(quirky music)
- There's something fishy about these shrimp.
And I don't mean the smell of raw seafood
in a warm car on a hot day which...
(groaning)
(laughing)
We're on our way to a lab to dissect the shrimp.
And see if they contain
some tiny evidence of a global problem.
Oh yeah.
That's a lot.
(laughing)
Little bits of plastic that have managed
to spread around the world.
And possibly into our food.
Oh wow, that's pretty bizarre.
They're in the air you breathe,
the water you drink, and the clothes you wear.
Microplastics are bits of plastic,
roughly defined as smaller than five millimeters.
Sometimes they're made deliberately.
Added to cosmetics or industrial cleaners.
Other times they're formed when wind, waves,
or other natural forces
tear larger pieces of plastic garbage apart.
Microplastics are just about everywhere in the world.
In 2019, researchers found them in snow in the Arctic
and in remote areas of the Swiss Alps.
And in another study, scientists found
thousands of particles in a single liter of seawater
from one of the deepest parts
of the ocean, the Mariana Trench.
But we're after samples closer to home.
Particles that may have found
their way onto our dinner table.
Here's what happens.
Some critters, like shrimp, eat bits of plastic
as they devour their usual diet of microorganisms.
Humans catch the shrimp,
and then they get shipped to places like this.
We picked out some shrimp imported from South America
to see if we could find
this plastic pollution for ourselves.
But first, we needed some help.
- My name is Debra Magadini.
I'm a researcher studying microplastics in marine organisms.
- [Mary Beth] Debra works at Columbia University's
Lamont-Doherty Earth Observatory.
Often helping high school students
run the exact experiment that we're trying today.
- Three years ago we stumbled upon
a collection of marsh fish that was done
for a previous study and they were about to get thrown out.
And I asked if we could keep them.
- [Mary Beth] And even in that random
sampling of marsh fish...
- We found lots of microplastics.
- Since then, Debra and her students
have dissected shrimp, oysters,
and many other kinds of seafood.
And just about everywhere they've looked
they found microplastics.
- Well I work with high school students.
And I will show you their reaction
when they see it in the scope for the first time.
(gasping) Oh!
Oh. (laughing)
- In fact, there have only been a few times
when she hasn't found microplastics.
In some shrimp carefully farmed in a pristine environment.
And in oysters from a remote bay in Washington State.
But these days, when she does a dissection,
she knows what to expect.
So how often do you find that in your shrimp samples?
- Every time.
- Every time?
Wow. - So far.
- Wow. - So far every time.
(upbeat music)
- [Mary Beth] To start off, it's back to bio 101.
- [Debra] These are huge.
- The vein that people talk about removing
when they de-vein shrimp, yeah those are intestines.
Which get packed with poop, and just maybe, microplastics.
First we cut out the shrimp's GI tract and stomach contents.
Trying to get every last bit of the guts into a test tube.
This gets gross.
- [Debra] Pouring it in there.
- Oh my god. - Yeah.
That's the stomach content. - Wow.
Then we pour hydrogen peroxide onto the resulting mess.
- This would actually burn you if you got it on your skin.
- We then bring the whole thing over to an oven.
Where it bakes at 50 degrees celsius for several hours.
When we come back most of the sample
has been digested away by the chemicals,
leaving this little bit of grit behind.
There's more in there besides microplastics.
There's bits of sand and who knows what else.
We run through a series of steps
to filter out the heavy stuff.
And finally we introduce a special dye
that only sticks to plastic
and makes it glow under UV light.
(spacey music)
It's the moment of truth.
We slip our slides onto the microscope.
Whoa.
And there it is.
We ended up finding microplastics
in all of the shrimp samples that we looked at.
Circular beads, long fibers washed off of laundry,
and messy irregular pieces that were once something larger.
- [Debra] Fragments from plastic bags, bottles,
straws, styrofoam coolers, flip flops.
- [Mary Beth] It was everywhere.
Which means that it was everywhere around these shrimp
before they got caught, too.
- [Debra] They're an organism that actually moves through
the water, so the amount of plastics in the shrimp gut
will, by inference, reflect the amount of pollution
that is in that particular body of water that it inhabits.
- [Mary Beth] But what does it mean that we found
microplastics in our proto-scampi?
Well, when it comes to human health,
we really don't know yet.
The World Health Organization recently found
that while there are a lot of microplastics
in drinking water they don't pose a major threat
to human health at current levels of pollution.
But they'd still really like to know more.
And drinking water is far from the whole picture.
Another study found that we eat tens of thousands
of particles of microplastic every year.
That estimate nearly doubles when you consider
that we're not just eating microplastics,
we're breathing them in too.
And just for the record, seafood like shrimp,
actually ranks pretty low
on the list of microplastic sources.
Remember, we dissolved the guts of the shrimp.
And people don't eat those.
It's more of an issue with bivalves,
like muscles and oysters, which we eat whole.
But even then, your intake is maybe a few micrograms.
But microplastic pollution is likely
to keep rising in the near future.
And we know even less about even smaller
particles of plastic called nanoplastics.
- The studies that are coming out are shocking.
It's everywhere.
It's in sea salt, it's in beer.
It's difficult to think where plastics are not present.
- We dump millions of tons of plastic
into the ocean every year.
And there is so much we don't know
about what happens after that.
What we do know is that these bits and pieces
aren't going away anytime soon.
- I think we need plastic, there's no question
that we will have it in our future.
But it is something that we need to figure out.
How do we handle it after we don't need it anymore?
(calm music)
- Hey everyone, microplastics aren't
the only thing lurking in the water.
If you want more Trial and Error videos
check out our lead testing video here.
And don't forget to like and subscribe.