The connections between ecological and human health

1.1 Human Health

If one wants to award meaning to the term 'human health', it is advisable to distinguish b e- tween the health of individuals (i) and the health of whole populations (ii).

(i) Individual health is described by the World Health Organisation as "not just the absence of disease or infirmity, but a state of complete physical, mental and social wellbeing" (McMichael 1993, p.57). Obviously, one has to scrutinize further what could be understood by physical, mental, and social well-being and how it could be measured. Ultimately, only the single individual herself can give further particulars.

(ii) Health of a population refers to the average state of health in a society. The indicators to measure the health of a population are infant- and maternal mortality, as well as life ex- pectancy (e.g. McMichael 1993, p.58). Moreover, McMichael (2001, p.328) states that popu- lation health "can be understood as a criterion of the population's social, cultural and eco- nomic performance, and of its stewardship of the natural environment".

1.2 Ecological Health

'Ecological health', 'ecological integrity', or 'ecological equilibrium' are phrases that are used arbitrarily and indiscriminately, but have only a limited formal and agreed definition. This will be shown by the following:

Firstly, and it is paradigmatically circular, the Faculty of Forestry (2004) describes ecologi- cal health as "both the occurrence of certain attributes that are deemed to be present in a healthy, sustainable resource and the absence of conditions that result from known stresses or problems affecting the resource." Secondly, Rapport et al (1998) define the term 'eco- logical health' as somehow related to 'vigor' (activity, metabolism, or primary productivity), 'organization' (diversity and number of interactions between systems components), and 're- silience' / 'counteractive capacity' (system's capacity to maintain structure and function in the face of stress) (cited in: Harris/Hobbs 2001, p. 196). They conclude by stating "the need for more detailed development of ecosystem health indicators" […] "that do more than provide vague general indicators of structures or processes" (ibid, p.200).

As long as one is not willing to work with insightful and multi-layered 'definitions' of such kind that 'define' ecological health as the presence of healthy resources, one has to examine thoroughly the corresponding (ecological) language systems in which terms like the given above, as well as for example (neighbourhood, global, dynamic, bounded, cyclic, trajectory) stability, resiliency, constancy, elasticity, persistence, resistance, inertia, equilibria, carrying capacity, etc. are explained in detail and clear indicators are given. This can just be named as a desideratum , but can not be done in this essay. Instead, all the attention is drawn to look at the phenomenon 'human health' within particular contexts.

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The health of populations has always been determined by fluctuating environmental and

political fortunes, along with an overlay of cultural practices and social values.

MCM ICHAEL 1993, p.78

2 Human health in context

In the following, it will be argued that human health, both of individuals and of the species homo sapiens over time, depends upon context or environment. 'Environment' may be dis- tinguished in natural, built, and social or social, economic, and natural environments. It goes without saying that these are artificial differentiations for analysis and that these env i- ronments are overlapping and criss-crossing. The crucial point here is to perceive health not as a isolated phantasm, but rather as a spatial, temporal and highly complex phenome- non. This perception shall be called an 'ecological perspective'.

2.1 Taking an ecological perspective

Ecology moved into the focus of public interest at the end of the 60s as the effects of (en- vironmental) pollution and the limits of the natural resources became more and more ob- vious. In the trend of the ecology discourse, ecology received an expansion in content and institution that extent further than that of 'hard' science. These days, ecology stands for a worldview:

The idea of limitless growth is considered to be problematic and in need of correction. Na- ture can bear changes only to a limited extent without suffering irreversible damage, - and humankind is but one limb of the global ecosystem upon which the existence of human- kind depends.

For the further investigations, it is crucial to overcome the classical scientific worldview that is atomistic, mechanistic, and dualistic. Within this view, the world is made up of iso- lated, discrete particles/quantities that exist independently of one another. Phenomena are explained in terms of strict cause and effect relations. Whereas this worldview emphasises separation, an ecological one rests upon a principle of interconnectedness. The world is not seen as divided into mutually independent parts and mutually exclusive attributes, but rather everything is seen as implicating, and being implicated in, the identities of other things, reality being a relational system of shared, interpenetrating essences. Circularity and feedback mechanisms are the suitable modi to explain phenomena (e.g. McMichael 1993, p.60; Berkes et al. 2003, p.31-83).

2.2 The delusion of perfect health and its connections to ecosystems

Within the ecological perspective, living beings, and thus humans, are not seen as isolated entities, but seen to develop in a co-evolution within and alongside their environment. Humans must adjust to a constantly changing environment and vice versa. The "[s]ystems

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of people and nature co-evolve in an adaptive dance" (Walters 1986, cited in Berkes et al. 2003, p.33).

As a consequence, […] perfect health for human species is simply not attainable; it is a mirage. (McMichael 2003, p.58) Because, [i]t overlooks our inextricable involvement with the ecological systems within human life exists, […][it] overlooks our ecological dependence upon the web of natural systems (ibid, p.60/61). Thus, health is not a matter of all or nothing, but rather of 'more or less'. It is about the adjustment of an individual or a population to and in its steadily changing milieu. This means that the definition for health given by the WHO cannot only be considered as highly unlikely, but as idealistic and naïve. Rather, it is the case that different levels of disease and infirmity are natural and essential components of the evolutionary process.

With such an "human-in-ecosystem perspective" (Berkes et al. 2003, p.70), human health might be described accordingly. This was achieved by the WHO in 1957 (cited in: McMichael 1993, p.74) by including the statement that health is a condition of the human organism which expresses adequate functioning under given ge- netic and environmental conditions.

The insight that human health is crucially linked to the environment has a long tradition. Hippocrates 1 already stressed "the importance of clean air, water and food to individual health" (ibid, p.60). More than 2000 years later, it was Rene Dubos, an early pioneer of m i- crobiology, who emphasised "the social-ecological dimension of human existence" (ibid, p.62) and "recognised the intimate connection between the ecology of human living and the health of human populations earlier than most" (ibid, p.62). He described health as "an expression of fitness to the environment" (ibid, p.74). Incidentally, this understanding leads to a reformulation of the famous formula by Chares Darwin "survival of the fittest" into "survival of the fitting" (e.g. Maturana et al. 1992).

Health of populatio ns depends upon the carrying capacity of life-supporting ecosystems. We can adapt to varied environments, we can control aspects of the environment and increase pro- ductivity (for humans) coopted ecosystems - but we cannot live without this ecological support sys- tem. (McMichael 1993, p.63)

A drastic example that illuminates the connection between environmental decline and hu-

man health, is the downfall of the Easter Islands, due to unsustainable agricultural prac- tices (Lomborg 2001, p.29). Examples of other, rather localised, health problems "arising from lead in the air, soil and water, from traditional urban air pollutants due to fossil fuel combustion, and from countless industrial and agriculture chemicals" (McMichael 1993,

1 Hippocrates (460 BC - 370 BC): Greek physician. Counts as founder of medicine as empirical science on the basis of unbiased observations and descriptions of the symptoms of the disease and of a critical diagnostic without speculations. The Hippocratic Oath is still today model for the vow of the physicians.

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