Making biodiversity conservation a public health issue, just as much as an environmental one, is imperative, given that a “healthy natural world” is essential to human survival. Yet it must be acknowledged that contemporary societies, through their ways of life and production, mistreat nature and are drifting away from it… often viewing the living world as a source of potential threats against which we must defend ourselves, such as the invasive tiger mosquito.

The aim of this issue of La Santé en action is to shed light on the multiple and complex links between biodiversity and health in light of scientific publications from recent years, which echo the concept of “One Health” (or “Une seule santé”) that emerged in the 2000s: it advocates the idea that the health of humans, animals, plants, and ecosystems is closely linked and interdependent. This is more or less the same approach as “Planetary Health,” whose interdisciplinary work studies the environmental and social determinants of health.

Positive Effects on Depression and Anxiety

Current knowledge regarding the relationships between nature, physical health, and mental health is crucial. Understanding how biodiversity functions allows us to better comprehend the harmful impacts humans have on natural systems—such as intensive livestock farming—which contribute to the emergence of zoonoses, infectious diseases that spread from animals to humans.

This issue thus presents:

• the biological mechanisms at work, and how plant aromas contribute to the immune stimulation of the human body; this is why current living conditions, cut off from the living world, foster certain chronic conditions;

• “the extinction of the experience of nature,” including for residents of rural areas, which is harmful to mental health, whereas green and blue spaces have proven positive effects on depression and anxiety, on stress, on concentration, and even on the quality of social relationships. The repercussions of biodiversity decline do not stop there; it fuels an “eco-anxiety” that urgently needs to be documented. It thus becomes clear that people’s well-being depends largely on the quality of the environment.

“Green gentrification”: the flip side of urban greening

One section of the report is devoted to the renaturation of urban areas, a strategic issue given the number of city dwellers. Several local governments have already embarked on this path; for example:

• in Albi, a medium-sized town in southern France, a “well-being index” has been established, which varies based on the distance residents must travel to reach a park or greenway; the goal is that, by 2026, everyone will be able to do so in less than 10 minutes on foot;

• in Ris-Orangis, a town in the outer suburbs of Paris with brownfield sites, the local urban planning scheme designates green spaces as protected areas; community gardens are being developed there and made available to residents so they can grow organic fruits and vegetables for personal consumption, and these spaces are becoming places for socializing.

However, developing nature in the city as part of a health promotion initiative faces certain challenges. This requires dialogue within local governments between environmental and health departments, which are not accustomed to cooperating. These public policies also require medium-term planning.

Furthermore, researchers warn of the pitfalls of such an approach: a phenomenon of “green gentrification” pushes disadvantaged households out of greening neighborhoods, exacerbating social and territorial health inequalities. Measures must therefore be taken to ensure that green and blue urban developments benefit working-class communities in the same way.

Reconnecting with the Natural World

This issue offers numerous examples of how people can engage in more nature experiences—starting at a very young age. At a daycare center in Seine-et-Marne, activities in the vegetable garden help stimulate young children’s senses and improve their sleep quality. At an elementary school in Doubs, teachers hold classes in the forest for half a day each week, even in winter; they observe that students cooperate more than in the classroom, becoming more independent and creative. Adults can become “naturalists” themselves, for example by participating in the scientific observatories of Vigie-Nature (run by the Natural History Museum): “ Living Beaches,” “Operation Butterflies,” “Long-Term Dragonfly Monitoring,” etc. Certain practices abroad are also inspiring: in Quebec, health and social services professionals issue “nature prescriptions” to encourage time spent immersed in green spaces, whether in Canada’s large parks or the neighborhood community garden.