What if we could diminish diseases and discover life-saving drugs by conserving natural habitat? Would saving ecosystems become more tempting if human health were on the line?
Well, although an underreported dimension of the destruction of wildlife habitat, human health is exactly what is at stake. Habitat devastation has played a role in the emergence of diseases that move between humans and other animals, such as Ebola, and even, some scientists argue, in the increase of incidences of Lyme disease. Loss of habitat has also had the accidental significance of eradicating access to possibly lifesaving drugs by abolishing the very places where those drugs originate.
CARE OF NATURE
Whether or not people care about nature for its own sake, these allegations for human well-being should stimulate them toward habitat and wildlife conservation, and raise conservation to the same level of importance as things such as stem cell and cancer research or struggles to eliminate HIV or malaria.
Undisturbed, wild animals and their habitats can serve as a wall that prevents the spillover of emerging infectious diseases — EIDs — from animals to humans. Because the diseases and the animals have evolved together, the diseases have little to no effect on those animals. When transmitted to humans, however, those pathogens can result in EIDs. It has been projected that 60% of recent EIDs have been zoonoses, and close to three-quarters of these started in wildlife. The clearing of undisturbed habitat to pave way for human activities such as agriculture has created blurred boundaries between wild and domestic animals, helping to enable the jump to humans.
CASES OF NIPAH AND HENDRA
This is what happened in the cases of Nipah and Hendra viruses, among others. The clearing of forests in Southeast Asia and Australia, respectively, led certain forms of flying fox fruit bats to move closer to farm animals (pigs in the case of Nipah; horses in the case of Hendra). The farm animals ate virus-ridden bat saliva or urine, became ill, and transmitted the disease to humans who came into contact with them. Neither virus was new, but both were kept from humans until habitat annihilation enabled the jump.
Zoonotic diseases exact a massive human toll — identified diseases account for at least 2.7 million deaths and 2.5 billion cases of human sickness annually. In the developing world, zoonotic EIDs can aggravate other public health challenges, such as lack of infrastructure and malnutrition resulting in increased bushmeat consumption, which can in turn present new varieties of EIDs. And zoonotic EIDs can have huge economic and social consequences as well, such as loss of employment and business — familiar outcomes during outbreaks. For example, pig farmers in Malaysia incurred a loss of US $244 million during a Nipah outbreak in 1998 and 1999 due to mass removing of pigs.
HALF OF HUMAN DRUGS
Almost half of human medicines come directly or indirectly from the natural world, even as less than 10% of all of the world’s biodiversity has been assessed for probable drugs.
Surveillance, detection and responses to these outbreaks are unfortunately low in developing countries, which are often particularly susceptible to the appearance of EIDs due to their closeness to areas of high biodiversity: As they develop, those countries and their people face higher exposure to zoonotic pathogens. Meanwhile, population density and increased global travel means transmission of these diseases will be real, even in the developed world.
HARM OF ZOONOTIC EIDS
The tremendous harm zoonotic EIDs wreak globally points to a commanding need to advance our understanding of the role of wildlife ecology and the wildlife-livestock boundary in their emergence. Increasing research in this area would offer tremendous benefit by improving our ability to predict which regions are most at risk and to prepare and respond to these threats. The recent surges in EIDs across the world underscore the importance of protecting wildlife habitat, both with speed and in scale.
And then there’s medication: Almost half of human medicines come directly or indirectly from the natural world, even as less than 10% of all of the world’s biodiversity has been appraised for potential drugs. Many lifesaving drugs, including some recent anti-cancer drugs, have instigated in nature.
SCRATCHING ONLY SURFACE
Yet all of this advancement is likely just scratching the surface of nature’s inconceivable potential to yield health-promoting substances. New species are continually being found. Discoveries of bacteria that survive in the unlikeliest of places have opened possibilities for even more new drug discoveries. And scientists have recently begun tapping into potential drug discoveries from other members of the microbial world, too.
Meanwhile, 60% of people worldwide depend almost entirely on plants for their primary medication. Animals are also used in parts of the developing world for traditional medicines. Yet, we are allowing the natural world to disappear without fully understanding what will be lost — or knowing at all, since we can only examine that some species are becoming extinct before humans even know about them. To protect these current and future sources of medicines, we need to protect the nature that provides them.
SAFEGUARDING HUMAN LIFE
Studying and conserving nature is as important as any other human health enterprise, and the health benefits of conservation need to be included alongside other discussions about saving nature. It is time to make the case that wildlife science and conservation are pertinent to everyone’s life. Too many people’s health will be in jeopardy if we don’t.