Ask An Expert: What The Heck Are Microplastics?

JOHN DANKOSKY: This is Science Friday. I’m John Dankosky. Today we’re doing a special hour about plastics. A little later this hour, we’ll talk about the future of plastics, new alternatives, and ways to break down what already exists.

But first, despite their small-sounding name, microplastics are a big deal. That’s because these tiny pieces of plastic debris can wind up just about anywhere. In fact, we know microplastics are in our oceans and in our soil, but they can also get into what we eat and what we drink. And since this is a relatively new problem, we don’t have a lot of long-term research on them.

But there are some great scientists doing work on microplastics and their effect on the environment. Their work has influenced legislation and the creation of innovations for combating plastic pollution. And one of those researchers is joining me now. Dr. Imogen Napper is a postdoctoral research fellow at the University of Plymouth in the United Kingdom. Welcome to Science Friday. Thanks for being here.

IMOGEN NAPPER: Thank you so much for inviting me.

JOHN DANKOSKY: And just to note, this segment was recorded in front of a live Zoom audience. You can learn how you can join a future behind-the-scenes radio recording on our website, sciencefriday.com/livestream. All right, to start, let’s get a definition here. What exactly is a microplastic?

IMOGEN NAPPER: So a microplastic is defined by its size. So very small plastic that’s less than 5 millimeters in length. So imagine that like size or smaller of your fingernail.

And then you can categorize it into primary and secondary. So primary microplastic has been made to be that size, so think of microbeads in facial scrubs. And secondary microplastic has degraded off a larger item, so think of a plastic bag breaking into tiny bits.

JOHN DANKOSKY: So some are made. Some are made to be bigger things that are broken down. Maybe you can talk about that process of larger pieces of plastic breaking down. Give us an example of what sort of thing happens and the types of microplastics we find from this type of degradation.

IMOGEN NAPPER: Gosh, plastic is really everywhere. So if you look around the room that you’re in right now– I’m wearing plastic clothes, I’ve got a plastic sofa, plastic carpet, plastic pen, talking to you through a plastic computer, or elements of. And the way that it breaks down eventually, if it’s in the natural environment, it can get tumbled around by the ocean, but the main way that it gets broken down is by sunlight and photo-oxidation.

In its most basic form, plastic is carbon and hydrogens put together in a long line called a polymer. And what sunlight does is it introduces an oxygen molecule, which is a double bond, which breaks the carbon and hydrogens basically in half. And that’s what fragments plastic. And that’s how we can find so many bits in the ocean.

JOHN DANKOSKY: So does this mean that every piece of plastic anywhere is eventually going to become a microplastic?

IMOGEN NAPPER: You could say that. Every piece of microplastic in the ocean is going to keep getting smaller and smaller, potentially into nanoplastics. And larger items– think of a carrier bag, if it goes into the ocean and it’s going to break down into microplastics, so it just keeps getting smaller and smaller and smaller. But it’s also been predicted that all of the plastic that’s ever been made is still on the planet today unless it’s been burnt.

JOHN DANKOSKY: So it hasn’t gone anywhere else. It’s just gotten so small we don’t necessarily see it, but it’s everywhere. And it’s so small, actually, that, as I said in the introduction, we could be eating these. We could be drinking them. What kind of effect does that have on our body?

IMOGEN NAPPER: There’s a lot of new research being developed about the risks to our health and to animals’ health and our ocean health. They’re getting so small that it’s been found in our drinking water, in beer, in salt, you name it. It’s everywhere.

And even as we’re talking right now, plastic fibers will be coming off my plastic jumper, and I’ll probably be breathing them in every now and then. So it’s of course a concern of how much there is in our day-to-day life, but nothing we should panic about our health at the moment. And there’s still so much we need to discover. There are some very clever researchers building on that research at the moment.

JOHN DANKOSKY: You said breathing them in?

IMOGEN NAPPER: Breathing them in. So we’re doing research that looks at plastics in the air. So I’ve got a friend who looks at, when we’re wearing clothes and we’re moving about– because most of our clothes are made out of plastic, such as polyester or acrylic– tiny fibers are coming off them all the time.

We actually did some research on Mount Everest, and an expedition team went out there and took snow samples all the way from Everest Base Camp to just below the summit at a place called Mount Everest Balcony. And in every single snow sample, we found plastic. And most of them were microfibers that we predict come off clothes. And there was a correlation where where more people were, we found more plastic.

So at Everest Base Camp, we found around 70 microplastics per liter of snow. But even just below the summit, at the Balcony, we were finding 10 microplastics per liter of snow. And the polymer type was similar to what they would be wearing. So we’ve predicted that these fibers had come off the climbers that were coming up the mountain.

JOHN DANKOSKY: So for the most part– and it’s very scary to think that you’re finding microplastics at the top of Mount Everest where not that many people have been, although more than perhaps in the past– you’re finding fibers that have probably been left from the clothing of the hikers who were there, as opposed to fibers that maybe have drifted across a continent and have ended up on Mount Everest because of getting into the atmosphere.

IMOGEN NAPPER: It’s probably a mixture of both, but finding the correlation that where more people were– it’s almost like a trail of breadcrumbs. Where the people are, you’re going to find more plastic.

JOHN DANKOSKY: I want to get back to this health effect. The state of California is getting ready to issue the world’s first guidelines for microplastics in drinking water. They’re trying to decide what a safe threshold is for microplastic content, understanding that there will be some microplastic content, probably, in any water. What do you think of this idea, and are we ready to start to set health guidelines– water safety levels, essentially– in terms of microplastics?

IMOGEN NAPPER: I think we still don’t know the full health implications yet. And the fact that we could be drinking them, they’re in our food, and we’re breathing in the whole time, by limiting it in our water supply, we’re still be going to get them in in other sources anyway. The thing that’s most important to me is just minimizing the amount of waste we create. And if we can minimize the amount of waste and completely change how we view plastic– it’s actually an incredible material.

And when I first started my PhD, I wrongly thought that it was evil, and it was the devil, and the only way that we could fix the problem was to just get rid of it. And I was wrong, and completely wrong. It’s a fantastic material that’s changed our lives. But where the problem is is that we’re making it for single-use applications that then we just throw away very quickly. And it’s such a persistent, durable material that’s designed to last a lifetime.

JOHN DANKOSKY: Nancy has a question here about our individual impact. Nancy, go ahead.

NANCY: Hi, thanks. Yeah, I was wondering, how can one person make a difference in reducing microplastics when this is such a large-scale problem?

IMOGEN NAPPER: Yeah, completely agree, Nancy. And my research has shown that the smallest change can have the biggest input. So even washing your clothes only when you need to will stop hundreds of thousands of fibers potentially entering the ocean.

We also did some research on microbeads in facial scrubs. No one knew how many microbeads could be in one bottle. And these microbeads are tiny plastic particles that were put into facial scrubs to act as exfoliants, so to get the dead skin cells off.

So for my first research project that I ever did, I got lots of facial scrubs– looked slightly crazy going to the supermarkets and getting 30 at a time. So I think they just assumed I wanted to be really clean. And I would spend crazy hours in the lab extracting them to see how many they were.

Originally, I thought maybe 100 or 200. But what we found was the opposite. We found three million tiny microbeads could be in one bottle of facial scrub. So in a squirt on your hand when you’re washing your face, there could be 10,000. Now these would go down the drain, similar to washing our clothes, through the sewage treatment works, potentially, and then into our oceans.

But the most exciting part was it showed me how consumers can have a really powerful voice. So people could go to the supermarket or the shop, and they could look at the ingredients list of the facial scrub, and if it contained polyethylene or plastic, you don’t buy it. You get a natural alternative instead, which is the same price or cheaper. Then industry started to listen to the consumer, because it was becoming very unpopular.

And hand on heart, I actually used to use these products. I never considered that they would have plastic in my facial scrub. And then industry started to listen, and they started to remove their microbeads voluntarily. And then from our research, it influenced governments around the world to ban microbeads in the US, in the UK, in Canada, in India, and throughout the world.

But the main thing it showed me is how consumers can have a really powerful voice, and it all started with the consumer. So never underestimate how small differences can make a huge impact. By not buying that one bottle of microbead facial scrub, you’re stopping three million tiny microplastics entering the ocean.

JOHN DANKOSKY: Are there any other products like that right now that are on the market that you’re looking at, where people could stop buying them and it really could help to save a lot of plastic going into our water system?

IMOGEN NAPPER: So luckily microbeads have gone, for the most part. We still to keep checking to check that industries aren’t using them. But for the most part, we’re all happy. But my bugbear is glitter, because most of glitter is plastic, and you see it so much in cosmetics. So if I could have a next thing to remove, it would be glitter.

JOHN DANKOSKY: Interesting. OK. Good to know. Judith from Baltimore has a question about some of the different types of plastic. Hi there, Judith. Go ahead.

JUDITH: Hi. Thank you. Is there any possibility there are any good plastics that break down into harmless elements?

IMOGEN NAPPER: We actually did some research looking at biodegradable and compostable plastics. And it was the longest experiment that I’ve ever done. So it was a three-year experiment, and I took samples every nine months. And I tested conventional carrier bags that had no biodegradable properties, biodegradable bags, and compostable bags.

And I put them in the soil, I put them in the sea, and left them hanging outside. The ones that were outside completely fragmented into tiny bits with that photo-oxidation, that sunlight we discussed. So they just went to microplastics, which you could argue is worse, because how do you clean up something that’s that small?

However, the biodegradable bags that were in the soil and in the ocean could still hold a full bag of shopping after three years. The compostable bag was still there in the soil, but did disappear in the ocean within three months. What it went into, we’re not sure.

But it showed me that it’s complicated. Just because something’s labeled as biodegradable and compostable doesn’t mean it’s necessarily going to break down in all environments. So we need to be really careful about greenwashing.

And I’m not saying they’re not a solution in the future, but in a really specific area they could work. So if you imagine a football stadium, where you might have some cups that are biodegradable, and they could be all removed and go to an industrial composter where it’s getting the heat and the moisture that they need, that would be fantastic. So we just need to make sure with industry and with consumers that we’re all singing from the same hymn sheet, and it’s completely clear and completely standardized so we understand how these products are going to behave.

JOHN DANKOSKY: And as you say, even in the ocean, if it breaks down entirely, you don’t know what it’s breaking down into.

IMOGEN NAPPER: Exactly. And we’re hoping to do some more research into that.

JOHN DANKOSKY: Christie from Evergreen, Colorado, has a question. Hi there, Christie. Go ahead.

CHRISTIE: Hi, good morning. I was wondering what the role is of plastic manufacturers. There are so many manufacturing facilities coming online. What role do they have?

IMOGEN NAPPER: So the plastic manufacturers are the key of making all of these wonderful products that we have in our day-to-day lives. And it all starts with something called nurdles, which are pre-production pellets. So they’re the tiny bits of plastic which are transported around the world. You find a lot of them on beaches, if a cargo ship ever loses some cargo and they end up spilling in the ocean.

But what the plastic manufacturers can do is discuss with industry and discuss with whoever needs these items, do we really need them? And is there a better alternative? And what I’m really keen to do is for every item that’s brought to the table that’s going to be made, we think of its circular economy.

So we think, OK, this water bottle is going to be made. What’s going to happen to it when it’s at its end of life? Can it be recycled? Can it be reused again? What’s the environmental impact? So we need to start thinking about the environmental impact right from when a product is being made, and that starts with the manufacturers and the industry that’s making them.

JOHN DANKOSKY: But you said this earlier– you really have begun to think that there are a lot of good that plastics do. The more you’ve learned about them, you understand their role in our society. It’s not like you’re saying, let’s ban all plastic.

IMOGEN NAPPER: Definitely. Plastic has really shown its worth. We need to treat it like gold. My mum still has jumpers from when she was my age that are plastic that she still wears, but she repairs them. Still has old Tupperware. My nana still has plastic items from when she was my age.

It’s a fantastic material that’s so durable. But we don’t need to make so many single-use applications, such as plates and coffee cups that could last a lifetime, but we use them for a matter of moments. So it’s really just changing the way that we think and we value plastic in our day-to-day life.

JOHN DANKOSKY: I’m John Dankosky, and this is Science Friday from WNYC Studios. I’m talking with Dr. Imogen Napper, a postdoctoral research fellow at the University of Plymouth in the UK. She studies microplastics. Why did you get so interested in this in the first place?

IMOGEN NAPPER: So I grew up in a small seaside town called Clevedon, which is in the southwest of the UK. And it’s an amazing old town, and we look over the estuary onto our neighboring country, Wales. But growing up, I never remember there being any plastic on the beach. And the thought of even doing a beach clean, I wouldn’t even fathom. I just didn’t think about that when I was younger.

But now I go back to the same beaches, and there’s beach cleans. I see plastic pollution. And I think, oh my goodness, this has happened in my lifetime. So what’s it going to be like in another 30 or so years?

And it upset me, but also, it was a big cause of curiosity. And I was able to mold that curiosity into research where I’m investigating– I’ve best been called a plastic detective. So I can look at the different sources and states of plastic to have my “piece of the pie” solution.

JOHN DANKOSKY: And that, I assume, helps you not get bogged down in just the enormity of this problem. It is something that, if you think about it, can make you pretty depressed, honestly.

IMOGEN NAPPER: I think we’ve all probably taken a walk down the park or down our street or to the beach, and we’re seeing plastic pollution, and it’s upsetting, because it’s our natural environment. But it’s important to remember the amount of good that’s happening. I even, just walking my dog today, saw someone pick up a bottle that wasn’t theirs and put it in the bin.

So we just need to remember that it’s our shared environment. We share the ocean. We share the air. We share our planet. So we need to treat it as shared and protect it like that.

JOHN DANKOSKY: And I like what you talked about, too, this thinking about even the things that we wear that are made largely of plastic that we can repair and reuse over time. I think, over the course of the last couple decades, we’ve come to think of recycling as putting a plastic bottle into a bin and somebody else is going to take care of it. But what you seem to be talking about is really thinking about, do I need that thing? And then recycling it if you can as many times as possible so that you’re not having to put it in that bin as often.

IMOGEN NAPPER: Exactly, just reusing it for another purpose. I have old tin cans I use as putting my pencils in, for example. So upcycling is a great way of giving something a new lease of life. But if your clothes break– and guilty as charged, I used to do this. If my jeans break or a jumper breaks, sometimes it’s just cheaper or just easier to go to the shop and just buy a new pair. But actually, what we should be doing is learning how to fix them, like in the good old days, to make our clothes last longer.

JOHN DANKOSKY: Well, that’s all the time we have. I’d like to thank everyone for so many great questions, but I’d also like to thank my guest, Dr. Imogen Napper, a postdoctoral research fellow at the University of Plymouth in the UK. Thank you so much for your time and your expertise. I really appreciate it.

IMOGEN NAPPER: Thank you so much, everyone.

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