A new WHO/Europe report specifically investigates the role of the environment, from the health perspective, focusing on animal-mediated diseases (in which animals are a “vehicle” for disease), expanding to include some noncommunicable diseases, such as those caused by chemicals that may contaminate food of animal origin, and injuries caused by contacts with animals, such as bites.
One Health is an integrative, cross-disciplinary approach to designing and implementing actions and policies at the human–animal–environment health interface. However, the role of the environment in this triad has often been overlooked. One Health has traditionally focussed on communicable diseases, such as zoonoses and diseases caused by antimicrobial-resistant pathogens and unsafe food.
The new report – “A health perspective on the role of the environment in One Health”, coordinated by the WHO European Centre for Environment and Health, builds upon the global and regional plans of action that WHO has been developing with the other One Health partners: the World Organisation for Animal Health (WOAH, formerly OIE), the Food and Agriculture Organization of the United Nations (FAO) and the United Nations Environment Programme (UNEP).
The report describes the role of the environment in One Health as trifold:
- The environment acts as a reservoir, where nutrients and living organisms are accumulated and transported. This includes disease agents such as bacterial species and antimicrobial resistance genes together with organic and inorganic residues, chemicals and metals.
- The environment is the substrate for chemical and ecological processes that provide a myriad of ecosystem services to humans, including those essential for human health. In the disease context, environmental processes transform chemicals to bioavailable (which can be absorbed by the body) and bioaccumulating (which build up over time, for example through contaminated food) forms. Evolutionary processes can create new pathogens that may infect humans, or propagate antimicrobial-resistant microbes and genes.
- The environment is a health mediator, inducing positive or negative health effects on animals and humans.