David Suzuki: How environmental destruction causes illnesses and diseases

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      Preventing illness is the best way to get health-care costs down. So why aren’t governments doing more to protect the environment? We’ve long known that environmental factors contribute to disease, especially contamination of air, water, and soil. Scientists are now learning the connection is stronger than we realized.

      New research shows that 60 percent of emerging infectious diseases affecting humans—those that rapidly increase in incidence or geographic range—start with animals, two-thirds from wild animals. Lyme disease, West Nile virus, Ebola, SARS, AIDS… these are just a few of the hundreds of epidemics that have spread from animals to people. A study by the International Livestock Research Institute concludes that more than two-million people a year are killed by diseases that originated with wild and domestic animals. Many more become ill.

      According to an article in the New York Times, “Emerging diseases have quadrupled in the last half-century.” The increase is mainly due to human encroachment into and destruction of wildlife habitat. For example, one study concluded that a four percent increase in Amazon deforestation led to a 50 percent increase in malaria because mosquitoes, which transmit the disease, thrive in the cleared areas.

      Another example from the article shows how interconnected life is. Development in North America has destroyed or fragmented forests and chased many predators away. This has led to a huge increase in white-footed mice, which carry Lyme bacteria. The mice are not good at removing ticks and their larvae and so the ticks pick up bacteria from the mice and spread it to other mammals, including humans. Because the number of Lyme-infected ticks has multiplied, more are transferring the disease to humans.

      “When we do things in an ecosystem that erode biodiversity—we chop forests into bits or replace habitat with agricultural fields—we tend to get rid of species that serve a protective role,” Lyme disease researcher Richard Ostfeld told them New York Times, adding that our actions tend to favour species that act as disease carriers.

      Global warming is adding to the problem. A study in the journal Nature, “Impact of regional climate change on human health”, notes that heart attacks and respiratory illness due to heat waves, altered transmission of infectious diseases, and malnutrition from crop failures can all be linked to a warming planet. And economic and political upheaval brought on by climate change can damage public health infrastructure, making it difficult for people to cope with the inevitable rise in sickness, according to a study in the Archives of Medical Research, “Global Warming and Infectious Disease”.

      Research has also shown that warming ocean waters are increasing the incidence of waterborne illnesses, including those caused by toxic bacteria in shellfish.

      This is costly to the economy as well as to human health and survival. The World Bank estimates that a severe influenza pandemic could cost the world economy $3 trillion. Environment Canada says air pollution alone costs the Canadian economy billions of dollars a year because of increased health-care costs, missed work days, and reduced productivity.

      A key solution, according to the One Health Initiative, is to look at the links between human, animal, and ecological health and to manage our activities in a sustainable and holistic way. The U.S.-based initiative is bringing experts in human, animal, and environmental health together to study these links.

      Another promising area of research is natural capital evaluation. Although it’s difficult, if not impossible, to put a dollar value on the numerous services nature provides, leaving them out of economic calculations means they are often ignored. Forests and green spaces filter water and store carbon. Urban green spaces provide cooling and protection from storms. And, ecosystems in balance help to protect us from disease outbreaks. Destroying these systems and replacing them with human-built infrastructure or paying for the consequences often costs much more than profits gained from exploitation.

      With the world’s human population now at seven billion and growing, and the demand for technology and modern conveniences increasing, we can’t control all our negative impacts. But we have to find better ways to live within the limits nature and its cycles impose. Our physical health and survival, and the health of our economies, depend on it.

      For more insights from David Suzuki, please read Everything Under the Sun (Greystone Books/David Suzuki Foundation), by David Suzuki and Ian Hanington, now available in bookstores and online. This article was written with contributions from David Suzuki Foundation editorial and communications specialist Ian Hanington. Learn more at www.davidsuzuki.org.

      Comments

      3 Comments

      Kim Collins

      Aug 16, 2012 at 5:40pm

      Where o where have all of the climate change deniers gone? It used to be that these comment sections were filled immediately with conspiracy theories, ad hominem attacks, and other time-wasting crap. Have they finally accepted the reality that our burning of fossil fuels is destabilizing the Earth's climate system? Does this mean that we can finally get on with doing something about it at the scale it requires? I think we should. Seems things are getting mighty serious:

      Talk privately to scientists involved in climate research and you find that they believe that almost everything is worse than they feared and accelerating dangerously. A clear example is in the melting of the Northern ice, now down in late summer by 30% from its recent 30-year average to 2005. It is at a level today (and last month was the least ice cover of any June ever) that was forecast 15 years ago for 2050! Dozens of ships last year made commercial voyages across the Northern waters where none had ever gone before 2008. A dangerously reinforcing cycle is at work: the dark ocean absorbs heat where ice reflects it, so the water warms and more ice melts. Other potentially more dangerous loops might also start: the Tundra contains vast methane reserves and methane acts like supercharged CO2. It warms the air and more Tundra melts and so on. For agriculture, which is very sensitive indeed to temperature shifts, it has become a very dangerous world. There is now no safety margin to absorb unexpected hits as we are seeing in the global crisis playing out in the Midwest today."

      http://www.gmo.com/websitecontent/GMOQ2Letter.pdf