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tarabell
09-05-2007, 04:04 PM
This is another of the kind of article "I never used to read", prompted by the bottled water article posted in today’s news. This one explains in unsettling detail where all our plastic is ending up. It’s not just visible pollution and expanding landfills and dirty oceans. The effects go much further--the following is just some highlights. I highly recommend the entire article.

http://www.orionmagazine.org/index.php/articles/article/270

Its correct name is the North Pacific Subtropical Gyre, though Moore soon learned that oceanographers had another label for it: the Great Pacific Garbage Patch. Captain Moore had wandered into a sump where nearly everything that blows into the water from half the Pacific Rim eventually ends up, spiraling slowly toward a widening horror of industrial excretion. For a week, Moore and his crew found themselves crossing a sea the size of a small continent, covered with floating refuse. It was not unlike an Arctic vessel pushing through chunks of brash ice, except what was bobbing around them was a fright of cups, bottle caps, tangles of fish netting and monofilament line, bits of polystyrene packaging, six-pack rings, spent balloons, filmy scraps of sandwich wrap, and limp plastic bags that defied counting.

In 1975, the U.S. National Academy of Sciences had estimated that all oceangoing vessels together dumped 8 million pounds of plastic annually. More recent research showed the world’s merchant fleet alone shamelessly tossing around 639,000 plastic containers every day. But littering by all the commercial ships and navies, Moore discovered, amounted to mere polymer crumbs in the ocean compared to what was pouring from the shore.

DURING HIS FIRST THOUSAND-MILE CROSSING of the gyre, Moore calculated half a pound for every one hundred square meters of debris on the surface, and arrived at 3 million tons of plastic. His estimate, it turned out, was corroborated by U.S. Navy calculations. It was the first of many staggering figures he would encounter. And it only represented visible plastic: an indeterminate amount of larger fragments get fouled by enough algae and barnacles to sink. In 1998, Moore returned with a trawling device, such as Sir Alistair Hardy had employed to sample krill, and found, incredibly, more plastic by weight than plankton on the ocean’s surface.

In fact, it wasn’t even close: six times as much.

When he sampled near the mouths of Los Angeles creeks that emptied into the Pacific, the numbers rose by a factor of one hundred, and kept rising every year. By now he was comparing data with University of Plymouth marine biologist Richard Thompson. Like Thompson, what especially shocked him were plastic bags and the ubiquitous little raw plastic pellets. In India alone, five thousand processing plants were producing plastic bags. Kenya was churning out four thousand tons of bags a month, with no potential for recycling.

“Plastic is still plastic. The material still remains a polymer. Polyethylene is not biodegraded in any practical time scale. There is no mechanism in the marine environment to biodegrade that long a molecule.” Even if photodegradable nets help marine mammals live, he concluded, their powdery residue remains in the sea, where the filter feeders will find it.

“EXCEPT FOR A SMALL AMOUNT that’s been incinerated,” says Tony Andrady the oracle, “every bit of plastic manufactured in the world for the last fifty years or so still remains. It’s somewhere in the environment.”

That half century’s total production now surpasses 1 billion tons. It includes hundreds of different plastics, with untold permutations involving added plasticizers, opacifiers, colors, fillers, strengtheners, and light stabilizers. The longevity of each can vary enormously. Thus far, none has disappeared. Researchers have attempted to find out how long it will take polyethylene to biodegrade by incubating a sample in a live bacteria culture. A year later, less than 1 percent was gone.

lightfoot
09-05-2007, 05:52 PM
"IN ONE SENSE, PLASTICS HAVE BEEN AROUND for millions of years. Plastics are polymers: simple molecular configurations of carbon and hydrogen atoms that link together repeatedly to form chains. Spiders have been spinning polymer fibers called silk since before the Carboniferous Age, whereupon trees appeared and started making cellulose and lignin, also natural polymers. Cotton and rubber are polymers, and we make the stuff ourselves, too, in the form of collagen that comprises, among other things, our fingernails."

Actually the DNA, RNA, and protein that we are composed of (among other things) are also polymers.

Unfortunately the title "Polymers are forever" is hugely misleading. The problem isn't polymers or even plastics per se; it's that these particular plastics are too stable. Polymers such as nylon break down in sunlight (this is why awnings and such are made of more UV-resistant materials such as Sunbrella), but even these degrade with time.

This is a serious problem, but promoting polymer-phobia or even plastic-phobia isn't the way to solve it.

desdemona
09-05-2007, 10:00 PM
Yeah from my little bit of hands on science I teach, polymers are just long chain molecules. For instance, mix Elmer's glue with starch and you get a polymer (maybe the glue itself is a polymer). Nothing particularly long lasting about that. I'd guess it depends on the polymer.


---des

hobbit
09-05-2007, 10:31 PM
Sounds almost like that science fiction story, which I've
been trying to re-identify for a while, where a guy finds
a bottomless hole in the ground. Throws a pen down it to
try and hear when it lands. Soon his local town is dumping
all their garbage there, because the hole never seems to
fill up. A few years later, most of the world is dumping
its garbage there, having simply accepted the magic of a
truly bottomless pit and everything is environmentally
great, no more landfills or disposal problems ... stuff like
spent nuclear waste and horrendous toxins go there too, just
get swallowed up forever.
.
A couple of decades later, our first guy is out strolling around
some beaucolic parkland, just enjoying life, and out of the
corner of his eye sees a small flash as something drops out
of the sky and lands in the grass. He goes closer and picks
up the object. It's a pen.
.
_H*

Tochatihu
09-05-2007, 11:07 PM
My bottomless pit of choice would be Mel's Hole:

http://www.nss2006.org/news_april1.htm

DAS

tarabell
09-06-2007, 12:13 AM
The author may have used too broad a term but I don't care what they call it. The more ground-up, invisible and widespread the stuff in the ocean becomes the more likely it's going to end up inside us as part of the foodchain.

xcel
09-06-2007, 01:00 AM
Hi Al and Doug:

___Both your stories put more then just a smile on my face :D :D :D

___Tarabell, I can just imagine all this garbage just floating in this circular path in the middle of the North Pacific. Eventually it reaches a saturation point at which some of it gets expelled and lands back from where it came. Can we screw ourselves any faster then we have been these past 100 years :angry:

___Good Luck

___Wayne

brick
09-06-2007, 10:31 AM
I wonder what all that plastic is worth?

locutus
09-06-2007, 10:55 AM
Sounds almost like that science fiction story, which I've
been trying to re-identify for a while, where a guy finds
a bottomless hole in the ground. Throws a pen down it to
try and hear when it lands. Soon his local town is dumping
all their garbage there, because the hole never seems to
fill up. A few years later, most of the world is dumping
its garbage there, having simply accepted the magic of a
truly bottomless pit and everything is environmentally
great, no more landfills or disposal problems ... stuff like
spent nuclear waste and horrendous toxins go there too, just
get swallowed up forever.
.
A couple of decades later, our first guy is out strolling around
some beaucolic parkland, just enjoying life, and out of the
corner of his eye sees a small flash as something drops out
of the sky and lands in the grass. He goes closer and picks
up the object. It's a pen.
.
_H*

That sounds like something from "The Outer Limits" (http://www.scifi.com/outerlimits/), which used to be one of my favorite shows. Awesome.



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