Health ecology



Health ecology (also known as eco-health) is an emerging field that studies the impact of ecosystems on human health. It examines alterations in the biological, physical, social, and economic environments to understand how these changes affect mental and physical human health. Health ecology focuses on a transdisciplinary approach to understanding all the factors which influence an individual's physiological, social, and emotional well-being.

Eco-health studies often involve environmental pollution. Some examples include an increase in asthma rates due to air pollution, or PCB contamination of game fish in the Great Lakes of the United States. However, health ecology is not necessarily tied to environmental pollution. For example, research has shown that habitat fragmentation is the main factor that contributes to increased rates of Lyme disease in human populations.

History
Ecosystem approaches to public health emerged as a defined field of inquiry and application in the 1990s, primarily through global research supported by the International Development Research Centre (IDRC) in Ottawa, Canada (Lebel, 2003). However, this was a resurrection of an approach to health and ecology traced back to Hippocrates in Western societies. It can also be traced back to earlier eras in Eastern societies. The approach was also popular among scientists in the centuries. However, it fell out of common practice in the twentieth century, when technical professionalism and expertise were assumed sufficient to manage health and disease. In this relatively brief era, evaluating the adverse impacts of environmental change (both the natural and artificial environment) on human health was assigned to medicine and environmental health.

Integrated approaches to health and ecology re-emerged in the 20th century. These revolutionary movements were built on a foundation laid by earlier scholars, including Hippocrates, Rudolf Virchow, and Louis Pasteur. In the 20th century, Calvin Schwabe coined the term "one medicine," recognizing that human and veterinary medicine share similar biological principles, and are interrelated. This one medicine approach, which had fairly clinical and individualistic connotations, was rebranded to "One Health," to reflect its goals of global human and animal health. Other integrated health approaches include ecological resilience, ecological integrity, and healthy communities.

Eco-health approaches, as currently practiced, are participatory, systems-based approaches to understanding and promoting public health and well-being in the context of social and ecological interactions. These approaches are differentiated from previous public health approaches by a firm grounding in complexity theory and post-normal science (Waltner-Toews, 2004; Waltner-Toews et al., 2008).

After a decade of international conferences in North America and Australia under the more contentious umbrella of "ecosystem health," the first "ecosystem approach to human health" (eco-health) forum was held in Montreal in 2003, followed by conferences and forums in Wisconsin, U.S., and Mérida, Mexico, all with major support from the IDRC. Since then, the International Association for Ecology and Health, and the journal Eco Health, have established the field as a legitimate scholarly and development activity.

Definition
Eco-health studies differ from traditional, single-discipline studies, which focus on one aspect of a complex issue. A traditional epidemiological study may show increasing rates of malaria in a region, but not address the reasons for the increasing rate; an environmental health study may recommend the application of a pesticide in specific amounts in certain areas to reduce spread; an economic analysis may calculate the cost and effectiveness of such a program. Alternatively, an eco-health study combines multiple disciplines, and familiarizes the specialists with the affected community. Through pre-study meetings, the group shares their knowledge and develops common understanding. These pre-study meetings often lead to creative and novel approaches and can lead to a more "socially robust" solution. Eco-health practitioners term this synergy "transdisciplinary" and differentiate it from multidisciplinary studies. Eco-health studies also value the participation of all active groups, including stakeholders and decision-makers. They believe issues of equity (between gender, socioeconomic classes, age, and even species) are essential to completely understand and solve the problem. Jean Lebel (2003) coined transdisciplinary, participation, and equity as the three pillars of Eco Health (Lebel, 2003). The IDRC now defines six principles instead of three pillars: transdisciplinary, participation, gender and social equity, system-thinking, sustainability, and research-to-action (Charron, 2011).

Examples
A practical example of health ecology is the management of malaria in Mexico. A multidisciplinary approach ended the use of harmful DDT while reducing malaria cases. This study reveals the complex nature of these problems, and the extent to which a successful solution must cross research disciplines. The solution involved creative thinking on the part of many individuals and produced a win-win situation for researchers, businesses, and, most importantly, the community. Although many of the dramatic effects of ecosystem change, and much of the research, are focused on developing countries, the ecosystem of the artificial environment in urban areas of the developed world is also a significant determinant of human health. Obesity, diabetes, asthma, and heart disease are all directly tied to environmental factors. In addition, urban design and planning determine automobile use, available food choices, air pollution levels, and the safety and walkability of the neighborhoods in which people live.