Health ecology

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^[6]. However, this was a resurrection of an approach to health and ecology traced back to Hippocrates in Western societies^[7]. 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.^[8]

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^[9]. In the 20th century, Calvin Schwabe coined the term "one medicine," recognising 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.^[10] Other integrated health approaches include ecological resilience, ecological integrity, and healthy communities.^[11][12]

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.^[13][14]

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^[15][16]. Alternatively, an eco-health study combines multiple disciplines, and familiarizes the specialists with the affected community^[17][2]. 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 "trans-disciplinary" 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^[18]. Jean Lebel (2003) coined trans-disciplinary, participation, and equity as the three pillars of Eco Health^[18]. The IDRC now defines six principles instead of three pillars: trans-disciplinary, participation, gender and social equity, system-thinking, sustainability, and research-to-action.^[19]

EcoHealth and One Health, while sharing a common foundation in systems-level thinking that challenges traditional biomedical reductionism, diverge significantly in their historical roots, core focus, and disciplinary scope^[18][19][13]. EcoHealth, grounded in the premise that human health and well-being are fundamentally dependent on the health of the environment, seeks a broad understanding of health that integrates the humanities with the natural, social, and health sciences. It is primarily concerned with the complex interactions between humans, ecosystems, and the socio-ecological factors that influence them . In contrast, One Health evolved directly from the fields of veterinary and human medicine, with a primary focus on human-animal disease transmission and the human-animal health interface ^[10]. Traditionally, One Health placed less emphasis on the role of the environment compared to EcoHealth, though its conceptual scope has recently expanded to include broader concerns such as food security, climate change adaptation, and biodiversity^[20]. Given these different traditions, they have developed distinct practices, leading to ongoing calls for closer collaboration to leverage their complementary strengths such as applying One Health's economic analysis to EcoHealth, or situating One Health research within the context of environmental degradation^[21]. While some scholars argue the two approaches will inevitably converge, others contend that persistent differences in discipline segregation and research practices currently limit integration, suggesting that methodologies to facilitate collaboration are still needed^[22].

• Planetary health