One health and sustainability: Two sides of the same coin

The recent occurrence of multiple pandemics, including COVID-19 and Mpox in people, and H5N1 influenza in multiple species of farmed and wild animal, has put One Health firmly on the political agenda.However, One Health has meant different things to different people, often focussed on infectious disease and often with an anthropocentric bias.In response to this, in 2022 the recently-convened One Health High Level Expert panel, of which I was a member, developed a definition of One Health which is holistic, disease agnostic and which aims to equally protect the health and wellbeing of humans, domestic animals, wildlife, cultivated and wild plants and ecosystems (https://www.who.int/publications/m/item/one-health-definitions-and- principles).In this context, however, it is important to note that pathogens and parasites are important components of ecosystem function in their own right.While we may aspire for humans and domesticated animals and cultivated plants to be disease-free, ecosystem function, including the maintenance of biodiversity and evolutionary processes, relies on a balance being sustained between hosts and pathogens, so we should really talk about healthy wild animals and plants at the population, rather than at the individual, level.A driver for a One Health approach is a realisation that the occurrence of disease threats, be they infectious or non-infectious, are almost always a result of human choices and activities.While it is easy to see links between chemical pollution and