We’ve become so alienated from nature that we no longer see ourselves as part of it; we no longer realize how it provides for us. We have forgotten that our health and well being, depends on our ecosystem’s health and well being. Instead, we are destroying our environment at an unprecedented rate. For the first time in history we are having an impact on nature on a global scale. We are actually disrupting the chemical, physical and biological cycles of our planet. We are leading other species to extinction at a rate not seen for 65 million years, since that asteroid crashed into the Yucatán and wiped out the dinosaurs. Our industry produces so many toxic chemicals and heavy metals that they are now found everywhere, even in Antarctica and the Arctic, which have no cities, let alone factories. We have acid rain and an ozone hole in our atmosphere, melting ice shelves, shrinking glaciers, and rising sea levels. We’re not only changing the composition of our atmosphere, but the global climate as well.

And we need to realize that these changes have consequences. Environmental degradation impacts directly and indirectly on our health in a number of ways. One of the most obvious is the phenomenon known as emerging infectious diseases: the appearance of approximately 30 new infectious diseases in the past few decades (such as HIV/AIDS, Ebola and more recently, SARS), as well as the expanding range of other previously known infections (such as West Nile Virus) and the reappearance of others that were thought to be under control (such as Cholera’s return to the Americas after a century’s absence).

One of the simplest examples is that of Lyme disease in the woodlands of the northeastern USA. In the absence on any large predators, the deer population has increased dramatically to the point where it is basically out of control. This has led to an explosive growth in the deer tick population, which transmits the disease. We forget that viruses, bacteria and parasites are more than just a nuisance―they are an integral part of the environment. (Proof of this is that you can actually predict, to a certain degree of accuracy, the number of new Lyme disease cases two years down the road based on this year’s acorn crop.)

Current climate changes are leading to an expansion in the range of mosquitoes, ticks and other vectors of disease. Warmer temperatures increase the reproductive rate of both pathogens and insects, as well as biting frequency of mosquitoes. When you consider that throughout history more people have died of mosquito-borne Malaria than of any other single cause, the potential repercussions are frightening.

Let us make a small detour and consider the conquest of the Americas, five centuries ago … a time of drastic social changes when two civilizations, two “worlds,” completely unknown to each other suddenly clashed. Europeans won out in the end not because of stronger armies, but because they brought smallpox with them, a disease which the Native Americans had never been exposed to. Within 200 years, it (and other diseases) wiped out approximately 90% of the native population. What we forget is that the Native Americans gave something back. When the Europeans went home, they took syphilis and tuberculosis back with them. This was unintended biological warfare, and the New World lost simply because smallpox will kill you in a couple of weeks, whereas tuberculosis can take decades to do the job, and because it is a lot harder to catch syphilis than smallpox.

And so nowadays, in a time when we as a species seem to have declared war on the rest of nature, it is easy to imagine that Mother Nature is fighting back the only way she can. But it is not that simple. The reality is much more complex, and this phenomenon of emerging diseases is probably best understood as merely another symptom of an environment seriously out of whack … because unfortunately, although we are clearly driving the process, we are not the only ones affected by it. With increasing frequency we hear of die-offs of marine species, from mollusks to crustaceans, from fish to sea mammals.

1987-88 saw the appearance of several new viruses among seals and dolphins worldwide, from the Gulf of Mexico, to Europe, to Siberia. However, all epidemics occurred in heavily polluted regions and in populations with very high burdens of the man-made organic pollutants including polychlorinated biphenyls (PCBs). These compounds readily bioaccumulate and are found in high concentrations in marine mammals and other species at the top of the food chain. These chemicals have also been shown to impair immune responses in seals and dolphins. PCBs are also linked to reproductive disorders: an estimated 80% of female grey seals in the Baltic Sea are thought to be infertile.

Microbial pollution in terrestrial run-off has been implicated in at least one die-off due to aspergillosis among coral sea fans in the Caribbean. And outbreaks of San Joaquin Valley Fever, a fungus that infects humans and animals in the U.S. Southwest has become a yearly visitor to otter populations off the California coast ever since 1991. (Prior to that it had only been witnessed once, in a single otter back in 1976.)

In addition to having to deal with an ever-shrinking nesting habitat, approximately 50% of the green sea turtles suffer from fibropapillomas. Although the tumors appear to be benign, the sheer number and size of the tumors can result in mechanical problems such as impaired vision and movement. What effect this will have on an already endangered population is uncertain. Climate change and warming oceans have been linked to the expanding geographic range of the mollusk diseases Dermo and MSX.

In addition, the past several decades have seen a dramatic increase in the occurrence of Harmful Algal Blooms (HAB). Among the factors linked to this increase are ocean warming and nutrient pollution. Under favorable conditions such as warm weather and excess nutrients, certain algae can exhibit explosive growth, leading to what we call Red Tides or Brown Tides. The rapid growth of algae can deplete local oxygen, leading to the suffocation of other marine species. In addition, several of these algae have developed powerful toxins which can result in large scale kills of shellfish, birds and mammals. At lower doses these toxins can still weaken the immune system, making animals more susceptible to infection by other pathogens. There has also been a noticeable increase in the incidence of human diseases (paralytic shellfish poisoning, amnesic shellfish poisoning, neurotoxic shellfish poisoning) which result from the consumption of seafood that has been exposed to these toxins. Even more troubling is the fact that Vibrio cholera, the agent responsible for Cholera, lives within certain types of these algae. The reappearance of cholera in South America after a 100-year absence followed a period of high algal blooms.

The last 40 years have also seen a dramatic increase in mortality of coral reefs. Already it is estimated that approximately 30% of living coral reefs have been lost forever. Within the next 50 years, we are likely to witness the demise of greater than 70% of this global coral reef ecosystem. In addition to the phenomenon known as coral bleaching (which was unheard of before the 1960s and didn’t become commonplace until the 1980s) we’ve seen a number of new infectious diseases of coral such as black band disease, white band disease, yellow blotch, dark spot, and white plague.

These have been but a few of the simpler examples in which environmental degradation is resulting in serious threats not only to our own health, but to that of other species as well. The list goes on and on, but this is probably depressing enough as it is. At least I hope all this has troubled you, because if it did, that means you care. And if you care, then we can start to do something about it. The more we talk about this sort of thing, the better. If we read about it, learn about it, then we can begin to create an awareness, a consciousness about the issues. We can start to change the way we think, the way we do business, the way we do science, the way we run our economy―in short, we can change our worldview. We can go back to a place where we realize fully that we are a part of nature, a part of our environment. How do we get there? By imagining it. Through education. By supporting environmentally-conscious candidates. By demanding eco-friendly goods and services. And by supporting your friendly neighborhood environmental center.
By: David Nuñez