[Pharmwaste] Plastics - Adored, Deplored and Ubiquitous

[DeBiasi,Deborah]

http://www.nytimes.com/2008/04/15/science/15angi.html

April 15, 2008

Basics

Adored, Deplored and Ubiquitous 
By NATALIE ANGIER

Come next Tuesday, in a move flagrantly timed to coincide with Earth
Day, the Whole Foods supermarket chain will no longer offer its
customers the plastic bag option. Seeing that "it can take more than
1,000 years for a plastic bag to break down in a landfill" and that "in
the U.S. alone, about 100 billion plastic bags are thrown away each
year," the company said it could not in good conscience contribute to
the crisis. 

Bravo. Now tell me this: What am I supposed to line my garbage cans
with? I always use plastic supermarket bags, and the Whole Foods ones
were by far my favorites - roomy and springy enough to hold a lot of
sodden waste without fear of breakage, always a plus when one is
disposing of, say, fish skins or cat litter. So if I have to buy plastic
bags by the box, that's better for the environment how? Forget about
paper bags for this purpose. When we were growing up in the Bronx, my
older brother recently reminded me, we lined our garbage can with
newspapers, a solution satisfactory to none but the roaches. 

A century ago, the Belgian-born chemist Leo Hendrik Baekeland ushered in
a materials revolution with his invention of Bakelite, a synthetic resin
that was molded into radio cases, lamps, buttons, dressers and other
Antiques Roadshow reliables. We have been emotional bobbleheads about
plastics ever since. We adore plastics for their versatility, lightness,
strength and affordability, and it seems we can't get enough: the United
States produced 6.5 billion pounds of raw plastic in December alone, up
2.3 percent from a year earlier. We deplore plastics for being cheap
petroleum products and fear we'll never get rid of them.

Yet scientists point out that the class of substances lumped together
under the plastics postmark is so broad and diverse that to condemn or
condone them categorically makes no sense. Moreover, the field is
evolving rapidly, as researchers strive to spin plastics from renewable
sources like sugar cane and grass clippings in lieu of fossil fuels, and
to outfit their creations with the chemical grace to decay once
discarded. "We can do a lot of interesting things, but there's more
research that needs to be done," said James A. Moore, a professor of
chemistry at Rensselaer Polytechnic Institute. The biggest catch in
reaching the new, greener stage of the plastics age, he said, "is that
we have to accept that it's going to cost money." 

Glancing around my office, I see how difficult it would be for me to
live plastic-free. I'm typing on a computer keyboard made partly of
molded polyvinyl chloride, which also serves as the source material for
that ultimate plastic item, the credit card. Some components of the two
black telephones on my desk are built of injection-molded acrylonitrile
butadiene styrene, a material that has the strength and toughness to
resist cracking when dropped, and hence is also used in motorcycle
helmets and luggage. My earrings are made of Lucite, a lightweight
acrylic that is embarrassingly popular among jewelry makers now. A
cottontop tamarin doll on my bookcase stares down through beady brown
eyes - probably acrylic as well - and its chirpy fake fur is woven from
polyester fibers. My desk and bookshelves are made of particle board, a
composite of wood chips and a plastic resin. Lining my wastebasket is,
yes, a plastic shopping bag, this one from Safeway, and like most
plastic bags it's made of polyethylene, "the largest-volume plastic" of
all, said Richard A. Gross, a professor of chemistry and biology at
Polytechnic University in Brooklyn. In fact, all my views arrive as
though Saran-wrapped, for I'd be blind without the blend of plastics
from which my rigid gas permeable lenses are cast. 

Uniting these and the hundreds of other plastics that pad our
mattresses, elasticize our comfort-fit jeans, suture our wounds, plug
our dental cavities, encapsulate our pills, replace our lost limbs,
lighten our cars and jets and crisscross our Kevlar vests is the state
of being a synthetic polymer. The term polymer refers to any long
molecular chain made up of smaller chemical units, or monomers, which
polymer chemists habitually compare to beads on a necklace or, when
they're going out for a nice dinner, to pearls on a strand. 

Life abounds with polymers. DNA, proteins and starches are polymeric
molecules, all concatenations of smaller molecules. Plastics are just
polymers in which humans, rather than nature, string the beads. Granted,
we're still pretty crude jewelers by comparison. The synthetic polymers
in the plastic skin of a garbage bag, for example, are monotonous skeins
of a single type of chemical bauble, ethylene, while the protein
polymers in a fish's skin are intricate arrays of as many as 20 distinct
amino acids, the monomers of which proteins are built.

What's more, whereas nature knows how to make thousands of different
polymers and can make them the same length and shape every time,
chemists have yet to master such fine control over their product line.
"The typical way a polymer is made is you throw your monomers into a big
pot and let them all react, as opposed to building them up one piece at
a time the way the body does," said Elliot P. Douglas, an associate
professor of materials science and engineering at the University of
Florida. "When we make a mixture, it's a mixture of all different
lengths." 

But our bodies and our plastics are by no means antithetical beasts. The
polymers in both cases tend to feature a lot of carbon atoms, carbon
having a readily linkable structure that makes it an ideal component of
life - of the lives we live now, and of the ancient, squeezed and
subliminated lives that constitute fossil fuels. It's also an ideal
constituent for monomers you want to toss together into your pot and
have a product with useful properties come out the other side, like
stretchiness, stickiness, ductility, disdain for electrical flow. 

The reason petroleum so often serves as the foundation for plastics
production is that it offers an ultraconcentrated source of carbon, but
carbon is carbon and with the right manipulations other handier
biosources like lawn litter will do. Add chlorine to your carbon
backbone for hardness and heat resistance. Tack little methyl groups to
the carbon backbone for durability, compactness and a ropy indifference
to chemical abuse. Extrude your melted mixture through die holes to form
pipes, hoses, drinking straws and fibers. Inject it into moldings shaped
like Barbie, Ken or a comb. Blow it out like a balloon and you've got a
new bag. When you're done, hand it over: I will put it to use.



Deborah L. DeBiasi
Email:   dldebiasi at deq.virginia.gov
WEB site address:  www.deq.virginia.gov
Virginia Department of Environmental Quality
Office of Water Permit Programs
Industrial Pretreatment/Toxics Management Program
PPCPs, EDCs, and Microconstituents
Mail:          P.O. Box 1105, Richmond, VA  23218 (NEW!)
Location:  629 E. Main Street, Richmond, VA  23219
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