Human health is dependent on biodiversity and on the natural functioning of healthy ecosystems. The world’s rich biodiversity is the foundation of environmental equilibrium, which is crucial to safeguarding human health. Biodiversity also provides us with models for medical research that help us understand human physiology and deal with disease.
Human actions such as pollution, deforestation and increase in population cause habitat fragmentation, degradation and eventual loss. The results are the extinction of numerous useful species and the proliferation of new and already existing harmful ones as well as pathogenic microorganisms; such as viruses and bacteria; leading to outbreaks of infectious diseases. Furthermore, biodiversity loss could cause antibiotic resistant diseases, nutritional deficiencies due to lack of food variety, water contamination, and poor air quality with subsequent increase in respiratory tract infections.
Malaria, for example, has become more widespread in the Amazon region, where deforestation creates areas of standing water thus forming breeding sites for the type of mosquitoes that plays a predominant role in the transmission of the deadly species of plasmodium, which causes malignant malaria in humans with high rates of complications and mortalities.
On the other hand, diseases such as bilharzia can be naturally fought by conserving the biodiversity of fresh-water snails. The presence of different snails in the area where parasite eggs are released from infected individuals can cause the miracidia, which is the small free-living larval stage of schistosomes (the type of flatworms that causes bilharzias) to enter the wrong snail and hence die without reproduction thus interrupting the cycle of the disease.
Furthermore, the World Health Organization (WHO) estimates that 80% of people in developing countries rely on traditional medicines derived mainly from nature for the treatment of a large number of common diseases. Just one example is the cone snail; beautiful but deadly because of its venomous toxins, it shows great promise as a source of new medically important substances such as ziconotide, which is a non-opioid and non-NSAID analgesic agent, that are used to relieve severe and chronic pains.
Dr. Aaron Bernstein, Harvard Medical School and the Center for Health and Global Environment, explains: “Cone snails, which have 700 species, may represent the greatest treasure trove of potential medicines of all organisms on Earth, but because they live on or near coral reefs, they are in danger”. They are in danger because the coral reefs are greatly damaged by various human practices such as overexploitation, dynamite fishing and climate change threats.
Not only that, human mental and psychological health is also greatly affected by biodiversity. Seeing nature or being outside lowers stress levels, calms heart rates, and diminishes road rage. In the presence of natural light, workers are happier and more productive and students do better on tests. More surprisingly, a new study from the University of Sheffield contributes an unexpected detail to this research; the extent of psychological benefits people gain from walking in a park correlates directly to the extent of biodiversity in that park!
It is critical for us as humans to realize the impact we have on biodiversity and that at the same time there would be no human existence without it. If no changes are made in the ways we use resources on Earth, biodiversity loss will continue until human lives can no longer be sustained. It is only through proper education and solidarity of nations in taking the proper actions towards the preservation of biodiversity, that the human race will be able to sustain life on Earth.
*The original article was published in the PSC Newsletter, 2nd School Semester 2009/2010 issue.