“Plastics” “Exactly how do you mean?”
“There’s a great future in plastics.
Think about it.
Will you think about it?”
This exchange comes from the movie “The Graduate,” where Mr. McGuire played by Walter
Brooke gives a young Benjamin Braddock, played by Dustin Hoffman advice about his future.
The Graduate was released in 1967, and that line has proven to be prophetic many times
over.
Nowadays, we’re surrounded by plastics.
That’s not surprising given that they’re cheap to produce, lightweight, easily shaped,
waterproof, strong, versatile, and durable.
Plastics are made from organic polymers—which are basically huge molecules that are created
by linking together a small molecular unit over and over again.
For example, the material used in plastic bags is called polyethylene which is created
by linking thousands ethylene molecules together into long chains.
Different polymers have different properties.
Polyethylene terephthalate or PET, otherwise known as polyester, is a highly recyclable
material that’s used in water bottles and fabric.
Polyvinyl chloride, or PVC, is a strong, rigid plastic often used in plumbing.
Polypropylene is flexible, and really simple to manufacture, so it’s used in various
consumer goods like the hinged lids on tupperware to shampoo bottles.
Now, the problem with most plastics, is that aren’t biodegradable and so they persist
in the environment long after they’ve been tossed out.
For example, the plastic litter that winds up in the ocean, doesn’t decompose, and
instead it gets trapped in the center of circular ocean currents, called gyres.
One really large collection of plastic trash is called the Eastern garbage patch which
is found in the Pacific ocean between California and Hawaii.
As the plastic sits in the ocean, it gets baked by the sun, and breaks into tinier and
tinier pieces, a process called photodegradation.
Plastic fragments that are smaller than five millimeters, or about half the width of a
fingernail, are called microplastics.
Microplastics can get down to the size of glitter - and like glitter, it can get everywhere
and stick to absolutely everything.
Microplastics wind up on the seafloor, the soil, and in the air.
That means they wind up in our food.
Studies have shown that store bought sea salts can contain several hundred microplastic particles
per pound of salt.
Other studies have found microplastics in bottled water, beer, and seafood.
Microplastics get consumed by various creatures and can linger in their digestive tracts,
so seafood that is eaten whole, like mussels and oysters are especially a concern.
So, since microplastics are in our environment, the food we eat, and the water we drink, it
makes since that they are inside of us too—this just hasn’t been shown directly until now.
In a recent pilot study researchers showed that microplastics were present in stool samples
from eight out of eight individuals and that the microplastics represented 9 out of 10
common plastics that they were looking for.
The particles varied in size but went down to about 50 microns which is roughly the diameter
of a human hair.
The significance of microplastics on human health is unknown.
On one hand it is promising that the human body is handling plastics down to 50 microns
by eliminating them in poop.
What isn’t known, is if microplastics are getting absorbed into the body and into the
bloodstream, and if that has an effect on our physiology.
It worrisome to think that chemicals from these plastics may be leaching into our systems.
A well known example of this are plastics made with Bisphenol A or BPA.
BPA acts a bit like estrogen in the body, so it may affect development, and disrupt
other hormonal processes in adults.
To wrap up, we have steadily introduced more and more plastics into our environment over
the past few decades, and it has gotten into our food, our water, and into ourselves.
The impact this has on our health remains to be seen, and needs to be explored, since
plastics aren’t going anywhere.