A few months ago, I read a press release announcing that researchers had discovered microplastics in chewing gum.

And this was just a press release.

The paper had not been published yet, but my first thought was, I gotta immediately test this myself.

Now, the plan to figure out if there are microplastics in gum is simple, and it's adapted from a method that people use to look for microplastics in tap water.

And the method is this, it's to mash up some gum.

And here I'm using an absolute classic, Double Bubble, in a mortar and pestle with some ultra pure water.

The idea being to extract any microplastics in the gum out into the water with the grinding action of the pestle, and then to take that water and run it through a 0.45 micron filter, and then look at that filter under the microscope and just count the number of microplastic particles you see, it's pretty simple.

At least I thought it was simple before I actually did it.

I don't know if you can tell, but this is not working.

Mashing the gum up in a mortar and pestle was really hard, took a long time, and didn't come close to achieving the same gum like texture that you get when you chew it in your mouth.

So I made this crucial decision, to chew the gum instead.

Normally you don't chew the science, but in this case, gum is made to be chewed.

And also, chewing gum is what happens out in the real world.

So if you're trying to model something that happens in the real world in your lab, or in this case my basement, you wanna try and be as accurate as possible, and chewing is more accurate than mortar and pestle.

There's no question about that.

So weird.

So what you're watching me do now is to chew the Double Bubble and spit at roughly 30 second intervals, dilute that with some water, and then try to run it through a 0.45 micron filter.

Simple plan that did not work, because it turns out that if you try to run any amount of spit through a half micron filter, even if it's diluted with water, within 10 seconds, you will clog the filter and you will end up, as I did here, with like 200 milliliters of Double Bubble infused spit.

Plan B. All this spit that wouldn't filter, I could have just thrown it away, but I didn't.

I saved it and I put it in the fridge because who knows, maybe later it would be useful, and later it was.

Anyway, then I took the filter off, put it in a clean glass Petri dish and let it dry overnight.

A couple days later, I pulled it out to look at it under the microscope and I could actually see stuff with my naked eye.

And look, you can just see it for yourself.

Look at all this stuff.

Each of these little boxes that you're seeing on the screen here is three millimeters by three millimeters.

So that particle, that like big old pink glob is, oh, I'd say about 800 microns in diameter.

What I do need to do is figure out whether this is microplastics or not.

These are confirmed microplastics.

Look at this for a second.

Absorb it into your brain.

Now look at this, which is what I isolated from Double Bubble.

To me, these don't actually look that similar.

But the thing is, microplastic is such a broad term that it includes pieces of this, and this, and this, and thousands of other different types of plastics as long as they're smaller than five millimeters.

Now, why would the researchers even test gum for microplastics in the first place?

Because the thing that makes gum, gum, the thing that makes it chewy and not dissolve in your spit, are these long polymers that chemically speaking are not all that different from plastic polymers.

And I think, look, that's even true if you're talking about natural gums.

Slightly controversial statement.

We can argue about it in the comments, but I think that you cannot make a gum without some sort of rubbery, plasticky polymer.

So the theory is, as you chew this giant piece of basically plastic that's in your mouth, the grinding action of your teeth will slice off little pieces of it, and those little pieces technically are microplastics because they are less than five millimeters in size.

If I were not in a basement with trash and dead insects, I would use infrared spectroscopy or Raman spectroscopy and I would take the stuff that I isolated from Double Bubble, I'd throw it in the spectrometer, and I would compare it to known samples of plastics.

And that would tell me essentially like is this thing a plastic or not?

I don't have any of that, but what I do have is something much simpler.

I'm using this blowtorch to heat up a needle to where it's glowing, and then very quickly bring it close to a piece of something that I suspect might be plastic.

And if it is plastic, it'll melt.

If it's not plastic, it won't melt.

This is called a hot needle test, and it's a lot harder to do than I thought it would be because you're basically using a macro lens or a microscope to guide a tiny needle to like a less than a millimeter distance from a thing.

And it's just, I messed this up in so many ways.

The few tries that I got that seemed okay, I did not see anything melt.

But that doesn't necessarily mean that these things are not plastic.

I think it just means that I suck at doing hot needle tests.

Fine.

Okay, another approach.

Chemically chewing gum is pretty simple.

It's got sweetener, gum base, flavorings, probably a preservative in there sometimes, depending.

My instinct here is that the only thing that is not soluble in water on this list is the gum base.

If gum base were soluble in water, it would dissolve as you were chewing it, you'd have Starburst instead of a chewing gum.

So what I wanna do is I wanna figure out, are these things on my filter paper soluble in water or not?

Now, you could argue that they probably aren't because I already had them in a bunch of water while I was doing the filtration.

But let's try with warm water, 'cause that would really be the nail in the coffin.

I'm heating up some filtered water.

I'm putting the filter paper on my fritted disc.

That's a fun word to say, fritted disc.

And then I'm taking a glass pipette, has to be glass 'cause I don't want to contaminate the sample with microplastic particles from a plastic pipette, and I am slowly dripping hot water onto this thing.

The water is very slowly diffusing outward through the filter from the drop.

That thing isn't going anywhere.

And I can see no discernible change in whatever that particle is.

So what does that mean?

The ideal in science is that you're totally impartial and you just follow the experiments wherever they lead you.

But the reality is that we're all human and we all have preexisting beliefs.

And so if you do a little experiment that tends to, you know, nudge you, what am I doing with my shoulders?

How is this a nudge?

Anyway, it tends to nudge you in the direction of a preexisting belief.

Then your preexisting belief is likely gonna get a little bit stronger.

And so at this point, I had developed a gut feeling that I had found microplastics in gum.

And so I decided to move on.

I decided to test three other gums.

Pür Gum.

Simply Gum.

My favorite gum of all time, Big Red.

Now, in case you're wondering, yes, none of these samples filtered.

And I did the same thing as I did with Double Bubble.

I took the stuff that wouldn't filter and I saved it.

Okay, and remember when I made the decision to save this earlier?

This is when you get the payoff.

This is when you realize why that decision was a good decision.

What I noticed is that after a couple hours of sitting around, all three of the test tubes had solid looking stuff collecting at the bottom.

I didn't think much about this at the time but this turned out to be super important and we will come back to it.

I wonder if that's about to be the bane of my existence.

So I put all the filter papers in Petri dishes, and then I left them to dry and I looked at them.

I looked at Big Red, and then I looked at Pür Chocolate Mint, and both of those gums had exactly the same type of particle that was in Double Bubble.

Well, don't worry, we'll get back to the Simply Gum.

So far three gums have produced these types of particles.

They all look very, very similar, but they don't look like the classic examples of microplastics.

So I emailed the researchers and I asked them, "Hey, can I send you some footage and you tell me whether you think it's microplastics or not?"

And they said nothing 'cause they didn't reply to my emails, and I sent more than one.

But hey, if you're watching this video right now, comment in the video below because the footage, it's all in the video.

Just watch it.

Tell me what you think.

And moving on, the thing about the Simply Gum sample was it looks totally different.

Like, look at it.

Look how different this is.

It's not clear to me that this is plastic.

First of all, the big chunks of these are way bigger than the other pieces of microplastic I've seen, or the things that I think are microplastic.

To me, this looks a little bit like sugar.

So it's pretty low on the water content, so maybe this is not enough water to dissolve the sugar and so I'm getting a bunch of sugar out.

At this point, the Simply Gum has thrown me for a loop.

I am completely confused.

But then I had a brilliant flash of inspired thinking.

No, look, I had a good idea.

And the good idea was this.

It turns out that people make DIY, do it yourself gum kits.

And in a DIY gum kit, you get all the ingredients of gum, but packaged individually.

You get the sugar, you get the flavorings, you get the, oh yeah, you get the pink color or whatever.

But crucially, you get gum base by itself.

It's so interesting to be chewing gum, no flavor, nothing.

Can't taste a thing.

Now, I'm pretty sure this is synthetic gum base and not chicle.

But here's the thing, if I test the gum base by itself and I see the same type of particle that I'm seeing in Double Bubble and all the other gums, that's pretty damning evidence that whatever is coming outta these gums is coming out of the gum base.

I did the exact same experiment with the gum base that I did with Double Bubble and the Big Red and the Pür Chocolate Mint.

So I dried the filter paper and then I looked at it and look, it is the same stuff that you see on Double Bubble, on Pür Chocolate Mint, on Big Red, it's the same.

Does that tell me that whatever these particles are, they are coming from the gum base?

No, it doesn't.

This is where my decision to chew the gum comes back to bite me in the butt.

Let's rewind back to when I was mashing the Double Bubble with a mortar and pestle.

When I did this, I also did what's called a laboratory blank or sometimes people call it just a blank.

It's a control.

You do everything you would ordinarily do, but you do it without the gum.

So here I am, I look like a doofus.

I am mashing up water in a mortar and pestle.

I'm literally going through the motions, but without gum.

Pouring water over imaginary gum.

I'm vacuum filtering imaginary gum.

I'm drying the filter in exactly the same type of glass Petri dish that I did with the gum.

Literally, everything is the same except there's no gum.

And when you do all that, here's what you get.

Look, it is a pretty clean filter paper.

There's not much on here.

I know it looks like, there's a lot of stuff on here, but compared to other stuff, there's not much on here.

This is how you know that when you do the gum sample, whatever you get out of that is actually from the gum, right?

That's what a control is.

But here's the thing, when I made the decision on the fly to chew the gum instead of mashing it up in a mortar and pestle, I got so excited that I did not do a laboratory blank.

I didn't do a spit control, so I went back and I did one.

I even fake chewed, chewing motions, imaginary gum.

Look at me just standing here like an idiot, chewing.

And by the way, when I did this, interestingly, it also refused to filter, which tells me that the thing that was clogging the filter came from my own spit.

And I also did the thing where I saved the top of the part that wouldn't filter.

I put it into test tubes.

This is, again, I did everything the same that I did with the gum samples.

Hello.

We're gonna look and see what's at the bottom of the test tube.

My expectation is nothing because there's no reason my spit would have a bunch of like microplastic in it or anything in it.

There's no reason my spit would have anything in it other than, you know, what's supposed to be in there.

So let's take a look.

This right here is the spit control.

And yeah, okay, I'm not imagining things, that is a solid at the bottom of the test tube.

I guess I better find out what that looks like 'cause if it looks like all the other gum samples, I could be in trouble.

So then I very nervously put the filter paper in a Petri dish and let it dry overnight.

Moment of truth.

What I've got under the macro lens here, I have not looked at it yet, is the spit blank.

Oh, no, no, no.

I mean, this looks indistinguishable from a gum sample.

Like if you had showed me this without telling me what it was, I would've thought it was Big Red or something.

Oh no, I just, I can't tell you how confused I am.

But then this is the paper.

It came out while I was in the middle of shooting.

That never happens.

I am very nervous because I'm about to read and find out everything that I did wrong when I was doing these experiments.

The microplastics released from chewing gum to saliva were isolated and digested.

They used a mixture of hydrogen peroxide and iron to chemically obliterate, oxidize, anything that was not a microplastic.

So I think what was happening with my samples is that my filter was getting instantly clogged with mucus and other biological stuff from my saliva.

And so any microplastics present above the filter never actually made it there because that liquid was never pulled through the filter.

After digesting and accounting for the controls of the researchers found that each gram of gum, so one gram, released on average a hundred particles of microplastics.

And to recap, I found zero particles of microplastics because I did it wrong.

Honestly, though, this paper seems pretty solid overall, so I would not be surprised if this finding gets replicated in the next couple years.

I am appropriately humbled, I think.

This kind of science is pretty different than the kind of science that I was doing in my last video, where if you're sort of exploring in a somewhat under-explored space, it's easy to make a new discovery.

And the new discovery like pops out at you.

It stands out.

It either works or it doesn't.

Science like this where you're trying to find a tiny amount of a contaminant in, you know, a large amount of, in this case, my own spit.

Maybe it's not harder, but it's different.

It's more painstaking, it's slower, it's a different flavor of science.

And I don't like this flavor.

This is not a suitable flavor for me.

Lisa Lowe, Jamie Leonard, and Sanjay Mohanty.

My hat's off to you.

You did things that I would never choose to do.

Oh, you know where I got this from?

I just realized, this is K-Pop, Demon Hunters.

This is Soda Pop.

♪ My little soda pop ♪