DEBATE DEBATE

David Waltner-Toews (W-T) has chosen to discuss an issue of fundamental importance, the role of environmental change and how it relates to human health, i. e., how to combine the socioeconomic and biophysical dimensions of human health. It is a complex challenge to grasp how relations between ecosystems are connected and influence the everyday life, health, and welfare of human beings. W-T applies an ecosystem approach to this task in his article.

In the introduction he asks, "What is health"? He mentions the World Health Organization's definition "...as a state of complete physical, mental, and social well-being, and not merely the absence of disease". W-T is critical of this definition. What he suggests is a redefinition of health as "absence from disease and pathology". I find this confusing in relation to the holistic ecosystem approach presented later in the article. For me, the above statement is a perception of health as a static and biomedical condition. I would have preferred another introduction, since this definition certainly stands apart from the rest of the article, and he never really returns to the meaning behind this redefinition.

If W-T intends to discuss the WHO policy starting with the 1948 founding document, such a discussion must be placed in some form of historical context, since the document is clearly biomedical and born within Western tradition. For W-T's overall global and ecosystem approach to health, I find more relevant a continuation of the Alma-Ata Declaration, which is now more than 20 years old, but which certainly focuses more on the importance of community involvement for improving health conditions. In a world of limited resources, mass unemployment, and health standards that are socially and economically far removed from such aims for the majority of the world population, neither the idealistic WHO definition nor that proposed by W-T provides a realistic starting point. Such ideal statements sound strange and dangerous in relation to my way of dealing with today's reality. They have the potential of creating new problems in establishing for whom and on what level in society the absence of disease or pathology can be defined. The WHO definition of health is part of the Western tradition and implies the notion of perfectibility. I would suggest a more processual view of the continuum between health and disease in the introduction, since this is what the author emphasizes later on in the article. We are all born, live, and die, and during this process we must deal with physical, emotional, and psychological strain. This is part of life, and only on an individual level can one decide whether to define one's situation as illness. This is valid for people with disabilities, those defined by society as mentally ill or abnormal, and persons with stress-related disease.

At any rate, W-T applies an ecosystem approach to health in the rest of the article. He defines a system as a set of elements which interact with each other within certain boundaries. He elaborates on the concepts of holarchy, attractor, and complex feedback loops, all central to understanding an ecosystem approach. Systems that are hierarchically nested within each other are called holarchical. As I understand the ecosystem approach, the point with concepts such as holarchies is to show that there is always interdependence between subsystems and supersystems. Central to this approach is that there is a systematic function; the supersystem is dependent on continuous cooperation with the subsystem. This is translated into another terminology by which everything is related to everything else, and the focus of this article is the relationship between global and local concerns in today's world. W-T makes these relations more transparent by giving examples of the importance of local activities and how they interfere with and influence global activities. That is to say, there is an interconnectedness between the holarchy of the ecosphere, ecosystems, and human systems, hence the connections between human health and ecosystem health.

I agree that we need some form of holistic approach for the integration of social, economic, and environmental interests in relation to human health in a systematic way. But even with this very broad approach to connect ecosystem health and human health, W-T does not talk about interdisciplinarity or how to establish cooperation between scientists. W-T writes, "Both scientific studies and participatory action research (PAR) are necessary ingredients of an ecosystem approach, and both must be reoriented to a systems understanding of reality." This is a huge task, but I agree that we have to begin the dialogue. The question is how to elaborate communications between people living in rural communities around the globe and researchers in a two-tier way. On the one hand, taking local knowledge seriously, and on the other, translating and making scientific knowledge understandable to people in rural areas of the world. W-T also writes, "How can we do scientific research and science-based development in support of health?" W-T gives examples to show that medical sciences both solve and create problems, displaying a certain humbleness of mind, which I like.

I believe that we need broad scientific cooperation among scientists from ecology, medicine, and social and cultural disciplines to solve many of today's health problems. But local participation and elaboration of dialogue with people in the communities are just as important. They often have concepts of health that go beyond merely the physical functioning of individuals. As I interpret it, this is also the intention behind W-T's approach, but he misses some of the "soft" aspects, such as the behavioral and cultural dimensions of people living in the communities. They are the ones affected by tropical, emerging, and other diseases.

Still, the author has taken an important step in this article in attempting to connect an ecosystem approach to different aspects of health-related issues, even though he deals largely with patterns of infectious and emerging diseases. W-T attempts to cross borders between ecological, sociological, and medical sciences and participatory action research. We know that there are linkages between human activities and alterations in ecosystem functions and services with direct consequences for disease transmission and some more indirect effects, and W-T highlights some of these connections.

We are now more than 6 billion people living on the planet Earth. If we want a sustainable future, different strata in society must work together. As scientists, we have to cross disciplinary borders to find new connections and black holes in our knowledge and understanding of the relationship between global processes, local impact, and individual behavior. W-T has taken one step in this direction, and more discussion is needed. The debate that took place in Rio de Janeiro during the IDRC meeting in November 1999 between ecologists, human ecologists, social scientists, medical scientists, development organizations, and PAHO representatives was a good initiative. It is through the creation of interdisciplinary forums and an open dialogue that we will realize that no one has a single all-encompassing competence for a sustainable future. We have to learn from each other and hopefully be part of a process which moves the contemporary and future ecosystem and human health situation in a positive direction.