not meet the minimum standards set by ILO.

Because of the high prevalence of manual and heavy physical work combined with lack of coverage of general health and social protection, developing countries and the NICs have several needs if they are to develop occupational health services. These needs include the strengthening of infrastructures, training of human resources, establishment of systems for registration of occupational injuries and diseases, establishment of institutes of occupational health, and establishment and updating of legislation and standards, as well as inspection of compliance with regulations. Due consideration should also be given to general health needs and to improvement of the health of the environment in these countries.

Due to the major changes in social and economic systems in the heavily industrialized Countries of Central and Eastern Europe (CCEE), the infra-structures for occupational health have weakened during the past few years. This is a consequence of splitting the large industrial concerns with well-established in-plant services into smaller independent enterprises that are not always able to maintain the services. The need of the CCEE countries for technical assistance, consultations and training in reorganization of occupational health and safety activities has been recognized. There is also a need to strengthen preventive general health services for the working population.

Advances in science and technology will lead to new developments in production systems. New information technologies, automation, further mechanization, new materials, growing production and use of chemicals, implementation of biotechnology on an industrial scale, low-impact processes, low-energy production and low-waste and recycling industrial strategies will have a great impact on production systems and the work environment in all parts of the economy, particularly in industrialized countries. This process of rapid change in production structures, often called the second industrial revolution, has a profound impact on conditions of work and on occupational health as well. Ensuring health and safety of workers as well as environmental health is key to the continued development of healthy new technologies.

The second industrial revolution which results from wide implementation of new information technologies and automation, biotechnologies, new production methods and materials and the development of low-impact, low-energy and low-waste industry generally has a positive impact on occupational health and safety, particularly in industrialized countries. Some new problems of workers’ health have, however, been identified. In addition, new patterns of employment and new types of work organization are seen. Ensuring health and safety in such changes is a key factor in determining their sustainability.

Such developments have already led to major changes in global and national economies and in technologies, as well as to rapid developments in manufacturing methods, working practices, organization of work, occupational structures, job demands, job contents and occupational health and safety, and the trend will continue. While the majority (60-70%) of employees in the OECD countries had blue-collar jobs in the 197Os, by the 1990s about 60-70% were employed in typical higher- or lower-level white-collar jobs (work in office environments). The overall impact of such developments on occupational health is likely to be positive, and exposure to many of the traditional physical, chemical, biological and mechanical hazards will be effectively prevented or controlled. At the same time, new job demands, the increased needs for processing and analyzing information, and several control room-like activities may increase the psychological problems of work such as mental stress. The new job content, new working methods and new equipment also place a high demand on the learning capacity of workers.

The implementation of new technologies, new demands for productivity and quality, and the need to support innovation and work motivation will lead to new types of work organization, new forms of employment, (including self-employment and subcontracting), new arrangements for hours of work, new management systems and possibilities for self-steering and participation. Due adjustment of occupational health and safety activities to these new developments is expected and there is a need to en-sure workers’ health in such new conditions. Such changes will make it necessary to introduce, train and educate each working individual in occupational health, thus enabling him or her to contribute positively to the health of the workers and the workplace.

Technology transfer is one of the major factors behind the economic development in both the industrialized and developing countries. Such transfer may occur in several different forms; in production carried out by multinational enterprises, as a national activity carried out by foreign investors or as an import of foreign technology. If performed according to the best principles proposed by the IL0 and other international bodies, such transfer can have a highly positive impact on both productivity and occupational health and safety. There are numerous examples, however, of the transfer of hazardous and obsolete technologies from industrialized countries to developing countries, to the NIC and to Eastern European countries in transition. Numerous international guidelines and conventions have been prepared by international organizations to prevent such hazardous transfer, but they are not yet effectively implemented every-where. In particular, the transfer of unshielded dangerous machinery and hazardous chemicals and substances has been reported to have caused an increase in occupational diseases and accidents among workers in the recipient countries. Several dramatic examples show the impact of the transfer of hazardous processes and waste to developing countries. The principle of the IL0 Recommendations on Multinational Enterprises, the London Guidelines on Export of Banned Chemicals and UNEP’s Basle Convention on Prevention of Transboundary Transportation of Hazardous Waste stipulate that nothing tht is unacceptable in the exporting country should be transferred to the importer, no matter what the legislation of the recipient country states about such a practice.

The technology transfer may have positive or negative impact on health of the workers and on health of the environment. Nothing that is unacceptable in the exporting country should be transferred to the importer, no matter what the legislation of the recipient country states about such practice.

In many developing and NIC countries, social change is associated with a - high rate of unemployment, active migration of rural people to urban areas, excessive urbanization with all its social problems and insufficient Government capacity to regulate urbanization and build up the required infrastructures for growing numbers of migrants. Workers seeking job opportunities in urban areas are often exposed to occupational and social hazards similar to those of workers in industrializing countries during the first industrial revolution 100 years ago and with similar severe impact on health and living conditions.

Universal minimum standards are needed for health, safety and social protection of workers in all countries. In order to prevent social dumping and over-exploitation of workers who are not able to defend them-selves, compliance with standards should be internationally controlled and should not be compromised for any reason.

Growing economic competition has led some countries to compete, not only in the quality and productivity of work, but also by minimizing the costs of labour by paying less than reasonable minimum wages. At the same time standards such as those for occupational health and safety may be set far below those accepted in IL0 International Conventions. Breaches of human rights, exploitation of unprotected workers, use of child labour, and high risks of health and safety are the consequences of such policies. Such social dumping has been found to be a vicious circle that has a ‘counterproductive impact on sustainable development. Inhumane working conditions should be prevented by adopting and implementing a universal minimum standard for health, safety and other conditions of work that cannot be compromised anywhere. International mechanisms for control of such standards should be generated. The social dimension should be included as an essential part of all international, national and ocal regulations and policies. Some countries require that development aid and loans, particularly for the establishment of industries and other economic activities, should be conditional on inclusion of appropriate occupational health and safety elements in such economic programmes.

Demographic trends and working conditions of the global workforce

About 2 400 million (45%) of the total 5 400 million population of the world and 58% of the population aged 10 years or more comprise the world’s workforce (Table 1). If informal work and work at home is taken into consideration the proportion of the working population is even higher. Some 1 800 million (75%) workers live and work in developing countries and about 600 million (25%) in the industrialized world. By the year 2000 almost 8 out 10 workers will be in the developing world.

Table 1. Working populations in the world in 1990 and 2000

Numerous demographic changes are foreseen in the working populations of both developing and industrialized countries. The absolute number of workers will increase with almost 500 million by the year 2000 and 90% of that growth will take place in developing countries. This implies the need to produce some 500 million new job opportunities for young people. In addition there is a need to employ the current 820 million unemployed or partly employed persons. Unemployment is likely to be a major problem during the remainder of the 1990s. In view of supporting an individual's management of life by his or her own action, every adult citizen of the world should be given an opportunity to sustain himself or herself and the dependants with his or her own work. The present high global rates of unemployment deviate strikingly from such an objective.

It is estimated that the global workforce will grow by 500 million by the year 2000 requiring that new job opportunities be created for young people. In addition, employment must be organized for over 800 million people who are currently unemployed. This implies that the total employment shortage will be about l-l.3 billion jobs by the year 2000. Unemployment is likely to remain a major long-term problem with adverse effects on health, working capacity and economy.

Increasing rates of unemployment are expected because of the increase in productivity as a result of technological development, new divisions of work, high population growth and economic recession in different regions. Most agricultural and manufacturing processes will become less labour-intensive, and services are not likely to absorb all the excess workforce no longer needed for primary and secondary production. Unemployment has been found to be associated with health hazards related to economic difficulties, major social problems, unfavourable lifestyles, risk behaviour and psychological problems as well as, in some instances, higher mortality. The vast majority of the new jobs are needed in developing countries. Governments should carry out policies which enable every citizen of the world to have employment that corresponds to his or her capabilities and needs, and ensures reasonable income in healthy and safe working conditions. International economic organizations and the ILO have emphasized that the only way to respond effectively to such a vast employment challenge is the promotion of small-scale enterprises and self-employment.

Dynamic changes are seen in the age structures of the working populations. Workers aged 60 years or more comprise 5.4% and 5.0% of the labour force in industrialized and developing countries, respectively. Adding those aged 50-59 increases the number of older workers threefold. A gradual increase in the average age of workers will be seen during the 1990s, particularly in the northern and Alpine areas of Europe. After the year 2000 more rapid ageing f the workforce will take place also in many developing countries. In some industrialized countries the aging of the workforce and the simultaneous negative or zero growth of the population will lead to overrepresentation of the elderly and under representation of the young.

Due to growing average age of workforce and high accident rates in some countries the number of handicapped people will increase. According to - the policies adopted internationally for handicapped persons the individuals with limitations in functional capacities have a right to participate in work provided their status of health permits it. Such individuals must be specially protected at work to avoid further loss of health and working capacity by adapting work and the work environment to their individual needs. Similarly appropriate services for rehabilitation and maintenance of their working capacity are needed. Much remains to be done to ensure equal opportunities for employment for underserved groups such as migrants, the handicapped, refugees and chronically ill workers.

The major demographic trends world-wide are the increasing average age of the workforce, growing work participation rates, growing participation of female workers, growing mobility, increasing literacy, and level of education of the workforce. There are special problems of vulnerable and underserved groups such as child workers and handicapped people whose special needs should be appropriately considered in occupational health programmes.

The growth of the older section of the workforce coupled with growing demands for better productivity will require measures to adjust working conditions to elderly workers, as well as resources to maintain and promote their health and working capacity.

The average global labour participation rate in the formal workforce among the male workers is 73%, the respective figure for females being 43%. Female participation in the workforce varies widely from 60% in industrialized countries to about 10% in North Africa and Western Asia. The rate of female participation is expected to grow in the future. In 1985 women represented 36.5% of the world's labour force. There is a growing need to develop equality at work between male and female workers as well as to ensure equal job opportunities for both genders.

To a great extent, the occupational health needs of about 100 million child workers in the world remain still unrecognized and the physical, mental and social development of these young individuals are likely to be affected. Drop-out from schooling may result in illiteracy while hazardous exposures and heavy workload present long-term health hazards to child workers.

The number of the child workers between 10 and 14 years of age is difficult to estimate for individual countries. The numbers are declining in the industrialized countries although even there child labour is still used. About 5% of the workforce in developing countries are child workers, with up to 7.9% in Africa. Serious concern has recently been expressed about the unhealthy working conditions of child workers and about associated adverse effects on young people’s health and physical, mental and psychosocial development. The number of young workers (15-24 years) is declining or will show decelerating trends due to falling birth rates and longer training periods in virtually all countries (with exception of certain developing countries). The decrease in the number of young workers will become even steeper after the year 2000. In spite of this, particularly in developing countries, young people have the highest risk of unemployment that prevents them from learning work practices and in a relatively short time affects their chances of ever finding employment.

Internal and international migration of the labour force is expected to grow during the next decade for several reasons. Rural populations are migrating to urban areas, especially in developing countries to seek employment and a higher standard of living. The degree of urbanization is expected to grow from 71.5% in 1985 to 74.8% by the year 2000 in industrialized countries and from 3 1% to 4 1% in Africa. Such migration will cause several employment, health, housing and social problems in the urban and suburban areas of the developing world.

Economic inequalities, wars, unemployment, destruction of the environment, and hostile political pressures increase the rates of international migration and the number of refugees. This international migration is likely to increase problems for internal migrants by, for example, exacerbating the problems of housing and unemployment. Migration of young labour from developing countries to industrialized ones will be a particular problem between Africa and Europe and between the Central and North America. Examples of exploitation of powerless migrant and refugee workers and social dumping can be found in several industrialized countries.

The most important provider of new job opportunities will be small-scale enterprises and self-employment. Several new employment patterns call for new approaches from occupational health programmes. In the absence of well developed organizations for occupational health and with a general shortage of resources, the development of health at work for persons in small-scale enterprises and for the self-employed will lie in the hands of the entrepreneurs who run those enterprises and the self-employed themselves. Several studies and practical experience show that these groups are not the most aware of the need for occupational health. Accordingly, the provision of training and information to both the entrepreneurs and the self-employed is an important step in the development of global occupational health. A number of studies by, for example, the IL0 have shown that a proper occupational health programme can substantially improve not only the health of persons who work in small-scale enterprises but also the economic productivity and sustainability of the undertaking.

A major part of the workforce in developing countries and 5-10% of the sector workforce in industrialized countries are occupied in home industries, in small service units or as casual workers. This part of the workforce and its workplaces are difficult to define and even more difficult to cover with any kind of service or information. Occupational health hazards may, however, be highly prevalent and there may also be substantial para-occupational exposures among family members and neighbors. The informal sector, home industries and several new types of self-employment are expected to be important in improving the future employment situation in both developing and industrialized countries. There is a need to develop relevant occupational health services for such new enterprises and new groups of employees.

The illiteracy rate of the adult population in the world is at the moment 39%, i.e. about 960 million. As many as 95% of illiterates live in developing countries. The literacy rate is expected to grow world-wide to 72% by the year 2000, though a decline is expected in Africa and in some of the least developed countries of Asia. Enrolment rates for secondary and tertiary (university) education are growing and the differences between the developing and industrialized countries will grow less. Middle-income countries in particular will increase their average levels of education, while sub-Saharan Africa and the least developed countries elsewhere will continue to suffer from a shortage of people with higher education. This in turn will create difficulties in supporting socio-economic and technical development because the capacity to absorb modem working methods and technologies is critically dependent on the availability of well-trained experts. While the improving educational level is likely to further the development of occupational health and safety, the shortage of higher education will negatively affect the development of occupational health in the least developed countries.

Situation and trends in occupational health and safety

Exposures and hazards
The occupational health standards of workers and workplaces vary substantially according to economic structure, level of industrialization, developmental status, climatic conditions, and traditions in occupational health and safety. 20-50% of workers may be subject to hazardous exposures at work in industrialized countries and the rate may be even higher in the developing and newly industrialized counties. Mechanical factors and physical and chemical agents are the main problems in manufacturing industries, while pesticides, heavy physical work, organic dusts, biological factors and accidents are the occupational burdens of agricultural workers. A number of studies show that in the most unfavourable conditions 50-100% of the workers in some hazardous industries may be exposed to levels of chemical, physical or biological factors that exceed the occupational exposure limits applied in the industrialized countries.

Because of the numerous problems of health at work and among working people, the need for occupational health is evident in all countries (industrialized, newly industrialized or developing) including the least developed ones. The types of problems may, however, vary substantially according to the national and local needs and conditions, cultural influences, and other local factors.

Depending on the country, type of economic activity and enterprise, up to 30.40% of workers, and in some high-risk industries more than half of workers in some countries may be exposed to hazardous physical, chemical, biological or ergonomic factors that seriously exceed the exposure limits adopted for many industrialized countries. As a consequence, high proportions of workers may show adverse health effects from their workplace exposures. Several recent surveys on psychological stress at work show increasing trends, particularly in industrialized countries. Such hazards have been shown to cause remarkable loss of health, well-being and working capacity and thus to affect the productivity, quality of working life, and economic status of individuals, companies and nations.

Even the industrialized countries - faced with an aging workforce, rapidly developing technologies, growing environmental concerns and extensive implementation of new information technologies - have to pay attention to the need to prevent occupational injuries, traditional occupational diseases caused by physical, chemical and biological factors, heavy physical work, and ergonomic problems. These problems apply increasingly, however, to smaller high-risk groups. For the majority of workers, the problems of the modem work environment‘, such as psychological stress, new models of work organization, computerization of tasks and indoor air quality in office buildings are priority problems. The ageing workforce also require the adaptation of the working methods and job demands to tit for the capacity and needs of the ageing individual. The maintenance and promotion of the working capacity of elderly persons is also a priority concern in many industrialized countries.

The rapidly industrializing countries still show industrial growth and often make use of technologies that are less advanced than those of industrialized countries. In such situations it may be difficult to manage all aspects of production such as, for example, health and safety at work and the health of the work environment as well as environmental health. Occupational accidents and traditional physical and ergonomic hazards and occupational diseases are an important problem and the need for further preventive and control measures is often poorly recognized. Notification and registration of such outcomes is often less developed and many of them remain unregistered. Mechanisms for prevention and control of occupational hazards are, however, less developed and many of the needs of workers’ health are not met.

The least developed countries that still employ the major part (up to 80%) of the workforce in agriculture and other types of primary production face occupational health problems that are different from those experienced in the industrialized countries. Heavy physical work often combined with heat stress, occupational accidents, pesticide poisonings, organic dusts and biological hazards will be the main causes of occupational morbidity. In the least developed countries these occupational factors are aggravated by numerous non-occupational factors such as parasitic and infectious diseases, poor hygiene and sanitation, poor nutrition, general poverty and illiteracy.

The special occupational health problems of working women are recognized in both the developing and industrialized countries. In the former, heavy physical work, the double work burden of job and family less developed working methods and traditional social roles are the factors that increase the burden of female workers. In the industrialized countries, where women also have the double work burden, lower-paid manual jobs are often left to female workers. Also the design of machinery and work tools are often made according to male anthropometry although female workers use such equipments. Women may also face problems of occupational exposures that are hazardous to reproductive health. In many service occupations the female workers may be exposed to the threat of violence from clients or to sexual harassment from fellow workers. Some studies indicate a higher than average risk of unemployment among low-paid female workers which may also have negative social and health consequences on families. Equal job opportunities for women and men and equal payment for the same job are still rarely seen around the world.

High numbers of physical, chemical and biological agents, as well as ad-verse ergonomic, physiological and psychosocial factors are found in to-day’s work environment. Such agents and factors, individually or in several complex combinations, threaten workers’ safety and health and reduce well-being and productivity. Some hazards have been well identified while some others, such as health effects of non-ionizing radiation and indoor air pollution, still need research and scientific risk assessment. Occupational health problems caused by new developments in working methods, production technology and work organization should be foreseen and assessed early enough to undertake effective preventive action. In the past few years new infectious epidemics have threatened the health of workers, particularly those in the health services. Also some old infectious epidemics such as tuberculosis have re-emerged in many industrialized countries and continue to cause a health hazard to workers in health care.

Mechanical factors, unshielded machinery, unsafe structures at the work-place and dangerous tools are one of the most prevalent environmental hazards in both industrialized and developing countries and affect the health of a high proportion of the workforce. Hazards caused by traffic in many countries are starting to reach epidemic dimensions. For example, in Europe about 10 million occupational accidents, 25 000 fatalities and al-most 150 000 fatal traffic accidents happen every year, a part of them being commuting accidents. There is a growing body of data showing that most accidents are preventable and that relatively simple measures in the work environment, working practices, safety systems and in behavioral and management practices are able to reduce accident rates even in high-risk industries by 50% or more in a relatively short period of time. On the other hand, ignorance of such precautions, particularly in sectors where production has grown rapidly, has led to increasing rates of occupational accidents. Accident prevention programmes are an important and technically feasible part of occupational health services; they are shown to have high cost-effectiveness and yield rapid results.

Though less frequent, major industrial catastrophes may cause great health losses and the workers are often the first and most severely affected victims. In a large-scale catastrophe the social, environmental and economic loss is so great that it is almost impossible to calculate. Many industrial catastrophes originate from technical failure, but human factors and the factors related to occupational health and the work environment often play a role. A predictive and preventive approach at the workplace, including adequate training in emergency response, may substantially reduce the potential for such hazards and the competence and knowledge of occupational health services should be used for this purpose. By limiting the risk of major accidents at the workplace it is possible to avert their consequences on the community and the environment.

Workers may be exposed to several physical factors such as noise, vibration, ionizing and non-ionizing radiation and microclimatic conditions which are known to affect their health. Between 10% and 30% of the workforce in industrialized countries and up to 80% in developing and newly industrialized countries are exposed to such physical factors and in some high-risk sectors such as mining, manufacturing and construction all workers may be affected. Noise-induced hearing loss has been found to be one of the most prevalent occupational diseases in both developing and industrialized countries. Numerous preventive means are available, including design of low-noise technologies and work methods, noise reduction at the source, enclosures, isolation of noise source, protection of workers’ hearing by personal protectors and, if other methods are not available, shortening of the exposure times. Similar preventive strategies have been developed for other physical factors, particularly for localized vibration and ionizing radiation.

About 100 000 different chemical products are in use in modern work environments and the number is growing constantly. Exposures are most prevalent in industries processing chemicals and metals, in the manufacture of several consumer goods (such as metal products and plastic boats), in the production of textiles and artificial fibers and in the construction industry. Chemicals are increasingly used in virtually all types of work, including non-industrial activities such as hospital and office work, cleaning, cosmetic and beauty services and numerous other services. The extent of exposure varies widely according to the industry, activity and the country. Fortunately only 1 500-2 000 chemicals are widely used, making assessment and management of risks easier, although not simple. Metal poisoning, solvent damage to the central nervous system and liver, pesticide poisoning, dermal and respiratory allergies, dermatomes, cancers and reproductive disorders are among the health effects of such exposures. In some countries more than half of the workers in certain high-risk industries may show clinical signs of occupational disease which also has an adverse effect on working capacity.

Some 200 biological agents, viruses, bacteria, parasites, fungi, moulds and organic dusts have been found to occur in occupational exposures. In the industrialized countries around 15% of workers may be at risk of viral or bacterial infection, allergies and respiratory diseases. In many developing countries the number one exposure is to organic and biological agents. The Hepatitis B and Hepatitis C viruses and tuberculosis infections (particularly among health care workers), asthma (among persons exposed to organic dust) and chronic parasitic diseases (particularly among agricultural and forestry workers) are the most common occupational diseases resulting from such exposures. The growing mobility of people from disease endemic areas to areas of low risk has increased the risk of disease, particularly to health care personnel. Immunizations can be used to control some hazards such as Hepatitis A and B, while for some others careful personal and occupational hygiene and use of personal protective devices or immunoglobulin (Hepatitis C) may be the main preventive strategy. A new occupational health problem affecting health service workers and certain other groups is the re-emergence of traditional epidemics of communicable diseases in, for example, Eastern Europe. The risk of occupational transmission of HIV to health care personnel has proved to be less probable than originally expected.

Growing attention was paid in the 1980s to the risk from reproduction health hazards of work and workplace exposures. Some 200-300 chemicals known to be mutagenic or carcinogenic tend to have adverse effects on reproduction (including infertility in sexes, spontaneous abortions, fetal death, teratogenesis, fetal cancer, fetotoxicity or retarded development the fetus or the new-born). Numerous organic solvents and toxic metals are associated with adverse effects on reproduction health. Many biological agents, such as certain bacteria, viruses and zoonoses, as well as heavy physical work, are also associated with an increased risk of reproduction disorders. The reproduction hazards caused by ionizing radiation have been well established, while hazards from non-ionizing radiation are under intensive study. Both male and female workers may be affected by occupational hazards but particular concern is given to the protection of women of fertile age and during pregnancy. In addition to the conventional preventive actions of occupational health and hygiene services, special arrangements have been made in some countries to re-move pregnant women from exposure that may be hazardous to the health of the mother or foetus. The modem occupational health approach considers the possibilities of primary prevention for protection of reproduction health of both genders in all stages of reproductive life of the worker.

About 300-350 different factors - chemical (e.g. benzene, chromium, nitrosamines, asbestos), physical (e.g. ultraviolet radiation, ionizing radiation) and biological (e.g. aflatoxins, tumor viruses) - have been identified as occupational carcinogens. The most common cancers resulting from occupational carcinogenic exposures are cancers of the lung, bladder, skin, mesothelium, liver, haematopoetic tissue, bone and soft connective tissue. Estimates for occupationally determined part of cancer morbidity out of the total cancer morbidity vary between 2% and 38%. Among certain occupational groups, such as asbestos sprayers, occupational cancer may be the leading factor in ill-health and mortality. Due to the special character of occupational cancer, the only effective strategy for its control is primary prevention that aims at total elimination of the exposure or at effective isolation of the worker from carcinogenic exposure.

There are estimated to be about 3 000 allergenic factors in our environment, most of them occurring as occupational exposures. Allergic dermatoses are one of the most prevalent occupational diseases and can lead to incapacity for work and to the need to move the worker to another occupation. The respiratory tract, followed by the skin surface, is the most important route for hazardous agents to enter the body. This makes occupational respiratory diseases the priority problem in any occupational health programme. Occupational asthma is caused by exposure to several organic dusts, micro-organisms, bacteria, fungi and moulds, several chemicals, both organic and inorganic. The growing tendency of the population to develop an allergic response, coupled with high numbers of allergenic exposures at work and better diagnostic methods, has led to a steady growth in the registered numbers of occupational asthma cases in several industrialized countries. Again the primary prevention approach is the most important preventive strategy. In addition to respiratory allergens, the respiratory system may also be exposed to mineral dusts that cause fibrotic responses and are often associated with an elevated risk of cancer. Pneumoconiosis has been found to occur in as many as half of workers most heavily exposed to silica, coal dust or to asbestos fibres.

Between 10% and 30% of the workforce in industrialized counties and between 50% and 70% in developing countries may be exposed to a heavy physical workload or to unergonomic working conditions such as lifting and moving of heavy items or repetitive manual tasks. The occupations most heavily exposed to physical workload are miners, farmers, lumber-jacks, fishermen, construction workers, storage workers and health care personnel (particularly those caring for the elderly). Repetitive tasks and static muscular load are found in many industrial and service occupations. Damage to the cardiorespiratory or musculo-skeletal system and traumatic injuries may be the consequence of such an overload of hazardous factors. In many industrialized countries musculoskeletal disorders are the main cause of both short-term and permanent work disability causing economic losses that may amount to 5% of the GNP. Most of the factors behind such exposures can be eliminated or minimized through design of adequate machinery and tools, and through automation, mechanization, improvement of ergonomics, better organization of work and training in appropriate work practices. In particular, the growing numbers of elderly workers and the female workforce require constant vigilance from the occupational health services to prevent hazardous ergonomic conditions and physical overload.

Up to half of all workers in industrialized counties judge their work to be "mentally heavy". Psychological stress caused by time pressure and hectic work has become more prevalent during the past decade. Other work factors that may have adverse psychological effects include heavy responsibility for human or economic concerns, monotonous work or that which requires constant concentration, shift-work, work under the threat of violence as, for example, police or prison work, and isolated work. Psychological stress and overload have been associated with sleep disturbances, bum-out syndromes and depression. There is also epidemiological evi-25.dence of an elevated risk of cardiovascular disorders, particularly coronary heart disease and hypertension. Severe psychological conditions (psychotraumas) may be seen among the workers involved in serious catastrophes or major accidents where human lives are threatened or lost.

In many industrial and service occupations, including health services, irregular working hours and frequent shift-work are associated with several physiological and psychosocial problems that affect the health of workers and require exceptional capacity for adaptation. In some countries up to 30% of industrial workers work shifts. Adaptation to unconventional diurnal rhythms varies widely between individuals. Ageing reduces capacity for adaptation and starting to work in three shifts is not recommended for any-one over 45 years of age. Insufficient adaptation of the individual to shift-work may also have an impact on safety; several major industrial catastrophes in the past decades have started during night shift. The recent studies indicate surprisingly high rates of sleeping episodes e.g. among traffic workers in the night shift.

Strategies to prevent adverse psychological factors are directed towards the elimination of psychological overload and stress by modification of the work environment, work organization and, if necessary, by changing managerial systems. Prevention and control includes organization of team-work, training and education, introduction of stress management methods for individuals at risk and psychological support from foremen, fellow-workers and psychologically competent occupational health services. Occupational psychologists also recommend increasing workers’ self-determination and self-regulation as preventive strategies. In case of threat of violence, measures for eliminating the likelihood of such hazards (e.g. working in pairs instead of working alone) and provision of adequate protective structures and equipment for cases of emergency will improve worker confidence.

Many types of work, such as seafaring, transport, and supervision of prisons may require longer shifts or longer periods to be spent at the work-place than the regular eight hours per day. In extreme cases such periods at the worksite may be several months. In such special conditions, the place of living and place of work are the same, which creates specific environmental and psychosocial problems and needs.

Such workplaces may increase in number in the future since mining, forestry and oil exploitation activities, for example, are moving increasingly to remote areas. Offshore oil and gas drilling is constantly expanding and moving further from the shore. Underwater mining may become a major source of ores in future. Research is needed on hazards and their prevention and on development of occupational health services for these new and special conditions.

A substantial number of hazardous exposures in the general environment and in the community environment are derived from industrial activities or from other occupational systems such as transport. Limiting the spread of such exposures from the workplace limits the numbers exposed and provides effective prevention and control with reasonable costs. The working population is exposed to the hazards both in the occupational environment and in the general and community environment. In assessment of the total exposure and health risks, all types of exposure should be considered. Occupational health experts have much valuable information that should be used more effectively for prevention of environmental hazards. In some countries formal arrangements have been made to strengthen collaboration between occupational health and environmental health and even to combine these approaches both functionally and organizationally. On the other hand, some occupational health units find it difficult to expand their activities into environmental health and prefer to limit themselves to issues of workers’ health.

Several social aspects of work may raise health concerns, for example, the gender distribution and segregation of jobs and equality at the workplace, social relationships between the managers and employees, and social support from fellow-workers are aspects of work that may enrich or reduce social contacts. In many services and public jobs the social pressure from customers, clients or the public may cause additional psychological workload. Measures for improving social aspects of work are mainly those that promote the creation of open and positive contacts at the workplace, support the individual’s role and identity at work and facilitate team-work.

Working conditions, type of work, vocational and professional status and geographical location of the workplace and employment also have a profound impact on the social status and social well-being of working people. Historically, occupational health programmes have been developed hand-in- hand with the improvement of social conditions for underserved and unprivileged occupations and groups of workers. In many countries, social policy and coverage of social protection is closely linked with employment, and occupational health issues may be understood as part of the social component of collective agreements. As the mobility of workers in-creases and high numbers of migrant workers are found in several countries their health, well-being and social support requires special attention in which occupational health experts have a role to play.

About 100 000 chemicals, some 50 physical factors, 200 biological factors and some 20 adverse ergonomic conditions, and an identical number of physical work loads associated with incalculable numbers and types of psychological and social problems have been identified as hazardous factors or conditions of work which usually occur in combinations and have several interactions. They contribute to the risk of occupational injuries, diseases and stress reactions, job dissatisfaction and absence of well-being. Most of such problems are in principle preventable and should be prevented in view of both interest of health and well-being, but also from the economy and productivity point of view.

Injuries, diseases and outcomes
The ILO estimates that there are 120 million occupational accidental injuries and 200 000 occupational fatalities a year world-wide. This means the average risk of accidents is 42 per 1000 workers with the risk of fatality at 8.30/100 000. The European risk averages are 25/l000 for accidents and 6.25/100 000 for fatalities. Estimation of occupational disease rates is difficult because of the shortage of data and variation in the definition of an occupational disease in different countries. Extrapolation on the basis of incidence in the ell-registered European countries (3-5/l000) gives a world annual incidence of 68-157 million cases of occupational diseases, of which about 30-40% may lead to chronic disease and about 10% to permanent work disability and, according to a crude estimate, about 0.5-l% to death. As indicated by WHO, in addition to formally registered occupational diseases high numbers of work-related diseases which are partially caused by occupational factors, aggravated by work or connected with lifestyles determined by work, occur among working populations. Globally, a major part of occupational diseases go undiagnosed and unreported.

120 million accidental injuries with 200 000 fatalities and 68-157 million cases of occupational disease are estimated to occur among the global workforce annually. In high-risk occupations one-fifth of the workers may annually contract an occupational accident or disease. Most of such morbidity is, in principle, preventable with the help of the modern occupational health approach. Many cases of occupational disease, however, go underdiagnosed and underreported and preventive actions are not undertaken

In addition to occupational injuries and diseases, workers in developing countries suffer several maladies due to bacterial, viral and parasitic infections, malnutrition, poor hygiene and poor sanitation. Such conditions further reduce working capacity and aggravate the effects of occupational hazards. In some of the least developed countries the average manual worker in indushy or agriculture may have several chronic infections. The average calorie supply of workers in the least developed countries is lower than what is needed to perform a full day of medium-heavy work (2400/kcal/d). The silicotic lung is more prone to contract tuberculosis, and lead exposure further aggravates anaemia caused by infections and malnutrition. Effects of many chemical exposures are aggravated by the poor nutritional status of the worker. The ultimate objective of occupational health is a healthy and productive worker, free from both occupational and non-occupational diseases. Occupational health also aims at the social and economic well-being of working people and promotes healthy, safe and motivating work and work environments. To achieve such an objective requires continuous improvement of the conditions of work and a comprehensive and multidisciplinary approach. Also the general morbidity of working populations should be considered. Particularly in developing countries and in small-scale enterprises the adoption of the primary health care approach may be needed to attain such goals.

The ultimate objective of occupational health is a healthy, safe and satisfactory work environment and a healthy, active and productive worker, free from both occupational and non-occupational diseases and capable and motivated to carry out his or her daily job by experiencing job satisfaction and developing both as a worker and as an individual.

The risk of occupational disease and accident vary substantially between different occupations. For example, in Finland there is a 30-fold difference in the occupational accident risk of low-risk and high-risk occupations and a 40-fold difference in the risk of occupational disease.

Even in conventional production procedures, certain jobs are more dangerous than others. At the same time, socio-economic characteristics and lifestyle may substantially increase the risk caused by occupational hazards. Lifestyle factors, such as tobacco smoking among asbestos-exposed workers, may substantially elevate the risk of occupational cancer. Identification of high-risk occupations and occupational groups is of great importance for focusing prevention and control and for setting priorities. Many high-risk groups consist of people of poor socio-economic status, illiterate, earning low pay and with poor social protection. For example, migrant workers have a higher risk of occupational accidents than do workers from the host country. Migrants are not able to defend their rights or reduce their risks on their own; improvement of their health situation requires extensive and long-term commitment from the employers, authorities and health professionals.

The health status of the working population varies greatly according to the general health situation of the country as well as the type of work and the standard of the work environment. Remarkable variation in the health of workers can be seen between the industrialized and developing countries. There are, however, also major differences in occupational health between countries with approximately the same level of socio-economic development, demonstrating the importance of policy choices. Each country is, however, critically dependent on a healthy workforce and its capacity to produce raw materials, goods and services effectively. It has been shown that a high standard of occupational health and safety correlates positively with the GNP per capita in all groups of countries - developing, newly industrialized and industrialized. On the other hand, loss of working capacity may cause great economic losses. Thus, hazardous working conditions are counterproductive to economic and social development, while a healthy, motivated and productive workforce in an optimal work-place is one of a country’s most valuable social and economic assets. A growing body of data show that the impact of occupational health is positive not only at the level of national economy, but also at the level of economy of an individual enterprise.

A high standard of occupational health and safety correlates positively with high GNP per capita. The countries investing most in occupational health and safety show the highest productivity and strongest economy, while the countries with the lowest investment have the lowest productivity and the weakest economies. Thus, active input in occupational health and safety is associated with positive development of the economy, while low investment in occupational health and safety is disadvantage in the economic competition.

Despite being important for national economies, the working population has seldom obtained a priority position on the health policy agenda - either internationally or in many countries with great occupational health problems. This is so in spite of the fact that substantial economic losses are caused by health and safety hazards at work and by reduction or loss of working capacity. Such loss may amount to lo-20% of GNP in some countries. The low priority given to occupational health is all the more surprising in view of the fact that most occupational health hazards are preventable. The World Bank recently estimated that up to two thirds of occupationally determined loss of disability-adjusted life years (DALYs) can be prevented. Furthermore, besides minimizing health and economic loss by prevention and control of health hazards at work, occupational health can also improve productivity, contribute positively to the quality of products, and improve job satisfaction and work motivation. It has also been seen in developing countries where the coverage of social protection is low that the well-being of the whole family is critically dependent on the health and productivity of the working member.

Poor occupational health and reduced working capacity of workers may cause economic loss up to lO-20% of GNP. According to the World Bank estimate, two thirds of occupationally determined loss of disability-adjusted life years (DALYs) could be prevented by occupational health and safety programmes.

Emerging problems
Individual occupational health problems exist in many countries at different stages of development, but their prevalence, distribution, intensity and consequences vary substantially. Accordingly, the occupational health needs and priorities of countries vary widely according to their stage of socio-economic development, economic structure, level of technology, geography and climatic conditions, demography of the working population, and the degree of development of occupational health and safety policies and infrastructures. Different problems, therefore, are new in different countries and enterprises. For example, in the rapidly industrializing countries the growing numbers of accidents may constitute a new problem while post-industrialized countries have shown declining accident rates for years.

The industrialized countries are moving to the so-called post-industrialized stage characterized by a low proportion of employment in agriculture (2.55%) no more than one-third in industry and the rest in services. As occupations change, work requires more mental ability, independence and a high standard of competence and skill. Traditional occupational injuries and diseases will still occur, but they will affect comparatively small high-risk groups. Psychological problems at work, including symptoms of stress, will be the most common occupational health problem in the industrialized countries in the latter part of the 1990s. Certain new psychosocial problems have been recognized, such as stress from threat of violence among female service workers who work alone and stress caused by social workers’ incapacity to help clients.

The occupational health needs of the newly industrialized and rapidly industrializing countries relate to hazards such as occupational accidents, occupational diseases caused by mineral and organic dusts, chemicals, toxic metals and solvents, physical factors such as noise and vibration, and biological factors such as viruses and bacterial infections. Heavy physical workload and ergonomic problems also cause high numbers of strain injuries, musculoskeletal disorders and accidents. Traffic accidents in com-muting to and from work are increasing. The prevention and control of such hazards has been successful in the industrialized countries and thus models for risk management are available. The problem is the low cover-age of the occupational health and safety infrastructures and, in some instances, lack of political will, legislation, inspection, education, training, information and even awareness of the importance of occupational health and of its positive impact on socio-economic development.

The new occupational health problems of industrialized countries tend to be associated with implementation of new technologies, new substances, psychosocial factors and the special needs of ageing populations and vulnerable groups. The problems of newly industrialized countries stem from the more traditional occupational accidents and occupational diseases. In developing countries the problems of heavy physical work, pesticides and heat stress, as well as several vegetable and other organic dusts and biological hazards are of highest importance.

The emerging occupational health needs of developing countries relate mainly to agriculture and other sectors of primary production. The role of the relatively small industrial manufacturing sector is vital to socio-economic development. Pesticide poisonings, organic and mineral dusts, heavy physical work, heat stress, occupational accidents, industrial chemical and physical hazards, and ergonomic problems make up the list of priorities. Transfer of hazardous technologies and substances from industrialized countries is a problem that developing countries cannot solve by themselves. Effective elimination and control of such severe occupational health and safety hazards is hampered by one-sidedly ambitious economic objectives, low coverage of legislation and inspection, non-existent or weak infrastructures for monitoring and services, and a universal shortage of expert manpower and institutions for occupational health. During the process of economic development, growing mechanization and chemicalization of agriculture and industry is expected, calling for preventive occupational health and safety actions.

Regulations and standards stipulating the minimum level of safety and health at work are important tools for improving working conditions since they apply to all workplaces and all employed persons. Traditionally all occupational health activities and standards have been designed according to the needs and capacities of an average healthy (male) worker of optimum working age (30-45 years). This group, though important, usually represents only about one-quarter of the total workforce. Other groups include older workers over 55 (about 20%) migrant workers (often a few per cent of the workforce), female workers (30-50% of the workforce) and in some countries child workers who may comprise a few per cent of the workforce. Up to 30% of the working population may have an a topic or otherwise vulnerable constitution and about IO-20% of the total work-force and up to 70% of older workers may have one or more chronic diseases that affect their working capacity or make them vulnerable at work. A few per cent of the workforce are permanently handicapped. Thus the majority of the workforce deviate substantially from the ‘average’ and their number is growing. The special needs of vulnerable groups should always be considered in planning the work environment, working methods, workplace standards and occupational health services. The principle adopted by WHO and IL0 is that each individual should be given the opportunity to participate actively in work without risk to his or her health; the principle also applies to vulnerable groups who may risk their health in conditions that may not be hazardous to the ‘average’ person. Such risk to the vulnerable may occur in conditions that meet the stipulated standards. Continuous vigilance is needed to monitor how conditions of work may affect vulnerable groups. Standards must reflect the need to protect such vulnerable groups and strong measures should be taken by every government to prevent discrimination against vulnerable persons in recruitment. Some governments have successfully provided specific economic incentives for employers who employ handicapped workers. The occupational health research and expert communities together with WHO Workers’ Health Programme are expected to give a health-based foundation for appropriate risk assessment and standard-setting in occupational health also in view of protection the health of vulnerable groups.

According to the principles of the WHO and ILO, each individual, healthy, handicapped or chronically ill, should be given an opportunity to participate actively in work without risk to get harm to his or her health and working capacity. Such individuals should be effectively protected against discrimination at work by provision of appropriate legal and other protective measures.

It has already been argued that the future growth of employment will primarily be in small enterprises and self-employment. Such small-scale activities often have many advantages for occupational health and safety, but competence and awareness is not always sufficient for prevention and control of hazards in high-risk jobs. The health and economic loss caused by poor occupational health standards and a hazardous work environment may become unreasonably high for the small-scale enterprise, though this is not always clearly recognized. Providing sufficient awareness, knowledge, technology, practices and services for effective occupational health and safety programmes in small-scale enterprises is costly and technically difficult. New activities, new service provision models and new collaboration links need to be developed for this purpose. Collaboration between OHS organizations, industrial and trade associations, chambers of commerce, promotion and extension organizations, training institutions, and various professional bodies are experimented in many countries.

Occupational health needs are becoming more specific and more complex. Such needs should be taken into consideration in designing training programmes for experts. In spite of positive developments in general health services, primary health care and specialized services, a special occupational health service with appropriate support systems, including clinical services for the diagnosis and treatment of occupational diseases, is still needed. Surveys of the occurrence of occupational diseases have clearly shown that the countries most advanced in preventive occupational health activity also record the highest numbers of occupational injuries and diseases. This finding may indicate that even higher numbers of cases occur in less developed countries but remain for the most part unrecognized and unregistered and consequently undiagnosed and untreated. Often low rates of diagnoses and reporting speak for inability of the health system to find occupational diseases and injuries.

Certain civil and military jobs are carried out in extreme environments, such as offshore oil and gas drillings, projects in remote areas and in unexplored areas or regions (tropics, space, and the ocean floor). Typical of such work is the narrow margin of safety and the high psychological, physical and social demands on workers. Knowledge, both theoretical and practical, should be systematically accumulated and documented on extreme working conditions and on human responses to such conditions. This knowledge should be evaluated and distributed to all who need it, including occupational health experts.

A 24-hour occupational health service may be needed for occupations where accommodation is on the worksite, as in offshore activities and sea-faring. Availability of effective and competent occupational health services may be vitally important, not only for individual workers but also for the safety of the whole operation. Again, special models for provision of occupational health services for such activities are needed, and relevant special occupational health measures and expertise needs to be guaranteed.

Work-related musculoskeletal disorders represent one of the major problems in occupational health for the 1990s and beyond. A similar large-scale need is to provide occupational health support in the prevention of psychological and psychosocial problems connected with work. In many countries such new needs call for reorientation of occupational health activities and may affect the structure, composition and training of occupational health service teams.

In most countries occupational health is not a priority and it is not given sufficient resources to carry out the preventive, control or curative activities that are necessary. Thus, many well-known occupational exposures continue to cause a negative effect on workers’ health, although prevention would have been both realistic and cost-effective. There is a bulk of convincing evidence that the occupational health approach is highly cost-effective in the prevention and control of occupational and work-related hazards and this approach should be given higher priority in national health and social policy.

Several new problems in occupational health are related to implementation of new technologies, the use of new chemicals and materials, application of new biotechnology, accidents in new production systems, new infections such as HIV, hepatitis C and other new viral and microbial diseases, the re-emergence of old epidemics such as tuberculosis, growing migration and mobility of people and workers and new types of organization of work. Numerous ergonomic problems and heavy physical workload are associated with musculoskeletal disorders, causing wide-scale loss of working capacity. The growing performance demands, time pressure and emotional workload in certain occupations (such as health care) are connected with stress symptoms and adverse health consequences.

The earliest possible prevention and control of preventable hazards would help minimize economic loss at national, company and individual levels and have a positive impact on the further development of work, health, productivity and quality. Occupational health is a positive factor in socio-economic development and in the development of the general well-being and quality of life of the population.

New types of employment and new occupational settings are being created as the result of certain types of part-time work, distant work, home work, family industries, work involving travelling and self-employment. The social protection systems, occupational health and safety services, and inspection and control systems may not cover these new workstyles or may cover them poorly. Workloads and hazards may, however, be dangerous not only for the worker but also for family members, neighbours and customers. New mechanisms for providing occupational health services for such work environments should be created and new strategies to provide training, information and advice for such groups of workers remain to be developed.

New technologies, substances and processes are being introduced to workplaces without previous experience of their potential health impact. Advance testing and assessment of hazards and risks is generally needed. Continuous monitoring of the possible occupational health effects of such new technologies should be exercised and care should be taken to introduce scientific criteria for planning of healthy and safe technologies and work environments. The capacity of occupational health experts to participate in the assessment of new technologies and in the provision of health criteria should be strengthened. For this, active research efforts are needed. Research for assessment and evaluation of various services and practical activities, including occupational health services, is also needed.

Preventive strategies aim at eliminating or reducing to acceptable levels the occurrence of hazardous agents and factors in the work environment, preferably at their source of generation/dissemination, secondly during their path of transmission, and lastly by protecting the worker. Specific measures include the selection of the least toxic materials, substitution of materials, substitution/modification of equipment and processes, correct operation and maintenance of processes and equipment, enclosures and closed systems, local exhausts and general ventilation, isolation of workers (e.g. by control rooms), good work practices and personal protective equipment (as a last resort). Information, training and education of workers and employers on hazards and their prevention (including on emergency response) should also be part of such strategies. In order to ensure the continued efficiency of preventive measures, environmental monitoring and health surveillance of workers, including biological monitoring whenever appropriate, should be carried out. The importance of anticipatory preventive action, by the selection of the safest and least polluting processes, equipment and materials, as well as the correct location and ergonomic design of workplaces, cannot be overemphasized..