The mounting misgivings over microplastics
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In this edition of The Naked Scientists, what threat do microplastics pose to our health, and the health of the planet? Like this podcast? Please help us by supporting the Naked Scientists
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00:00:00
[Music]
00:00:17
Hello, welcome to the Naked Scientist Podcast, the show where we bring you the biggest breakthroughs in science, technology and medicine with me, Chris Smith.
00:00:26
From this week, what threat do microplastics pose to our health and the health of the planet?
00:00:32
From Cambridge University's Institute of Continuing Education, this is the Naked Scientist.
00:00:46
Plastic pollution has led to an explosive rise in tiny pervasive particles dubbed microplastics and nanoplastics, which have infiltrated biological and even geological systems across the planet.
00:01:00
The worry is that these could lead to serious health harms.
00:01:04
And last week, two papers looking at this subject peaked to our interest.
00:01:08
One considered baby birds eating diets polluted with plastic, while the other looked at the health and productivity of plants that at the end of the day we all depend on to feed us.
00:01:18
So we thought we should explore this topic in a lot more detail, investigating microplastics and asking what impacts they might be having and how.
00:01:28
But what exactly are they?
00:01:29
Richard Thompson is a professor of marine biology at the University of Plymouth and he coined the term microplastic over 20 years ago.
00:01:37
The small pieces, if you like, of the everyday plastics that we're familiar with in bottles, in crisp packets, parts of cars and aeroplanes that will break down in the environment over time into smaller and smaller pieces.
00:01:50
And then there are also sources that come from the wear of products while we're using them.
00:01:55
So the pieces enter the environment small and there rise, for example, from the abrasion of tires as you drive a car along the road or of textiles and clothing or even the walking around in them actually.
00:02:06
We've shown that millions of particles can be generated in a domestic wash, but over an annual cycle you probably generate as many these microplastic fibers while you're walking around.
00:02:16
It is part of a continuum and we've got evidence of harm stretching right to the way along that continuum where plastic pollution can cause harm.
00:02:24
You know, the larger items, the rope and netting can cause entanglement.
00:02:28
Smaller pieces, a few centimeters in length, are readily ingested by sea birds and turtles and can block the digestive tract.
00:02:36
Some of the smaller microplastics have the potential if they're eaten to pass from the digestive tract into the circulatory system.
00:02:43
Well, where are they then?
00:02:45
Is it just an ocean problem or if we look, land, sea, are they everywhere?
00:02:51
I can't, of course, say that they're everywhere.
00:02:54
The science can't tell us at the minute because we haven't looked everywhere.
00:02:56
What I can tell you is that pretty much everywhere we have looked, we've found them.
00:03:00
They're in the air we breathe, they're in the water we drink and they're in the food we eat.
00:03:05
We've found them from shorelines right down to the deep sea.
00:03:08
We've found them from the poles, literally to the equator.
00:03:11
And when we first did some of that work, I was astonished to find concentrations of microplastic in Arctic sea ice and in deep sea sediments that were greater than some of the concentrations I was finding in local waters near to me in Plymouth,
00:03:25
which is compared to the population of the Arctic or the deep sea considerably bigger and considering these particles come from humans, I was really surprised how all pervasive they were.
00:03:35
And I think there's an important point there to recognize about pollution from particles as opposed to substances that can dissolve or in sea water.
00:03:44
I remember my marine pollution, lecture saying the solution to pollution is dilution.
00:03:50
If you're dealing with a particle, those particles have the potential to disperse and become reconscentrated at distance and if they're harmful, that means that they could have potentially harmful effects at a distance because they can become reconscentrated.
00:04:06
And how might they cause harm and if they're everywhere, presumably nothing is immune from potential impact from them because we know that with, say,
00:04:16
asbestos decades ago, we thought this was an amazing material and indeed it is structurally fantastic, but when it breaks down into tiny particles, it gains a much more insidious behaviour.
00:04:27
So is this the sort of situation we're now confronted by with plastic?
00:04:31
We're going to start finding health harms that we never thought perhaps were out there.
00:04:35
When we first began using what we regard as an amazing material.
00:04:40
Well, plastics, of course, are amazing materials and used responsibly.
00:04:44
They have the potential to reduce our environmental footprint and to bring immense societal and economic value.
00:04:51
I think it's about learning to use them more responsibly than we have so far.
00:04:56
You're right.
00:04:57
They are everywhere now.
00:04:59
There are wide range of laboratory studies demonstrating potential for harmful effects on a range of different organisms, for example, reducing the capacity of small marine worms to gain weight in the normal way,
00:05:10
to put on weight and you might think, well, that sounds like some sort of slimming pill, but actually over a lifetime, that's going to reduce their focundity, their reproductive output, if you like, it's going to reduce their potential for survival.
00:05:22
And if you're a predator that feeds on one of those worms, it could reduce the food intake that's available to you.
00:05:27
But that's just one example.
00:05:28
It's a wide range of examples of evidence of harm.
00:05:32
We're seeing uptake by plants as well.
00:05:35
We humans are really just another species and the scientific consensus here is that while we've got reports of plastic in humans, and that doesn't surprise me because they're in the air.
00:05:47
We breathe.
00:05:48
The water we drink and the food we eat at the moment, understanding how those microplastics cause harm in humans is an emerging field.
00:05:57
Is this another asbestos?
00:05:59
People often ask me that question, it's impossible to say, and I certainly don't want to demonize plastics.
00:06:05
They've got the potential to bring a wide range of environmental benefits and economic benefits and have the potential to help us fix some of the problems on the planet.
00:06:13
I think it's about using them more responsibly and making sure they don't escape to the environment in any form because we now got considerable evidence of the potential for harm.
00:06:23
And that's harm to wildlife, it's economic damage, and it's potential harm to human health and well-being.
00:06:30
Richard Thompson, professor of marine biology at the University of Plymouth there.
00:06:34
So what might the health impacts be on us humans?
00:06:37
How heavily are we being exposed, and when we are, what actually happens if anything?
00:06:42
Well, studies have shown that plastics entering human lungs and intestines are getting into the heart, our brains, the water blood vessels, and are even being picked up in semen.
00:06:53
This suggests there may be potential consequences including increased risk of stroke, dementia, and possibly fertility costs, but is it too early to tell?
00:07:03
Tomorrow Galloway is professor of eco-toxicology at the University of Exeter.
00:07:08
There are all sorts of different ideas about how microplastics might impact human health.
00:07:12
Some of those relate to the presence of the small pieces of plastic themselves, so physical damage and others relate to the presence of different chemicals, particularly plastics additives that might be present in those plastic particles,
00:07:25
and then might leak out into the body.
00:07:27
A most of the suggestions relate to things like oxidative stress and inflammation, so the presence of those tiny little bits of plastics cause inflammatory changes to different tissues in the body.
00:07:39
The other thing that people have worried about is that plastic is made for oil, and it will go around collecting up a cargo of other oil-based molecules, and when you put these into your body,
00:07:49
it might offload that cargo into your tissue, so although there is a physical plastic effect, there may also be chemical damage going on as well.
00:07:57
That's right, the so-called Trojan horse effect, the suggestion is that that can happen based on lots of hydrophobic chemicals or contaminants in the environment, and also metals that might be floating around,
00:08:09
particularly in things like combustion from cars or air traffic.
00:08:13
How do we think, though, that these particles replete with their cargo, get into the body in the first place?
00:08:20
The most obvious route into the body is that most microplastics are ingested with food or drink.
00:08:26
They pass from the gut, there is evidence to suggest that the smaller particles can pass across the gut, then to the circulatory system and circulate through the blood.
00:08:35
It's also becoming obvious that there are plastics floating around in the air, so particularly fibrosmicroplastics.
00:08:42
These can be inhaled and entered the body through the lungs and then enter from the lungs into the bloodstream.
00:08:49
What sort of level of exposure do we all have?
00:08:52
Are we talking about a handful of particles here and there?
00:08:55
Are we talking about significant burdens of this stuff that we are breathing in and also eating?
00:09:01
The suggestion is that the vast majority of the microplastics that we ingest are in things that we eat and then pass into food substances from packaging.
00:09:10
Packaging is most likely a much larger source than, say, ingesting seafood that might already have microplastics in it.
00:09:17
As to exactly how much we're exposed to, well, that's one of the problems because we're not entirely sure it's very difficult, it's very technically challenging to do those kinds of measurements and know exactly how much there is in any particular human body at any particular time.
00:09:32
What's about all of us have microplastics in our bodies or ingesting them and excreting them at any particular time?
00:09:39
Is it a one way street then?
00:09:40
Once it's in, does it stay in or does it come and go?
00:09:43
The suggestion is that it comes and goes.
00:09:45
Particles that are taken up across the gut pass into the lymphatic system and the blood system and then they can circulate through the body.
00:09:53
And ultimately they'll be cleared through the liver and the kidneys and they'll be excreted in feces and urine.
00:10:01
So, although they might circulate in the body, the vast majority will be excreted after a certain period of time.
00:10:08
What we don't really quite understand is what happens to the particles that might be retained within the body, particularly the smaller sized particles that are much harder for us to measure.
00:10:17
And what organs are we particularly concerned about?
00:10:20
Well, a lot of the organs that have been studied have been highly vascularised organs, so that means organs that have a high blood flow.
00:10:28
So, things like the liver, the heart, even the testes and the ovaries.
00:10:33
These have all been studied and shown to have tiny pieces of plastic present in them.
00:10:37
What we don't know is whether that has any significance yet for human health.
00:10:42
Indeed, it must be a hard one to prove because I suppose we've got different people alive in different places for different lengths of time with different levels of exposure, different diseases.
00:10:53
So, trying to tie this together and show that a core of causal relationship must be really, really tricky.
00:11:00
Absolutely, and you've got the heart of the problem there because we're not talking about one individual thing that people are exposed to.
00:11:07
We're talking about lots of different kinds of plastics, of different shapes and sizes.
00:11:12
We're talking about people in the general environment who are exposed to all sorts of different things at any particular time.
00:11:19
They'll be eating different food, they'll be living different lifestyles.
00:11:23
A lot of the ill effects that we are expecting, or we are predicting might occur due to plastics and microplastics, are very diffuse things.
00:11:33
They're chronic disorders.
00:11:34
We're not talking about acute toxicity here that you could definitely say somebody's collapsed from plastic poisoning, say, in the same way that you might look at lead or arsenic or highly toxic substances.
00:11:46
They're looking at very subtle effects and they're very hard to identify in population studies.
00:11:52
Do you think it's the USbestos?
00:11:55
I think there are all sorts of things that we don't yet know about microplastics.
00:12:00
One of the most interesting things that we can try to understand is how plastics relate to other particles that we might have in our body.
00:12:07
So, what is our expose home?
00:12:09
How are we exposed to different particles?
00:12:11
How are we exposed to different chemicals?
00:12:14
How many of those what might we be able to avoid?
00:12:16
Is it an issue that we're breathing in all sorts of different things altogether?
00:12:21
And what can we do to reduce our risk?
00:12:23
I think those are the most important things to focus on.
00:12:25
So we just don't know yet.
00:12:27
Are the plastics innocent passengers in our body or might they have harmful consequences?
00:12:33
That was Tamara Galloway, she's professor of ECHO toxicology at the University of Exeter.
00:12:38
The Naked Scientist Podcast is produced in association with Spitfire, cost-effective voice, internet and IP engineering services for UK businesses.
00:12:48
Find out how Spitfire can empower your company at Spitfire.co.uk.
00:12:53
Music in the programme is sponsored by Epidemic Sound, perfect music for audio and video productions.
00:13:02
And this is the Naked Scientist Podcast with me, Chris Smith.
00:13:06
And this week we're taking a closer look at the latest research on microplastics and how they might be harming our health and also the health of the planet.
00:13:14
A bit later we'll hear how even plants might be affected.
00:13:18
First though, as we've just been discussing, meaningfully tying plastic exposure to health harms is extremely hard to do.
00:13:25
But there are ways to begin to build a body of evidence.
00:13:29
Remember that study I mentioned earlier about baby birds eating plastic?
00:13:33
It just came out in science advances and it does address some of the outstanding questions.
00:13:38
The team in Hobart have collected samples of blood and stomach contents from Sable Sheerwater seabird chicks.
00:13:45
Those with higher exposures to plastics had protein circulating in their blood indicative of damage to their stomach lining, and they also showed signs of neurological impacts as well.
00:13:56
Alex to Jersey, from the University of Tasmania, authored the study.
00:14:00
Seabirds have been well documented to consume plastics.
00:14:03
We've learnt about this since the '60s, but what we know about plastic and ingestion in seabirds really comes down to the lethal impacts.
00:14:12
We're seeing birds that are entangled or we're seeing them dying of starvation or really emaciated and sickly looking individuals.
00:14:19
But we wanted to look really early on in the condition and understand what are the health impacts of just having a few pieces of plastic in your stomach, because they're seemingly many individuals out there living what looks to be a normal life while carrying this plastic burden in their stomach.
00:14:35
How did you pursue it?
00:14:37
We had down to Lord Howe Island, every April and May, to contribute to a long-term monitoring program at the Sable Sheerwater and to document their extremely high rates of plastic ingestion and we'll go and grab some birds and we took a blood sample.
00:14:53
Blood samples are awesome.
00:14:55
If you've got something wrong, a human will or us, we'll go down to the GP and the first thing our GP will do is probably request a blood test and it can be a really great tool to start to begin to investigate what's going wrong.
00:15:06
At the time of blood sampling we also encourage the birds to vomit.
00:15:10
This process is called the barging and so we'll also be able to remove their stomach contents and see just how much plastic is sitting in the stomach of that bird.
00:15:18
Right, okay.
00:15:19
And so you can then marry up what the blood is showing you with what the plastic burden is so you can kind of say, well, one might be associated with the other.
00:15:27
Yes, exactly right.
00:15:29
And we've got two groups.
00:15:30
We've got birds that don't have any plastic and then birds that do have plastic so we can really start to disentangle what the health consequences are of that plastic burden.
00:15:38
And presumably the origin of that plastic is what the parents are feeding them.
00:15:43
That's correct, yeah.
00:15:44
And what do you find then?
00:15:45
So when you marry up those blood samples with the plastic burden, is there an impact?
00:15:51
Yes, there's definitely an impact.
00:15:53
And to do this we looked at proteins and proteins are a great tool.
00:15:56
We used a technique called proteomics, which allows us to look at the most abundant proteins, whether you're digesting food or responding to an infection or you know, getting ready for a migration.
00:16:07
We can start to see proteins change within the body to help your body prepare for those things.
00:16:12
And there are certain hallmarker proteins that will help us to look at the health of your overall body or how your organs might be functioning.
00:16:19
So what sorts of things are wrong with the birds that have a high plastic load?
00:16:23
The least surprising thing was that we saw a change in the stomach proteins.
00:16:29
But what's really interesting about this is that the stomach is quite unique in nature as these proteins should stay within the stomach because they're highly specialized to that acidic environment.
00:16:38
They're working in an environment that's got a pH of 1 to 2.
00:16:42
And so these proteins have no biological function outside of the stomach.
00:16:45
But fascinatingly we were seeing a higher concentration of stomach derived proteins within the blood.
00:16:52
And so this is kind of showing that in those high plastic impacted birds that we're getting a breakdown in that stomach permeability.
00:16:59
And this isn't massively surprising.
00:17:01
You can imagine having big places of plastic in your stomach rubbing up against your stomach wall that were likely to get perforations and this plastic causing leakage within the stomach.
00:17:09
Next up would probably be the filtering organs.
00:17:12
So with the kidneys and liver, they produce copious amounts of proteins, one in particular that the liver produces is the albumin.
00:17:19
And this is one of the most abundant proteins within the blood.
00:17:22
And within the high plastic impacted birds, we saw quite a large decrease in the production of albumin.
00:17:28
So it shows that these liver and kidneys are not functioning as they should be.
00:17:32
Right.
00:17:33
And what else did you see?
00:17:34
The most surprising to me was a decline in a protein called BDNF, which is a brain derived proteins.
00:17:42
And there's this fantastic researcher at Utah's called Jessica Collins.
00:17:46
And her research has found that low levels of BDNF is a signature of cognitive decline in elderly people.
00:17:52
And we are seeing a similar signature in these chicks.
00:17:56
And this is fascinating because these chicks are 90 days old and they should be living well into their 30s.
00:18:00
So to be seeing evidence of cognitive decline at such a young age is quite alarming.
00:18:05
Obviously in this paper, you have taken a measure of plastic and then you've measured these other physiological markers of health.
00:18:13
One, we don't know at this stage that one causes the other, but it's very, very tempting to speculate that they're connected in some way.
00:18:20
So what do you think the mechanisms are behind all this?
00:18:24
It is incredibly hard to pick that apart.
00:18:26
We've talked about a few different hypotheses within our paper.
00:18:29
But you know, microplastics could really be at play.
00:18:32
We've seen evidence of them embedded in tissues when we're in a crop seed, the same species previously.
00:18:37
Unfortunately, we didn't have access to tissues.
00:18:39
So it's really hard to start to make those links.
00:18:43
To what extent does this begin in the egg?
00:18:46
And to what extent does it then get reinforced by feeding?
00:18:50
Have you looked at eggs to see if parents are making eggs that already contain a plastic burden and therefore might already be setting their chicks up to fail and then they make the problem worse by what they feed their chicks?
00:19:04
Yeah, we would love to do an egg study, but it can be incredibly challenging to find those eggs and then be, have enough of a cohort to create a study.
00:19:14
So that's an incredible like big wish study.
00:19:16
You know, there's some birds that are fine and they're not getting plastic and they're going off on their merry way.
00:19:21
So we can attribute a lot of this to the chicks that are being fed copious amounts of plastic from their parents.
00:19:27
And what is the food that the parents bring back?
00:19:29
Is it a fish based diet?
00:19:31
Now they're therefore getting it out of the oceans.
00:19:33
Yeah, so these birds will typically eat fish or squid and within the plastic that they pick up, we say that they tend to fail out white or blue pieces.
00:19:41
So it's thought that they're you know, selecting this plastic by misidentifying prey.
00:19:49
I suppose then there's two possibilities aren't there.
00:19:51
There's physically giving the young big bits of plastic we can see, but then feeding them animals like squid and fish that may have themselves ingested small particles of plastic with whatever toxic burdens attached to that.
00:20:06
So they could be getting a double whammy here.
00:20:08
Yeah, it can be really incredibly challenging to start to pick that apart.
00:20:12
You know, proteomics is a great tool.
00:20:14
It's proteins are highly conserved across taxa.
00:20:17
And so it is quite likely that we're seeing these impacts across a numerous amount of species that consume plastic, which include humans.
00:20:24
And so I would love to be seeing this tool more commonly used within wildlife conservation to start to really paste together the full picture of plastic impacts on our wildlife.
00:20:32
A fabulous study, but the message is worrying, isn't it?
00:20:36
That was Alex to Jersey there.
00:20:37
She was talking to us about her paper just out in science advances.
00:20:41
Predictably, we've dwelled very heavily so far on the potential human and animal health costs from plastic exposure.
00:20:48
But there is growing concern that plants might be hit too and their ability to carry out efficient photosynthesis, in other words, grow, could be compromised.
00:20:58
This really matters because plants are of course nature's solar panels that turn solar energy into food for other living things.
00:21:05
Microplastics, some scientists are showing, can physically block sunlight from reaching the right parts of the plant, and they can also lead to the formation of reactive molecules that further compound the damage.
00:21:17
With this in mind, Chinese scientists have this week attempted to model the extent and the productivity cost of the problem.
00:21:23
It could, they argue, increase the number of people at risk of starvation by 400 million in the next two decades.
00:21:31
Richard Lampit, professor at the National Oceanography Centre, has been taking a look at the paper for us just out in PNAS.
00:21:38
Well, this is a really important study because it focuses on one of the most important issues of environmental pollution and that of producing food crops.
00:21:48
So what they do is they produce the model which calculates, which leads to a calculation of what is the loss of productivity of our farms and our seas as a result of plastic pollution,
00:22:02
microplastic pollution.
00:22:05
And these are really big numbers, they come up with 10-12% reduction in the chlorophyll content, that's the pigment which enables plants to grow.
00:22:14
And what we've got is a reduction in main crop production of 4-13% and 0.3-7% for the aquatic side of things.
00:22:24
So these are really big reductions as a result of plastic pollution.
00:22:28
And it's something we need to be very careful about and be concerned about.
00:22:31
And looking at it another way, how many people does that not feed?
00:22:36
So the order of several hundred million people are going to be deprived of food as a result of this pollution.
00:22:43
Now is that the here and now?
00:22:45
Is that the status quo or is that taken to its logical conclusion with the current trends being what they are?
00:22:52
That's in the here and now, but what they did was what is going to happen in the future and if there are is a reduction in the amount of plastic pollution, how many people would be saved from this level of starvation?
00:23:06
What do they invoke as the mechanism though?
00:23:08
How do they think that the plastic particles are cutting down the photosynthesis in the plants so that it has this dramatic knock on effect for productivity?
00:23:17
Well, it's quite good evidence, certainly in terrestrial environments, that plastics do affect productivity.
00:23:25
I mean, it certainly does occur, what it's doing is it's in some way affecting the defense mechanisms of plants so that as a result of that, they react in a way which is not appropriate and then their productivity decreases.
00:23:41
And certainly in areas, particularly in China, where we've got about 12 percent of the farmland is covered with plastic mulch, which does lots of good things in general,
00:23:51
retaining moisture and keeping the soil warm.
00:23:54
But in spite of that, there is this very large amount of plastic which gets into the soil and does affect the productivity of those plants that are growing them.
00:24:05
This is very much a model, so they've taken what we think is the case, scaled it globally and then said, and if that is the case, this is the consequence.
00:24:15
So is that a reliable way of doing this?
00:24:18
This is really where I have a bit of a problem with the paper because it's taking an enormous number of assumptions.
00:24:25
Every step of the way is plagued by major uncertainties and so you end up with conclusions which really, in my opinion,
00:24:36
are not very robust.
00:24:38
Really important, as I said earlier, to get this sorted out, to understand this, but this sort of implied accuracy is really not supported by the data.
00:24:48
As far as I could understand, and in fact, a lot of the data, which they say they are using, is not quoted, so one's not able to find out how good those data are.
00:25:00
So lots of big uncertainties right away along the line going for instance to the effects on the chlorophyll, the pigment concentration, how does that translate into productivity,
00:25:11
how does productivity for plants convert into food production, particularly in the aquatic area in the seas and rivers, which I'm a bit more experienced in.
00:25:22
There's a really big uncertainties in those links.
00:25:26
Nevertheless, if we have got half a billion people potentially going hungrier than they should because of a lower productivity as a consequence of this, it's still an important viable mechanism and presumably deserves more attention.
00:25:41
Oh gosh, yes, there's absolutely no doubt about that.
00:25:43
Much more attention has got to be given to this, because this is obviously a fundamental issue of our ecosystem and the ecosystem's services is how much food do they produce.
00:25:53
So if those are getting impacted in the way that is indicated in this paper, then we've got to be concerned about it, along with all the other effects of plastic on ourselves and on the environment from an ethical as well as a practical point of view.
00:26:07
Thanks to Richard Lampit from the National Oceanography Centre there.
00:26:11
So at the moment there's evidence of a smoking gun linking wide-scale plastic pollution with health impacts potentially across the biosphere.
00:26:19
But what I asked marine biologist and microplastic specialist Richard Thompson who opened the show for us should be our next move.
00:26:27
Yeah, it's a really good question and often I feel it can be a distraction, you know, if we make a mess, I think it's almost in human nature to want to clean it up immediately.
00:26:37
The challenge here is though, at the minute, the quantity of plastics going into the environment across the whole size spectrum is so immense that clean up and focusing on cleanup alone would be a little bit like trying to mop the bathroom floor while the tap was still running and the bath was overflowing.
00:26:53
We need a more systemic answer and some of that is going to involve reduction in the quantities we use.
00:26:59
If we think about the waste hierarchy, it's reduce, reuse, recycle and it's clear to me there are some plastics that we could manage without but some plastic products, you know, whether that's a single use carrier bag,
00:27:11
a single use water bottle, are we using plastics only in ways that are essential?
00:27:18
What we really need is criteria to ensure that the plastics that are used and the products that are used are safer and more sustainable than they are today.
00:27:26
That's safer in terms of the chemical composition.
00:27:29
We also need to make sure that the plastics are more sustainable.
00:27:33
You can do that by reusing some plastic items, the single use carrier bags, the refillable water bottles and beyond that for the plastics that are essential to us, we need to try to design them to be more circular and that's going to need us to simplify the format so that we can scale up recycling efforts.
00:27:50
People say to me, you know, we can't recycle our way out of here or recycling has failed and it has to an extent because we're only recycling globally less than 10 percent of all the plastics we produce.
00:28:01
It's not just a problem associated with recycling technology.
00:28:05
The challenge as I see is that we're failing to make items that are compatible with circularity.
00:28:11
You look at the thousands of different chemical additives, the dozens of different chemical permutations, the complex products that we're making for single use applications that have multiple layers of different types of plastic that make them almost impossible to recycle.
00:28:25
In short, in order to improve that third R, the recyclability, the circularity, so that we're using end-of-life plastics as the carbon source for new plastics.
00:28:35
If we can do that, we decouple ourselves from the waste that we've talked about in the oceans and on the land, but we also decouple ourselves from the use of fossil oil and gas as a carbon source.
00:28:46
When I talk to product designers, they say they were never asked to think about end-of-life.
00:28:50
Even for a single use bottle, that seems incredible to me, that you're designing something that brings convenience to humans for an instant, yet can persist on the planet for hundreds of thousands of years.
00:29:02
That's the bit that's got to change.
00:29:04
We've got to think about plastics right from the design stage to make sure they're safer, more sustainable, don't escape to the environment, and don't, therefore, release microplastics.
00:29:15
Indeed, the solution to pollution is not dilution.
00:29:19
Richard Thompson from the University of Plymouth, there.
00:29:22
That's all for this episode.
00:29:23
Do join us next time, though, for our weekly take on the latest scientific breakthroughs, including why whale-wee is critical for ocean health and diversity, and also we're looking at the rising tide of antimicrobial resistance and what we can do about it.
00:29:37
If you've enjoyed this programme and you enjoy what we do for you each week, do please consider supporting the naked scientists we rely heavily on the donations that you send us to keep the show on the road.
00:29:47
You can do that by going to nakedscientist.com/donations and thank you very much indeed to everyone who has.
00:29:54
We are really, really grateful.
00:29:56
Meanwhile, it remains for me to say the naked scientists comes to you from Cambridge University's Institute of Continuing Education.
00:30:03
We're supported by Rolls-Royce.
00:30:05
I'm Chris Smith and for more all of us here at the naked scientists team, thank you very much at home for listening to us and until next time,
00:30:17
goodbye.
00:30:21
[Music]
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