DEBATE DEBATE 7
An ecosystem approach to health and its applications to tropical and emerging diseases
Uma abordagem ecossistêmica à saúde e suas aplicações às doenças tropicais e emergentes
David Waltner-Toews 1
1 Department of Population Abstract Disease and health outcomes occur within a complex socio-ecological context charac- Medicine and Network terized by feedback loops across space and time, self-organization, holarchies, and sudden for Ecosystem Sustainability and Health, University changes in organization when thresholds are reached. Disease control programs, even if they are of Guelph. successful, may undermine health; conversely, programs in agriculture and economic develop- Guelph, Ontario, ment designed to improve health may simply alter disease patterns. A research and development Canada N1G 2W1 strategy to promote sustainable health must therefore incorporate multiple scales, multiple per- spectives, and high degrees of uncertainty. The ecosystem approach developed by researchers in the Great Lakes Basin meets these criteria. This has implications for community involvement in research, development policies, and for understanding and controlling tropical and emerging diseases. Even if unsuccessful in achieving specific outcome targets, however, the requirements of this approach for open and democratic communication, negotiation, and ecological awareness make its implementation worthwhile. Key words Ecosystem; Tropical Medicine; Public Health; Health
Resumo As manifestações de doença e de saúde ocorrem em contexto socioecológico complexo, caracterizado tanto por circuitos de retroalimentação, que atravessam o espaço e o tempo, quan- to pela auto-organização, holarquias e mudanças bruscas ao nível da organização ao atingir-se certos limiares. Mesmo programas de controle de doenças bem sucedidos podem prejudicar a saúde; inversamente, programas agrícolas e de desenvolvimento econômico projetados para me- lhorar a saúde podem alterar os perfis das doenças. Assim, uma estratégia de pesquisa e desen- volvimento voltada à promoção sustentável da saúde deve incorporar múltiplas escalas e pers- pectivas e elevados graus de incerteza. A abordagem ecossistêmica desenvolvida por pesquisado- res na Bacia dos Grandes Lagos satisfaz tais critérios, com implicações importantes para a parti- cipação comunitária em pesquisa e políticas de desenvolvimento, bem como para a compreen- são e controle de doenças tropicais e emergentes. Ainda quando a abordagem ecossistêmica não obtém êxito quanto a metas específicas, exigências de comunicação aberta e democrática, nego- ciação e consciência ecológica justificam sua implementação. Palavras-chave Ecossistema; Medicina Tropical; Saúde Pública; Saúde
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Introduction et al., 1992). Furthermore, health is directly re- lated to the achievement of desirable and fea- For several decades after World War II, many sible goals, and disease is but one constraint on parts of the world undertook committed efforts achieving those goals. Thus the achievement of to eradicate diseases through applied biomed- health is a social activity within biophysical ical sciences and promote health through pub- constraints, rather than a biomedical activity lic programs fostering social and economic eq- within social constraints. Furthermore, those uity. Both efforts seemed to be successful. who possess the skills required to prevent and Then, in the closing years of the twentieth cen- treat disease – analysis, diagnosis, treatment, tury, the efforts to promote health were largely professional authority – are ill-equipped to abandoned in favor of increasing economic promote health. Disease prevention and con- activity per se, at the cost of rapidly rising in- trol programs, in fact, may actually create ill- come disparities within and between countries health. If nothing else, an ecosystem approach (UNDP, 1999). At the same time, infectious dis- to health makes this transparent. eases once thought to be all but eradicated have begun to reemerge as serious problems throughout the world (Lederberg et al., 1992; Why do we need approaches Waltner-Toews, 1995). All of this is occurring in to improving or achieving health? a context of global environmental change oc- curring at speeds and a scale unprecedented in Despite the disclaimer of health being “not recent human history. This would appear to be merely the absence of disease” in the WHO defi- a good time to reconsider how we think about nition, nearly all efforts to improve human human diseases, health, and their ecological health in the past century have been aimed at and social contexts. ridding the world of various diseases. Indeed, those accomplishments are so remarkable that one might ask, given the obvious benefits of What is health? freedom from smallpox, measles, and polio, why one would even bother to discuss alterna- Good health, according to the preamble of the tives to disease control. Why not simply throw World Health Organization, is “... a state of out our vague and luxurious notions of “com- complete physical, mental, and social well-be- plete physical, social, and mental well-being” ing and not merely the absence of disease or in- and simply redefine health as “absence from firmity.” This is clearly a utopian definition, a disease or pathology”? Based on the concept of heaven-on-earth which humanity may well health as the capacity to achieve culturally de- strive for, but never – except in rare moments fined goals, and on the failures of the biomed- perhaps when good wine and good friends ical model, I would like to suggest that there conspire together – achieve. Microbiologist are sound practical and theoretical reasons for Rene Dubos, as an antidote to this utopianism, not doing this. suggested that good health was simply a First, many disease-control programs are “modus vivendi enabling imperfect [people] to no longer effective. The rising tide, globally, of achieve a rewarding and not too painful exis- multi-resistant organisms and pesticide-resis- tence while they cope with an imperfect world” tant insect vectors is the direct, unintended re- (Last, 1988:57). A Dictionary of Epidemiology sult of therapies we use to control or elimi- (Last, 1988:57) also proposes a more pedestri- nate them. One short-term response to these an, but perhaps more workable, definition of “counter-attacks” is simply more of the same – health as: “A state characterized by anatomical, more vaccines, more drugs, more pesticides – physiological, and psychological integrity, abili- as has been proposed by the Institute of Medi- ty to perform personally valued family, work, cine in the United States. In some ways, this is and community roles; ability to deal with phys- like responding to successful guerrilla warfare ical, biological, psychological, and social stress; by proposing bigger conventional armies and a feeling of well-being; and freedom from the weapons. I suggest that it is time to ponder the risk of disease and untimely death.” wisdom of our bio-military metaphors and lin- In general, definitions of the health of plants, ear causal thinking, to address the flaws in rea- animals, people, communities, and ecosystems soning and tactics we have employed to date, include some notion of current balance and and to use our much vaunted intelligence as a harmony and some notion of reserve (Waltner- species to find more creative solutions. Toews & Wall, 1997) or capacity to respond and Second, success in programs which mani- adapt to a changing environment (Constanza festly promote health in some dimensions –
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such as improvements in agriculture to address ble competing ones – are appropriate, which food shortage – have had unintended negative responses are “correct”, and who should carry effects on other aspects of health, such as dis- them out. Physicians and veterinarians who ease. Simple talk of creating “supportive envi- are well equipped to diagnose and treat are in ronments for health” is characterized by the general very poorly trained to promote health, optimism of a race horse with blinders. Water which requires negotiation and adaptation. management programs have had particularly Current health and disease control pro- devastating effects by favoring several tropical grams often work against each other across or- diseases. Dams are built to generate electrical ganizational scales. Drawing inferences about power, to control flooding, and to generate populations based on studies of individuals is wealth (all of which are demonstrably support- termed the atomistic fallacy, and is widespread ive of health). Nevertheless they also expand or and widely tolerated in epidemiological stud- create new habitat for flora and fauna which ies. Ironically, the converse fallacy – drawing cause disease, and remove sources of natural inferences about individuals from population renewal from farmland (Hunter et al., 1982). In studies – is vigorously guarded against. What Bangladesh, epidemic Kala azar (leishmania- this means is that all efforts are focused on sis) has occurred in populations living within finding individual determinants of disease, and flood control embankments (Minkin et al., the broad systemic conditions – the very condi- 1996), and malaria epidemics, mad cow dis- tions which determine whether or not healthy ease, and cyclosporiasis have all been associat- human communities are sustainable – are ed with aggressive agricultural programs (Walt- largely, by design, ignored. Thus we have the ner-Toews, 1999). absurdity of governments in some industrial- More specifically, this cross-sectoral blind- ized countries giving away groundwater to pri- ness means that control of some diseases vate companies, who then wrap it in plastic through, say, environmental restructuring, and sell it back to the original owners of the leads to the emergence of other diseases. This water (the citizens of the country) under the is most obvious in foodborne diseases, where pretense that this is good for their individual the industrialization and centralization, which health. Even if the water in the bottle could be quite naturally accompanied regulations on demonstrated to be superior to tap water canning and pasteurization to control botu- (which it is not) it would still have major nega- lism and brucellosis, have resulted in the cre- tive consequences for population health be- ation of large ecological niches and associated cause of the energy and resources required for large-scale epidemics of diseases such as sal- manufacture and disposal of the bottles. monellosis. In North America, policies and Problems are solved at an individual level practices which encourage a voluminous and but become major problems at a regional or cheap supply of food, and which on the one global level. Thus, saving children through vac- hand serve as a preventive against starvation, cination without concomitant programs in ed- tend on the other hand to undercut the eco- ucation, nutrition, agriculture, and sustainable nomic and ecological sustainability of farmers livelihoods undermines the health of whole and to create a whole new array of nutritional communities and condemns them to slow and and disease problems associated with obesity. painful death and disintegration (McMichael, Disease control programs themselves can 1993). Indeed, the tension between sustain- also undermine health in at least two ways. able population health, which requires a cer- They can disrupt ecological systems which tain death and replacement rate, and individ- make health possible. Thus we are faced with ual health, for which death is the ultimate neg- the dilemma that DDT is useful in bringing ative outcome, has no solution within current malaria under control, but at the same time biomedical models (Waltner-Toews, 2000). The endangers the integrity of the interactions idea that death and maybe even disease might among insect pollinators, birds, and food pro- in some sense be important for sustainable duction which make sustainable livelihoods, health cannot even be conceptualized in a nor- and health, possible. Secondly, and less obvi- mal biomedical framework. ously, food supplementation, vaccination, and Finally, current disciplinary-bound ap- drug treatment programs based on a biomed- proaches to health, which focus on biomedical ical model can undermine the ability of people and personal behavioral issues, inhibit health to adapt resourcefully to their own environ- researchers and workers from addressing the ments. They do this by reinforcing the notion real causes – which reflect irreducible interac- that it is appropriate for outside experts to de- tions among economics, politics, and ecosys- termine which outcomes – among many possi- tems. This is addressed more fully in a later
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section of this paper on emerging infectious health must at least encompass multiple eco- diseases. logical, social, and health outcomes, and “not The practical problems, contradictions, and just the absence of disease”. These multiple dilemmas that have arisen in our quest for less outcomes need to be expressed in a context of disease and better human health do not simply a set of interactions, with people inside them, reflect lack of investment in public health and rather than looking at the environment as an scientific infrastructure: sewers, water sup- external “support” or “threat” to health. Sec- plies, laboratories, vaccines. These are all im- ondly, to be adequate to the new tasks facing portant. However, this dis-investment in the us, any new theory and plan of action must ac- public good, widespread under conditions of count for problems of scale and inter-scalar globalization, is itself a product of a lack of ap- connections. preciation of the nature and complexity of the Systems theory explicitly addresses the problems we are addressing. connections between various elements, and thus provides a useful starting point. A system is simply a set of elements which interact with The theoretical basis for a new each other within a certain boundary. Many approach to health attempts have been made to reduce people, farms, households, or ecosystems to well-de- The world we live in can be described as what fined, machine-like systems which can be sim- Russell Ackoff has called “a mess”, that is, “in- ulated mathematically. While such models pro- teracting problems or issues that are not easy to vide some useful information, those which are appreciate as a whole” (Flood & Carson, 1993: the least realistic tend to provide the strongest 11). Furthermore, it is clear that the complexity implications for action, while those that are the we see in the world around us is not only a most realistic provide understanding but sug- property of the world we are studying, but also gest no obvious solution to the problems being a property of the interaction between ourselves studied. Puccia & Levins (1985) suggest that and the world. Normal, conventional science there are unavoidable trade-offs in systems assumes an objective, external observer. For modeling between generality, realism, and pre- public health and ecological issues, where peo- cision. “No model”, they state, “can be general, ple – researchers and subjects alike – are inter- precise, and realistic”(Puccia & Levins, 1985: 9). nal to the subject being studied, this assump- In the face of this intransigence of the mess tion is untenable. we are in, some scholars retreat to the details Causal models used by epidemiologists and of reductionism, with the assurance that if they biomedical researchers tend to be linear: spe- are not helping the situation, they may at least cific disease outcomes are defined and studies be supplying data which might be useful. How- are designed to identify determinants of those ever, the systems literature itself seems to pre- outcomes. In all but a few rare occasions, epi- sent us with a kind of post-modern smorgas- demiological studies focus on determinants of bord of systems ideas, ranging from chaos and disease in individuals. Models of disease can catastrophe to soft, dynamic, complex, and rarely accommodate the disease outcome itself ecosystems. Some authors (Funtowicz & Ravetz, as a cause of other outcomes which themselves 1994) argue that the interactions between peo- connect back to the disease, or to other dis- ple and ecosystems reflect an “emergent com- eases or health measures. For instance, we have plexity”, which cannot be captured by even our tended to assume that if scientists identify most sophisticated complex systems models. smoking as a cause of cancer, or tick bites as This may be true, and should engender humili- the vehicle for infection by a parasite, then the ty into all our actions, but does not provide a public health and behavioral changes neces- very useful guide for action itself. sary to prevent these diseases will be made post haste by an informed public. Cross-scale interactions between individual health and SOHO systems disease outcomes, agricultural and economic policies, social expectations created and rein- Among the options available in the new sys- forced by advertising and entertainment, cul- tems smorgasbord is a set of ideas which brings tural habits of scientists and non-scientists, together conventional, soft, complex, chaotic, evolutionary ecology, and epidemic diseases management, participatory, and ecosystems. are rarely studied. These ideas, subsumed under an umbrella of Based on the problems identified above, “the ecosystem approach”, are based on the any new approach to studying and promoting view that the mess we live in can be usefully
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understood as self-organizing, holarchic, open dynamics literature as exergy) and information (SOHO) systems (Kay et al., 1999). are pumped into the system, the feedback loops become organized in such a way as to make Holarchy more effective use of the entering resources, build more structure, and enhance their own A SOHO system is characterized by patterns of survivability. It is this combination of feed- interaction occurring in nested hierarchies backs, boundaries, and openness which results (sometimes called holarchies: Checkland & Sc- in what is called self-organization. Self-organi- holes, 1990; Allen & Hoekstra, 1992). Unlike say, zation is necessary for life to occur. All living a military hierarchy, in which there is a chain things – organisms, ecological systems, socio- of authority, each unit (holon) in a holarchy is ecological systems – must remain both bound- both a whole thing and a part of something ed, with a set of internally relatively stable in- larger. For instance, individual people are parts teractions, and open to receiving resources and of families, which are parts of neighborhoods energy, and dumping waste, if they are to re- or villages, which in turn make up larger com- main alive. munities and so on. This means that an initia- Some elements in any ecosystem are more tive, such as improving public hygiene, taken tightly connected than others, and more essen- at any given scale (for instance the neighbor- tial to their mutual well-being and/or the well- hood) has implications for holons of which it is being of the system overall. The importance of a part (the city) as well as the holons of which it connections is not determined by sector (agri- is comprised (individuals and families). The culture, health, business, social, environmen- speed of change at one scale (say introduction tal), but by flows of useful energy, resources, of genetically engineered crops at a field scale) and information related to patterns of self-or- may disrupt ecological and social systems of ganization. Thus, activities which enable a which they are a part, and which have co- community to make more effective and elabo- evolved over much longer periods of time, so rate use of natural resources and information that the expected benefits (improved nutrition are likely to have a greater impact on the via- to individuals) may not accrue in the expected bility of a given population than health care ac- way (Giampietro, 1994). tivities. As already suggested, these feedback loops Feedback loops in SOHO systems tend to organize themselves in certain patterns which are coherent. Sys- The interactions in SOHO systems are can be tems researchers call this self-organization “at- represented as a mixture of positive and nega- tractors”. Most ecosystems – because of the en- tive feedback loops. For instance, people en- ergy and resources available to them – seem to gage in various economic activities – such as have a propensity to fall into a certain limited clearing land for agriculture, irrigation, mining, set of possibilities. Despite advertising claims house-building – in order to make money to to the contrary, not everything is possible, and improve the quality of their lives. Wealth gen- we cannot all become whatever we want. We – erated by these activities may be used to build and the ecosystems and societies we live in – better roads, schools, and sewage disposal fa- are comprised of physical elements which con- cilities. People who have more schooling may strain our possibilities. Nevertheless, human be better able to solve social and public health intentionality and creativity can push or alter problems – at which time they may see that these constraints, which may result in new sys- some of the activities which made the schools tem states – or just in general disintegration. In possible may themselves be identified as prob- the latter case, if life is to continue, some new lems. Agricultural activities or manufacturing sets of mutually supportive interactions need may, for instance, result in greater pollution of to arise. C. S. Holling, drawing on studies of the water supply and the environment, heavier forest fires and spruce-bud worm infections, stress on energy use, and general deterioration has described a normal pattern of develop- of the ecosystem. Some diseases may be pre- ment in many ecosystems which depends on at vented when swamps are drained or damns are least one stage of local disintegration. Accord- built, even as habitats for new ones are created. ing to his “lazy-eight” model, these ecosystems follow a path from exploitation of disconnect- Self-organization, attractors, and surprise ed resources into greater conservation and stored energy, creative destruction with release In natural SOHO systems, it appears that, as of biomass (small patches of fires or infesta- high quality energy (referred to in the thermo- tion), reorganization, and then exploitation
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again (Holling, 1986). Farmers follow a very people will look at the situation (and evaluate controlled version of this as they plant, hus- it) differently. Where one person sees the ex- band, harvest, cultivate, and then plant again. citement of economic activity, another person Changes between system states may be sees deforestation, where one person sees dis- quite sudden. Ideas of thresholds and break- ease control by draining swamps, another per- points are well-known in both the epidemio- son sees loss of wildlife and clean water provid- logical and ecological literature (May, 1977; Kay ed by the filtering effects of wetlands. Where et al., 1999). Disease organisms increase to crit- one person sees disease control through metal ical levels at which time the probability of ade- roofing, another person sees increased eco- quate contact increases to the point where the nomic and environmental costs and less com- epidemic explodes. fortable houses. This means that, as the scien- There is good evidence that ecosystems can tific description gets better, the problems are exist in different steady states, reaching critical not necessarily resolved, only clarified. points and then suddenly reorganizing, during One challenge to creating systems descrip- which time there may be drastic changes in tions is that of selecting what to put into them species composition and diseases. Research on and what to leave out. We cannot describe every- ice cores from Greenland has indicated that thing about everything! Nor does it seem ap- global temperature changes on the order of 5- propriate for expert scientists (which scien- 16oC have occurred over mere decades during tists?) to determine what is important and de- global climatic changes in the past (Severing- sirable for everyone else. The scientific, ecolog- haus & Brook, 1999; Taylor, 1999). Such “flips” ical information is important, but not suffi- are attributed to the crossing of temperature cient. For this reason, some researchers have thresholds required to keep global ocean cur- developed the idea of extended peer groups rents moving in particular ways. These kinds of and “post-normal science”. In normal science, threshold effects followed by catastrophic one’s disciplinary peers determine the “success” changes between attractors have been demon- and “quality” of one’s work. If we are talking strated for a variety of systems, social as well as about sustainable, healthy communities, then ecological (Casti, 1994; Kay et al., 1999). clearly there are others who will have some- This means that gradualist views of disease thing important to contribute. This is especial- changes in relation to climate, for instance, ly important given the uncertainty of scientific may be a very poor basis on which to base or- predictions with regard to complex systems. ganizational response plans, and hence under- Given this complex theoretical base and the mine that part of health which comprises the uncertainty of our knowledge, how can we do ability to adapt and respond to stress. On the scientific research and science-based develop- other hand, these insights may also be used to ment in support of health? create health benefits disproportionately large relative to the apparent effort. Putting speed bumps on all city streets, and narrowing them, What is the ecosystem approach? could within a few years result in cleaner air, The practical implications of thinking less respiratory disease, and healthier people in terms of complex systems who walk more. Of course this would also re- sult in the loss of income from motor-related The concept of an “ecosystem” dates back at activities and a change in the physical struc- least to British ecologist Arthur Tansley in 1935, ture of the cities and in the structure of the na- and has undergone various permutations in tional economy. Paying farmers for managing the decades since then (Bocking, 1994). The landscapes sustainably as well as for producing ecosystem approach, as described in this paper, commodities would change the entire struc- is a conceptual and management approach de- ture of rural communities, migration to cities, veloped and applied by ecologists working with international trade, patterns of foodborne dis- the International Joint Commission of the ease, and global economic power. While the ex- Great Lakes (Allen et al., 1991). These huge act outcome in either case could not be pre- freshwater lakes, which straddle the Canada- dicted, an informed public could at least see US border, are ringed with some of the biggest the general shape of the system options. industrial cities in North America, such as Chicago, Cleveland, Hamilton, and Toronto. In Multiple perspectives this situation, standard approaches to environ- mental management, which were designed for Because such complex feedback loops have smaller areas or parks not usually inhabited by both positive and negative effects, different people, did not seem appropriate.
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Combining insights from ecosystem ecolo- logical constraints. Continual learning based gy, complex systems theory, catastrophe theo- on free flow of information and mutual respect, ry, and hierarchy theory, ecosystem researchers and investment in democratic local gover- and managers developed a process that antici- nance, are keys to success (Funtowicz & Ravetz, pates change (without predicting its exact tim- 1994; Roling & Wagemakers, 1998). ing and nature) and creates adaptive solutions This means that, in the ecosystem approach, in a participatory manner. The process itself the practical, social, and institutional dimen- grew largely out of the work of Peter Check- sions are of as much concern to researchers as land, a systems scientist and specialist in busi- the scientific and scholarly concerns. This can ness management (Checkland & Scholes, 1990). get very complicated very quickly, if we re- Arguing that human activity systems could not member that these systems are holarchies. be understood or managed like machines, he Thus, even if the people in one region can agree developed a seven-step “Soft Systems Method- on a common plan of action, they will need to ology” which focused on how to understand pay attention to the larger system of which the goals, perceptions, and transformative ac- they are a part. On the one hand, urban neigh- tions of people in organizations. This method- borhoods may not be able to solve all their wa- ology is best worked out for organizations ter problems without help from city or even which have definable goals. Allan & Hoekstra national authorities in charge of water distrib- (1992), among others, have explored how to ution systems; on the other hand, if local combine such a methodology with the insights neighborhoods clean up their streets simply gained from natural sciences and ecology. Still by shipping garbage elsewhere, this may create others, such as James Kay and members of the a much bigger, more concentrated problem “Dirk Gently Group” (The Dirk Gently Group is than the one we started with. Thus local par- an informal network of researchers into the ticipatory action, while essential, is always problems of decision-making under conditions conditional, just as individual freedom in of complexity and uncertainty. Membership society is conditional on interactions with oth- varies, but includes Silvio Funtowicz, Gilberto er “layers” in the holarchy (Waltner-Toews & Gallopin, Mario Giampietro, James Kay, Bruna Wall, 1997). De Marchi, Tamsyn Murray, Martin O’Connor, Both scientific studies and participatory ac- Jerry Ravetz, and David Waltner-Toews) have tion research (PAR) are necessary ingredients struggled with the problems of how to accom- of an ecosystem approach, and both must be modate human activity systems, multiple per- reoriented to a systems understanding of reali- spectives, and the constraints of ecological and ty. Participatory development without science energy networks. is just politics; science without participatory According to the Ecological Committee of development is an academic exercise, and the International Joint Commission, in the without a systems perspective, neither can be ecosystem approach “there is not one material used effectively to promote sustainable devel- ecosystem to which our definitions must con- opment or ecosystem health. There is no single form. Rather, the human actor must accept re- way to visually represent this kind of multi-lev- sponsibility for erecting definitions and be pre- el, multiple perspective research (nor is it the pared to change them when the purpose of the intent of this paper to describe the details of description changes” (Allen et al., 1991:5). Gen- such an approach). Several models have been eralizing this understanding to recognize that proposed. A cube with axes representing scale, there are many human actors, with many legit- perspective, and system goals may be used to imate perspectives, Kay & Schneider (1994:38) classify research and management activities have argued that using an ecosystem approach (Figure 1, as adapted from VanLeeuwen et al., means “changing in a fundamental way how 1998). Kay et al. (1999) have proposed a two- we govern ourselves, how we design and operate armed schematic which emphasizes the inter- our decision-making processes and institutions, actions between natural sciences and socio- and how we approach the business of environ- cultural visions (Figure 2). Murray and col- mental science and management.” leagues (Murray et al., 1999) have proposed a Central to an ecosystem approach rooted in flow diagram, the Adaptive Methodology for complex systems theories, then, is the notion Ecosystem Sustainability and Health. This puts that achieving sustainability requires bringing the emphasis on process, and may give greater together a variety of legitimate stakeholders, guidance for planning and action (Figure 3 – drawing on a variety of accepted bodies of Murray et al., 1999). knowledge, to negotiate a learning path based However this is represented, biomedical re- on a series of conflict resolutions within eco- searchers, sociologists, anthropologists, natur-
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Figure 1
A framework for classifying agroecosystem health initiatives.
Health Effectiveness
Dimension Integrity Biophysical Social Economic
Field
Farm
District
Watershed Hierarchy
Ecoregion
Ecozone
Biosphere
Adapted from Waltner-Toews & Nielsen, 1995.
al scientists, and ecologists – both professional diseases in developing countries. It is another and lay – must work together to describe the step in this process to identify how changing important patterns of natural resource use and housing types might modify the evolution of dynamics of the ecosystems in which the com- virulence in malarial parasites. Ewald (1994), munities live. At best, what emerges from this among others, has discussed how enclosed collaboration is an evolutionary understanding housing, which removes prostrate victims of of how the current system came to be, what the malaria from the pool on which mosquitoes key interactions are which determine its cur- feed, will likely lead to an evolution of malaria rent state, and, based on historical evidence, to more benign forms. It is also known that what kinds of options (attractors) are available. metal roofing provides less habitat for Chagas They also describe the system both in terms of disease vectors; nevertheless, such roofing car- the functioning of the diverse flora and fauna ries with it ecological costs (use of materials that are present, and in terms of their functions and energy) as well as economic costs which for capturing and disseminating useful energy may outweigh their benefits. These pieces of (exergy) (Kay et al., 1999). Finally, the research information must be integrated – bringing dis- process itself involves negotiation of goals and ease into a health context – as we work inten- implementation of desirable and feasible ac- sively with communities in specific places to tions. Within the ecosystem approach, policies, create healthy social and ecological systems programs, and actions serve the same function (Gitau et al., 1996; Murray et al., 1999; Yassi et as hypotheses and experiments in laboratory al., 1999). science. Because the ecosystem approach is based Where does disease fit into this? One might on a holarchic view of reality, part of the re- begin by re-thinking disease classification in search is to find ways of creating regional and terms of ecological contexts, rather than sim- global economic, health, and environmental ply using Linnean classifications. For example, policies which facilitate, rather than hinder, Mara & Alabaster (1995) have devised an envi- this work. Health issues need to be put into a ronmental classification of housing-related holarchic understanding, so we do not run into
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Figure 2
An adaptive Self-Organizing Holarchic Open (SOHO) system approach (Kay et al., 1999).
Develop a SOHO ecosystem description Develop an issues framework v v Science • Identify stakeholders and other participants
• Identify ecosystem of interest (extent) v Culture
v (actors) and other • Hierarchical description (scale and type, • Describe current governance and and Values Knowledge nesting)
institutional relationships and their evolution
• System description (structure & processes, v v • Issue identification and analysis by actors external influences) (i.e. Checkland CATWOE) v • Attractor analysis (including feedbacks v • Define integrity & sustainability in terms and propensities) of a vision for the future • Evaluation of current integrity Complex • Hierarchical mapping of human concerns v General
• Synthesis (narrative description System idenfification Systems v and preferences onto the SOHO ecosystem of self-organizing behaviour) Vision Theory description v v
ecological vision and v
v Scenarios
possibilities preferences
v v v
Which self-organizing entities (SOHO
Systems and attractors) do we want to encourage v Collaborative v Approaches and when? Processes
v v v
Design the context Design the human & ecological infraestructure and circumstances required to encourage the desired SOHO
v
The continuing process of learning, revisioning, Ongoing adaptative management resolving tradeoffs, and planning by the parties to adapt to the unfolding situation. This will entail the ongoing evolution of governance arrangements.
Governance
The continuing collection of and synthesis Monitoring...... Management Development and implementation of strategies of information into a narrative of the present to promote/discourage self-organization in the and anticipated evolution of the system. context of the communal vision and plan. This involves the identification of extenal contextual changes, flows into and from the system, and feedback loops which are to be encouraged and discouraged. generally this entails managing human activities rather than direct intervention in the system.
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Figure 3 with people to identify goals, to understand the socioeconomic and ecological constraints and AMESH: the Research Process. opportunities facing them, and to negotiate resolutions rather than “find” solutions, helps those people to become healthy by definition.
Historical v Implementation Cross Talk There is no biomedical solution which can be Reconstruction imposed from the outside to promote health.
Seeking Solutions v Thus, an ecosystem approach to health pro- v motes health in the very means it uses to un- Monitoring derstand and promote health. Secondly, since & Evaluation v the ecosystem approach embeds the social Synthesizing the Stakeholder Analysis goals of health within our best understanding
System Descriptions v v of the ecological context, it is more likely to be Policy & Governance v
Analysis v Issue Analysis sustainable than an approach to health issues which is based on the fantasy of a social reality
v disconnected from the biosphere. v Multiple System Linking System Analyzing the System v v Descriptions Descriptions Descriptions Implication of the ecosystem approach for research on tropical and emerging diseases Adapted from Murray et al., 1999). Emerging, reemerging, and newly recognized diseases in both the tropics and in temperate zones, represent failures – failures to under- the situation in which problems are solved at stand the socio-ecological systems we live in, an individual level but become major problems and failures to respond to new understandings at a regional or global level, or vice versa. For as they are uncovered. What we learn from these instance, programs which focus on increasing failures will largely determine how successful global food production often undermine local we are in creating sustainable and healthy hu- food security and health because they fail to man communities on this planet. account for cross-scale issues related to com- Descriptions of emerging diseases and caus- munication and control. Conversely, control of es of emergence have been reviewed in several malaria or the plague in local communities major reports and conferences (Lederberg et al., means that controls must also be put in place 1992; Levins et al., 1994; Waltner-Toews, 1995; at regional levels to prevent reemergence local- Meslin, 1997). The Institute of Medicine in the ly. At the same time the cost of control, the ne- United States, in a 1992 report, identified half a cessity for multi-sectoral cooperation, and the dozen forces which were resulting in the emer- consequences of failure are considerably high- gence of new diseases and the resurgence of er at the regional level. The only way out of this old ones (Table 1 – Lederberg et al., 1992). Pe- bind is through global eradication, or the cre- ter Drotman of the Centers for Disease Control ation of adaptive strategies to live with the dis- has pointed out that 150 years earlier, in a re- ease through better nutrition, public health in- port to the Prussian government regarding a ty- frastructure, social support networks, and eco- phus epidemic in Upper Silesia, Rudolf Virchow nomic equity, all of have been demonstrated to identified causes and made recommendations mitigate the impacts of disease without eradi- which are eerily similar to those of the Institute cation. Ultimately, local actions will not be sus- of Medicine (Table 2 – Drotman, 1998). What is tainable if there are not broader supportive clear from both reports – and remarkable given policy environments; conversely, if local com- that both men were basic biomedical scientists munities and ecosystems fail, there will be no – is that the causes identified are social, environ- global economy or healthy global bio-village. mental and political. This would come as no sur- prise to anyone who has done serious research in the area (Evans et al., 1994; Farmer, 1996). How will the ecosystem approach Nevertheless, while Virchow’s recommen- aid in achieving health ? dations are overtly social and political – and hence based on the evidence – those of the Health is related to the ability to achieve desir- IOM seem unconnected with the causes (Table able and feasible goals. Therefore, working 3). They are at best technical, and at worst
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merely self-serving (at least for biomedical sci- Table 1 entists). Where, one might ask, are the recom- mendations related to some of the root causes Factors in emergence of new diseases (Lederberg et al., 1992). they have identified – technology and industry, international trade, investment in public health 1) Human demographics and behavior. infrastructure? Based on the evidence present- 2) Technology and industry. ed, should health researchers not be making 3) Economic development and land use. strong health representations to organizations 4) International travel and commerce. like the World Trade Organization and the 5) Microbial adaptation and change. World Bank, not on how to clean up the disease 6) Breakdown of public health measures. mess after the fact, but on how to prevent the mess in the first place? It would almost ap- pear that the ideological lenses through which emerging diseases – indeed diseases in gener- al – are being studied, preclude acting on the evidence. This, if nothing else, should raise a Table 2 warning flag that those who study disease are not necessarily well-equipped to promote Some of Virchow’s recommendations to the Prussian government regarding health, and that new modes of thought are re- the typhus epidemic in Upper Silesia, 1848 (adapted from Drotman, 1998). quired to promote health at the beginning of the new millennium. 1) Political reform and local self-government. Tropical diseases obviously are related 2) Education. specifically to tropical climate, flora, and fau- 3) Economic reform. na. However, if we consider the diseases select- 4) Agricultural reforms, including development of cooperatives. ed by the World Health Organization’s TDR Pro- 5) Road building. gram (leishmaniasis, onchocerciasis, Chagas 6) Requirement that professionals such as teachers and physicians speak disease, leprosy, tuberculosis, African try- the language of the local people. panosomiasis, schistosomiasis, dengue, lym- phatic filariasis, and malaria), it is also clear that many of these do not simply occur in the tropics because of climate and landscape. In- search on drugs and vaccines are largely driven deed, even the tropical climate is subject to by private enterprise economics and a post- strong influences by the climate-changing be- Cold War fear of seeming to be interested in the havior of industrialized countries, and land- public good, rather than on the evidence. scapes are being transformed by industrializa- Even if the financial powers could be per- tion processes within tropical countries. Dis- suaded to look at the evidence, however, we eases such as leprosy and tuberculosis have oc- need to admit that we are working in a differ- curred – and continue to occur – in colder cli- ent context than that which the Europeans mates where poverty creates homes for them. faced at the beginning of the 20th century. The Even those diseases which are likely constrained planet is considerably more crowded, north- by the ecology and climate of the tropics, such erners are a great deal more insatiable in our as Chagas disease, can clearly be strongly influ- consumption of resources, and the whole hu- enced by social and economic practices. Many man enterprise now threatens the ecological tropical diseases are thus not only diseases re- integrity of the planet which makes our lives lated to climate and environment, but are dis- possible (UNDP, 1998). So, on the other end of eases of poverty. In epidemiological terms, the political spectrum, we must say that mas- conditions of poverty increase the probability sive public works programs and environmental of adequate contact and hence increase the restructuring of the kind which freed Europeans likelihood of epidemics. The disappearance of from infectious disease need to be more care- many infectious diseases – such as cholera, lep- fully considered with regard to their effects on rosy, tuberculosis, and malaria – has had much ecosystems (which Virchow did not consider). more to do with housing, nutrition, and water The ecosystem approach is a way to bring management than with any advances in bio- together the socioeconomic and biophysical medical science (Dubos, 1965). This is well es- dimensions of health. Nevertheless, what it tablished and, I would hope, non-controver- brings to our understanding of emerging dis- sial. These public health interventions require eases is not so much a way of identifying new public investments. Current drives to evade variables – though it certainly forces us to cast these requirements by arguing for more re- our net much broader than in conventional re-
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Table 3
Recommendations for action by the Institute of Medicine’s Committee on Emerging Microbial Threats to Health (adapted from Lederberg et al., 1992).
1) Development and implementation of more effective State, federal, and global surveillance systems. 2) Expansion of National Institutes of Health (NIH)-supported research on agent biology, pathogenesis, and evolution, vectors and their control, vaccines, and antimicrobial drugs. 3) Generation of stockpiles of selected vaccines. 4) Expedite pesticide registration for vector control and stockpile those pesticides. 5) NIH give increased priority to research on personal and community health practices relevant to disease transmission and education “to enhance the health-promoting behavior of diverse target groups.”
search – but a new way of organizing how we tions? And 1b) That all economic, agriculture, think about them, and how we respond to and business policies, approvals of new tech- them. Emerging diseases demonstrate to us nologies, and so on be justified in terms of our how our understanding of nature, and our best understanding of their likely systemic ef- management responses, have been limited. In fects, and that they not be undertaken unless particular, our understanding of how social and those who live in the system agree that those ecological variables appear to behave as com- effects are acceptable and/or that we have in plex adaptive systems changes how we think place adaptive mechanisms to deal with those about social, economic, or environmental changes. management programs. Some of the lessons to 2) The failure to account for holarchy. Cur- be learned have been previously reviewed for rent efforts aimed at preventing diseases in in- foodborne diseases (Waltner-Toews, 1996, 1999) dividuals are currently undertaken with little and infectious diseases in general (Levins et al., thought as to the consequences for popula- 1994). This paper will emphasize three particu- tion or ecosystem health. Similarly, population- lar failures in our understanding and response based programs tend to have a strong autocratic which have characterized recent discussions flavor to them which undermines their success. on emerging diseases. These failures and in- Failure to account for holarchy has resulted sights based on them lead directly into a series in global trade policies which generate wealth of recommendations (Table 4). for the global economy, leading to the destruc- 1) The failure to understand non-linear in- tion of local ecosystems and the maintenance teractions, chaotic attractors, and catastrophic of local poverty and infectious diseases (Walt- thresholds. This failure is apparent in the way ner-Toews, 2000). This is because global and in which economic development, agricultural regional policies often destroy local socio-eco- trade policies, and the like are treated, as if logical boundaries; individuals whose only loy- they were somehow issues separate from social alty is to the global market undercut the in- and mental, as well as physical, well-being. It is tegrity of local social and ecological systems. also apparent in current gradualist expecta- Of course, healthy individuals, communities, tions of the consequences of global warming. and ecosystems interact with their surround- The promotion of health in an ecosystem con- ings and change in response to them. However, text must account for multiple inter-related globalized commercial trade is just another health outcomes, of which disease reduction is form of introducing alien and often invasive but one. Furthermore, it will focus not so much species into ecosystems; totally free trade is on linear predictions of health improvement comparable, at the local community and ecosys- through fixed programs (which appears to be tem level, to pulling the skin off a live animal. impossible), but on creating adaptive organi- Yes, there is more immediate flow of nutri- zational responses. ents – but this inevitably leads to local death. This leads to my recommendations 1a and Some protectionism is simply an act of sur- 1b related to system dynamics: 1a) Research vival. Indeed, the very idea of interaction with should be expanded on the changes in ecosys- an environment presupposes the integrity of tems which will most likely push them into the the boundaries across which the interaction domains of new attractors. What, researchers takes place. I must underline, however, that ho- should be asking, are the likely health, environ- larchical thinking drives us not to isolationism, mental, and social effects of such reorganiza- nor to globalism, but to interactions with a pro-
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Table 4
Recommendations to understand and control the emergence of new diseases based on an ecosystem approach to health.
1) Recommendations related to system dynamics: a) Research should be expanded on the changes in ecosystems which will most likely push them into the domains of new attractors, and what will be the likely health, environmental, and social effects of such reorganizations. b) That all government policies – economic, business, agriculture, health, new technology approval – be justified in terms of our best understanding of their likely systemic effects, and that they not be undertaken unless those who live in the system agree that those effects are acceptable and/or that we have in place adaptive mechanisms to deal with those changes.
2) Recommendations related to holarchies: a) Research should be expanded on the holarchic boundaries which are important for relative socio-ecological stability and containment of diseases. b) Policies should be developed which respect holarchic boundaries, make explicit environment-economy-health feedback loops within those boundaries, and which encourage trade across those boundaries.
3) Recommendations related to long term evolution: a) Research should be expanded on the co-evolution of ecosystems – including the microbial populations within them – over time. b) New health, economic, and environmental initiatives take into account possible long-term effects on the system dynamics. c) That relatively uninhabited ecosystems be protected from further human invasions by economic and political policies until such a time as we have a fuller understanding of the nature of the infectious agents in the system as currently evolved.
found respect for boundaries and scales. Con- than two billion people worldwide with serious trolling the emergence of new diseases and micro-nutrient deficiencies, which may be creating healthy human communities depend considered a major non-infectious emerging on maintaining the tension within holarchies. disease (Welch et al., 1997). Farmers chose new Recommendations 2a and 2b are therefore varieties because they grew faster and made that 2a) Research be expanded on the holarchic them more money. This displaced a variety of boundaries which are important for relative so- other crops and in the process restricted the di- cio-ecological stability and 2b) Policies be de- et for billions of people. They also became con- veloped which respect holarchic boundaries, siderably more dependent on fossil fuels (for make explicit environment-economy-health fertilizers and pesticides), contributing to the feedback loops within those boundaries, and mining of non-renewable resources, global which encourage trade across those boundaries. warming, and the emergence of new diseases, 3) The third failure is one of long-term vi- both infectious and non-infectious. Hence a sion, and hence perhaps the most forgivable. caloric shortage problem was solved in such a On the one hand, this is the failure to take into way that the system was reorganized in funda- account the ecological, evolutionary effects of mentally unsustainable ways. social and economic programs. The obvious The new wave of genetically modified or- examples are those, like Lyme disease, where ganisms is being introduced based on the same reforestation and expanding deer populations, naïve view of nature that brought in the first coupled with encouragement of people to en- wave of introductions, with the probability joy outdoor life, have also had negative dis- they will further destabilize ecological systems ease-emergence effects. But the failure is more (Giampietro, 1994). This will no doubt result in widespread than that. changes to micro-flora which will lead to the This is also evident when apparently nar- emergence of new epidemiological patterns of rowly focused changes are proposed – such as disease. Certainly this is what has already hap- the introduction of new genetic varieties of pened with regard to many foodborne illness- plants on a wide scale. For instance, the intro- es, such as bovine spongiform encephalopathy, duction of “green revolution” varieties appears antibiotic-resistant Salmonella DT 104, and now to have played an important part in the verotoxin-producing E. coli, all of which have systemic changes which have resulted in more emerged in the agrifood system as unintended
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side effects – based on naïve and narrow un- Achieving health for all: derstandings of social and ecological systems – Beyond complexity, beyond 2000 of economic policies intended to promote cheap food. Agricultural and economic devel- Because components of ecosystems interact in opment policies can also be held responsible ways that undermine our ability to make pre- for the (re)emergence of malaria in several dictions, in particular because of the kinds of parts of the world. phenomena associated with attractors and An understanding of possible long-term ef- threshold changes, it is essential that anyone fects may not lead us to abandon social pro- interested in sustainable health take a broad, jects and policies. Indeed, as Ewald and other ecosystemic approach. Furthermore, because evolutionary ecologists have pointed out for of our limited ability to predict outcomes, it is malaria and cholera, these may be used to good important that we maintain our flexibility and advantage to devise programs to control dis- our options. ease. But these long-term scenarios should at In practical terms, this means that local bio- least cause us to build into their structure and and social diversity must be maintained as a implementation mechanisms to detect proba- way of maintaining some reserve to respond to bly long-term impacts and to compensatory the certain changes ahead. An ecosystem ap- mechanisms for those who are likely to suffer proach to emerging diseases, then, involves, on from those changes. the one hand, monitoring changes in the struc- This is not only a failure to see the long- tures of ecosystems which are leading to the term effects of human social projects, however, creation of different and often larger niches but a failure to understand that ecosystems for potential pathogens. On the other hand, it have co-evolved over a long period of time and means working to stop the most dangerous of that when we invade or disrupt those systems, these changes – working to influence national we do so at some peril, not just to the ecosys- and international economic and political poli- tem (rain forest destruction) but to ourselves, cies which are creating the disease-promoting as we become entangled in life cycles that conditions. It means doing our research in evolved without us, resulting in the emergence such a way that the goals such as food security, of diseases like Ebola virus and Kyasanur For- health, and a convivial life can be achieved est disease. without threatening the ecosystems which pro- Hence, recommendations 3a, 3b, and 3c are: vide the services that make human communi- 3a) Research be expanded on the co-evolution ties possible. of ecosystems – including the microbial popu- Because systemic descriptions and resolu- lations within them – over time. This will re- tions are context-specific, and because we are quire the establishment of long-term sites in talking about bringing together multiple sys- various parts of the world and incorporating tems descriptions, some argue that the amount various types of human activities. Such long- of time, energy, money, and work required to term sites have been set up for “pure” ecologi- do this research is impossible in practice to cal studies; the bases for such teaching-learn- achieve. This criticism is based on outmoded ing sites have already been established in sev- ideas of both research and development. Al- eral on-going projects in various parts of the though the ecosystem approach to health re- world. What is needed now is to rationalize quires a major commitment of people’s activi- these, give them some permanent long-term ties, these activities are those which should al- funding, and expand the range of researchers ready be going on in any society: planting crops, involved; 3b) That new health, economic, and building bridges, educating children. Within an environmental initiatives take into account ecosystem approach, every policy decision is a possible long-term effects on the system dy- hypothesis, and every management plan is a namics; and 3c) That relatively uninhabited test of that hypothesis. Research becomes an ecosystems be protected from further human integral part of the daily decision-making and invasions by economic and political policies evaluating activities of households, commu- until such a time as we have a fuller under- nities, regions, and global institutions. This standing of the nature of the infectious agents is precisely what makes this an adaptive ap- in the system as currently evolved. proach; it does not assume that Truth – relative to sustainability and health – can be estab- lished once-and-for-all with a few definitive experiments. We define health at our boundaries – as individuals, communities, nations and global-
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ly – and we achieve health by communicating “manage” the planet for health, but we can and negotiating across our boundaries. Think look for opportunities to better adapt and feel ecosystemically, act holarchically, should be at home – to be healthy – in an uncertain and the rallying cry of health workers around the contradictory world. Even if our hopes are mis- world. There is good evidence that the ecosys- placed, however, and the specific disease con- tem approach can help us achieve a global vi- trol and health outcomes we seek are not sion of health, but the uncertainty and contra- achieved, fundamental requirements of the dictions which it is attempting to accommo- ecosystem approach for open and democratic date must ultimately be applied back to itself. communication, tolerance, negotiation, and If nothing else, the ecosystem approach brings ecological awareness will surely have made the home the deep understanding that we cannot effort worthwhile.
Acknowledgments
I would like to thank the International Development Research Centre (Montevideo) for their financial sup- port. I would also like to thank James Kay, Tamsyn Murray, and other members of the Dirk Gently Group (Jerry Ravetz, Silvio Funtowicz, Mario Giampietro, Bruna de Marchi, Martin O’Connor, Gilberto Gallopin, Silvia Tognetti, Henry Regier, George Francis, Nina- Marie Lister et al.) for keeping these debates alive.
References
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Debate on the paper by David Waltner-Toews modification. Unfortunately Pavlovsky did ven- Debate sobre o artigo de David Waltner-Toews ture too far forward, since he appeared to be satisfied with understanding leishmaniasis and the then-emerging tick-borne encephalitis. We can, with reasonable confidence, accept that the ecosystem approach to infectious dis- eases began with Pavlovsky. Waltner-Toews’ ar- ticle presents ecosystem analysis as a recent invention, which it is not. A large number of Luiz Jacintho Pavlovsky revisited. New clothes for ecology in researchers have employed one or another da Silva epidemiology. A commentary on An Ecosystem method of ecosystem analysis for understand- Approach to Health and its Applications to ing and controlling infectious diseases (Audy, Departamento of Medicina, Tropical and Emerging Diseases, by David 1958; May, 1958; Burnet et al., 1972; Croll et al., Faculdade de Ciências Waltner-Toews. 1983; Blower et al., 1991). In fact, the extensive Médicas, Universidade Estadual de Campinas. use of the term “tropical” to define a broad ar- Superintendência de The ecological approach to understanding dis- ray of diseases is inappropriate. Globalization Controle de Endemias, ease dynamics in populations is at least as old has erased boundaries between endemic and Secretaria Estadual da Saúde, São Paulo. as Hippocrates (Hippocrates, s.d.). From Hip- disease-free areas; these diseases are not a pre- [email protected] pocrates until the dawn of the bacteriological rogative of tropical ecosystems, albeit the latter era, disease theory was mostly ecological in na- are doubtless extremely favorable to their oc- ture (Galen, s.d.). In fact, not truly ecological currence. according to the current scientific definition, What distinguishes contemporary ecosys- but ecological in nature. According to the Hip- tem analysis of diseases is the ecological para- pocratic definition, an endemic was a disease digm adopted (Science et Vie, 1996; Earn et al., determined by the nature of a certain place. 1998). Virchow, cited by Waltner-Toews, con- Demos had a broad meaning, and could be un- cluded the obvious. Appalling living conditions derstood as people or population, but also as in mid-19th century Silesia made the associa- place, home. Under this definition, climatic, tion obvious; it was not the result of scientific hydrological, and behavioral determinants reasoning, but only of sound common sense. were seen as the main forces. This view of dis- The failure of post-War economic development ease occurrence and distribution persisted for projects in the Third World and of large dis- centuries. Hippocrates’ writings were recycled ease-control programs preceded the late 1970s by Galen (Galen, s.d.) in the early Christian era debt crisis. The Marshall Plan had been a suc- and resisted even the Galilean modernization cess in Europe; malaria eradication was also a of science during the Renaissance, surviving as success in Southern Europe and the Southeast- the mainstay of medical and public health sci- ern United States, but fell short of its objectives ence until the late 18th century. Hippocrates in the Third World. Worse yet, many develop- and Galen are not the main subject of discus- ment projects, like irrigation schemes and hy- sion here, but it must be noted that their con- droelectric dams, caused diseases to spread cept of disease was ecological. Disease was a (Hughes et al., 1970; Gordon-Smith, 1975). Cul- consequence of local conditions, which had to tural traits of target groups conflicted with be- be favorable for a particular disease to occur. havioral changes needed for disease control. It Diseases were named after the respective sce- gradually became obvious that infectious dis- narios in which they occurred, such that differ- ease control programs demanded a more com- ent scenarios gave rise to different diseases. prehensive approach than the prevailing linear Pavlovsky (Pavlovsky, s.d.), a little-known reasoning. parasitologist from what was then the Soviet The ecosystem approach proposed by Walt- Union, can be considered one of the first to ner-Toews is no doubt interesting, but the the- propose a reasonably well-structured theory of oretical basis is not clearly presented. Modern infectious disease ecology. Unfortunately, in ecological theory differs from Pavlovsky’s. the late 1930s Soviet epidemiology (and indeed Modern science has abandoned the passion for Soviet science as a whole) were not very well precision to embrace a love of the imprecise, known in the West, and Pavlovsky’s theory of the uncertain. Chaos theory is finding its place the natural nidality of transmissible diseases in virtually all scientific disciplines (Hénon, had a very restricted circulation (Audy, 1958; 1989; Casti, 1995; Science Illustrée, 1996; Earn Marr, 1995). Nonetheless, Pavlovsky succeeded et al., 1998). Waltner-Toews commits a Freudi- in furthering the understanding of disease oc- an slip when he discusses attractors and cata- currence and the consequences of ecosystem strophic changes, which are an integral part of
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chaos theory. Waltner-Toews’ ecosystem ap- pp. 345–362, London: Academic Press. proach is more than a cookbook recipe for un- HÉNON, M., 1989. La diffusion chaotique. La Récher- derstanding and controlling infectious diseases, che, 20:490-498. but this is not made clear as he expounds on its HIPPOCRATES, s.d. On Airs,Waters, and Places.
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tradition. For W-T’s overall global and ecosys- hence the connections between human health tem approach to health, I find more relevant and ecosystem health. a continuation of the Alma-Ata Declaration, I agree that we need some form of holistic which is now more than 20 years old, but which approach for the integration of social, econom- certainly focuses more on the importance of ic, and environmental interests in relation to community involvement for improving health human health in a systematic way. But even conditions. In a world of limited resources, with this very broad approach to connect mass unemployment, and health standards that ecosystem health and human health, W-T does are socially and economically far removed from not talk about interdisciplinarity or how to es- such aims for the majority of the world popula- tablish cooperation between scientists. W-T tion, neither the idealistic WHO definition nor writes, “Both scientific studies and participato- that proposed by W-T provides a realistic start- ry action research (PAR) are necessary ingredi- ing point. Such ideal statements sound strange ents of an ecosystem approach, and both must and dangerous in relation to my way of dealing be reoriented to a systems understanding of re- with today’s reality. They have the potential of ality.” This is a huge task, but I agree that we creating new problems in establishing for whom have to begin the dialogue. The question is how and on what level in society the absence of dis- to elaborate communications between people ease or pathology can be defined. The WHO living in rural communities around the globe definition of health is part of the Western tradi- and researchers in a two-tier way. On the one tion and implies the notion of perfectibility. I hand, taking local knowledge seriously, and on would suggest a more processual view of the the other, translating and making scientific continuum between health and disease in the knowledge understandable to people in rural introduction, since this is what the author em- areas of the world. W-T also writes, “How can phasizes later on in the article. We are all born, we do scientific research and science-based de- live, and die, and during this process we must velopment in support of health?” W-T gives ex- deal with physical, emotional, and psychologi- amples to show that medical sciences both cal strain. This is part of life, and only on an in- solve and create problems, displaying a certain dividual level can one decide whether to define humbleness of mind, which I like. one’s situation as illness. This is valid for peo- I believe that we need broad scientific co- ple with disabilities, those defined by society operation among scientists from ecology, med- as mentally ill or abnormal, and persons with icine, and social and cultural disciplines to stress-related disease. solve many of today’s health problems. But lo- At any rate, W-T applies an ecosystem ap- cal participation and elaboration of dialogue proach to health in the rest of the article. He with people in the communities are just as im- defines a system as a set of elements which in- portant. They often have concepts of health teract with each other within certain bound- that go beyond merely the physical functioning aries. He elaborates on the concepts of hol- of individuals. As I interpret it, this is also the archy, attractor, and complex feedback loops, intention behind W-T’s approach, but he miss- all central to understanding an ecosystem ap- es some of the “soft” aspects, such as the be- proach. Systems that are hierarchically nested havioral and cultural dimensions of people liv- within each other are called holarchical. As I ing in the communities. They are the ones af- understand the ecosystem approach, the point fected by tropical, emerging, and other dis- with concepts such as holarchies is to show eases. that there is always interdependence between Still, the author has taken an important step subsystems and supersystems. Central to this in this article in attempting to connect an ecosys- approach is that there is a systematic function; tem approach to different aspects of health-re- the supersystem is dependent on continuous lated issues, even though he deals largely with cooperation with the subsystem. This is trans- patterns of infectious and emerging diseases. lated into another terminology by which every- W-T attempts to cross borders between ecolog- thing is related to everything else, and the fo- ical, sociological, and medical sciences and cus of this article is the relationship between participatory action research. We know that global and local concerns in today’s world. W-T there are linkages between human activities makes these relations more transparent by giv- and alterations in ecosystem functions and ing examples of the importance of local activi- services with direct consequences for disease ties and how they interfere with and influence transmission and some more indirect effects, global activities. That is to say, there is an inter- and W-T highlights some of these connections. connectedness between the holarchy of the We are now more than 6 billion people liv- ecosphere, ecosystems, and human systems, ing on the planet Earth. If we want a sustain-
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able future, different strata in society must work together. As scientists, we have to cross disciplinary borders to find new connections Emilio F.Moran The discussion by David Waltner-Toews covers and black holes in our knowledge and under- considerable ground and is stimulating as a standing of the relationship between global Indiana University. whole. It correctly diagnoses our contemporary processes, local impact, and individual behav- Blomington, problems as stemming from sectoral and disci- Indiana, United ior. W-T has taken one step in this direction, States of America. plinary thinking, with all the inevitable blinders. and more discussion is needed. The debate that Indeed, he reviews the frequent failures that re- took place in Rio de Janeiro during the IDRC sult when we mean to do good but fail to foresee meeting in November 1999 between ecolo- the consequences of our interventions at high- gists, human ecologists, social scientists, med- er or lower levels in complex system hierarchies. ical scientists, development organizations, and I was particularly taken by his Table 4 of rec- PAHO representatives was a good initiative. It ommendations, which seem to be sensible and is through the creation of interdisciplinary fo- appropriate as first steps to health in the new rums and an open dialogue that we will realize millennium. There can be little quarrel with the that no one has a single all-encompassing author that we need more complex systems competence for a sustainable future. We have thinking or that this approach (together with to learn from each other and hopefully be part participation by the populations affected in the of a process which moves the contemporary process) is likely to lead to better health out- and future ecosystem and human health situa- comes. My main critique of the author is that tion in a positive direction. he fails to provide either details on how his Great Lakes Basin program or the Dirk Gently Group are attempting to implement this ap- proach or evidence for improved outcomes from such efforts. Without evidence for how a SOHO approach leads to improved health and well-being, it is unlikely that its adoption will follow. There are many inherent difficulties in the approach that must be dealt with (and the author only rarely alludes to them): divergent and/or competing interests among sectors of the human commu- nity; the free-rider problem; the challenge of building robust institutions based on trust and reciprocity (in a world where these are increas- ingly scarce); mechanisms for allocating costs in multi-tier systems, etc. In other words, the sectoral model has pre- vailed because it makes it easier to manage simple, single-tier systems created to facili- tate operations, allocate charges, and produce reasonable results (while ignoring upstream and downstream consequences). The proposed SOHO approach is conceptually more attrac- tive but riddled with all kinds of new chal- lenges for its “managers” or modelers. Particu- larly if such systems are non-linear and chaotic (as they must be), the uncertainty of outcome in itself is a political challenge for those who wish to implement it. Most human communi- ties are not likely to be receptive to outcomes characterized by uncertainty. The author and his colleagues need to move from the appeal- ing conceptual and diagnostic stage to an op- erational model if we are to hope for imple- mentation of this idealistic goal in the 21st cen- tury. We certainly need alternatives to health and business as usual.
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intervene on complex ecosystems; the public health perspective, the contribution of the Cristina de In this interesting article Waltner-Toews dis- ecosystem health notion (or metaphor, as sug- Albuquerque cusses the notion of ecosystem health and the gested by Gallopín, 1994), to understanding Possas insights it can provide for confronting the and confronting the complexity of epidemio- emergence and complexity of infectious dis- logical profiles and the emergence of diseases. Escola Nacional eases. According to him, those who possess the First, some ecologists view the incorpora- de Saúde Pública, skills required to prevent and treat disease are tion of the health paradigm for ecosystem re- Fundação Oswaldo Cruz. ill-equipped to promote health. As some au- search and monitoring change to maximize thors have pointed out before (Levins et al., ecosystem health as problematic (Gallopín, 1994) he notes that disease prevention and con- 1994). The definition of health is crucial here. If trol programs tend to ignore complexity and health is defined as something that might be may, in fact, create ill-health. In his view, these kept constant (“people die and ecosystems failures result from our limited ability to pre- evolve”), then the notion of ecosystem health dict outcomes and from our incapacity to ac- would not be appropriate to deal with sustain- count for holarchy and to understand non-lin- ability in a dynamic and changing world. In ear interactions, chaotic attractors, and cata- contrast, other arguments, as proposed by strophic thresholds in complex ecosystems. Waltner-Toews in this article, provide a defini- Background information is necessary to tion of health that can be broader, incorporat- understand the contributions and possible ing into this approach the notions of balance limitations of the ecosystem health approach and harmony on the one hand and capacity to proposed in this article. The notion of ecosystem respond to changing environments on the oth- health was first introduced by Rapport (1989) in er. From this perspective, the notion of ecosys- an international meeting of the Association for tem health can provide interesting insights. Great Lakes Research and was developed later Second, from the public health perspective in other publications. In 1994, an international the issues concerning the contributions of workshop on Agrosystem Health was organized ecosystem health are even more complex. On by the University of Guelph with the support of the one hand, the ecosystem health notion can IDRC. The discussions focused then on the con- provide a crucial and missing ecosystem ap- tributions of the health paradigms to understand proach to understand the complexity of epi- agroecosystems: vigor, resilience, and system demiological profiles and the emergence of organization, as suggested by Constanza (1994), diseases. On the other, in a world where the and on the comparative advantages of the economy and societies are being transformed ecosystem. health concept over sustainability. by accelerating globalization and local policy According to some authors (Smit & Smithers, communities are gaining political and econom- 1994), for practical purposes the concepts were ic power, it is important to stress that the con- essentially the same, while other authors (Walt- ceptual force of the ecosystem health approach ner-Toews, 1994) suggested that the health par- will certainly depend on our capacity to incor- adigm could provide a more appropriate basis porate these social and political dimensions for thought and action in agroecosystems. In into a new theoretical framework. this workshop, it was noted that sustainability Ecosystems have become complex social and ecosystem health are tightly connected but ecosystems (agro-industrial ecosystems and ur- are distinct concepts and that their more exact ban ecosystems) increasingly transformed by relationship remained to be determined. human activities, interacting and expanding in Simultaneously, in the health field, some re- ways never before imagined. Globalization is search groups developed ecosystem approach- increasing local demands for political power es to emergence and resurgence of infectious and participation, stimulating pressures for so- diseases worldwide. In 1991, in the United cial inclusion in sustainable development, par- States, the Harvard New Diseases Group start- ticularly in developing countries where social ed a transdisciplinary research agenda in this exclusion and poverty are dramatic. Therefore, area. Contributions were published later in the monitoring change in the structures of ecosys- Annals of the New York Academy of Sciences tems leading to niches for potential pathogens (Wilson et al., 1994) and in other publications. to emerging diseases, as proposed by Waltner- The issues discussed in Waltner-Toews’ ar- Toews, requires a new approach. On the one ticle can therefore be explored from two dis- hand, ecological frameworks consider the vari- tinct epistemological perspectives: the ecolo- ability of the physical and biotic environment gist’s viewpoint, the contribution and useful- but tend to homogenize people without taking ness of the health paradigm to understand and into account different social systems, classes,
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or even the commodity as a physically power- ful social construct, tending to omit social as- pects of survival. On the other, the social sci- José Maria G. There are three main types of world views: ences correspondingly make use of social dif- de Almeida Jr. holistic, fragmentary, and fractal (Almeida Jr., ferentiation without linking it to patterns of ex- 1994; Almeida Jr., in press). The ecosystem ap- posure and vulnerability to the biological and Universidade proach is by definition holistic, because it takes physical environment. de Brasília. abiotic, biotic, and cultural factors into ac- Contributions by the social and political sci- count, along with a flow of matter and energy ences to understanding and dealing with the across space and time. Accordingly, the con- macro-processes permeating ecosystems and cept of holistic health (or, for that matter, health reform strategies should be integrated ecosystem health) involves all the patient’s into a new “social ecosystem health” paradigm mental and family circumstances (social, eco- (Levins et al., 1994; Possas & Marques, 1994; nomic, etc.) rather than just the physical and Levins & Lopez, 1999). Bringing together the biological aspects of disease. socioeconomic and biophysical dimensions of There is no doubt that Waltner-Toews’ health and trying to understand how social and ecosystem approach to health deals with the ecological variables appear to behave in com- subject as a whole rather than merely examin- plex systems, as Waltner-Toews has suggested, ing it in a fragmentary way. But what about require more than incorporating these new el- mind in his model? The lack of this dimension ements into theory. It is necessary to bridge in is, in my opinion, the central weakness of his a new theoretical framework the conceptual otherwise intelligent, instructive, and useful and methodological gaps between paradigms paper. from social sciences and ecology, which have It seems to me that the author fails to take historically been kept apart. the reality of mind into account (at least in an explicit way) in keeping with the scientific tra- CONSTANZA, R., 1994. Supplementary comments on dition of not dealing with elusive categories. the concept of ecosystem health. In: Agroecosys- This is a regrettable mistake. For example, what tem Health: Proceedings of an International Work- can be said of hard epidemiological data on shop (N. O. Nielsen, ed.), pp. 29-30, Ottawa: Uni- versity of Guelph/IDRC/CGIAR. high blood pressure caused by hidden emo- GALOPIN, G. C., 1994 Agrosystem health: A guiding tions (Mann, 1999)? Or eye movement desensi- concept for agricultural research?. In: Agroecosys- tization and reprocessing (EMDR) as a power- tem Health: Proceedings of an International Work- ful psychological procedure, developed mainly shop (N. O. Nielsen, ed.), pp. 51-65, Ottawa: Uni- by Shapiro (1995) as a therapy for overcoming versity of Guelph/IDRC/CGIAR. anxiety, stress, and trauma?. LEVINS, R.; AWERBUCH, T.; BRINKMAN, U.; ECKARDT, I.; EPSTEIN, P.; MAKHOUL, N.; POS- The fact is that the role of mind-body inter- SAS, C. A.; PUCCIA, C.; SPIELMAN, A. & WILSON, action in health and disease is so well recog- M. E., 1994. The emergence of new diseases. nized today (Benson & Marg, 1996) that it must American Scientist, 52:60. be incorporated into any health-disease mod- LEVINS, R. & LOPEZ, C., 1999. Toward an ecosocial el, especially a holistic one. view of health. International Journal of Health In addition to the above general remark, I Services, 29:261-293. wish to propose some questions to the author: POSSAS, C. A. & MARQUES, M. B., 1994. Health tran- sitions and complex systems: A challenge to pre- 1) How does the ecosystem approach to diction? Annals of the New York Academy of Sci- health relate to (1) gene therapy, (2) transgen- ences, 740:285-296. ics, and (3) cloning?. RAPPORT, D. J., 1989. What constitutes ecosystem 2) “Many tropical diseases are thus not only health? Perspectives in Biology and Medicine, 33: diseases related to climate and environment, 120-132. but are diseases of poverty.” In making this con- SMIT, B. & SMITHERS, J., 1994. Sustainable Agricul- flictive affirmation, it seems that Waltner-Toews ture and Agroecosystem Health. In: Agroecosys- tem Health: Proceedings of an International Work- does not really believe in tropical diseases as shop (N. O. Nielsen, ed.), pp. 31-38, Ottawa: Uni- diseases of poverty. versity of Guelph/IDRC/CGIAR. 3) How does the author fully explain Dubos’ WALTNER-TOEWS, D., 1994. Ecosystem health: A formidable “mirage of health” concept (Dubos, framework for implementing sustainability in agri- 1959) in light of the proposed ecosystem ap- culture. In: Agroecosystem Health: Proceedings of an proach to health, particularly with respect to International Workshop (N. O. Nielsen, ed.), pp. 8- 20, Ottawa: University of Guelph/IDRC/CGIAR. emerging diseases? WILSON, M.; LEVINS, R. & SPIELMAN, A., 1994. Dis- 4) Waltner-Toews’ ecosystem model of health ease in Evolution. Annals of the New York Acade- is part of an overall view of sustainable devel- my of Sciences, 740. opment. It would be interesting to know the
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author’s opinion of an international effort to- haps not even the most important part. A larg- wards that end. er question for epidemiologists is to under- stand why disease rates rise and fall over time, ALMEIDA Jr., J. M. G., 1994. Desenvolvimento eco- why some populations have different rates logicamente auto-sustentável: Conceitos, princí- from others. Such questions are best answered pios e implicações. Humanidades, 38:284-299. when there is recognition that the health of a ALMEIDA Jr., J. M. G. Holística: Por Uma Visão Estra- tégica de Desenvolvimento Ecologicamente Auto- population is an ecological index – that is, it Sustentável. (in press) tells us about the balance between that popu- BENSON, H. & STARK, M., 1996. Timeless Healing. lation’s biological needs and the capacity of the New York: Scribner. environment to meet those needs. In the longer DUBOS, R., 1959. Mirage of Health. New York: Harper. term the level of a population’s health reflects MANN, S. J., 1999. The Hidden Cause of High Blood the adequacy of the carrying capacity of the Pressure – Changing the Myths. London: Thor- sons. environment. If we are slow to appreciate this, SHAPIRO, F., 1995. Eye Movement Desensitization and it is largely because humankind’s cultural de- Reprocessing – Basic Principles, Protocols, and vices, especially technological adaptations and Procedures. New York: Guilford. the buffering effects of imports, modulate the environmental carrying capacity; for humans (in contrast to other wild species) the carrying capacity is not externally fixed. This paper alludes to the ecological dimen- sion of human health. It describes, for exam- ple, how environmental interventions by hu- man societies alter the risks of transmission of various infectious diseases. The theoretical base Anthony J. This paper addresses a complex topic: the for “ecosystem health” is presented in terms of McMichael “ecosystem approach to health”. We health sci- nested relationships – holarchies – and the in- entists can readily lose our way among some of terdependencies between levels and compo- London School of the concepts in this unfamiliar domain. We are, nents. Nevertheless, the paper fails to make Hygiene and Tropical frankly, not used to thinking of health and dis- quite clear just what is the “ecosystem ap- Medicine. ease within an ecosystem-based framework; proach”. Is this because that approach cannot we prefer to attribute disease causation to be defined so much as intuited from a generic events or processes that arise and act at the understanding of how ecological systems and level of the individual. This, for half a century, processes work? Is this a phenomenon that is has been the dominant expectation of epidemi- subject to multiple interpretations, one that ologists, and their methods are well-honed to takes us into the uncertain and chameleon-like this expectation. realm of non-normal science (Funtowicz & Scientists in the Western world are the in- Ravetz, 1994)? tellectual heirs to three centuries of a very dif- Elsewhere, Waltner-Toews and colleagues ferent conceptual framework, that is, Newton- have surveyed the historical progression of at- ian science that views the world as a mechani- tempts to model influences on human states of cal system amenable to reductive analysis. This health (VanLeeuwen et al., 1999). The earliest has been the science of disaggregation, quan- model, from the 1930s, was the classical trian- tification, and assumed orderliness; the sci- gular host-agent-environment model which ence that assumes a gradualist relationship, elaborated the specific, one-agent-one-disease wherein a small change in the initial condi- Germ Theory. In the 1950s, the British epidemi- tions of some process will cause a small effect, ologist Jerry Morris propounded a social-eco- while larger changes will induce larger effects. logical model in which the host was differenti- This is the scientific tradition within which doc- ated into genetic and experiential components, tors “have sought to localize disease within the the environment was differentiated into physi- body, to identify specific pathological lesions, cal and social, and the “agent” became behav- first in organs, then in tissues, then cells and iors of the person. Here was a pioneering inte- now molecules... A germ, toxin, or gene can be grative view of how diseases such as heart dis- held to account for most ailments, and the im- ease arose within modern urban society – this portance of predisposition, constitution, and so- was social realism, but with no explicit recog- cial or environmental circumstances has di- nition of the role of the natural environment minished” (Anderson, 1999:49). and its life-support systems. In the 1970s and This conventional biomedical view is not 1980s various attempts were made to extend wrong. But it is only part of the story – and per- these models, within a social-environmental
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context. These mandala-like models recog- cal dimensions of health. Nevertheless, what it nized nested layers of influence, interactive brings to our understanding of emerging dis- processes between those layered factors, and eases is not so much a way of identifying new the several dimensions of “health” – physical, variables – though it certainly forces us to cast mental, and spiritual. In the 1990s a more elas- our net much broader than in conventional re- tic, permissive, “butterfly” model of biophysi- search – but a new way of organizing how we cal and social-psychological influences on think about them and respond to them.” physical, mental, and spiritual health has been We are not yet very good at thinking in propounded (Bormann, 1996). terms of complex systems dynamics, in terms And so we enter the 21st century, having of holarchical relationships, nor within a long- progressed from simplicity, linearity, and box- term time frame. Striving for an ecosystem view es-and-arrows to complexity, multidirectional- of human health and disease requires us to un- ity, and porous, interacting spheres of influ- derstand these concepts. Faced by the chal- ence. This leads us to talk more comfortably lenge of finding ecologically sustainable ways of “life course epidemiology” and to seek an of living for over six billion people, this under- “ecosystem approach” to health. The Newton- standing of human population health is essen- ian mold has been broken, though not discard- tial. This paper helps us along that path – a ed. This is what Wulff (1999:50) has referred to path that requires some large-frame humility, as the impending return of biomedicine to- not small-frame biomedical hubris. In Waltner- wards the Aristotelian world view, “the theories Toews’ words: “Within an ecosystem approach, about open self-organizing systems, chaos, frac- every policy decision is a hypothesis and every tals and non-linear dynamics [that] have al- management plan is a test of that hypothesis.” ready provided new and important insight into the mechanisms of nature”. ANDERSON, W. H., 1999. Perception of disease and We get further clues later in this paper. Walt- its meanings. Lancet, 354(Sup.4):49. BORMANN, F. H., 1996. Ecology: A personal history. ner-Toews says we must use both current de- Annual Review of Energetics and Environment, scription and an evolutionary understanding. 21:1-29. Positivism is inappropriate. We must have a FUNTOWICZ, S. & RAVETZ, J. R., 1994. Emergent “feel” for why the system is like it is, and a feel complex systems. Futures, 26:568-582. for what “health” (as an index of biological func- VAN LEEUWEN, J. A.; WALTNER-TOEWS, D.; ABER- tioning within the system context) signifies. NATHY, T. & SMIT, B., 1999. Evolving models of human health towards an ecosystem context. The issue is clarified as he explores the mean- Ecosystem Health, 3:204-219. ing of “ecosystem health” for infectious dis- WULFF, H. R., 1999. The concept of disease: From ease: “What distinguishes many so-called tropi- Newton back to Aristotle. Lancet, 354:SIV49. cal diseases is that they occur in settings where the links between local ecosystems and local communities are intense and obvious.” [quoted from a preliminary version of the article].We can, he says, replace Linnaean branching clas- sification with generic groupings based on common ecological origins, e.g., housing-relat- ed infectious diseases in developing countries. We can see more clearly the interplay between William E. Rees Commentary: an ecosystem local and global needs. We see the environment approach to survival as an interactive medium; like Heraclitus’ river, School of Community it is never the same twice. We also begin to see and Regional Planning, “…human civilization – primarily Western tech- University of British that disease and death are part of a larger, Columbia. noindustrial urban society – will self-destruct, healthy, ongoing ecological narrative, with the producing massive ecological damage, social succession of generations. chaos, and megadeath.” (Smith & Sauer-Thomp- Finally we see more explicitly the political son, 1998). dimension to all of this, the dimension that David Waltner-Toews presents a strong case goes beyond phenomenological description. for ecosystemic thinking – indeed socio-ecosys- This may shock the purist ecologist. But, then, temic thinking – in the future control of tropi- we are talking about the human animal, the cal and emerging diseases. Several key points species that supplements “nature” (genes) with stand out, particularly the association of many “nurture” (cumulative culture). Waltner-Toews diseases with poverty (exposure to vectors un- says that: “The ecosystem approach is a way to der crowded, unsanitary conditions); the mul- bring together the socioeconomic and biophysi- tiple disease-favoring effects of the ecosystem
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disruption accompanying the expansion of hu- These are not trivial questions. Should pre- man activities, and the growing recognition vailing growth rates continue, we can expect an that “normal” predictive (Newtonian) science additional five-fold expansion of economic is an inadequate foundation for either popula- output and up to four billion more members of tion heath or ecosystem management. Indeed, the human family by 2050. Given the prevailing the behavior of complex dynamic systems de- values of consumer society, the massive expan- mands humble recognition that the best strate- sion of the human enterprise necessarily means gies for maintaining population health are like- the continuing dismantling and contraction of ly to be those that enable society to adapt with nature (Rees, in press). Feeding the expanding minimal damage to unanticipated systems population requires the invasion and destruc- change. tion of pristine ecosystems; globalization com- If the paper has a major substantive flaw it moditizes nature while marginalizing the non- lies in its paradoxically near-static approach to market – but vital – life-support functions it the dynamic systems it is analyzing. There is provides; liberalized global trade and export- little reference to the rate or nature of global led ‘development’ create economic incentives change. Certainly the ecosystemic approach to over-exploit resource systems; production would be a powerful tool if the world were in agriculture and forestry homogenize natural ecological steady-state, but Waltner-Toews’ ar- ecosystems and impose unstable monocul- guments are all the more compelling in the real tures that can be maintained only at great eco- world of dynamic change. nomic and material cost. Meanwhile, despite And this is definitely a world of dynamic the unprecedented expansion of the economy, change – the past two centuries have seen the a quarter of humanity still lives in abject pover- massive expansion of the human enterprise on ty and is increasingly at risk from environmen- the one hand, accompanied by the precipitous tal collapse and accompanying disease. (The erosion of ecosystems and the life-support widening income gap poses an unprecedented services they provide, on the other. Most criti- moral challenge to the world. In 1960, the rich- cally from the perspective of socio-ecological est fifth of humanity earned ‘only’ thirty times disease control, this anthropogenic explosion/ as much as the poorest fifth; by 1990 the ratio implosion continues unabated. Much of the was about 60:1 (UNDP, 1994) and is on its way contemporary world is currently ‘enjoying’ an to 90:1 today.) In short, all the factors Waltner- unprecedented stretch of continuous material Toews identifies as favoring ecosystems col- growth. Indeed, the global economy has tripled lapse and new diseases, are running amok in size and the human population has bal- across the planet. looned by 30% to six billion since 1980. Mean- The destabilizing effect on the ecosphere is while in the course of industrialization, half the beginning to show. According to the Interna- world’s forests have been logged or converted tional Red Cross’s 1999 World Disasters Report, (rate:130,000 km2 yr-1); half the land on earth singular events such as Hurricane Mitch and has been modified for human use; half the the El Niño weather phenomenon, plus declin- world’s wetlands have been lost; 70% of its ma- ing soil fertility and deforestation, drove a jor fish-stocks have been placed in jeopardy; record 25 million people from the countryside atmospheric carbon dioxide has risen 30% and into crowded, under-serviced, disease-ridden climate change is upon us; and biodiversity shantytowns around the developing world’s loss is accelerating (extinction is now at least rapidly growing cities. This is 58% of the world’s 1000 times the “background” rate). total refugees. The Report predicts that devel- Mindful of the emerging possibility of cata- oping countries in particular will continue to strophic systems “flips”, Waltner-Toews recom- be hit by super-disasters driven by human-in- mends research that will identify and protect duced atmospheric and climatic change, eco- “holarchic boundaries” to avoid critical systems logical degradation, and rising population being drawn into “new attractors”, and policies pressures. This is a recipe for a global popula- that will protect relatively pristine ecosystems tion health calamity. As Waltner-Toews writes, from “human invasion”. He also recognizes that “the ecosystem approach brings home the we must address the chronic poverty that ex- deep understanding that we cannot “‘manage’ poses ever greater absolute numbers of people the planet for health…” (my emphasis). Let us to new and emerging diseases. However, he hope it also brings home the understanding provides no indication of how these policies that humanity’s best chance for survival with might be implemented or whether they can dignity rests with our learning better to man- succeed on a finite planet dedicated to materi- age ourselves. al growth.
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REES, W. E. Patch disturbance, eco-footprints, and bi- mental and social dimensions, even though it ological integrity: Revisiting the limits to growth. is the object of extensive discussion and appar- In: Ecological Integrity: Integrating Environment, ent consensus. Conservation and Health (D. Pimentel & R. Noss The biomedical model is reaffirmed daily eds.). Washington, D.C.: Island Press. (in press) by immense research and intervention struc- SMITH, J. W. & SAUER-THOMPSON, G., 1998. Civi- lization’s wake: Ecology, economics and the roots tures, based on an enormous and lucrative in- of environmental destruction and neglect. Popu- dustrial and services framework, worshipped lation and Environment, 19:541-575. by many, but considered scarcely useful and even iatrogenic by (a few) others. Considering the scientific research component alone in the United States, the National Institute of Health alone invests 14 billion dollars a year. But we do not have to look that far for examples, since in Brazil the scarce resources for health allocat- ed through the Ministry of Health and its affili- ated institutions basically serve to reaffirm this Maurício L. Interventions in the environment same Western biomedical model. Barreto and society in the quest for health: With recent advances in molecular genet- how scientific can we be? ics, more than a few believe that human ills (in- Instituto de Saúde cluding health problems) are located in the Coletiva, Universidade There is no doubt that one of the current char- genes and the molecules coded by them. For Federal da Bahia. acteristics of many scientific fields is to seek those who so believe, issues like the environ- all-encompassing models capable of providing ment, society, and other blah-blah-blahs are more convincing and useful explanations for merely ideological elements that feed the polit- the phenomena under study. No matter how ical action of a handful of upstarts, or in a more much I reflect on the notion that science can useful way, when properly presented, to serve develop itself on its own strengths, I take a firm as an enticing introduction to the discourse of stand with those who view science as funda- even the very proponents of the biomedical mentally tied to the search for solutions to con- model. This reminds us of Pasteur’s Revolution, crete problems, even though this may require a transcendental moment in the progress of investigative projects in the short, medium, scientific knowledge; however, when it was long, and very long terms. Such effort can be contextualized within the philosophical hue of understood as one of the most useful exercises Positivism it transmuted the idea of microbial in strategic planning, and as such the under- causality of disease (a huge step forward in late taking entails risks, since of course part of the 19th-century scientific knowledge) into dog- effort fails to materialize in the form of actual ma, a fact with repercussions that are still felt products. At any rate, we may always ask: a so- today and that have hampered (if not com- lution to what? a solution for whom? The arti- pletely impeded) other approaches to health cle under debate aims a cutting but fair cri- and human diseases. An analysis of recent ad- tique at the biomedical models flourishing vances in biology and molecular genetics shows around disease. In such models the idea of how these fields have spawned a new revolu- health, no matter how embellished it may be, tion in knowledge of the human body, but that is never understood beyond the notion of cure they have simultaneously fed a growing legion (or prevention of disease at most). Such mod- of ideas that once again seek to reduce human els are hardly useful whenever one thinks of health to its biological determinants, consider- health as something positive (and here it is un- ing discussions of man and the environment or necessary to repeat the well-known WHO defi- man and society as merely ideological, with no nition) rather than as the mere absence of dis- scientific basis. ease. If we do think along these lines, we can The paper currently under debate touches only ask what should be done by all those who on these and other discussions and proposes a criticize, find fault, or even abhor such models? model, the “ecosystem approach”, which is cer- Of course this question is asked frequently, but tainly appealing since it “brings together the so- the answer is not at all easy (Barreto, 1998). For cioeconomic and biophysical approach to example, in a recent review of the child health health”. Obviously, if the biomedical model cur- issue, Ehiri & Prowse (1999) discuss the extent rently predominates when the issue is knowl- to which preventive and promotional pro- edge concerning the causes of health and dis- grams reflect the Western medical care model, eases, what can we expect from the interven- with little emphasis on child health’s environ- tions to be conducted vis-à-vis supposedly
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known problems? A question that remains to seeking its own alternatives in order to issue be answered is whether we can propose effec- opinions on the effectiveness of existing health tive and scientifically sound interventions interventions and thus offer scientifically based without a clear causal model for health prob- alternatives to bolster the country’s social lems. Elementary scientific logic tells us that health policies (Acheson et al., 1998). Some be- when we intervene in reality we must avail our- lieve that epidemiology’s multifactorial causal selves of reasonable models on which to test models only serve as a counterpoint to tradi- the intervention, but that each intervention al- tional biomedical models when they are based so needs to be empirically tested. Herein lies on the idea that health (as a biologically based an imperfection left by incomplete scientific event) is, in the final analysis, a social phenom- progress, that is, the scarcity of resources for enon (Tesh, 1998) and that in order to be effec- evaluation of interventions. If we now some- tive, proposals generated from the perspective times spend decades discussing whether a giv- of social epidemiology must seek not only sci- en vaccine is effective, we can only imagine entific support but above all social and politi- tackling the daunting task of evaluating a com- cal backing (Heymann, 2000). plex and much less clearly outlined interven- tion as proposed under the “ecosystem ap- ACHESON, D.; BARKER, D.; CHAMBERS, J.; GRA- HAM, H.; MARMOT, M. & WHITEHEAD, M., 1998. proach”. Independent Inquiry into Health Inequalities. Of course the ideas laid out here may sug- London: The Stationery Office. gest a paralyzing and backward-thinking type BARRETO, M. L., 1998. Por uma epidemiologia de of “scientism”, as opposed to the “progres- saúde coletiva. Revista Brasileira de Epidemiolo- sivism” of the “ecosystem approach”. No, I gia, 1:104-130. would never think that actions should neces- EHIRI, J. E. & PROWSE, J. M., 1999. Child health pro- sarily be governed from beginning to end by motion in developing countries: The case for in- tegration of environmental and social interven- scientific rationality, as indeed is the status that tions? Health Policy and Planning, 14:1-10. the “ecosystem approach” seeks. However, I be- HEYMANN, S. J., 2000. Health and social policy. In: lieve that interventions in human populations Social Epidemiology (L. F. Berkman & J. Kawachi, are politically defined, with a greater or lesser eds.), pp. 368-382, New York: Oxford University degree of rationality and scientific basis. There Press. is no doubt that human health underwent in- TESH, S. N., 1988. Hidden Arguments: Political Ideol- terventions before scientific knowledge exist- ogy and Disease Prevention Policy. New Brunswick: Rutgers University Press. ed, and sometimes even with great success. In short, I do not believe that we have “sci- entific” answers to many of the main issues af- fecting human health. We know that many things are wrong, we share in the criticism con- tained in the paper, and we agree with the ur- gent need to “address the flaws in reasoning and tactics we have employed to date”. Howev- er, all this serves more to orient the agenda for a scientific program and less to orient scientifi- cally based interventions. Meanwhile, there is a wide range of evidence suggesting that changes are needed in society and the environ- ment to achieve better health standards, but that this agenda is far from being defined in merely scientific terms. At most, the sciences in their current stage can provide clues for po- litically organized societies to choose the best actions, or sometimes the lesser of two evils, with a view towards solving their health prob- lems. It was no coincidence that the report by an expert committee named by the UK Min- istry of Health to recommend policies for re- ducing existing health inequalities noted that interventions in this field had rarely been sub- mitted to controlled evaluation methods; how- ever, this did not keep the committee from
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The author replies ic agents, back to the agent-host-environment O autor responde triad, and now to a more complex and sophis- ticated understanding of inter-relatedness. From both da Silva’s and Foller’s comments, it is clear that I have not communicated with suf- ficient clarity that the ecosystem approach, be- cause it requires local participation to define the elements and relationships of interest in a given ecosystem, is necessarily rooted in cul- David Waltner- I am grateful to the respondents for their cri- ture as well as nature. However, as Cristina de Toews tiques both of the arguments I have made, and Albuquerque Possas points out, there are ten- of the less-than-clear way in which I presented sions between the scientific tendency to ho- them. They have been generous in making al- mogenize, and the cultural tendency to partic- lowances for my own struggle with understand- ularize. The ecosystem approach, drawing on ing and presenting the theory and the practice what has been called Post Normal Science of an ecosystem approach to health. I have (Funtowicz & Ravetz, 1994), incorporates these tried to incorporate the editorial comments in- tensions by requiring negotiation and what to the article itself in such a way as to clarify my James Kay has called “cross talk” (Kay et al., arguments but not, in the interests of real de- 1999). Because of this, implementing “ecosys- bate, to change them. tem approach to health” programs must face I feel the need to clarify the context of the not only deficits in our understanding of socio- article and make a few general comments. I ecological systems, but very real and often was invited to take the ecosystem approach to daunting political power struggles. We contin- health and apply it to how we think about trop- ue to debate these issues, and how to deal with ical and emerging diseases. I have elsewhere them, in workshops sponsored by the Network discussed concepts and models of health in for Ecosystem Sustainability and Health (NESH), some detail, and in this article focused only on as well as on our web-site (www.nesh.ca). the tension between health – which I describe Given the practical issues of competing in- as a negotiated construct within biophysical terests, governance, and uncertainties not just constraints – and disease, which is merely among disciplines, but among researchers and one of many constraints (Waltner-Toews & non-researchers, both Foller and Moran won- Wall, 1997; Waltner-Toews, 2000). Secondly, the der about implementing this approach. They ecosystem approach to health, which is a par- are quite correct to see these as challenges, but ticipatory research and management method- I think Moran is unduly pessimistic. Conflict ology, firmly rooted in complex systems theo- resolution in the development context has re- ries (which include elements of chaos and cat- ceived considerable attention in recent years astrophe theory), needs to be distinguished (see, for instance, Buckles, 1999). Furthermore, from ecosystem health, which is an attempt to we have found, at least at the local community apply health management ideas to ecosystems. level, that many people understand, accept, Whereas the ecosystem approach states that and can work with uncertainty and compro- “there is not one material system to which our mise if they are part of the investigative and definitions must conform”, ecosystem health management process. Many government insti- tends to take a more biomedical view that there tutions have problems implementing policies is indeed one material system on which we can on public health and environmental issues be- agree, and whose health we can assess. Thus cause they assume that their “experts” can ade- ecosystem health tends to focus on outcomes, quately define the risks and hence impose so- and the ecosystem approach tends to focus on lutions on the public. The public will shoulder process. This is obviously not a clear division, risks they have chosen, but not those imposed. rather a difference of focus. In this context, the major practical constraints Luiz Jacintho da Silva is quite correct in cit- to implementing this approach relate to democ- ing the historical antecedents of viewing dis- racy, a sense of a common good beyond the in- eases in ecological context. What distinguishes dividual household, and knowledge (not nec- Hippocrates, the 19th-century sanitarians, essarily formal education, but the ability to ar- Pavlovsky, and Virchow from this current effort ticulate understanding and argument). In many is a changed understanding of the natural poor countries, the third component is miss- world and our place in it. We have gone from a ing. In North America, a lack of the second purely empirical sense of inter-relatedness, to component has proven to be the major prob- miasma theories, to a focus on specific etiolog- lem. Again, there are exceptions; some of us
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have found modern students of science in field, since it quite clearly demonstrates that North America to be unable to clearly articu- health, as a state, is a moving, probably unat- late understandings and arguments. I did not tainable, target. Studies using the ecosystem discuss specific methodological tools in the ar- approach may be classified in static form (Fig- ticle, but the process invariably involves trian- ure 1), and portions of it may be teased apart gulating results from a combination of meth- and made to appear linear (Figure 2), but the ods, ranging from those developed by partici- process overall is always, in practice, an itera- patory action practitioners (which are usually tive one of continuous re-negotiation of goals central), to those used in conventional scholar- defined from different perspectives, actions, ly inquiry, Soft Systems Methodology (Check- assessments, changed understandings, and re- land & Scholes, 1991), influence diagrams, and negotiation (Figure 3). This is not a process with newer dynamic simulation models and Geo- a beginning and an end, and reflects the fact graphic Information Systems. The specific tools that good health is a function of both the out- used are determined by the questions being comes and how they are achieved. Health in asked by the participants. this context is not so much a mirage as a sense José Maria G. de Almeida Jr. raises several of well-being that we need to continually rede- interesting and important points. Since my fine and renew as the world changes. wife is a counselor-therapist, I am well aware Dr. Lima Barreto’s comments raise the of EMDR (which links mind and body at an in- question of whether the ecosystem approach, dividual level), as well as the broader literature as here defined, is science at all. John Robin- linking mental and social conditions to bio- son, Director of the Sustainable Development physical health at more encompassing sys- Research Institute at the University of British temic levels in the socio-ecological holarchies Columbia, has argued that what we are talking (e.g. Evans et al., 1994). Health in the tropics about is “co-generation of knowledge”, and that has both socioeconomic (e.g., poverty) and eco- by referring to it as a kind of “post-normal sci- logical (e.g., climate) constraints. One of the ence” we are giving unwarranted credit to sci- ways we have dealt with that in implementing entists (personal communication). People like the ecosystem approach is to require local, Funtowicz and Ravetz tend to see this as an en- public participation defining the research ques- richment or expansion in the nature of science, tions and the management options. The process in which the primary task of scientists is to itself empowers people and promotes health; help us find ways to live with what appears to this is what I mean by saying that the means be irreducible uncertainty. That is, in address- achieve the ends. ing questions marked by epistemological and I consider gene therapy to be a medical pro- ethical conflicts and where the stakes and un- cedure and not a health promotion technique, certainties are high, a new kind of public sci- and cloning faces the same problems as other ence, responding to an expanded peer group, genetic engineering of organisms, in that (among is required. This is still, I think they would ar- other things) it changes the rate of change at a gue, a systematic gathering of knowledge in the particular scale (the individual) and hence cre- pursuit of general laws, open to scrutiny and ates serious disturbances at other, co-evolving evaluation and verification by peers, and thus scales which cannot adapt as quickly (Giampi- qualifies as a kind of science. One could argue etro, 1994). Bill Reese makes this point much that this is simply a sort of “rational politics”, a more forcefully in his comments. If I have down- politics informed by science. Barreto’s response played the rapidity of change and the potential to this is that political interventions are only for catastrophe it is because, from a practical partly rational and scientific. As, I would add, point of view, I have found that such descrip- is the very notion of health. Indeed, one mem- tions of the situation, while probably true, tend ber of our NESH group – not coincidentally, I to foster some combination of panic with de- think, a Peruvian – has argued that we pay far spair, numbness, or totalitarianism. Indeed, I too little attention to the forces of political would argue that many of the lists of quantita- economy in our ecosystem approach. Survey- tive indicators of sustainability generated by in- ing the political and health landscape at the ternational agencies reflect these tendencies. beginning of the 21st century, I have no con- Faced with the urgency of systemic breakdown vincing response to this. The struggle to find and hemorrhaging of species, my veterinary reasonable resolutions to complex and often training tells me that calm, considered inter- tragically absurd situations is a struggle, I think, ventions may get us further toward our goals. worth pursuing. Still, Dubos’ “mirage of health” can be dis- Barreto wonders how we can measure suc- couraging for anyone working in the health cess. The ecosystem approach is focused on re-
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solving the practical, complex problems of how and an activist, I think that the ecosystem ap- we can live well (with health), as one species proach to health, as defined in this paper, among many, on this planet. In a constantly which struggles as much with process as with changing context, how can we know if we have outcome, offers (at least to the extent to which succeeded? In at least one of our projects (in the ideal is realized) some hope for dealing with Kenya) we derived two sets of indicators for questions where conventional science and pol- measuring success – one created by the research itics appear to be at an impasse. Nevertheless, I team, and one created primarily by the vil- do not believe that we will ever find a definitive lagers. The latter, we found, were the more use- way of coping with the uncertainty, tragedy, ful – though much more difficult for researchers and wonder of the human condition. For this to measure – because they reflected the quali- reason, music, poetry, stories, and rituals will ties of life that people actually cared about. always be essential for achieving health. But Nevertheless, health is also a concept full of that is another paper. contradictions, in which for instance, global health may dictate restrictions on local health, BUCKLES, D., 1999. Conflict and Collaboration in and population health in a context of ecologi- Natural Resource Management. Ottawa/Washing- ton, D.C.: IDRC/World Bank Institute. cal constraints requires the death of some indi- viduals. Indeed, we face many tragedies which have no technical solutions. As both a scientist See the original article for all other references.
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