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by Laurel Hopwood, Human Health & Environment Chair, NEO Sierra Club
Global Warming continues to spiral out of control – disrupting
the delicate balance of disease in nature. One can’t turn on the
news without hearing about some new virus or bacteria, or the latest
outbreak of the Bird Flu or West Nile virus. This piece was originally
published as an op-ed in 1995. Eleven years later, it’s even more
relevant than ever before.
 When Ebola Outbreak reached the big screen, we shuddered with fear.
Soon it was forgotten. After all, chances are remote that here in the
United States, epidemics of hemorrhagic diseases, like Ebola, would become
a reality.
Then again, is the changing ecology leading to the emergence of deadly
microorganisms?
It was the latter part of the twentieth century in Lyme, Connecticut,
a quiet seaside town. Deforestation happened, by the hands of man. Denuded
forests led to an overabundant growth of aggressor flora, unchallenged
by predators. With an imbalance of deer, rodents, and ticks, Lyme disease,
a vector borne illness, became prevalent. The emergence of this crippling
disorder shows how improper balance of flora, fauna, and microbes can
lead to the development of new disease phenomena.
 Mix together the following ingredients: global warming with depletion
of natural resources. What happens? Insects which usually die off in
cold weather survive and flourish in novel areas. The outcome: proliferation
of vector borne diseases, such as malaria, dying, yellow fever, and sleeping
sickness.
Changes in agricultural practices and deforestation in South America
in the 1950s disrupted the natural habitat of field mice. The mouse population
swelled. Hungry mice were desperate and they helped themselves to human
food. But that wasn't the only consequence. They ended up excreting urine
where human food supplies were stored, which carried viruses causing
hemorrhagic disease. As the urine dried and joined dust particles, an
airborne epidemic began. At the same time, DDT used for mosquito abatement
worked its way through the food chain. Cats died, upsetting the predator/prey
balance. While the cats were away, the mice were at play - spreading
lethal viruses.
In Bangladesh, cholera sat dormant in algae in the cold Bay of Bengal
waters. The algae attached themselves to ships heading to Peru in 1991,
allowing the cholera organisms to get a free transcontinental ride through
the ocean's cesspool. The cholera organisms awakened to find themselves
in warm waters, and then sickened millions of people.
Global warming and changing rainfall patterns contributed to extraordinary
rainfall in the Midwest in the early 1990s. As the Mississippi River
flooded, pesticides and nitrogen rich livestock waste ran off into the
Gulf of Mexico. Industrial wastes, such as PCBs, added to the toxic mix.
Seals, dolphins, whales and porpoises developed chemically induced immunodeficiencies.
Massive die-offs ensued.
All life forms are connected, usually in complex, imponderable ways.
Without question, the ecological stability must be a significant part
of every equation.
Reprinted with permission from the
author.
Photo 1 Credit: CDC/Dr. Fred Murphy
Notes:
This micrograph reveals human hepatocytes infected with the
Ebola virus, the cause of Ebola hemorrhagic fever.
The Ebola pathogen is a member of the Filoviridae family of RNA viruses.
It is known to be spread through close contact with an infected host.
Mortality rates of an individual with hemorrhagic fever range from 50-90%.
Photo 2 Credit: James Gathany
Notes:An. Minimus is one of the mosquito species responsible
for spreading the drug-resistant P. falciparum parasite in Thailand and
Vietnam. As a result, drug-resistant malaria has become one of the most
important problems faced by those involved with malaria control in recent
years.
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