Preserving biodiversity reduces the risk of disease: the greater the diversity of species in nature, the better human health will be
We know how important it is to preserve biodiversity and the richness of the natural environment in which we are immersed - it affects our health and the planet. However, the latest studies attest to a direct connection between the destruction of biodiversity and the spread of pandemics: the greater the diversity of species in nature, the better our living conditions.
More and more studies attest that modern pandemics (Ebola, SARS, Covid-19) are man-made. The loss of biodiversity caused by human activities such as deforestation, intensive agriculture, land use would seem to be the common thread in the health emergencies of recent years. To prevent new pandemics there is therefore a need to pay particular attention to the protection of biodiversity.
Felicia Keesing, professor and author of the study that shows the connection between biodiversity and the spread of epidemics, tries to clear the myth that wild areas with high levels of biodiversity represent particularly suitable habitats for the spread of diseases: according to this theory, the more animals there are , more pathogens can be encountered. In reality it is quite the opposite: biodiversity itself is not a threat, on the contrary - it protects us from species that carry pathogens and bacteria.
Zoonotic diseases (i.e. those transmitted to humans from an animal) are caused by pathogens that reach humans through other species. A pathogen can travel from one host to another through droplets of saliva contained in the breath or sneezing, through body fluids, feces, or with the bite. Natural biodiversity (and the loss of it) can relate to this migration path from one species to another and help break the chain that would lead the bacterium to humans.
But how?
Rick Ostfeld, co-author of the research, argues that species that thrive in industrialized and degraded habitats are often "better" at harboring pathogens and passing them on to humans. On the contrary, in environments little affected by humans and with a greater diversity of animal species, these "reservoirs of pathogenic bacteria" are less likely. Biodiversity would therefore have a protective effect. Researchers have shown that innate biodiversity can reduce the risk of infectious diseases through a weakening effect: species belonging to different communities would dilute the impact of host species which thrive when diversity declines, as already demonstrated for a significant number of species. diseases.
Human impact (land use) has been linked to the emergence of infectious diseases in humans in many studies. When this happens, longer-lived and larger species eventually disappear, while smaller organisms tend to proliferate. Bats, primates and rodents have been reported as the animal species most capable of transmitting disease to humans.
"If we destroy biodiversity," says Rick Ostfeld, "we end up favoring the animal species with the highest tendency to become vehicles of disease, increasing the risk of pandemics for humans."
Source: PNAS
We also recommend:
- Wildlife-borne pandemics thrive when nature is destroyed
- Intensive farming has caused most of the infectious diseases. "We risk other pandemics," experts warn
- To prevent the next pandemic, we should be concerned about the legal wildlife trade
