The United Nations-led Millennium Ecosystem Assessment was a critical step in mapping out the nature and extent of human reliance on ecosystem services and the ways in which altering natural ecosystems could negatively impact people. One of the services mentioned in the MA was human health. The World Health Organization defines health as a state of complete physical, mental, and social well-being. Health is one of the most important issues constraining human development throughout the world and is involved in at least five of the eight Millennium Development Goals.
Human communities experience different levels of health depending on the levels of ecosystem degradation where they live. To date, there has not been any comprehensive examination of the relationship between the natural world and human health. The published literature consists of a number of case studies exploring such mechanisms, but very few actually delve into cause and effect relationships between ecosystem alteration and public health outcomes. Those scientists and policy-makers interested in understanding potential relationships are left with largely anecdotal information that is clearly insufficient for informing decision-making on conservation, public health, or both.
Additionally, there is currently no overall framework to guide future research; nor is there a framework in which existing case studies can be placed to develop robust predictions of the potential human health effects of ecosystem alteration. This severely limits the ability of both the conservation and public health communities to search for settings in which conservation and public health might combine resources and collaborate on policy interventions to address shared objectives.
For its part, the public health community has not systematically considered the role that natural ecosystems may play in affecting human health. Similarly, the conservation community has not systematically considered how loss or conservation of natural ecosystems may be impacting public health. However, interest on both sides is increasing as awareness grows in regards to the ways that management of natural systems may impact disease and associated societal costs.