How bad are microplastics?

Microplastics are everywhere. How did they get there, and should we worry?

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Episode Transcript

Speaker 1 (00:07):
The history of plastic is intimately tied to the history
of the game of billiards. In the eighteen sixties, the
billiard's industry had a problem. The game was super popular,
but it was hard to keep up with the demand
for high end billiard balls because the material used to
make the balls was limited. The material was elephant tusks,

(00:28):
and it took about two tusks to make a complete
set of balls. A major billiard ball company offered a
ten thousand dollars reward for anyone who could come up
with a sturdy alternative. John Wesley Hyatt was inspired by
this call, and he came up with an alternative to
tusks that became the first industrial plastic. Now, the initial
prototypes had the downside that they were highly flammable, and

(00:53):
there were rumors that they would sometimes explode upon impact
during a game. Or maybe that's an upside because it
would make the game a lot more exciting. But anyway,
today plastics are ubiquitous. They're in our tires, our clothes,
they line our paper cups, they make disposable medical equipment
which helps protect us from transmissible diseases, and the microphone

(01:14):
in computer that I'm using to record this episode have
plastic in them too. It's kind of hard to imagine
life without plastic. We're probably all aware that plastic has
downsides too. We're not really good at disposing of it properly,
for example, And there's now garbage patches in the ocean,
which are spots where currents have aggregated the trash we've

(01:34):
released into the sea. And we've probably all seen images
of animals like turtles and birds that have died from
consuming or getting trapped by large pieces of plastic. And
those are the easy to see problems. In the last
decade or so, we've become more concerned with the plastics
that are harder to see, the micro and the nanoplastics.
These are bits of plastic less than five millimeters in length,

(01:57):
which is like about the length of an ant, and smaller,
much smaller. Some of these tiny plastics are made on
purpose for use in things like cosmetics, and some are
just the teeny tiny bits of bigger pieces of plastic
that have broken down over time. These tiny pieces of
plastic are now found around the globe. Even pristine environments

(02:18):
that rarely see people will see our plastics because super
small plastic pieces go airborne, and they move with air
currents around the world closer to home. We've found very
small pieces of plastic in human hearts, brains, testicles, and more.
It's even been found in baby maconium, which is a
baby's first poop, so it's working its way through a

(02:40):
fetuses as well. How worried should we be? This is
an episode of Daniel and Kelly's Extraordinary Universe, So you've
probably already guessed that the answer is, well, we don't
really know. We haven't been studying this for very long,
and as we'll discuss, it's a hard problem to study,
and it's not feasible or maybe even design mirable to
stop using plastics entirely. So what do we do about

(03:04):
microplastics if we decide we should be worried? Welcome to
Daniel and Kelly's Plastic Universe.

Speaker 2 (03:24):
Hi. I'm Daniel. I'm a particle physicist, and I'm a parent,
so I always think we should be worried.

Speaker 1 (03:30):
Hello. I'm Kelly Wayne or Smith. I study parasites and space,
and I have severe anxiety, so I also always worry,
and actually being a parent made that a little bit worse.

Speaker 2 (03:40):
All right, Well, then my question for you is do
you think worrying helps? I mean, I know this is
like culture of worrying. Jewish mom send each other messages
like start worrying. Now you could probably like hire a
room full of Jewish mom somewhere, like worry on your behalf?
Have you know nine dollars an hour or ninety nine?
I don't know think that worrying helps. Does it make

(04:02):
us think deeply about all the possible issues? Does it
make us better scientists? What do you think?

Speaker 1 (04:07):
I think?

Speaker 2 (04:08):
What's the upside of worrying?

Speaker 1 (04:09):
It depends. I think so. I think Zach doesn't worry enough.
And so there have been a couple of times where
I've felt like I've had to step in to get
the worrying level up to the right amount so that
we could take care of some problems that needed to
get taken care of.

Speaker 2 (04:24):
Was that when your stove was on fire recently? For example?

Speaker 1 (04:26):
Uh no, I I actually when I opened up the
stove and I looked inside and I saw the fire,
which was not my food, thank you very much, It
was something else. My first thought was I should call Zach,
and my second thought was what would he do? I

(04:46):
don't need to call Zach. And then it turned out
that Zach's brother had given me a fire extinguisher, So
who I needed was Zack's brother. Thank you, Marty, and
I pulled out the fire extinguisher. Everything was okay, I
need to change the heat element or whatever. But I
think you need to worry a little, but you need
to not overdo it. And I massively overdo it. Zach
underdoes it, and then I think we average are worrying

(05:09):
and we get the right amount of stuff done. But
what do you think, Well.

Speaker 2 (05:11):
I have this friend who's a neuroscientist who thinks that
worrying is what makes us better scientists, because you like
wake up in the midlight you're like, wait a second,
what if this part of that paper is wrong? What
if blah blah blah blah blah, How would I know
for sure? And then you come up with another test
to verify that, And so it really helps make your
science bulletproof because you sort of put yourself in the

(05:33):
mind the reviewer and ask all the critical questions, and
you worry about being embarrassed in front of your colleagues
when your results are shown to be an artifact. So
I think that it is helpful in that sense, and
it also helps you prepare for eventualities. Like the reason
I buy insurance is because I worry about stuff, right,
But I agree that it can go too far. It
can be unproductive for sure. But you know, I think

(05:54):
on this podcast we aim for just the right level
of worrying. We aim to educate you enough to make
knowledgeable choices about your life.

Speaker 1 (06:02):
Right, Yes, that's right, that's exactly right.

Speaker 2 (06:04):
And so you hear all about disgusting parasites you will
probably never get and don't have to worry about. But
now you know enough not to go swimming with snails
in Venezuela or whatever it was.

Speaker 1 (06:15):
Well, and you know what questions to ask your doctor
when you go see here you go, Yeah, something like that.
That's our goal.

Speaker 2 (06:22):
That comes from a person who has repeatedly gone to
the doctor convinced he had toe cancer.

Speaker 1 (06:27):
Toe cancer in particular. Is there something weird about your
toes that that makes you think they're cancer?

Speaker 2 (06:33):
Is No, I am just a hypochondriac and am capable
of convincing myself that's some weird thing. It's probably cancer
and a better of the doctor. And I'm the kind
of guy who shows up the doctor without a list.
Here's seven reasons why I'm dying. Let's go through them.

Speaker 1 (06:47):
Ah.

Speaker 2 (06:48):
And you know, a good doctor is the one that,
like knowledgeably but patiently walks you through the reasons why
you're not dying today.

Speaker 3 (06:56):
That's right.

Speaker 1 (06:56):
So I came. I came with my own list for
the same thing for the doctor. And after I went
through the list, the doctor said, can I ask you
some questions? Can I give you a survey for anxiety?
And we discovered Kelly doesn't have cancer. Kelly has severe anxiety.
So thank you to that doctor for listening to what
I wasn't saying.

Speaker 2 (07:16):
And so today we're actually doing an episode about something
I've been wondering about whether we need to be worried about,
but I wasn't knowledgeable enough about it to know whether
worrying was justified or just my anxiety.

Speaker 1 (07:29):
And you know what, it's nice to get clear answers,
but you're not getting that today. Daniel also, sorry, but at.

Speaker 2 (07:36):
Least I'm going to be brought up to the forefront
of current.

Speaker 1 (07:38):
Knowledge, right, that's right, that's right.

Speaker 2 (07:40):
You will me so I won't have to be worried
that I don't know enough to worry. So there you go.

Speaker 1 (07:45):
All right, there you go. Well, so let's start by
seeing what the general public thinks of this question, or
at least what the extraordinaries, who are probably not a
random subset of the general public. Let's see what our
extraordinaries think. So I asked, should we be worried about
microplastics or why not?

Speaker 4 (08:01):
Probably not. I've seen articles that microplastics are everywhere and
they're going to ruin our health in the environment, but
I've never seen them give irrelevant context, such as what
the biological effects are. I'm open to learning more, but
in the meantime, I'm not too worried about it, and
I'll continue to worry instead about climate change and my
own diet.

Speaker 5 (08:21):
I certainly believe that we should be worried about microplastics.
First of all, there is a coating of plastic around
the world so thick that anthropologists are considering naming our
current epoch of the plastic scene because it'll form a
permanent layer that doesn't even begin to show all the

(08:43):
potential harmful effects of the microplastics.

Speaker 2 (08:46):
Our immune system simply has not evolved to remove plastics
from our bodies, and the more they accumulate, then the
more we can expect trouble.

Speaker 3 (08:55):
Microplastics have been discovered all over the globe, I believe
in Antarctica. We don't know absolutely sure the link and
mechanism to problems, but it can't be good.

Speaker 6 (09:08):
In about seventy five years, we went from there being
none to now being so pervasive that they can be
found in the deepest depths of the ocean and even
in our brains. I would love to know what these
materials can be doing to our health and the rest
of the ecosystem, so we can support policies that limit
its production and perhaps even help clean it up.

Speaker 7 (09:29):
Yes, I do think we should be worried about microplastics.
We don't know how our bodies, animals, and the environment
are affected by these things, and we should investigate more.

Speaker 2 (09:39):
All right, So a lot of people out there feel
like there might be something to worry about. At least,
it's somewhat alarming that there's plastics everywhere. We don't really
understand what they might do or how they might interfere
with the function of this incredibly complex Goldberg machine we
call our bodies.

Speaker 1 (09:55):
Yeah, that's right, And I thought it was interesting. One
of our listeners mentioned that to sometimes suggest we could
call this era the plastic scene, because if you geologically
dig through, you can see a layer where plastic has
essentially been accumulating as we've made it go like airborne
and all over the planet. And so I feel like,
you know, if you look at human impacts first, you'll
see like a layer that's a bit radioactive from all

(10:18):
of our nuclear tests, and then you'll see a plastic layer.
And you know, we've done a lot of beautiful things,
but I don't feel like geology is telling a beautiful story.

Speaker 2 (10:26):
Wow, what a record we are leaving.

Speaker 1 (10:28):
Huh, that's right, that's right. But we do a lot
of amazing things with plastics, right, And so one of
the things that kind of frustrated me when I was
you know, I tried to see how other people have
covered this topic, and there's a lot of people being like, oh, plastics,
they're horrible, and like, I get it. I get it.
I'm an ecologist. I worry about the environment. I worry
about the impacts on animals. I worry about the impacts

(10:49):
on us, But plastics really make our lives a lot better, right, Like,
I think you need to keep in mind the trade.

Speaker 2 (10:55):
Offs here, give me a top five reasons why plastics
are good for humanity?

Speaker 1 (10:59):
Well, I mean, so we've got like all of the
disposable plastic medical equipment that helps make sure that we
don't transmit diseases to each other. That's pretty great. Most
of our clothes now, even clothes that are made of
natural fibers quote unquote, have some plasticky stuff in them.
And you know, I think making clothing more affordable and
making it so that everybody can afford to where things

(11:20):
that make them feel nice is huge and great. And
in general, I don't know that I'm going to go
for all five because I don't know that people really
care about Kelly's top five things. But in general, I
think there's a lot of things that are now within
the price range of the average American that wouldn't be
if we had to use quote unquote natural substances. And
natural substances aren't necessarily always better for the environment. So,

(11:42):
for example, we started this episode with the story about
wanting to find a different material to make billiard balls
out of because we were using elephant tusks. Oh no,
so everything's a trade off. You know, if we were
to get all of our products from nature. That would
be pretty damaging to the environment also, and so I
don't know, I'm Kelly. So the message here is it's complicated.

(12:02):
It depends you need to look at it from a
number of different angles.

Speaker 2 (12:05):
Well, so tell me how long have we had plastic
I imagine it's something that came about in the space age,
like the sixties seventies, you know, Dow chemicals invented or something.
I'm pretty fuzzy on the history here. Educate me.

Speaker 1 (12:18):
Well, So that billiard ball example, that was one of
the first examples of someone making a plastic y substance.
It was celluloid and it was a hard substance so
that you could bounce billiard balls off of each other
without having them like sort of dent and bend in
ways that would impact how they moved. They were slightly flammable,
which I mentioned in the introduction, and so if they

(12:39):
spang together sometimes they would set on fire, which would
actually make me watch a game of pool. And so,
but large scale production didn't really start until the nineteen fifties.
Around the nineteen fifties the nineteen sixties, like single use
you know, plastic spoons, single use plastic everything really became
fashionable as a way to make our lives easier, and

(12:59):
they were really they were much less expensive than a
bunch of the other stuff. And so since the nineteen fifties,
the amount of plastic in our lives has been increasing
at a tremendous rate. And that's the big plastic stuff.

Speaker 2 (13:10):
And so help me understand why, Like, if we knew
how to make this stuff for one hundred years, why
do we only really begin making it in large volume
in the fifties. Was this after like post World War
two industrialization or something else.

Speaker 1 (13:23):
I didn't look too much into the history of plastics,
but my sense is that it did take a while
to figure out the chemical processes. And so, you know,
plastics as a category, like encompasses loads of different kinds
of plastics that are good for a lot of different purposes.
And so I think it took us a while to
figure out how to make different kinds of plastics, what
they're good for, how to industrially scale up so that

(13:44):
we could, you know, use them for lots of different stuff.
How do you make injection molds for this kind of stuff.
I think all of that just took a while.

Speaker 2 (13:51):
All right, And so we're talking about plastic spoons and
plastic medical equipment. I know Katrina uses it for her diabetes,
she has these tubes, et cetera. But nobody's manufact cturing microplastics.
What are microplastics exactly?

Speaker 1 (14:03):
Well, people are manufacturing microplastics as I understand it, the
bulk of the plastics. So the bulk of the plastics is,
you know, you get a plastic bag, you get a
shirt with some plastic in it, and it ends up
either in a landfill or it ends up in the ocean,
and over time it breaks down. It could be because
UV radiation is breaking it down into pieces. It could

(14:24):
be because there are just fibers on your shirt that
go airboard and they end up on the floor in
your carpet in your home. So they come from big
plastic breaking down, but they do also come from purposefully
making small pieces of plastic. So for a while, it
was fashionable to have microbeads in like exfoliation stuff, so

(14:45):
like cosmetic stuff for like washing your face to help
like move dead skin cells off. We now have rules
in both the US and Europe against that kind of stuff,
but you can still end up with microplastics in I
think you can have them like in moisturizers. They almost
act like ball bearings, just making it so that things
go on a little bit smoother. But let's do some
definitions here. Microplastics are defined as things that are five

(15:08):
millimeters in size or less. That's true. Big, Yeah, that
is pretty big. That's like an ant, right, that's something
you could see. So anything five millimeters in size or
less is a microplastic. But we also have a category
called nanoplastics, and these are one micrometer in size or less,
So these are probably not something you're likely to see.

Speaker 2 (15:27):
I hold on, microplastics are millimeter sized, nanoplastics are micrometer sized.
Why don't they line up the name with the size, Like,
why don't nanoplastics be nanometer and microplastics be micrometer? Wouldn't
that make sense?

Speaker 1 (15:42):
That would make sense. And it's a bit ironic that
the physicist is complaining about naming. But I'm not gonna say.

Speaker 2 (15:51):
You know what they say, Every accusation is a confession.

Speaker 1 (15:53):
That's right, that's right. I don't know who's to blame
for this naming system, but yes, you're right, it's not intuitive.

Speaker 2 (16:00):
Pico plastics are one nanometer in size. That's all right.
So we have microplastics, which are actually kind of big nanoplastics,
which is super duper small. But how much of this
really is around?

Speaker 1 (16:13):
First, I want to say, it's really hard to estimate.
And while I was reading, the more recent papers are
estimating more and more and more. And that's because we
have better and better techniques for identifying smaller and smaller
pieces of nanoplastic. So it's pretty easy, like by eye
to count how many pieces of plastic fibers that are
five millimeters long are in a water sample, for example,

(16:35):
but looking at objects that are one micrometer or less
is much harder. But there's an estimate that fifty one
trillion microplastic particles are floating in our ocean. Trillion, trillion, trillion,
I said, trillion, Yeah, oh my gosh. I read this
book called A Poison Like No Other by Matt Simon,
and it's all about microplastics. And he talks about how

(16:55):
microplastics have been found in invertebrates in the Marianna ste
Trench in the most remote mountainous regions you can go to,
and like this has just permeated our entire world. So
you know, when we drive down the road, we kick
plastics off of our tires. Some of those go airborne.
They take air currents, you know, to the ocean or

(17:16):
across the ocean. Anywhere you go and sample, there's a
really good chance that you are going to find a microplastic.
I feel like I should at a caveat. I do
feel like that book over sells what we know about
the risks a bit. But if you are looking to
be scared and you're looking to understand where all the
microplastics are and how much of them are out there,

(17:37):
that book is encyclopedic in its laying out of where
we find these things and how they might be hurting us.

Speaker 2 (17:43):
I'm still having my mind blown by the number. Fifty
one trillion. Yeah, more microplastics than there are stars in
the galaxy. Like if Elon Musk wanted to buy all
the microplastics for a penny each, he couldn't afford it.
It's just hard to grapple with that number.

Speaker 1 (17:59):
It is, and again you should consider that number to
have huge error bars. But for example, like there was
a study looking at how many pieces of microplastics are
in a bottle of water, and you you know, you
think when you get a bottle of water, you're getting
something that's nice and clean. Some bottles of water had
essentially no pieces of plastic in a liter of water.
Others had up to ten thousand particles of plastic in

(18:19):
a liter of water.

Speaker 2 (18:20):
Oh boy, they should list on the ingredients including ten
thousand part plastic.

Speaker 1 (18:24):
That's right, well, and a lot of it probably depends
on like, you know, how were those water bottles stored.
Did they get like left out in the sun for
a few hours, because that breaks it down. Now plastics
are starting to come out, and part of why the
numbers get so big when you're talking about how many
pieces of microplastics are in the environment is that they
don't break down really well. So a big plastic bag

(18:45):
will break down into much smaller component parts, but after
that they don't break down the way something biological would.
So when you've got biological stuff out there, you have
decomposers that go and they eat it and they turn
it into other stuff. There are some plastic war is
that we're discovering, some like bacteria that can break down plastic,
but in general, plastic is a thing that wasn't really

(19:06):
in our environment in super high quantities in the past,
so evolution doesn't necessarily have a way to break it down.
Nature doesn't really have a way to break it down,
and so they tend to accumulate and they break down
to like some point where they're very small, and then
often they appear to stop breaking down and then they
just accumulate in these small sizes.

Speaker 2 (19:24):
So that's the thing I'm trying to wrap my head
around is that plastic feels really stable, and you know,
if you have a coke bottle, you expect it's still
going to be there in one hundred years or a
thousand years or whatever. So why do they break down
at all? Like why do macroplastics turn into microplastics and
then stop breaking down. I would expect they're either stable
and a coke bottle is going to be here in
a million years, or it's going to break down into

(19:46):
like you know, atoplastics or whatever. The smallest fundamental bit
of plastic is why do they sort of stop breaking
down at the microplastic level.

Speaker 1 (19:54):
Well, I feel like that's a chemistry question, So I'm
a little angry, but I'm kidding, But I think what's
happening is that, like, you know, if you've got and
I am joking, but you've got like a big piece
of plastic.

Speaker 2 (20:10):
I just like how you said, I'm angry, but you
said it with a smile.

Speaker 1 (20:14):
I'm hard to read too, so so you know, So
imagine you've got like a plastic bag floating on the
surface of the ocean. It's getting hit by UV radiation
and that's starting to like break some of the bonds
and break it into small parts. Those tiny pieces eventually
get so small that they sort of break away from
the rest of the bag and they start to sink.
And as they sink, they sort of end up out

(20:35):
of the reach of UV radiation, and they end up
in the sediment, or they can end up in the soil,
or they end up in the gut of something else.
And in some cases they probably do keep breaking down.
Like it's possible that our stomach acid breaks them down
a little bit. But I think in general plastics, part
of why they're so useful is because they are sturdy,
and it takes a lot to break them down. And
so maybe in a million years, of five millimeter fiber

(20:58):
plastic piece will disintegrate into its like atomic pieces. But
it's going to take a while.

Speaker 2 (21:03):
I see. I'm always amazed at the power of UV radiation.
You know, in my house, if you burn something on
a pan so you can't scrub it clean, you just
put it outside for like a week, oh and the
sun will break it up. It's amazing what UV radiation
will do. Thank you, Southern California.

Speaker 1 (21:20):
Wait, wait, what is your Okay, what does your backyard
look like? And how many animals have you attracted by
doing that? Because I live in a place where animals
want to be and they'd be licking those plates and
it would be gross.

Speaker 2 (21:31):
That's fine, that's helpful. You know, some squirrel wants to
use their you know, long teeth on that thing scrape
some of that burnt oatmeal off the pan, like, please
help us out.

Speaker 1 (21:39):
Man, all right, all right, some rabbit raccoon wants to Okay.

Speaker 2 (21:43):
All right, So we have plastics everywhere? How long has
this sort of been something we've known about, Like plastics
came about in large quantities like fifty seventy years ago.
Was it very soon after that that we discovered that
they were everywhere?

Speaker 1 (21:55):
I mean, I think when plastics started to go mainstream.
It was, you know, easy to say plastics rolling down
the street on a windy day or something like. I
think we've been aware of macroplastics as as a problem
for a long time. We're not very good at disposing
of them. They tend to end up in the oceans,
they tend to end up in animals. So we've known

(22:15):
that's been a problem for a while. And it probably
didn't surprise anyone when we first started talking about the
fact that it breaks down into tiny pieces. But the
first time of tension was really brought to this issue
was when a marine ecologist named Richard Thompson wrote a
paper about how he was collecting samples of sediment from
beaches and estuaries and the subtitle zone in the United Kingdom,

(22:37):
and he found microplastics in all of those places. And
he looked at plankton samples, so these are like tiny
little samples from the water column. And he looked at
samples from the nineteen sixties and then at various dates
getting closer to the present, and he found microplastics back
from the nineteen sixties. But he also found that they
were increasing over time and that even you could find
them inside of the bodies of little invertebrates that live

(22:59):
in the world, and so he noted that we don't
know the environmental consequences of having this stuff in the water,
but it's in the water. This problem is getting worse,
but it still took about a decade before people started
really digging in and particularly thinking about the impacts on
human health.

Speaker 2 (23:15):
I love this example of digging through past samples collected
for completely separate reasons and finding evidence or answers to
a question you have later on. This is why you
should always keep all of your samples and all of
your notes, because who knows how it's going to be
useful later. This is incredible. I love that.

Speaker 1 (23:33):
This is why museums are so important, because they do
they keep those samples for you, and they're in a
location where anybody can request them. So somebody, and you know, Peru,
can think of a question that requires American water samples
from the nineteen sixties or something, and if a museum
has them, they can get those data. So anyway, yay
for archiving, material behavior.

Speaker 2 (23:52):
Record keeping exactly all right. So it sort of came
to the fore in the early two thousands, and then
has the field sort of exploded in research.

Speaker 1 (24:00):
Yeah, the last ten to fifteen years, we've become a
lot more interested in what it's doing in freshwater systems,
what it's doing in oceans, what it's doing in our bodies.
And let's take a break, and when we get back
from the break, we'll start digging into that stuff. All right,

(24:32):
So we have already established that microplastics are like everywhere,
they're kind of unavoidable, and so let's start digging into
you know, whether or not we need to worry about that.
So one thing that you maybe need to worry about
a little bit is that they bioaccumulate. So you might
have heard this word from you know, Rachel Carson's book
Silent Spring about DDT and how as you move up

(24:55):
the food chain you get more and more concentrated levels
of the chemicals. And so an example for microplastics is
that there was a study looking at the soil in
Mexico and they found that microplastics were a bit less
than one particle typically in each gram, But if you
pulled an earthworm out per gram of earthworm, you would

(25:19):
find almost fifteen particles. So the earthworms were going through
the soil and as they would ingest a piece of microplastic,
it was like staying in them. And then they looked
at chickens that were eating the earthworms, and there were
one hundred and thirty particles per gram of chicken feces
because you know, chickens were eating those. And so as
you go up the food chain for the same like mass,

(25:40):
you're finding more and more of these particles.

Speaker 2 (25:42):
So why do the earthworms accumulate them? Is it because
they get filtered out of the soil and they stay
in the earthworms Like there's something inside the earthworm that's
like accumulating these things.

Speaker 1 (25:52):
So if you were to take a snapshot of what's
inside of that earthworm, over like a year of an
earthworm's life, and I don't know how long earth works live,
it might not be a year, but like there might
be a lot of particles that they ingested but they
pooped out. But because they're going through so much soil,
if you take a snapshot, they might have about fifteen
particles per gram of earthworm because they're just moving through

(26:15):
tons of soil and just sort of accumulating it as
they go.

Speaker 2 (26:18):
But in order to accumulate it, they have to eat
more than they poop, so they preferentially don't poop out microplastics, right,
Otherwise they would have the same density as the soil.
Like if you just pass a tube through the soil,
it's going to have exactly the same density as the
soil unless there's some filter in there that's like accumulating
the microplastics or preferentially not pooping them out.

Speaker 3 (26:40):
Right.

Speaker 1 (26:40):
Yep, Yeah, that's a great point. You're right, they're accumulating them.
They might poop some of them out, but in general
they tend to be accumulating them.

Speaker 2 (26:46):
Yeah. Interesting, And so then the chickens eat those and
then it gets more concentrated, and eventually when you're eating chicken,
it's like half plastic.

Speaker 1 (26:54):
Yeah, not necessarily half plastic, but there's a fair bit
of plastic in there. But one thing that's important in
mind is that not all plastic matters the same from
a standpoint of ingesting it. So you can get plastics
in your body either by inhaling it because a lot
of it goes airborne, or by ingesting it, and our
bodies will defecate and urinate out a lot of the

(27:17):
plastics that we consume, and if you breathe it in
are what is it called our mucociliary elevator or something
basically like we will like hawk it up. And actually
maybe Matt wants to remove that sound effect.

Speaker 2 (27:31):
I don't think no, I think you should keep that.
And I just wish that the audience could see the
face you made.

Speaker 1 (27:40):
I was pretty expressive there. But so you know, you
cough it up and then you can spit it out
or swallow it and then it'll end up in your
feces and anyway, all very gross. But our body has
ways of getting rid of a lot of this stuff.
But if you've got nanoplastics that are small enough, they
can pass across our alveoli, which is a point in
our lungs where our lungs are sort of in facing
with our blood, and they can get into our bloodstream,

(28:03):
or sometimes they can move across our gut into the
rest of the body. So very small pieces can end
up in other parts of the body where they're not
going to get removed, or they're much less likely to
get removed.

Speaker 2 (28:13):
And I've heard it said that we eat like a
credit cards worth or a bottle cap worth of plastics
every year or every week or whatever. Is that true,
or is that people overworrying.

Speaker 1 (28:23):
There was a study that came up with that figure
and that went like global, just like microplastics, it ended
up everywhere. But there was another study that looked at
the numbers a little more critically and they ended up
deciding something like you would require twenty three thousand years
or something like that to acquire the amount of plastic
that that paper was estimating. And so that I think

(28:46):
what most of us have heard about plastic getting in
our body is pretty overblown. But that said, they have
found plastic in human brains. So this was they did autopsies,
so somebody had already paid away and they looked through
the brain to look for plastics and they found it.
Plastics have been found in plaques in our arteries, so

(29:08):
when your arteries are getting clogged, there's some little pieces
of plastic in there.

Speaker 2 (29:11):
Two.

Speaker 1 (29:11):
It has been found in testicles, kidneys, livers, like anywhere
you can imagine, maybe not wanting plastic to be, plastic
is there. And we found plastic in maconium. Daniel, do
you remember, I mean I probably said it wrong, let's
just be clear, but do you remember what maconium is?
This is a word I only needed to know the
definition of once or twice in my life.

Speaker 2 (29:32):
Oh, it sounds familiar. It sounds like mucus. Is it
something gross inside the body?

Speaker 1 (29:38):
It's your baby's first poop?

Speaker 2 (29:40):
Oh, of course, yes, of course, mconium. I remember that.
Now it's weird looking.

Speaker 1 (29:45):
Yeah, yeah, yes, it's weird looking, and it has plastic
in it, and so that means it's probably microplastics or nanoplastics.
Probably nanoplastics are passing from mom to the fetus, and
the fetus is already, you know, defecating them out pretty soon.
So we start our life with these microplastics with us.

Speaker 2 (30:02):
And we talked recently about water filtration systems and these
amazing processes that clean up our water. Are microplastics too
small to be filtered out?

Speaker 1 (30:12):
No?

Speaker 3 (30:13):
Not so.

Speaker 1 (30:13):
About ninety five percent of the microplastics that go into
the wastewater treatment plant are removed through the various processes.
There's a lot of microfibers that go to wastewater treatment
plants because a bunch of the wastewater that goes to
those treatment plants is from when we wash our laundry
or from like our shampoos and body washes. And stuff,

(30:35):
and our clothes every time we wash them are shedding
loads of microplastics, and so lots of stuff gets to
the wastewater treatment plants. About ninety five percent of it
gets removed. Sometimes the sludge that gets collected at some
of these plants will get used for other purposes, like
as a fertilizer, and in that case the microplastics could
get back into the environment. But if they're just put

(30:56):
in a landfill, they're probably going to be fine. But
a lot of them do still get through these wastewater
treatment plants, and there were some data from twenty fourteen
to twenty sixteen that estimated that something like eight to
thirteen billion pieces of microbeads were being released from treatment
plants into freshwater systems every day. And we're trying to
use fewer microbeads, but there's still a bunch of these

(31:18):
getting into our freshwater systems. But they also get into
freshwater systems or our oceans through other routes. For example,
a huge source of plastic is our tires, and so
when we drive, we're wearing some of the plastic off
of those tires, and that ends up either in the
air or sometimes it ends up on the side of
the road, and then the next time it rains, it

(31:39):
takes those little pieces of plastic into our rivers and
our lakes, and then in some cases it brings it
to our oceans. And so yeah, those are some major
sources of plastic into our aquatic systems.

Speaker 2 (31:49):
And so it's everywhere, and we found in our bodies,
including our brains and all the other important bits. Why
is this an issue or is it an issue or
why might it be an issue for our health?

Speaker 1 (32:02):
Yeah, so we're not super clear on it. First all,
I want to say that we've done some experiments on fish,
and the fish seem to get kind of messed up.
So fish end up, you know, they eat the little
invertebrates that eat the microplastics, and then they accumulate it
in their own body. And we found that microplastics can
mess with things like how the fish move, It can

(32:22):
damage their intestines. I think in some cases we found
that it reduces their growth, and it seems to reduce
their growth because it essentially like takes up space in
their gut and they like feel like they've eaten, but
they haven't eaten anything that's nutritious and so you know,
they lose weight and that can impact their reproduction and
stuff like that. So we know that there are some
examples where it's been a problem in fish, but fish

(32:44):
are swimming in this environment with loads of microplastics, so
that might not tell us what we need to know
about people. So here are some of the top issues
that we worry about for microplastics. One of the main
issues that we worry about is that these microplastics tend
to to attract and stick to other stuff in the environment. So,

(33:05):
for example, they stick to heavy metals PCBs, which are
polychlorinated by phenols and some other kinds of toxic material,
and they get what's called sorbed by the plastic.

Speaker 2 (33:18):
Absorbed, not absorbed, just sorbed.

Speaker 1 (33:22):
I think it's sorbed.

Speaker 2 (33:23):
Is that what the kids are saying these days?

Speaker 1 (33:25):
Wow, that's what the science kids are saying these days.
Very generous to call us kids. But so they pick
up these toxic compounds and then when they get into
your body, they could release those toxic compounds. And so
while a piece of plastic on its own might not
cause a problem, if it's bringing, for example, mercury into

(33:45):
your body and then depositing the mercury. The mercury could
be the problem. Does that make sense?

Speaker 2 (33:50):
Yeah, absolutely it does.

Speaker 3 (33:52):
Yeah.

Speaker 1 (33:53):
Other things that tend to stick to these fibers include bacteria,
and there's some concern that the way bacteria aggregate, they
form like biofilms where maybe they could be sharing like
antibiotic resistant genes or something. This sounded a little bit
more speculative from what I could tell. But bacteria stick
to them, and so do viruses, and so these pieces
of plastic could be ways that bacteria and virus make

(34:14):
it into your body.

Speaker 2 (34:15):
So basically they're dirty, they're not just weird and artificial
and everywhere they're dirty.

Speaker 1 (34:21):
They are. But this also contributes to why they're so
hard to study, right, because whether or not plastic is
bad for you is going to depend on what the
plastics saw before it went to you. So like the
same kind of plastic and an environment with no mercury
might do nothing, but the same kind of plastic in
an environment where it can pick up mercury and then
get to you could cause a lot of trouble.

Speaker 2 (34:42):
Yeah, exactly, And these things must be easier to study
in the lab. And then that doesn't really answer questions
about what happens in reality where most of us live.

Speaker 1 (34:50):
Amen, Yes, it gets super complicated. So then another thing
that makes it all complicated is that added to the
plastic are chemicals that help you, for example, make plastic
that are soft and are like easier to move. So
for example, if you think of your water bottles, that's
you can squeeze those, it bends a little bit. But
then there's other chemicals that make plastics stiffer and harder.

(35:12):
So for example, if you have a Nalgene bottle, when
you squeeze that, it doesn't have much give. And so
these chemicals that we add to the plastic can also
cause problems in addition to the plastic. So for example,
there's a class of chemicals called thalates. What it's pH thh.

Speaker 2 (35:34):
What pH that's not allowed?

Speaker 1 (35:37):
No, not in the English language. It shouldn't be. But
so I'm just gonna thallates. I'm just gonna call I'm
gonna pretend to the p is silent. The pH is silent.
And these tend to be used to soften plastics, and
they're pretty common in our bodies. So there was a
survey done in eight to ten out of the baby's
surveyed had thollates in their body, and nearly all of

(35:58):
the adults that were surveyed it had them too. And
this chemical is associated with reduced sperm count and motility.

Speaker 2 (36:06):
No, I know, I don't like that. That's not good.

Speaker 1 (36:08):
No, But the results here are mixed. So like, if
you were making a million sperm and now you make
nine hundred and fifty thousand sperm, should you care? And
the answer is, maybe.

Speaker 2 (36:21):
Those are fifty thousand of my boys we're talking about here.

Speaker 1 (36:23):
You weren't gonna make use of all those boys anyway, Daniel.
So there was a study that was looking at like
people who had various amounts of exposure to this stuff
and how long it took for them and their partner
to get pregnant or you know, for the woman to
get pregnant. Yeah, And it looked like there wasn't necessarily
an association between exposure to a certain kind of thallate

(36:46):
and how long it took to get your partner pregnant.
And so the point is, maybe sperm counts are lower,
but that doesn't necessarily result in infertility issues all the time.

Speaker 2 (36:56):
All right, But sperm counts I think are dropping anyway, right,
and we've been talking about how there's fertility issues already,
so anything that pushes sperm counts lower is definitely not
going to be good for fertility, right. I think you're
arguing that this is a small effect, but still a
small effect on average can have some measurable impact on
the number of babies.

Speaker 1 (37:16):
Born, right, Yes, And there are some communities who would
argue that a big part of the decline infertility could
be because of things like plastic related chemicals in our
water or whatever are being ingested with the food that
we eat, and so yeah, it could play a role,
and it could play a role in aggregate. Maybe it's
just playing a small role in that overall trend. There's

(37:37):
some work done in lab animals like mice that do
find definitely quantifiable impacts from exposure to thalites on the mice.
And so the question is if a mouse has infertility,
does that mean that a human's going to have infertility?
We don't necessarily know, And often animals in the lab
are exposed to much higher concentrations of the chemicals than

(37:58):
we are exposed to on a day to day basis,
for example, and so it's hard to know how to
tie those things together. But there is some risk that
these chemicals are having some impacts on fertility related issues.
But we don't really know how much we should be
worried about this happening for humans yet.

Speaker 2 (38:15):
All right, So, Kelly's given us two reasons to worry
so far. They can trap stuff, they can be toxic chemicals.
When we come back from the break, we're going to
hear about more reasons to worry, including Daniel's number one
reason to worry about microplastics. Oh okay, we're back and

(38:49):
we're talking about all those little bits of plastic that
are everywhere in the earth and in you right now
swimming through your body? Are hundreds thousands? How many bits
of micropack are in each of our listeners?

Speaker 1 (39:01):
Kelly, Oh I that would be very hard to quantify.
I don't know exactly how many pieces are in each
of us.

Speaker 2 (39:07):
We want numbers. I want an individual list of numbers
for each listener.

Speaker 1 (39:11):
Okay, well, give me a lot more money. And also
there's going to need to be a lot of slaughter
because to get those numbers usually requires an autopsy. So
let's just say we probably all have at least a
microplastic piece in us, and that's probably quite an underestimate.

Speaker 2 (39:24):
All right, but it sounds like if you really want
to know, and you're willing to volunteer for an autopsy,
Kelly will give you a solid answer. Nope, that's a no. Okay,
that's a nope. Do not ship your body to Kelly
to get an answer to this question, turns out nope,
All right, nope.

Speaker 1 (39:39):
Oh so you said you were going to tell us
your number one fear from microplastics, So go ahead, let's
hear that.

Speaker 2 (39:44):
Yeah, Well, my number one reason to worry about microplastics
is we don't understand the body. It's a big, complicated system,
and there's lots of things that we do to it
all the time that we don't understand how it works.
Like I think thailan All still not fully understood. Why
does thilan All work, or why do all these sechoactive
medications work, And so there's just a lack of a
mechanistic understanding of how this is how the body works.

(40:06):
It seems to me like you just throw a bunch
of plastic in there. You can't predict what's going to happen,
and so many weird and terrible things are happening to
people all the time, it's hard to know like how
much of this is due to eating plastic or not
eating plastic. And so to me, the number one concern
is something we can't predict because the system is too complicated.

Speaker 1 (40:26):
And I think that is absolutely spot on. Yeah, I
totally agree with you. And one point that I want
to go back to really quick. We were talking about
thalates and there are possible impacts on the human body.
I want to be clear that we do know that
at very high doses, at high exposure, these things definitely
are bad. So the question isn't thalates good or bad?
The question is thalates at very low concentrations are they

(40:52):
bad enough that we want to give up all of
the benefits we get by having thalates. And there's another
chemical that we have the same discs, and that chemical
is bis phenol a, And just like with thalites, we
don't totally understand whether we need to be worried about
it and how much we need to be worried about it.
But we know that this finyl a acts like estrogen

(41:12):
in the body. So in some cases it mimics estrogen,
making your body think there's more estrogen, and in other
cases it will like bind to receptor where estrogen should
be and now estrogen can't get to it, and so
your body should be getting a message from estrogen and
that message isn't going through.

Speaker 2 (41:27):
And so this is a great example. People are like, BPA,
what could it do? It's probably fine. O turns out
maybe it's not fine.

Speaker 1 (41:35):
Yeah, And there was a study that found that about
ninety three percent of people have BPA in their urine,
so just about all of us are exposed to it.
And for all of these chemicals, you might be most
worried if a fetus or a baby is being exposed
when like tons of development stuff is happening. And so
there were rules saying like, hey, look we need a
lot less bysfhinyl a in things like baby bodels because

(41:55):
we're worried about what tinkering with estrogen could do. There's
some evidence that it's associated with increased blood pressure, type
two diabetes, cardiovascular disease. Long down the road, it also
can impact the brain and the prostate gland of feces
and stuff. Lots of reasons to worry.

Speaker 2 (42:12):
You said prostate gland of feces, but I think you
mean fetuses.

Speaker 1 (42:16):
I did I feces.

Speaker 2 (42:19):
You just got poop on the brain. I get it.

Speaker 1 (42:22):
No I do, I do. Sorry, the brain and prostate
gland of fetuses not feces. Anyway, lots of reasons to worry.
So we tried to cut down on the use of
byspinyl a. But the problem is that this chemical is
really helpful for making plastics stiffer and harder, and so
we've replaced bisphinyla with something that has a very similar

(42:43):
shape because we want that same shape so that we
still get our nice hard plastics. So we've replaced it with,
for example, bisphinyl s, and we think that actually, maybe
this other thing does a lot of the same stuff
to our body that bisphinyla does. So when you see
a bottle that says doesn't contain BP, that doesn't mean
that it doesn't contain a very similar bisfunyl thing. So yeah,

(43:06):
it's hard to replace these things while still keeping the plastics.
We love doing the things that we love them to do.

Speaker 2 (43:13):
I love those indications on food that make you feel like, oh,
it's healthy, Like when you look at jolly ranchers and
they say fat free and you're like, yeah, that's because
it's one hundred percent sugar. That's right, that's right, doesn't
make it a health food.

Speaker 1 (43:27):
I like things that are like cholesterol free. I'm like, well, yeah,
because it it couldn't have cholesterol in it, because we
know where cholesterol comes from. And it's like, no rat
feces in this. It's like, well, it shouldn't have rat feces,
and what does that imply about the other material?

Speaker 2 (43:41):
Anyway, It's but I do appreciate the nuance here that
you could say, let's just get rid of all of it.
But you're right that plastics have improved our lives and
there's positivity there. And it sounds like we're being, you know,
shills for big microplastics, as ironic as that name is,
but it's true that, you know, you wouldn't want to
just get rid of plastics even if there is a

(44:02):
cost to human health, because it also saves lives. Right,
having these medical supplies et cetera, et cetera does save lives.
And so really the question, as always, is a nuanced one.
It's like, does it do more harm than good?

Speaker 1 (44:13):
Yeah? And so let's dig in for a second into
all the reasons why it's hard to really understand why
this stuff is bad for people. So one we talked
about how you can cough, sneeze, poop, or pee a
lot of this stuff out. So just because you're exposed
to something like bisfinil A doesn't mean that your body
isn't going to excrete it before it causes any damage

(44:34):
or break it down before it causes any damage. But
maybe it is causing damage, and so we need to
research this a lot more to figure out how we
get exposed to it, how our bodies respond to it,
how much of it is bad. But there does seem
to be a move, for example, in Europe to decrease
the amount of allowable things like bisfineles, because we are
deciding as the data comes in, oh, this is a

(44:56):
little scary, we don't want to risk it. The other
problem is that plast sticks come in loads of shapes
and sizes, and some of them are more likely to
get into our bloodstream, for example, than others, and when
they break down, they break down into thousands of different chemicals,
many of which we haven't looked at for health impacts yet.
So it could be that like ninety percent of plastics

(45:18):
are okay, but there's ten percent that break down into
super toxic stuff and that's what's causing the problem, or
maybe all the chemicals that it breaks down into are bad.
I don't want to sound like you've got me worried
now that I sound like I'm a shill for big microplastic.
This stuff is complicated, and you need to decide on
your own how worried you are about it. We also

(45:38):
don't have very good methods for counting and quantifying plastics
in the human body. I mentioned that you can look
at this stuff during an autopsy, but then once you've
got these micro or these nanoplastics that you've collected from
an autopsy, how do you know what kind of plastics
they were in particular, and what about it was bad?
So you know, maybe one plastic in the brain has

(45:59):
thali attached to it and one has bispinyl a, And
how do you quantify the total impact of all of
that on our bodies. It's very complicated when there's lots
of stuff interacting. And one thing that also makes it
complicated is that for things like bysfhinyla, this old phrase
the dose makes the poison doesn't really stand. So for

(46:19):
things like mercury, probably the more mercury, you ingest the
worse it is, we don't want to have a lot
of that. But with a lot of hormones, they have
this weird way of interacting with our body where low
doses and high doses can have the biggest impact, but
intermediate doses sometimes have low impacts. So it's almost like

(46:40):
the letter you if you're looking at it on a graph.
And so it's not necessarily the case that more and
more and more and more is worse, but having a
little bit could be really bad, or having a lot
could be really bad, And so it just makes it
even harder to figure out these associations and try to
get a handle on how bad and what doses are
okay for people.

Speaker 2 (46:59):
Okay, then give me a overview of like potential things
to worry about in terms of effect on human health.
I'm not going to have more kids, so I don't
really need to worry about my boys swimming anymore. But
beyond fertility, what concerns are there for human health?

Speaker 1 (47:13):
Okay, So again we don't really understand the mechanism totally
for some of this stuff, but one concern is that
there might be earlier puberty. So, for example, from the
nineteen seventies to today, I think puberty has moved up by
something like a year on average. And so the question
is do having all of these chemicals that mimic estrogen

(47:34):
in the environments, is that, for example, moving up puberty
time for women and women who enter puberty earlier, I
believe they have a higher risk of things like breast
cancer later on. So there could be bigger implications than oh, man,
I've got my period a year earlier. It could have
more health impacts down the line. There's also some proposed

(47:54):
link between obesity and microplastics. So obesity has increased in
the United States, you know, roughly along the line as
are increasing use of plastics. But a lot of things
have changed about the United States over that amount of
time too. You know, it's probably easier to get fast
food and less healthy food, So it's really hard over

(48:15):
time to tease these things apart. But plastics could be
playing a role because we have seen that some kinds
of plastics and the chemicals that they carry into our
bodies change the way our bodies metabolize food and the
way our bodies make fat cells and stuff like that.
And we found that lab animals and domestic pets are
more likely to be obese as well, and those are

(48:37):
animals that are exposed to plastics a lot because of us.
And so you know, maybe we're seeing an indirect effect
in our lab animals and our pets that.

Speaker 2 (48:45):
We have to be very cautious in concluding anything from
correlation studies, right, because yes, these things could just be random.
Like if you've seen the correlation between ice cream and murder, right,
it's very tight. Doesn't mean ice cream causes murder. It
means you tend to have ice cream more in the summer,
and people tend to commit murderers more in the summer,
maybe because they're not getting enough ice cream. Actually, so
maybe ice cream suppresses murder.

Speaker 1 (49:07):
Who knows, that's right. Maybe I think we probably all
need more ice cream.

Speaker 2 (49:11):
Now we're big shells for ice cream.

Speaker 1 (49:12):
Great, I'm okay with that that.

Speaker 2 (49:14):
I'm okay with microplastic free big ice cream. All right,
there you go. So we're worried about puberty, we're worried
about ovcity. What else should we be worried about?

Speaker 1 (49:24):
There's some concern about cardiovascular issues. So, for example, there
was a twenty twenty four paper in the New England
Journal of Medicine, where people went through surgeries to remove
plaques in their arteries. So this is like removing the
build up of stuff that was clogging up the stuff
in the arteries leading to the heart. And after they
removed that stuff, they put it under a microscope and
they looked to see if they were microplastics in there,

(49:46):
and about half of the people that they looked at
had microplastics in there, a couple different kinds of microplastics.
They tried to quantify the different kinds, but then they
followed those people for thirty four months after the plaque
was Removedeople who had microplastics in there were more likely
to have encountered a myocardial infarction, a stroke, or death. Essentially,

(50:10):
their heart was likely to have some additional problems in
the like year and a half or more after plaque
removal if those plaques had plastic.

Speaker 2 (50:19):
Infarction is a word. It's not just a typo for infraction.

Speaker 1 (50:22):
And infarction is an obstruction of the blood supply to
an organ or region of tissue, typically a thrombosis or embolists,
causing local death of the tissue.

Speaker 2 (50:29):
So yes, it's also a word that, for some reason
is just hilarious. It's a word like weasel or booger, infarction.
It just sounds funny to me. I don't know, I
know it's not funny when it kills you, but it's
a funny word.

Speaker 1 (50:40):
Yes, yeah, yeah, A booger is funny when it happens
to you, and infarction is not. But uh, maybe a
booger's not funny depending on the context. But anyway, it
makes me laugh. So you mentioned that a problem with
observational studies is that you don't know what is causing
the correlation. So, for example, it could be that the
people who had microplastics in their plaques are people who

(51:04):
were more likely to I don't know, get McDonald's that
are in those like plastic wrappers, and you know, something
about their diet resulted in them having more microplastics, and
then they didn't change that aspect of their life after
the surgery, and that's what led to the problems they
had down the road. So it's really hard to tease
apart cause and effect and you know what is causing

(51:26):
this problem when you're looking at an observational study.

Speaker 2 (51:29):
All right, So there's lots of reasons to worry, but
we don't have a great mechanistic understanding or really an
idea for what problems could be caused. So what can
we do? What are your prescriptions for improving our lives?

Speaker 1 (51:43):
Yeah, so I'd say that the emerging picture is that
there are reasons to potentially worry.

Speaker 2 (51:49):
There's always reasons to worry, Kelly.

Speaker 1 (51:51):
There's always reasons to worry, I know. And so you
can decide how concerned the information we've talked about, how
concerning that is to you. But there are some things
you can do in your day to day life to
protect the environment. Let's start with those. So one, there
are like filters that you can get that go on
your laundry machine to collect some of those microfibers so
that they don't go into the wastewater treatment plant and

(52:13):
then they don't go into the ocean. You can, you know,
try to buy clothes that are meant to last a
little bit longer so that you're not buying as many
clothes and that would result in less you know, microplastics.
You could take public transportation so that you're not wearing
out your own tires. There's lots of little things that
you could.

Speaker 2 (52:30):
Do you can invent flying cars so I don't need
tires anymore.

Speaker 1 (52:34):
Well, I think some people are working on devices to
collect plastic as they get released from tires, and that
seems like it could be pretty tough. You'd maybe never
get all of it, but you know, you could try
to work on technologies that make this stuff easier to
remove from the environment. But if you're worried about your
own personal risk, some things that you can do include

(52:54):
eating from glass or metal containers instead of plastic. If
you have tupperware containers, don't wash them in your dishwasher
because that gets really hot it starts breaking down the plastics.
Those microplastics could come off in your food. Things like
vacuuming regularly are important because you're dropping plastic fibers all
the time from your clothes and they end up on

(53:14):
the floor and then they can get kicked up into
the air as you're walking around. Maybe not drinking bottled
water because those tend to have plastics, but there's also
plastic in tapwater. But if you get a reverse osmosis filter,
you can take some of it out, but those are expensive,
and if you remove the microplastics, you're also removing minerals
and salts and stuff, and you might want to add

(53:35):
some of that stuff back in. A lot of this
stuff is complicated, so you need to decide what are
your most likely exposure risks and how concerned are you,
because again there are trade offs, maybe a lot of
this stuff at doses. You know, like I live in
the middle of nowhere. I don't probably breathe in a
lot of tire stuff. My water comes from the ground,

(53:56):
and while groundwater does sometimes have some plastics, my groundwater
where I am probably doesn't have a lot of it.

Speaker 2 (54:01):
So we should all move in with you.

Speaker 1 (54:02):
It sounds like I mean no, no, actually, because then
then it wouldn't be quite as pristine. But anyway, like,
I'm not too worried about my exposure to plastics because
I use a lot of ceramic and stainless steel stuff,
so I'm not too worried. But you know, you should
think about the various ways you encounter plastic in your
life and then decide if you are concerned or not,

(54:24):
and if you want to make any changes, it's up to.

Speaker 2 (54:26):
You, And as is my habit, the night before we record,
I usually ask Katrina what she thinks about an episode
just to hear she has some ideas. So I asked
her what she thought we could do to reduce our microplastics.
And here's what she had to say.

Speaker 8 (54:41):
Well, eating fiber forms a matrix that will protect you
from all toxins. Think of it like a brit of filter,
where it's sucking up the toxins and preventing them from
being absorbed into your body. So if you're eating fiber,
then you've got this gel that sticks with you down
to your colon. If there's also microplastics in your food

(55:02):
and water, it gets sucked up into that so that
it doesn't get absorbed by your intestinal cells.

Speaker 2 (55:08):
So Katrina is big on fiber, so maybe no surprise
that she prescribes fiber for everybody.

Speaker 1 (55:13):
Yeah, I was going to ask if the answer to
every question in the Whites and household is beans.

Speaker 2 (55:17):
Beans, She seeds beans fiber. It's good. She's just rooting
for the microbes inside everybody to help with the microplastics.

Speaker 1 (55:26):
Well, we could probably all use more fiber anyway. And
there are some studies in mice, for example, that find
that microplastics disrupt the gut microbiome, so fiber can help
you in the battle against plastics in a lot of
different ways, and so, you know, I want to be
clear throughout this episode. You know, I've tried to make
sure I was including caveats about whether or not this
is likely to be important, Like I don't want people

(55:46):
to be freaking out. There are some reasons to be concerned,
but at the moment, there's just so many different places
we can encounter plastics, and so many different kinds of plastics,
and so many different contingencies that matter, like where the
plastic was before it got to you. That we just
don't have a very good handle on this problem yet.
And this is all the more reason to invest in

(56:08):
basic science so we can try to understand this better.
But like so many risks in life, you got to
kind of decide for yourself, how concerned am I going
to be given what we know about this.

Speaker 2 (56:17):
So don't worry too much, don't worry too little, worry
just the right.

Speaker 1 (56:21):
Amount that's right, Just the right amount. Good luck with that.
And the reason we talked about microplastics today is because
a listener sent us an email saying I would love
to know more about microplastics. So I sent this episode
to them, and let's see what they had to say.

Speaker 9 (56:36):
Plastic is a wonderful material and all its different applications
and all the different fields where it's an essential material.
Although I don't believe that we.

Speaker 10 (56:49):
Need to be more picky how we use plastic, and
we need to cut some products from our lives, especially
the disposed of single use ones that are quite unnecessary.
I believe I'm deeply concerned for the effect microplastics have

(57:09):
on smaller creatures, especially.

Speaker 9 (57:11):
Ocean creatures as you mentioned in the episode, and.

Speaker 11 (57:15):
The effects that they may have on their larger food
chains and ecosystems. It might sound bleak, but I'm less
so concerned for the effects on human health, as we are,
of course the responsible ones. But thank you Daniel and
Kelly for the episode is informative. I learned some new things,

(57:40):
and thank you for picking my suggestion.

Speaker 1 (57:43):
Thank you very much for that feedback. We did end
up focusing a lot on human aspects of impacts of microplastics,
but there's definitely evidence that microplastics and aquatic ecosystems are
bad and impact a variety of different organisms in negative ways.
So I think at a minimum, it would be important
for all of us to think about how we can

(58:04):
cut back on plastics in our lives, and we should
think about what we're doing too organisms beside ourselves. So yes,
thank you for making that important point.

Speaker 2 (58:12):
All right, well, thanks everyone for sending in your questions,
for being curious about the nature of the world. Though
we don't have a clear prescription about how you should
live your life, at least now you're better informed about
what we do and don't know about microplastics.

Speaker 1 (58:31):
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