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42. United Nations Environment Program (UNEP): Environmental Destruction and Zoonotic Diseases

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As of May 17, 2020, the number of people infected with COVID-19 has reached 4.63 million. In 2016, a report released by the United Nations Environment Program (UNEP) already referred to zonotopic diseases, or “the blurred boundaries between zoonotic diseases and ecosystem health”  as one of the emerging environmental issues, among the following issues: the role of the financial sector in environmental sustainability; trouble in the food chain due to plastics in the environment; impacts of climate change in the ecosystem; toxin accumulation in crops triggered by climate change; illegal trade in wildlife

Below are some excerpts from the report with relevance to COVID-19:

The 20th century is a time of unprecedented ecosystem change, and the population and livestock have increased in tandem with the dramatic loss of natural ecosystems and biodiversity. As a result, to date, wildlife-to-livestock pathogens and zoonoses to humans have spread worldwide. 75% of all new infectious diseases and 60% of infectious diseases that affect humans are zoonotic diseases, and human infectious diseases appear every 4 months on average. Although many infectious diseases are caused by wild animals, livestock also serve as epidemiological vectors between wild animals and humans. In particular, infectious diseases are associated with intensive livestock management that is genetically similar within groups and groups, and this is also the result of prioritizing productivity over resistance to infectious diseases in breeding. An example of livestock becoming a “bridge of infectious diseases” is the avian influenza virus that spread from wild birds to humans through chickens.

The emergence of zoonotic diseases is associated with environmental changes and disturbance of ecosystems, such as agricultural intensification, human settlementencroachment into ecosystems such as forests. Zoonotic diseases are also opportunistic and affect hosts already stressed by  environmental, social and economic conditions.

Zoonoses threaten economic development. In the last few years, several new zoonotic diseases have been reported worldwide as causing or thretening to cause pandemics. These include Ebola, bird flu, Middle East respiratory syndrome MERS, Rift Valley fever, severe acute respiratory syndrome SARS, West Nile virus, Zika virus, etc. The pathogens that cause these have long been host to wildlife. Over the last 20 years, these have cost more than $100 billion, but if the outbreaks had become a pandemic, the losses would have amounted to trillions of dollars (now a reality with COVID-19).

Other important zoonotic diseases include food-borne pathogens such as Salmonella and Listeria. In 2015, the first global assessment of food-borne diseases was conducted and its effects were reported to be comparable to those of malaria and tuberculosis.

Ecosystem integrity, which maintains diverse species, helps control infectious diseases so that one pathogen does not spread or become dominant. The ecosystem changes as the population grows. Forests have been cut down, lands have been opened up for agriculture and mining development, and the ecosystem that used to be a buffer between humans and animals that carry pathogens is clearly diminished or lost. Zoonosis spreads across three sectors: environment, agriculture, and health, but it is often the case that there is no mutual cooperation mechanism, and the framework for policy coordination for infectious disease control is weak. Successful zoonoses control requires a sensible legal and policy framework, well-functioning institutions, adequate financing, rapid detection systems and intervention implementation plans.

A significant contstrating to  involving agriculture in the control of zoonosis is the lack of cooperation between medical and veterinary specialists, leaving concerns over zoonosis aside. The cost of zoonotic control appears to be enormous compared to the benefits of public health alone , but it is clear that the benefits outweigh these costs if the benefits to the agricultural sector, wildlife and society are considered.



UNEP (2016). UNEP Frontiers 2016 Report: Emerging Issues of Environmental Concern. United Nations Environment Programme, Nairobi. 

Pick Up 21. New Coronavirus Pandemic ― Earth Day and Biodiversity


Contributor: IIYAMA Miyuki (Research Strategy Office)