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Berenice I. F. Goelzer, MPH (IH), CIH

Office of Occupational Health

World Health Organization

Geneva, Switzerland





First of all, I would like to say how honoured I am to receive the 1996 William P. Yant Award. 


On this occasion I must express my gratitude to all those who have inspired and helped me throughout my career, from my graduate schools days at the University of Michigan, under the guidance of the unforgettable Warren A. Cook, and later, at the University of Pittsburgh, where Morton Corn shared with me years of knowledge and experience - to my practice in Brazil, where support from Brazilian occupational health pioneers, and also from NIOSH was invaluable.  I still remember when a vertical elutriator for our first byssinosis study in Brazil was personally packed for me at NIOSH. 


I would like to acknowledge the work of European colleagues who have given such an impulse to our profession in this part of the world, as well as that of occupational hygienists in developing countries, working usually under very difficult conditions in a profession most often unknown.  I would also like to mention those occupational hygienists who believed in international occupational hygiene and promoted the creation of the International Occupational Hygiene Association.  I cannot name all the people who have influenced my work but I certainly must thank them all because their enthusiasm and perseverance have helped me throughout the years to keep my own enthusiasm and perseverance, as well as the hope to see our profession universally recognized one day. 


I would like to say that the 1996 Yant Award also honours the World Health Organization, where I have been working for the last 21 years, bringing the contribution of our profession to the realization of one of the constitutional principles that led to its creation:  


the enjoyment of the highest attainable standard of health is one of the fundamental rights of every human being without distinction of race, religion, political belief, economic or social condition”.



In view of my experience, I shall refer mainly to developing countries.  However, in practically any country there are regions of underdevelopment in occupational health and hygiene where hazards that have been known for centuries still continue to cause new cases of preventable diseases, one sad example being silicosis.


The Need for Occupational Hygiene


Work is one of the most powerful and rewarding forces in human life, indispensable for the individual, for the community and for the development of nations.  Unfortunately it can also be the source of much suffering.  As Pierre Hamp[3] wrote:  “We live on the suffering of others.  ...  How many people earn their living pleasantly ?  Many do so in unpleasant and often intolerable conditions”. 


As a matter of social justice, human suffering related to work is unacceptable.  I would like to quote what Ramazzini said, about 300 years ago:  “It is but a sad profit which is achieved at the cost of the health of workers...”


Another aspect is that harmful workplace agents and factors often result in appreciable financial loss due to the burden on health and social security systems, to the negative impact on production and to the associated environmental costs.  People should not have to endure, and countries cannot afford, such damaging effects.


According to the World Bank “a burden of 36 million disability adjusted life years (DALY’s), or 3 percent of the global burden of disease is caused each year by preventable injuries and deaths in high-risk occupations and by chronic illness stemming from exposure to toxic chemicals, noise, stress, and physically debilitating work patterns” (World Bank, 1993).  In a sample of industrialized countries, the International Labour Organization estimated economic costs of occupational injuries and associated production losses to be of the order of 1 to 4 % of the GNP;  in developing countries this cost should be much higher.


Many countries are becoming industrialized and are undergoing rapid economic growth, often disregarding, or not having the means to deal with, the steady increase in the associated health and environmental problems. 

It is important to attain not only economic, but also social development.  Workers should not pay with their health and life for development, and neither should the environment be destroyed;  it should be possible to ensure that the present world population meets its needs for food, water, energy and shelter without causing adverse effects on health and on the environment, and, without depleting or damaging the global resource base, hence “without compromising the ability of future generations to meet their own needs” (WCED, 1987).   Unless measures are taken now, the situation may become uncontrollable in the years to come.


Workers have a right to a healthy and safe work environment, which is a realistic goal in view of the knowledge and technology available today for the prevention and control of hazardous agents in the workplace. 


Occupational hygiene is instrumental in ensuring this right;  furthermore, it also protects surrounding communities and the environment, and contributes to safeguarding natural resources and improving production, thus linking work, health, environment and development aspects.   It is therefore a key public health profession, needed wherever there is a workplace.   


Present Working Conditions and Occupational Diseases in Developing Countries


In spite of all the progress made, appalling working conditions, which were observed since ancient times and impressed people like Plinius the Elder, Agricola, Ramazzini, and later, Alice Hamilton at the turn of this century, are still shocking those of us who have the opportunity to visit certain workplaces, on the eve of the twenty-first century !  


Although hazardous exposure occurs everywhere, the situation is particularly serious in most of the developing countries, where many people, including children, often work under precarious conditions.  Current statistics do not reflect the global occurrence of occupational diseases and impairment;  however, there are studies which demonstrate that they are appreciable problems. 

In many developing countries, the most prevalent diseases and impairments resulting from occupational exposure include:


·  pesticide intoxications;

·  lead poisoning;

·  acute and chronic solvent intoxications;

·  silicosis and other pneumoconiosis;

·  hearing loss;

·  diseases caused by biological agents; 

·  diseases caused by heat stress;

·  musculoskeletal disorders.


Studies correlating sound exposure data with the associated health impairment are scarce, particularly in developing countries.  However, the prevalence of health impairment among persons working under very poor conditions is a good indicator of the situation;  a few examples from published data are provided here.


Uncontrolled exposure to agricultural chemicals constitutes an appreciable occupational health problem in developing countries, where a large proportion of the economically active population is in agriculture, sometimes 80%, as in some African countries.  


In developing countries, cases of pesticide poisoning demonstrated through clinical investigations and biological monitoring, although often numerous, constitute but a sample of the actual prevalence among exposed agricultural workers.  Studies on pesticide poisoning and cholinesterase inhibition, carried out among agricultural workers in Latin America,  indicated that 10-30% were affected (Finkelman and Molina, 1988).   A study in 4 Asian countries showed that about 24% of 821 pesticide users in Malaysia and about 30% of 144 users in Sri Lanka had cholinesterase inhibition exceeding the WHO proposed “hazard level” (Jeyaratnam et. al., 1987). 


In Costa Rica, an epidemiological study carried out between 1980 and 1986 showed that 3300 persons were hospitalized and 429 died (60 % of the deaths were due to Paraquat);  high risk groups for occupational poisonings included agricultural workers in the age group 15-29 years, female workers and banana plantation workers (Wesselings et al., 1993).  


Public health workers engaged in vector control are another target group for pesticide poisoning;   for example, a very large study carried out in Pakistan, involving 7500 field workers who sprayed a Malathion[4] formulation for malaria control, disclosed about 2800 cases of poisoning (including  5 fatalities), which started to occur soon after the beginning of the spraying programme (Baker, 1978). 


Studies in Latin America have demonstrated up to 37% prevalence of silicosis among miners (PAHO, 1990);  other studies have shown a silicosis prevalence of 50% among miners over 50 years old.  In 1990,China reported 358,808 cumulated cases of pneumoconioses including 6,461 new cases of silicosis.  In India, a prevalence of silicosis of 55% (with 50% of male silicotics below 25 years of age) was found among workers engaged in the quarrying of shale sedimentary rock and subsequent work in small poorly ventilated sheds;   it was also observed that, in a few years, people (including children) became severely ill and an estimated 150 died every year (Durvasula, 1990).   The same author reported levels of respirable dust exceeding 25 to 90 times the ACGIH TLV, and a prevalence of silicosis of 31%, in small potteries.


In the last 10 years, among 778 workers who had some respiratory complaint and were examined in the outpatient clinic of the National Foundation for Occupational Health, São Paulo, Brazil, 50.6% had a confirmed diagnosis of occupational lung disease, asthma being the most frequent (about 31 %), followed by silicosis (more than 10%) (Mendonça et al. 1994).


Concerning lead exposure, a study on storage battery manufacturing, in India, reported air concentrations around 37.5 mg/m3 and a 67% prevalence of lead poisoning (with clinical symptoms) among the exposed workers (Durvasula, 1990).


A survey in Thailand, involving small enterprises of less than 50 workers, disclosed among workers (mostly under 30 years of age), a number of work-related illnesses:  22 % had lead poisoning or absorption; 27% had upper respiratory diseases, and, 6 % had chronic obstructive pulmonary disease (World Bank, 1993).


A study in a steel mill in Argentina disclosed that 58% of workers had noise-induced hearing loss and 50% had obstructive lung disorders (Rodríguez, 1990).  One study in a textile mill in Egypt showed that 67% of the examined weavers had appreciable noise-induced hearing loss (Noweir, 1968).  


In Sri Lanka, a study among tea blenders demonstrated that 25 % had chronic bronchitis; a study in 5 ginneries demonstrated that 17 % of workers had chronic bronchitis and 77.8% had symptoms of “mill fever” (Uragoda, 1977).  


Studies in Egypt demonstrated prevalence of byssinosis of 12% - 78%, the worst situation being that at sorting operations, followed by carding and spinning (Noweir, 1976).  A study in Colombia revealed a 28% prevalence of byssinosis among 191 workers exposed to cotton dust (PAHO, 1994). 


In developing countries, overexposure to vegetable dusts and the resulting health impairment are much more frequent than it seems, because this occurs among working populations with little or no access to expert medical diagnosis.  For example, a previously unknown disease - the “rice millers’ syndrome” - was identified in Malaysia among rice mill workers exposed to rice husk dust (Lim et al., 1984). 


Biological agents have not received sufficient attention from occupational hygienists because, besides being more easily labelled as non-occupational, they are usually considered of interest only among workers in rural areas and hospitals.  It is true that such agents constitute a serious problem in rural areas of developing countries;  for example, a study in 38 districts in Ghana demonstrated a strong correlation between schistosomiasis infection and agricultural dams, since, in the worst affected areas, the prevalence in the surrounding population, which was below 30% before the dams were built, jumped to more than 70% (Hunter et al., 1993).  Yet, biological agents have a broader impact than sometimes believed as they range from parasites affecting agricultural workers in developing countries to spores and bacteria contaminating indoor air in sophisticated offices.


Although ergonomic factors usually draw more attention in industrialized countries, they also take their toll in the developing world, with consequences such as musculoskeletal disorders, particularly low back pain and impairment resulting from repetitive motion, stress and fatigue.  This is due mainly to lack of adequate design and selection of equipment, indiscriminate importation and use of ergonomically unsuitable machinery, and, lack of adherence to the required work practices and schedules.  For example, in Brazil, in 1987, in São Paulo alone, 284 cases of tenosynovitis were registered, mostly among young keyboard operators (FUNDACENTRO, 1990) .   Monotonous, repetitive and frustrating work is the bane of many workers all over the world.


With industrialization, adverse psychosocial factors and stress are also taking on increasing importance as the social environment changes, and people suffer from displacement from rural to urban industrialized areas, introduction to unfamiliar machinery and equipment, separation from extended families, crowding, city violence - all of which may become part of a worker’s daily life influencing health and well being.


      Isolated studies with small cohorts give only a glimpse of what must be actually occurring among the global working population, estimated by the ILO as 2.4 billion !


Occupational diseases, which contribute significantly to increased morbidity and mortality, particularly in developing countries, are very often under-diagnosed and under-reported, or are diagnosed as non-occupational, thus constituting what is often referred to as “the silent epidemic”.  

In Latin America, for example, it is estimated that only about 1% of occupational diseases are duly reported (PAHO, 1994). (REMARK: a later PAHO report, in 1998, gave 1-5%,   instead  of 1%).  I do not believe that this estimate is farfetched, in view of my personal experience of talking to occupational physicians around the world, who have very often observed signs and symptoms obviously related to occupational exposure - such as perforation of the nasal septum, advanced silicosis, Burtonian line in the gums - among persons not reporting work related complaints.


Two published examples from Brazil further corroborate the fact that this estimate is not implausible.  One study disclosed 21 cases of mercury poisoning, among 30 sugarcane workers, where a mercurial fungicide had been utilized;  in the whole region, only one occupational disease had  been  reported  that year (Frumkin and Camara, 1991), and it was not mercury poisoning !  Another study in a tuberculosis hospital disclosed,  among 3,440 patients previously diagnosed as having only tuberculosis, 119 cases of silico-tuberculosis;  none of  the silicotic patients - whose occupations had been granite drilling, sandblasting, rock grinding, work in the ceramics and glass industry, and in foundries - had been thought of as suffering from an occupational disease (Mendes, 1978). 


As occupational health and safety programmes are developed and reporting is improved, the prevalence of occupational diseases usually shows an increase, although in reality they must be decreasing due to some preventive action.  For example, in Moroccan mines, for the period from 1975-1990, there was a 100% increase in notified occupational diseases (95 % being cases of silicosis), while there was a 70% decrease in occupational accidents (which are rarely hidden as occupational diseases so often are).


Particularly among workers in rural areas, small industries and the informal sector, health impairment is seldom linked to work.  Even when such workers have access to health care services, these are rarely competent in occupational medicine, and, even if and when they are and the link is established, very seldom is there adequate reporting of  the findings to governments and, even less frequently do they appear in the international literature. 


Such occurrences are only disclosed when a study is carried out with the purpose of investigating the health status of a certain group of workers, or when a certain type of recurring health impairment attracts particular attention.  This was, for example, the case with 50 deaths from leukaemia and destruction of bone marrow, disclosed by the haematology programme in Istanbul, Turkey, among workers who had been working in the manufacture of shoes and hand bags, using a cheap glue with benzene as its primary solvent, in small poorly ventilated shops and who had thus been greatly overexposed to benzene (WHO, 1992a).




Countries have reached varying stages of occupational health and occupational hygiene development and practice, with different problems and different perceptions, so that many scenarios can be observed at the same time on the international scene.


Perception of workers’ health problems


Decision makers and even workers involved, often do not perceive clearly or accept the existing occupational health problems and the importance of preventing hazardous occupational exposure.  Sometimes what is lacking is the political will and motivation to apply or fight for the application of available solutions. 


The reasons are many;  it is not only a question of awareness and knowledge, but also of socio-economic and cultural aspects, which vary from country to country. 


One reason is that the consequences of uncontrolled workplace hazards are seriously under-estimated.  Besides, other public health problems may influence the perception of the importance of workers’ health within a framework of national priorities.  Poor working conditions with no controls;  air, water and soil pollution;  hazardous waste disposal, and, far away stratospheric ozone depletion, may easily fade into the background when seen against pressing needs for water, food and shelter, control of communicable diseases, and reduction of high infant mortality.


The worst scenario though is when there is awareness of the problems but immediate economic gain is placed higher than workers' health and environmental protection.


Perception of the need for occupational hygiene


Yet another matter is the perception of the need for action on the work environment to protect workers’ health, that is, the essential role of occupational hygiene.


There are situations when the concern for workers' health exists but is limited to medical interventions.  There are occupational health services, which do not include occupational hygiene, and where “prevention” relies solely on medical surveillance - including biological monitoring, early detection, or diagnosis of occupational diseases.   These may be indispensable adjuncts to primary prevention, but can never replace it since they can only confirm exposure or disease.  “Early” is already too late for the detection of such irreversible impairment as occupational hearing loss, silicosis, and occupational cancer.


In the history of occupational health, the shift from a purely medical approach to the understanding that prevention should start at the workplace, in order to eliminate or control hazards before health impairment occurs, marked the beginning of occupational  hygiene -  that is, the change of focus from the “sick worker” to the “sick environment”.  This shift, however, has not yet taken place in many parts of the world.


Furthermore, lack of understanding of the professional ethics and commitment involved in the practice of occupational hygiene, has generated suspicion, among workers, that occupational hygienists may be biased towards the employers, and vice versa. 


Varying degrees of resistance to occupational hygiene, on the part of other occupational health and safety professional groups that feel threatened by a new profession, make the situation even more difficult.


Another problem is the belief, by some, that occupational hygienists are “people who measure”, with the implication that what is done with the results is outside their scope of action, that the interpretation of the obtained data should be left to the biomedical personnel, and the control measures, to the safety and ventilation engineers. 


In some countries the only officially recognized occupational health professions are occupational medicine and safety engineering.  This has often been reflected in limited or inadequate attention to the field of primary health hazard prevention in the workplace.  I once visited a large foundry where considerable investment had been made in an exhaust ventilation system;  when I asked about the frequency of routine checks and maintenance (it looked as if it really needed it !),  the plant physician told me “this is an engineering problem so ask the safety engineer” and, when I did so, the safety engineer replied that “airborne contaminants pose health hazards, so ask the physician”.  An outside engineering firm had designed and installed the ventilation system, apparently with no concern for its routine checking and maintenance, and never provided any follow-up.  The distressing conclusion was that no one felt really responsible;  the company had made an appreciable investment and the workers were given a sense of “clean air” that might not be true !


Approaches to occupational hygiene practice


      Again, it may happen that occupational hygiene services are established in a governmental department or an institution, and are well equipped with excellent instrumentation, but are unable to present, or orient towards effective solutions to workplace problems, because the comprehensive approach to occupational hygiene is lacking.


It is not unusual to see more attention given to exposure assessment and monitoring than to hazard prevention and control.  The fascination exerted by sophisticated equipment and by numbers is, for some reason, greater than the interest in designing pragmatic solutions to prevent exposure.


Even when hazard prevention and control are on the programme of occupational hygiene services, either at a governmental or workplace level, setbacks are often encountered, for example:


·       control relying mostly on industrial ventilation and personal protection (not always efficient), without due consideration to other applicable measures, such as alternative technology, substitution of materials, modification of processes, and good work practices;


·       preventive measures taken in an ad hoc manner, rather than integrated into effective, carefully planned, well managed and periodically evaluated programmes, and,


·       lack of anticipated preventive action, as well as of coordination with environmental protection.


The comprehensive approach to occupational hygiene, covering “anticipation, recognition, evaluation and control”, must be promoted all over the world.


Even when all the above aspects are understood and accepted, there may be a lack or shortage of financial resources;  the fact that I do not go into this aspect does not mean that I underestimate its importance. I am focusing on those shortcomings which may be overcome by knowledge, experience and collaboration among occupational hygienists everywhere.




If the need for occupational hygiene practice is to be met, there must be developments in legislation, human resources and services, following appropriate and realistic approaches.




There is no doubt that a legal framework is needed to ensure the protection of workers’ health.  However, occupational health legislation is a starting point;  it has no effect unless enforcement and control are ensured, through adequate resources, staffing, programmes and services.   In many developing countries, legislation coverage constitutes another problem as it does not always include agricultural workers, small enterprises, and the informal sector.


Enforcement has been a problem from the start; the first bill aiming at some control of working conditions, in England  - the  “Health and Morals of Apprentices Act” of 1802, implied state intervention in private enterprise, but it did not alarm employers “because the Act was totally ineffective as no proper system of inspection or enforcement was provided.” (Luxon, 1984).  The same statement could be made today in many situations.


Even well meant occupational health legislation may fail in ensuring effective protection of workers’ health.  One mistake that has drawn my attention is the adoption of occupational exposure limit values as the only instrument to enforce legislation to protect workers’ health, in situations where there is no infra-structure of services to carry out the required quantitative evaluations. 


Whenever facilities for sampling, analyzing, measuring, calibrating, are scarce or inexistent, legislation which requires monitoring to prove compliance or non-compliance with adopted occupational exposure limit values, may actually have a negative rather than a positive effect on workers' health protection.  It has happened that legislation allowed employers to get away with not controlling hazardous exposure because enforcing officers were materially unable to prove it quantitatively. 


Lengthy and expensive environmental or biological monitoring procedures may just not be feasible in certain situations, and if feasible, may not be affordable, particularly in developing countries.


Even when feasible and affordable, monitoring capabilities may be better used in checking the efficiency of control measures after their implementation (which is often overlooked) rather than in confirming the obvious.  There are laws in certain European countries requiring that uncontrolled hazardous operations, such as electroplating and sandblasting, be evaluated only after the required controls are installed, not before; this should set an example particularly for nations where the field of occupational hygiene is just emerging.


“Recognition-evaluation-control” may need to be changed to “recognition-control-evaluation”, when dealing with obvious and serious hazards, and even to “recognition-control” if, in addition, evaluation is not feasible. 


In order to be effective, legislation must take into account the circumstances in which it is applied.  Legislation in terms of “control interventions” may often be more practical and cost-effective than legislation relying solely on limit values.  In fact, controlling to the lowest feasible level is the safest principle.


The American Conference of Governmental Occupational Hygienists (ACGIH), a world leader in the establishment of acceptable exposure levels, has repeatedly stated that their threshold limit values cannot be used to establish “fine lines between safe and dangerous” (ACGIH, 1995).   Moreover:


·       values established for one country do not necessarily protect workers in other countries where a number of aspects may differ significantly, for example, socio-economic factors, duration of working week and work schedules;


·       workplace exposure is usually combined;  this is particularly relevant when there is synergism or potentiation of effects, which are not yet fully accounted for, among other limitations.


Nevertheless, a simplistic approach of focusing solely on compliance or non-compliance with these values has repeatedly been adopted in many developing countries, through what I consider a “misuse” of the TLV’s.  


Furthermore, there are many uncertainties in the establishment and interpretation of occupational exposure limits.  There are also uncertainties in the assessment of the exposures which actually occur in the workplace.


The correct appreciation of these uncertainties, the full understanding of their meaning, and professional judgement in deciding on actions to be taken, are essential to ensure that “the practice of industrial hygiene will be a science and an art and not a mindless application of numbers and techniques”, as Morton Corn put it so well in his Cummings Award Lecture ten years ago (Corn, 1986).  This fundamental difference between a “person who measures” and an occupational hygienist has not yet been fully understood everywhere in the world.



The problem in many developing countries is that, in the absence of competent persons able to pass sound professional judgement, a solution is often sought by just “importing” existing occupational exposure limit values, and considering that occupational hygiene practice limits itself to measuring concentrations, or intensities, and comparing the results with adopted tables.  In fact, it is difficult to define the borderline between problems related to legislation and problems related to human resources.  It is during the training of occupational hygienists that more emphasis should be placed on “problem-solving” than on “rule-following’.  


Human resources


This is a key issue.  Unfortunately, the knowledge, experience and professionalism required to practice occupational hygiene are not yet universally available.  In many parts of the world, there is an acute shortage of competent professional occupational hygienists and all efforts should be made to overcome this serious shortcoming.


Some countries have regulations requiring that the principles of occupational hygiene be applied to the work environment, even if not officially recognizing the profession.  These have been very adequately called, by Burdorf, “occupational hygiene in disguise regulations”.  If there are competent persons, the situation may be kept under control;  however, when there are not, the result may be that the required tasks are performed by persons who are not fully qualified, leading to voluntary or involuntary “malpractice”.  This may easily go undetected, with disastrous results:  no effective protection of workers' health, lives endangered, and/or, unnecessary expenditures of precious time and resources. 


Legal instruments for preventive interventions in the workplace must necessarily be accompanied by the development of adequate professional competence.  It is paradoxical to require by law the performance of tasks which fall within occupational hygiene competence, while ignoring the need for this profession.


Everyone knows what a physician, an engineer, or a lawyer is.   Their training and practice may not be quite the same in different parts of the world, but there is a fundamental understanding of these professions and this, in addition to definite responsibilities, gives “recognition, influence and opportunity[5]” to all who practice them.  This is not yet true for occupational hygiene everywhere in the world.


In fact, misconception still exists in relation to a well established profession as occupational medicine.  Many people think that a doctor whose patients include workers is “an occupational physician”.  Some years ago WHO sent to many countries a questionnaire including a question on the number of available occupational physicians;  the official reply from one developing country was 630, whereas an occupational physician working in that same country replied 2 !   It is not surprising that many are baffled as to what occupational hygiene really is when, even in many developed countries, our profession is not yet fully established and officially recognized.


Many of us are fighting for international harmonization of concepts and requirements for occupational hygiene training and practice;  why is this important ?


Regardless of differing circumstances, it is indispensable to arrive at a universal understanding of what occupational hygiene is and what the profile of an occupational hygienist should be.


Besides, in addition to knowledge, experience and a code of ethics, a profession requires competence and quality assurance in the performance of its defined tasks and responsibilities.


Quality means credibility and it can only be universally assured for occupational hygiene, if and when well defined and harmonized requirements are laid down and followed, worldwide, for its training, including areas of knowledge, curricula and training approaches, as well as for its practice, including the recognition of competence.   Accreditation of courses and certification of professionals, even where not immediately feasible, should be aimed at as a goal.


Only when such requirements are met, we can expect to see occupational hygiene officially recognized as a high level profession everywhere.


This does not mean that occupational hygiene should be practiced in the same manner, in any situation, regardless of local conditions - in fact, the “art” of adapting and applying sound scientific and technical knowledge to each specific case is an essential requirement of our profession.


Programmes and services


The World Bank (World Bank, 1993) estimates that “feasible interventions” in the work environment could avert 36 million DALY’s per year !  (and this is based on reported impairment).  This is proof, if proof were needed, that proper occupational hygiene programmes or services, both at the national and workplace level are essential. 


Many developing countries lack services altogether, or approaches used in existing services are inappropriate, or the utilization of resources is inefficient.  However, if we share the wide experience already available, both in successes and in failures, we can prevent repeated errors. Shortage of funds is not the only problem;  the proper use of even limited resources may result in much better and more efficient services.


Multidisciplinary approach and team work


The protection of workers’ health and of the environment requires a multidisciplinary approach involving occupational health, safety and environmental professionals;  this includes occupational hygienists, occupational physicians and nurses, ergonomists, work psychologists, safety and environmental engineers.  The harmonious balance of a multidisciplinary approach, though difficult to achieve, should be promoted worldwide.


Intersectoral cooperation, interdisciplinary understanding, team-work and close collaboration among all concerned professionals, are indispensable.


Although occupational hygienists usually have to focus on specific technical issues, they should not lose the perspective of global health and its determinants.  An integrated approach is required to solve workers’ health problems, with due appreciation of public health, socio-economic and other factors beyond the workplace.


On the other hand, occupational health services should include or have access to occupational hygiene expertise when envisaging preventive action, otherwise they may fail to protect workers’ health, placing too much emphasis on the medical aspect and overlooking indispensable primary prevention.


Alternative approaches


In certain developing countries, classical and comprehensive occupational health and hygiene services cannot be provided everywhere and at all levels. 


Occupational hygiene in particular is often assumed to be “too sophisticated” a field, applicable only if considerable material means, such as modern equipment and laboratories, are available.  However, this is not necessarily so.  Rather than leaving large sectors of the working population completely without the benefits of occupational hygiene, means should be sought to optimize resources and broaden the scope of action of the often very few existing occupational hygienists. 


The “primary health care[6]” approach, adopted by WHO and many of its Members States facing a multiplicity of health problems with limited resources, may be used as a source of inspiration.

If properly planned and applied, under the supervision of experienced occupational hygienists, a “primary health care” approach to occupational hygiene might help countless workers all over the world.  It would involve appropriate simple methodology and training of those who form the “first line contact” with working conditions (e.g., the workers themselves, supervisors, community health workers, people in health care centres) to:


·       recognize obvious hazards and dangerous work practices;

·       identify and localize conspicuous hazard sources;

·       recommend simple control measures;

·       recognize conditions which offer immediate danger, or are somehow suspicious and seem to require further study, and report on them to the next level of competence, for example, in a governmental department.


This would require simple but very well designed check-lists.  When working conditions are very bad, lives may even be saved by people having elementary knowledge, such as:  which chemicals can penetrate through the skin;  which conditions may lead to the accidental formation of toxic agents, or, which work practices are particularly dangerous.  Nevertheless, efficient lines of communication with fully qualified occupational hygienists are essential.


Common mistakes in the establishment of programmes


The acknowledgement of a problem is the first step towards its solution, therefore in order to improve existing occupational hygiene programmes and services, and to avoid mistakes when establishing new ones, it is important to look at some of the shortcomings which are often encountered, particularly in developing countries:


·       planning


Lack of planning has jeopardized many a programme.  In order to ensure that objectives are adequately established and efficiently achieved, making the best use of the available resources, elements such as the nature and magnitude of prevailing hazards, characteristics of the working populations to be served, legal requirements, existing infrastructure and support services, should be the object of preliminary analysis.


Planning should also include the definition of an organizational structure, profile of the required human resources and plans for their development (if  needed), assignment of responsibilities, provisions for facilities, equipment, operational requirements, communications and information, as well as for periodical and critical evaluation aiming at continuous improvement.


·       equipment


Mistakes over equipment are a recurrent problem in developing countries and may result from purchasing before the real needs have been established, before the required skills for operation, maintenance and repairs have been developed, and/or before competence to carry out all steps of each procedure (e.g., sampling and analysis, including calibration) has been ensured.


·       allocation of resources


Unwise allocation may be more of a problem than lack of resources.  Amazing discrepancies may often be observed in the importance given to different steps of even the same procedure and hence in the allocated resources.

It is not unusual to encounter situations where qualified chemists, in “state of the art” analytical laboratories, are analyzing samples which were collected with poorly calibrated equipment, or, to realize that samples which were collected with excellent equipment are not at all representative of workers’ exposure because an adequate sampling strategy was not followed.  The old saying “no chain is stronger than its weakest link” should be more often recalled.  


Another shortcoming which has caused the blockage of many a service, particularly in developing countries, is the underestimation of operational costs.   This does not refer only to material aspects, such as expendable supplies, spare parts, transport (vehicles, fuel, maintenance) and travel, but also to matters such as information update and maintenance of staff competence.


·       communications


Ineffective means of communication have often jeopardized the efficiency of team work and the feasibility of intersectoral collaboration. 


Continued exchange of information and joint efforts among occupational hygienists and other occupational health, environmental and related professionals, are key to solve workplace problems, together with broader issues such as environmental protection and health promotion.


·       information 


Some years ago it could be said that, in terms of telecommunications, what applies to industrialized countries could not possibly apply to the rest of the world;   however, in recent years many developing countries have increased their telecommunications capabilities at a remarkable rate.   As improved means of communication reach even the remotest areas in the world, access to up-to-date information becomes increasingly feasible. 


Rather than saying “developing countries cannot afford the price of information links”, the reasoning should be “developing countries cannot afford not to have access to information links”.   The most expensiveinformation is that which is not where it is needed, when it is needed, particularly “life-saving” information.


A mistake often made in developing countries is to give low priority to information technology in connection with occupational health and hygiene programmes.   At the early stages of development of such programmes, or services, it might be even more helpful to have ready access to up-to-date, relevant information on toxicology, risk assessment, recognition and prevention of hazards, than to have expensive sampling and analytical equipment.  Personal computers, CD-ROM readers and access to the Internet become more and more usual and should be envisaged for occupational hygiene services, all over the world.


On-line networked services provide an ever-increasing amount of information relevant to workers' health and environmental protection.  Moreover, communication through electronic mail facilitates discussions and exchanges of experiences among occupational hygienists everywhere.  Information which is mostly accessible to the scientific community can thus be given much wider dissemination;  its benefits can be extended from the laboratories and research institutes to the real world, helping to bridge the “knowledge-application gap” and to decrease inequalities between countries.  This may be even more important than generating new theoretical knowledge.  


·       managerial shortcomings


Poor executive management may be a serious hindrance to the development of efficient programmes and services.  Managerial skills which are indispensable for competent leadership include ability to:


·   make decisions as to goals to be reached and actions required;

·   inspire team work, with full participation of all concerned; 

·   remove obstacles to the completion of the required tasks;

·   establish realistic time-tables, according to priorities and available resources, since the implementation of successful programmes is a gradual process.


Programme managers should be able to distinguish between what is impressive and what is important;  detailed quantitative evaluations are very impressive, but more important are the decisions and actions taken thereafter.


·       health and safety of the staff


This has been the source of many problems;  occupational hygienists and their assistants are not always appropriately protected against the often serious hazards to which they may be exposed in field surveys and in laboratories.


In certain parts of the world, endemic tropical diseases, such as malaria, and other public health problems should be borne in mind, particularly at a time when there is so much movement of professionals throughout the world.  Depending on the type of work, provisions, such as immunization or even antidote for snake bites, may be required.


Quality assurance


Quality of the profession


The competence of those in charge of controlling workplace exposure is crucial as people's health and lives are often at stake.  Accreditation of courses and certification of professionals are critical to ensure acceptable standards of occupational hygiene competence and practice.


The International Occupational Hygiene Association promoted a survey of existing national certification[7] schemes, already published (Burdorf, 1995) together with recommendations for the promotion of international cooperation in assuring the quality of professional occupational hygienists, which include the following:

·               the harmonization of standards on the competence and practice of professional occupational hygienists;

·               the establishment of an international body of peers to review the quality of existing certification schemes.


Other suggestions in this report include items such as:  “reciprocity”, and “cross-acceptance of national designations, ultimately aiming at an umbrella scheme with one internationally accepted designation”.


Quality of the procedures


“Work done” is not necessarily “work well done”;  all occupational hygiene procedures should be correctly carried out, which requires a systematic approach to quality control.  


The concept of “quality assurance” relates primarily to activities which involve measurements.  Whenever sampling and analytical procedures are required for exposure assessment, both should be considered as a single procedure from the point of view of quality assurance.  Sources of errors should be found and the errors corrected.  Both internal quality control and external quality assessments, or proficiency testing, should be applied in occupational hygiene laboratories.  Laboratory accreditation is a very important control tool and should be promoted.


Although not yet applicable in many parts of the world, the establishment of quality assurance schemes should be regarded as a goal to be eventually reached, so that all occupational hygiene services may gradually develop in the right direction. 


It is paradoxical to consider that, in a certain developing country, it is too premature to enforce quality assurance requirements and, at the same time, adopt legislation based on compliance with occupational exposure limit values.  If one is not feasible, the other is not acceptable, since to rely on evaluation results without having a sufficient degree of confidence in their reliability not only may be misleading but also generates unnecessary expenses.


Quality management systems


International standards for quality management systems are being increasingly followed worldwide, including in many developing countries, to manage quality aspects of products and services, in the most effective way.   Similar standards for environmental management are being finalized.


Corresponding standards applied to occupational health and safety, hence also to occupational hygiene, would serve all countries, either in the immediate context or as models to guide progress in this field towards the right goals.  


However, while management systems related to products concentrate on the consistency of production, equivalent systems for occupational health and safety should also ensure the appropriateness and quality of the end product.  In this case it is not only a matter of consistent management, but consistent management to achieve relevant and worthwhile goals.  A system that would ensure only managerial consistency would be equivalent to a measuring instrument which is very precise but whose “zero setting” is off, and which therefore systematically gives inaccurate results. 


The competence of all involved in applying and verifying any standard is vital.


Related Issues


Public Health


An understanding of public health is important, particularly when factors outside the workplace constitute significant health determinants and add to occupational hazards, which is frequently the case in developing countries.


Not only there are conditions which affect the workers' health status, thus aggravating the adverse effect of occupational exposures, but there may be interaction between workplace hazards and the surrounding communities.  This is particularly true of the informal sector (“cottage industries”) and agricultural work, where it is not unusual for the working and living environment to be the same.  For example, people have been even fatally poisoned when, through ignorance or negligence, containers which had previously contained toxic materials were used for water and food.


In urban areas, hazards may easily spread from the workplace;  appreciable lead exposure of workers and their neighbouring communities has been demonstrated in connection with informal small enterprises recycling lead-acid batteries (Matte, 1989). 


Industrialization and Import of Hazards


New techniques for faster production usually generate more hazardous agents, if not accompanied by the required controls.  A classical example is what happened in the granite quarries in Vermont, USA, around the beginning of this century, when hand tools were replaced by pneumatic tools which generated much more dust, without appropriate controls.  A dramatic increase in the mortality rate among the granite drillers ensued, which was firstly attributed to tuberculosis and later found to be silicosis;  this was, however, reduced in the years which followed the introduction of adequate controls (Burgess et al, 1989).  


This example is mentioned because similar occurrences are frequent now in many developing countries.  Modern techniques and high-speed machinery and equipment, such as drills, crushers, electric saws, are introduced (often in replacement of traditional slow processes) without the required health and safety protective measures, thus leading to increased hazardous exposure.


Industrialization has often been linked with export/import of hazards in ways that include the following:


·       processes, machinery and equipment no longer acceptable in a certain  industrialized country, from the point of view of health, safety and environmental protection, are exported to developing countries where regulations are less strict, or poorly enforced;


·        machinery is exported without the required controls;


·       modern machines and equipment are exported but the required know-how for their correct operation is not ensured, with the result that unskilled workers utilize them without proper training, hence unsafely.


A related issue, which constitutes a serious global problem, is the transboundary movement of hazardous products and wastes, particularly damaging when dealing with highly toxic waste and when the receiving country is neither fully aware of the extent of the hazard nor competent to adequately handle it.   In this connection, it should be mentioned that the OECD[8] nations, with about 15% of the world's population, are responsible for the production of almost 80% of all hazardous industrial waste. 


Environmental Health    


Environmental pollution is definitely interlinked with workplace agents and the adequacy of occupational hazard prevention and control programmes.  Harmful chemicals which are eliminated from a work process, will neither affect the workers, nor pollute the environment.  Moreover, many control systems, based on product re-cycling, protect not only the workers, but also the environment and the natural resource base, thus contributing to a safe and sustainable development.


Environmental disasters and other tragic events have occurred as a result of inappropriate, or non-existent, control strategies and emergency procedures in the workplace, as well as of inadequate disposal of hazardous wastes in community garbage dumps or normal sewage systems.  Actions in the workplace not only impact on the immediate vicinity but also much farther;  important transboundary environmental problems generated or aggravated by work processes include long-range transport of air pollutants, damage to the stratospheric ozone layer and the “green-house” effect.


As an outcome of the United Nations Conference on Environment and Development (UNCED) held in Rio de Janeiro, Brazil, in June 1992, the “Agenda 21” was prepared hopefully to ensure the protection of our health and our planet throughout the 21st century (UNEP, 1993), through local and global action.  The Agenda recognizes the important role of occupational hygiene, as demonstrated in recommendations such as the following:


“... establish industrial hygiene programmes in all major industries for the surveillance        of workers' exposure to health hazards ...”

“... emphasize preventive strategies to reduce occupationally derived diseases ...”




International collaboration may be instrumental in developing or strengthening national capabilities to recognize and solve occupational health problems.  Sharing of knowledge and experience also contributes to avoiding duplication of efforts and wasting valuable resources. 


International collaboration has led to many achievements in the health field, one successful example being the eradication of smallpox from the world and the eradication of polio in certain regions.


International Organizations


Many United Nations specialized agencies have activities related to workers’ health and the environment, for example, the World Health Organization (WHO), the International Labour Organization (ILO), the United Nations Environment Programme (UNEP) and the United Nations Industrial Development Organization (UNIDO).  Such activities include the preparation of scientific documents, recommendations, manuals and guidelines, as well as technical cooperation.


As to WHO, in order to achieve its ideals, all factors which impact negatively on health must be controlled, and those which impact positively must be enhanced.  Among WHO’s functions, some are included which relate directly to occupational hygiene, for example: “to promote, .... the improvement of nutrition, housing, sanitation, ..., working conditions and other aspects of environmental hygiene”.


The WHO Occupational Health Programme has therefore an occupational hygiene component, aiming at:


·       the development of occupational hygiene worldwide, at a high level of professional competence, and as an integral part of occupational health multidisciplinary programmes;

·       the worldwide adoption of adequate methodologies for the recognition of occupational hazards and for exposure assessment in the workplace;

·       the worldwide promotion of hazard prevention and control in the work environment, through appropriate technologies, also accounting for environmental protection and sustainable development;

·       the promotion of international collaboration and the sharing of technical and scientific knowledge on occupational hygiene, among countries around the world, with a view to decreasing the often wide inequalities in this field. 


WHO collaborates closely with other relevant international organizations, as well as with a number of international and national professional associations, including the International Occupational Hygiene Association (IOHA) and the International Commission on Occupational Health (ICOH) - which are Non-Governmental Organizations in Official Relations with WHO, as well as with the American Industrial Hygiene Association, USA, particularly the International Affairs Committee.


Examples of International Collaborative Action in Occupational Health


Global Strategy on Occupational Health for All (WHO, 1995a)


An important international effort was the recent development of the “Global Strategy on Occupational Health for All”, through the WHO Network of Collaborating Centres in Occupational Health, comprising 52 institutions in 35 countries around the world (WHO, 1995b).  The purposes of the Strategy are:


·       to identify the main needs and establish priorities for action at the country and global levels, and,

·       to trigger the necessary awareness and political commitment to develop appropriate occupational health services, through intersectoral coordination and international collaboration.


This Strategy is in line with WHO’s constitutional function of directing and coordinating international efforts in the health field, and was based on certain fundamental principles which include the following: 

occupational health and safety is an integral component of the health concept, which is part of socio-economic development”. 


The recommended key principles for international and national occupational health policies are:

§       avoidance of hazards (primary prevention)

§       safe technology

§       optimization of working conditions

§       integration of production with health and safety activities

§       government's responsibility, authority and competence in the development and control of working conditions

§       primary responsibility of the employer and entrepreneur for health and safety at the workplace

§       recognition of workers’ own interest in occupational health and safety

§       cooperation and collaboration on an equal basis by employers and workers

§       right to participate in decisions concerning one's own work

§       right to know and principle of transparency

§       continuous follow-up and development of occupational health and safety

      The contribution of occupational hygiene is of particular importance for the achievement of the four first principles.  It is expected that a worldwide response will contribute to the implementation of this Strategy.


Silicosis Control and Elimination


      Silicosis, whose aetiology has been known for centuries, is a perfectly preventable disease.   

Nevertheless, millions of workers, mostly but not exclusively in developing countries, are exposed to airborne dust containing free crystalline silica, and, even though there is much under-reporting, a very high number of silicosis cases are still known to occur throughout the world.  Examples from developing countries were previously presented, but this problem affects also industrialized countries.  For example, in theUSA, 9 cases of silicosis were diagnosed among only 90 sandblasters who were examined in a study conducted in 1989. 


In order to surmount this situation, it was decided, during the Joint ILO/WHO Committee on Occupational Health at its 12th Session, in April 1995, to develop a joint programme aiming at the global reduction and eventual elimination of silicosis. 


In accordance with the WHO Global Strategy on Occupational Health for All, due emphasis will be given to the “key principle of primary prevention”, by promoting and supporting the development of national capabilities in the field of prevention and control of dust exposure in the work environment.  As Alice Hamilton said: “...obviously, the way to attack silicosis is to prevent the formation and escape of dust ...”. 


International Collaborative Action Specifically in Occupational Hygiene           


Consider the following examples of international collaborative action involving occupational hygienists and other scientists, from different agencies, institutions and associations, in different parts of the world, who have worked together so that, based on their individual experience, a consensus could be reached on the best approaches, guidelines and advice on specific matters.


Development of Human Resources


It is of utmost importance to extend the benefits of appropriate occupational hygiene training worldwide.  International meetings, workshops and training activities provide a unique forum for fruitful discussions in this field. 


The preparation of educational materials, reflecting experiences from around the world, greatly contributes to the wide dissemination of available knowledge thus enhancing the development of adequate human resources.


The Conference on “Training and Education in Occupational Hygiene: an International Perspective”, held in Luxembourg, 1986, as a joint activity by the European Commission,  WHO and ACGIH, stimulated much thought about the need for international collaboration in this field.  At that time the International Occupational Hygiene Association (IOHA) was only a dream in the minds of those committed to have our profession developed and strengthened worldwide.


In 1987,  IOHA was founded and one of its first activities was to hold, jointly with WHO, a workshop on “Occupational Hygiene Training”, which took place in Geneva, in April 1989.


A significant landmark in the consistent development of occupational hygiene worldwide was the meeting held in WHO, Geneva, in 1991, jointly with EURO/WHO and with collaboration from the European Commission and IOHA.  The outcome of this meeting was the publication “Occupational Hygiene in Europe - Development of the Profession” (WHO, 1992b).  This was a historical step since, for the first time, consensus was reached in Europe on the profile of the occupational hygienist and the required areas of knowledge.   The creation of graduate occupational hygiene courses in some European countries followed this international activity, which has certainly paved the way for the universal harmonization of occupational hygiene training, decisive for the worldwide recognition of our profession.  The key issues of accreditation of courses and professional certification were also emphasized in the WHO meeting.


International collaboration for the development of human resources continues as efforts to promote consistent occupational hygiene training, at a high level, are kept up in different parts of the world. Collaborative activities in this respect are being started in Latin America.


Project on “Hazard Prevention and Control in the Work Environment - Prevention and Control Exchange (PACE)”


At this point I would like to quote a Zen proverb:   “Knowing and not applying is the same as not knowing”.


The vast knowledge on occupational hazards and their prevention is not yet fully applied;  an unacceptable number of occupational diseases still occur everyday.  Lead poisoning and silicosis, for example, have been known for centuries;  nevertheless, exposure to their etiologic agents remains uncontrolled in countless workplaces throughout the world, still providing “text book” cases of perfectly preventable diseases.


The WHO Office of Occupational Health launched the “Prevention and Control Exchange (PACE) Programme”, at an international meeting, held in WHO, Geneva, September 1994, involving occupational hygienists from different parts of the world, with the following main objectives: 


·       to promote awareness and political will concerning the need for prevention and control as a priority element of occupational health programmes, and,


·       to strengthen, at the country level, technical and managerial capabilities for the utilization of successful approaches to the prevention and control of health hazards in the workplace, integrated into adequate programmes, emphasizing anticipated preventive action and environmental protection.


An advocacy document - “Prevention and Control Exchange (PACE) - a document for decision-makers” (WHO, 1995c) - was prepared and widely distributed around the world.  Its intended readership includes persons in a position to influence national legislation and enforcement, as well as those who can promote and contribute to effective primary prevention at the workplace level, particularly occupational health professionals, managers, production engineers, supervisors and workers. 


Furthermore, articles about PACE have been published in Australia, Brazil, France, Germany, The Netherlands, Poland, Sweden, Thailand, UK and the USA (Swuste et al., 1995), thus giving wide dissemination to the PACE initiative.


Other PACE activities include:


t     the exchange and dissemination of existing knowledge and information on the prevention and control of occupational hazards; 


For this, the following material is under preparation:


“PACE - Directory of Resources in the Field of Hazard Prevention and Control in the Work Environment” which includes information on published material, competent institutions and agencies, CD-ROM’s and other databases, including on Cleaner Production, and relevant Internet Resources;  this Directory will also be disseminated via the Internet.


“PACE - Case Studies on Control Solutions for Small-scale Industries”, for the dissemination of practical approaches to the control of workplace hazards, particularly applicable to small enterprises, and, for the promotion of applied research in this field.


t     support to the development of the required human resources


For this, an educational module - “PACE - Hazard Prevention and Control in the Work Environment:  Airborne Contaminants” - is envisaged.  This module, comprising a manual and training videos, will present innovative approaches and reflect international experience on the subject.  There has also been collaboration with actual training activities in different countries.


Project on “Reference Method and Quality Assurance Schemes in the Evaluation of   Exposure to Airborne Fibres in the Workplace”


Whenever evaluating occupational hazards, the wrong decision can cost in terms of workers' health, if there is under-estimation of the hazard, or in terms of unnecessary expense of resources, in the case of over-estimation.  Although it does not replace primary prevention, the evaluation of airborne fibres in the workplace is needed for exposure assessment and for testing the efficiency of control measures. Harmonization of methodology is important to permit comparison of results and inter-laboratory collaboration, and eventually to permit the establishment of international quality assurance schemes.  Therefore WHO, with collaboration from other international and national agencies and institutions, carried out a project, whose result is the publication “Determination of Airborne Fibre Number Concentrations - a Recommended Method, by Phase Contrast Optical Microscopy (Membrane Filter Method)”.  The next step will be the promotion and hopefully the implementation of an international proficiency testing scheme.




Looking at the world at large, one can observe the whole history of occupational health and occupational hygiene happening at the same time.  In the past, each step, each achievement, took a long time, sometimes decades, sometimes centuries !  The great difference, at present, is that these steps can now be conquered at a much faster rate, because the barriers of ignorance are being increasingly replaced by bridges which can be more easily crossed.  How fast these bridges will be crossed depends largely on us because passwords for crossing them include sharing and collaboration among occupational hygienists everywhere.



Bibliographic References


ACGIH (1995-1996) “Threshold Limit Values for Chemical Substances and Physical Agents and Biological Exposure Indices”, American Conference of Governmental Industrial Hygienists, 6500 Glenway Avenue, Bldg. D-7, Cincinnati, OH 45211-4438, USA.


Baker, E. L. Jr. et al. (1978) “Epidemic malathion poisoning in Pakistani malaria workers”, Lancet, 1:  31-34.


Burgess, W. A. and M. J. Ellenbecker, and R. T. Treitman  (1989) “Ventilation for Control of the Workplace Environment”,  John Wiley and Sons, New York, USA


Burdorf, A.  (1995)  “Certification of Occupational Hygienists - a survey of existing schemes  throughout the world”, International Occupational Hygiene Association (IOHA)          


Corn, M. (1986) “Asbestos and Disease:  an Industrial Hygienist’s Perspective” (1986 Cummings Award Lecture), Am. Ind. Hyg. Assoc. J., 47: 515, American Industrial Hygiene Association, USA


Durvasula, R. (1990) “Occupational Health Information Systems in Developing  Countries - India, a Case Study, presented at the “IV Takemi Symposium in International Health - Working Populations and Health in the Third World:  Problems and Policies”, 29 September - 1 October 1990, Harvard School of Public Health, Boston, USA.


Finkelman, J. and G. Molina (1988) “Pesticides and Health - Situation in Latin America”,  Metepec, Mexico (1988 revision of 1987 report from the Pan American Centre for Human Ecology and Health)  (in Spanish).


Frumkin, H. and V. M. Câmara  (1991) “Occupational Health and Safety in Brazil”, American Journal of Public Health, Vol. 81, No. 12, December 1991.


FUNDACENTRO (1990) “Tenossinovite e Trabalho:  Análise das Comunicações de   Acidentes de Trabalho (CATs) registradas no Munícipio de São Paulo, Revista Brasileira de Saúde Ocupacional No.70, Vol. 18 (Abril, Maio, Junho 1990),  FUNDACENTRO (National Occupational Health Foundation), São Paulo, Brazil (in Portuguese)


Hunter J. M., L. Rey. L. Y. Chu, E. O. Adekolu-John and K. E. Mott  (1993) “Parasitic diseases in water resources development -  The need for intersectoral negotiation”,  World Health Organization, Geneva.



Jeyaratnam, J., K. C. Lun  and  W. O. Phoon  (1987) “Survey of acute pesticide poisoning among agricultural workers in four Asian countries”,  Bulletin of the World Health Organization, 65: 521-527.


Lim, H. H. et al. (1984) “Rice millers’ syndrome:  a preliminary report”, Br. J. Ind. Med., 41: 445-449.  


Luxon, S. G. (1984) “A History of Industrial Hygiene” (1984 Yant Memorial Lecture), Am. Ind. Hyg. Assoc. J., 45: 731, American Industrial Hygiene Association, USA


Matte, T. D. et al. (1989) “Lead poisoning among household members exposed to  lead-acid battery repair shops in Kingston, Jamaica (West Indies)”,  International Journal of Epidemiology, 18: 874-881.


Mendes, R. (1978) “Epidemiologia da Silicose na Região Sudeste do Brasil”  (Epidemiology of Silicosis in Southeast Brazil), Doctoral Thesis presented to the School of Public Health, University of São Paulo, Brazil (in Portuguese)


Mendonça, E. M. C, E. Algranti, R. de C. C. da Silva and J. T. P. Buschinelli (1994) “Ambulatório de Pneumopatias Ocupacionais da FUNDACENTRO - resultado após 10 anos”, Revista Brasileira de Saúde Ocupacional, 22: 7, Fundação Jorge Duprat Figueiredo de Segurança e Medicina do Trabalho, São Paulo, Brazil (in Portuguese)


Noweir, M. H., A. El-Dakhakhny and F. Vali_ (1968) “Exposure to Noise in the Textile Industry of the UAR”, Am. Ind. Hyg. Assoc. J., 29: 541, American Industrial Hygiene Association, USA


Noweir, M. H., A. El-Dakhakhny, H. A. Osman and M. Moselhi  (1976) “An Environmental and Medical Study of Byssinosis and Other Respiratory Symptoms in the Flax Textile Industry of Egypt”, J. Egypt. Publ. Health Assoc., 51: 95


PAHO (1990) “Country Reports.  Subregional Meeting on Workers’ Health in the Countries of the Andean Area”, Lima, Peru


PAHO (1994) “Health Conditions in the Americas”, Scientific Publication N. 549, Vol. I, PAHO/WHO, Washington, D. C., USA 


Rodríguez C. A. (1990) “Salud y trabajo:  la situación de los trabajadores en la Argentina”, Bibliotecas Universitarias, Centro Editor de América Latina, Buenos Aires, Argentina (in Spanish)


Swuste, P., M. Corn and B. Goelzer (1995) “Hazard Prevention and Control in the Work Environment - report of a WHO meeting”, Appl. Occup. Environ. Hyg., 10: 455


UNEP (1993)  “Earth Summit:  Agenda 21, The UN Programme of Action from Rio”, United Nations Environment Programme, Nairobi, Kenya


Uragoda, C.G.  (1977) “An investigation into the health of kapok workers,” Br. J. Ind. Med., 34: 181-185.                                         


WCED (1987) “ Our Common Future”, World Commission on Environment and Development, Oxford University Press, Oxford, UK


Wesseling, C., L. Castillo and C.G. Elinder (1993) “Pesticide Poisonings in Costa Rica”, Scandinavian Journal of Work, Environment and Health, 19: 227


WHO (1992a) “Our Planet, Our Health: Report of the WHO Commission on Health and Environment”,  World Health Organization, Geneva, Switzerland


WHO (1992b)  Occupational Hygiene in Europe:  Development of the Profession.  European Occupational Health Series No.3.  WHO Regional Office for Europe, Copenhagen, Denmark


WHO (1995a) “Global Strategy on Occupational Health for All”, World Health Organization, Geneva, Switzerland


WHO (1995b) “WHO Collaborating Centres in Occupational Health”, WHO/OCH/95.2, World Health Organization, Geneva, Switzerland


WHO (1995c) “Prevention and Control Exchange (PACE) - a document for decision-makers”, WHO/OCH/95.3, World Health Organization, Geneva, Switzerland


World Bank (1993) “World Development Report - Investing in Health”, World Bank, Washington, D. C., USA;  published for the World Bank by the Oxford University Press, Oxford, UK

[1]  Presented on 21 May 1996, at the American Industrial Hygiene Conference and    Exposition, Washington, D.C., USA, and published in the November 1996 issue of the American Industrial Hygiene Association Journal.

[2]   The term “occupational hygiene” is used throughout this lecture rather than its USA equivalent term “industrial hygiene”.

[3]  Pierre Hamp (1876-1962), French writer, particularly concerned with industrial life and injust working conditions.

[4] Partially converted to iso-Malathion as result of inadequate production and storage.

[5]  “Recognition, Influence and Opportunity” was the theme of the 1996 AIHCE

    (American Industrial Hygiene Conference and Exposition)

[6]“Primary health care” is based on practical, scientifically sound and socially acceptable methods and technology, made universally accessible to individuals and families in the community, through their full participation, and at a cost that the community and country can afford to maintain, at every stage of their development, in a spirit of self-reliance and self- determination.


[7]   understood as “a formal scheme based on procedures for establishing and maintaining knowledge, skills and competence of professionals” (Burdorf, 1995)

[8] OECD = Organization for Economic Cooperation and Development