Episode Transcript
[00:00:06] Speaker A: Hello and welcome to Great Exchanges.
[00:00:09] Speaker B: Great Exchanges is the show where we look forward to the Great Exhibition Road.
[00:00:13] Speaker A: Festival on Saturday the 7th and Sunday.
[00:00:15] Speaker B: The 8th of June.
[00:00:17] Speaker A: That weekend, exhibition Road is closed to traffic. It comes alive with cutting edge experiments, mind bending technology, music, dance, art, live science shows and even flash mobs. Everyone is welcome and of course it's free.
In Great Exchanges we meet some of the scientists from Imperial College London who are exhibiting at the festival and introduce them to members of the community with lived experience of the topics they're researching.
It's a dialogue between science and community.
In this episode we're looking at plastic. It's indispensable, it's involved in almost every facet of our lives and it's everywhere to the point that we now generate 360 million metric tons per year of global plastic waste.
To discuss the challenge of plastics, I'm delighted to welcome, from Imperial, Catherine Welsh.
[00:01:15] Speaker C: Hi, Piers, thank you for having me. It's great to be here.
[00:01:18] Speaker B: And Molly Parry.
[00:01:19] Speaker D: Hi, good morning.
[00:01:20] Speaker A: You're both looking at innovations in the manufacture of plastic and we also have Carolina Fattori from Urbanwise London. Carolina leads a team of volunteers on a weekly litterbik on the canal around Labrad Grove.
[00:01:34] Speaker E: Hello, Piers, Good morning.
[00:01:36] Speaker B: Hi there. Now you have to clean up a lot of this plastic because one of the things you do Urbanwise is you lead a group that cleans up the canal up there at the top of Ladbroke Grove. Could you tell us a little bit about that work?
[00:01:51] Speaker E: Yes, for sure. So the project Greener Canal side started in August, is a project from Urbanwise London and we aim to clean regreen and empower people to be part of the community.
So so far, since we started in August, we have been removed 425 kilos or of rubbish from the canal waters and the tow path is a huge amount.
[00:02:22] Speaker B: Wow.
[00:02:23] Speaker E: Yeah.
[00:02:24] Speaker B: And a lot of that, of course, is plastic.
[00:02:27] Speaker E: I would say most of it is plastic. And not everything that we collect can be recycled because of the state we found it because it's on the waterways. We are the only charity actually cleaning the waterways.
So it's a big work.
[00:02:44] Speaker B: Plastic, on the other hand, is incredibly useful. We use it for everything.
Why has it become so omnipresent?
[00:02:52] Speaker C: Yeah, that's a great question.
Yeah. Plastic is, like you said, very useful material. We use it in most parts of our daily lives. You know, from the drinks we buy in the shop to food packaging. Our clothing pipes in your kitchen, your car tires will have plastic in them. It's very Versatile. There's many different types of plastic. It's very durable, it lasts for a really long time. It's also very cheap, you know, plastic? Yes. A lot of it is made from oil, but only about 6% of the oil industry is used to make plastic and it's very cheap to do so.
And so it's very versatile in its usage, which is great.
[00:03:33] Speaker B: Molly, plastic's only been around in a commercial quantity since the 50s.
How's it taken over our lives so completely in 75 years?
[00:03:44] Speaker D: Yeah, so plastic, as Katherine said, is incredibly versatile and that means it lends itself to pretty much any application that you can think about. It's incredibly lightweight and it's incredibly durable. So whilst you might think about packaging, while you might think about plastic as sort of packaging in the supermarkets, plastic bottles, wrapping of vegetables, if you take a look outside, you'll also see that there's plastic in our bins, in our window frames, in our charging points for electric cars. And these kinds of applications are exposed to quite harsh weathering conditions.
So it's important that they're incredibly durable.
And this is one of the reasons that plastic has reached these kinds of applications.
We can also mass produce things.
So for example, in the medical industry, we can produce things like syringes and scalpels, completely sterile in the high scale rates. So that we've managed to completely change the medical industry.
And this wouldn't be possible without single use plastics. So they're not intrinsically bad, they're very accessible and they're very, they're very versatile. So that we can pretty much make plastic a suitable alternative to any application that we can think of, if we so desire.
[00:05:05] Speaker B: Would it be fair to say that all the things that make plastic great are also the things that make them a problem?
[00:05:13] Speaker C: Yeah, that's a really good point, actually, because like we're saying it's very durable and it's quite resistant to harsh conditions. But indeed those are the things that have made it a problem. It doesn't degrade in the environment.
And I think it's interesting to maybe think about do we want actually products which might not last as long, so they are degradable, you know, that shift. Because the focus really for industry has been make something that lasts a long time so we don't have to replace it, but not considering the consequences if we never have to replace it, where's it going to go?
[00:05:47] Speaker B: Carolina, what are the kinds of things that you find in the canal, the.
[00:05:51] Speaker E: Plastic items and if you can imagine, on earth, so from helmets, bicycle Helmets, sanitary pads, disposable gloves, bags, toys, lots of toys.
So we have been talking to a particular business where they have children in the site and the children have been throwing things in the canal.
So what we did as volunteers, we collected, we wash it and we brought back, we took back to the business. And through that they became more aware of the problem and the problem stopped happening. So I think lots of it is about awareness, people. Even though so many information has been around for such a long time, people are not aware of the issue with plastic. And through the volunteering, when we pass the net in the water and we see how many little pieces of plastic there is, people get shocked. The best people to work with are children.
First of all, they are fearless, so they go everywhere, they collect anything and they have a lot of energy. And second thing is, they get so shocked and they get so upset about people doing that. And I think they would take that back home and talk about it in schools and with the families, because people don't know. And there is such a deep diversity of ways of recycling through the borrows that makes everyone very confused.
So that I think is one issue that we could address.
Every. Every bottle recycled the same way and we have the same plastics.
And that will simplify much the issue, I believe.
[00:07:32] Speaker B: Yeah, I mean, that sounds like a very simple solution, but it's not the solution, is it? That's being worked on.
[00:07:41] Speaker C: No, not entirely, I think. Yeah. Simplifying plastic waste is. It can be quite tricky because there's so many types of plastic that we produce, and they can't all be recycled in the same way, recycled into the same material. So.
And then when it comes to the plastic materials that we have, even if you have the same material for a plastic water bottle, Coca Cola versus Fanta, they can be different colors and that's different chemicals going in there. So even very similar plastics can be very different.
So it becomes very hard to separate out and recycle the different types of plastic.
[00:08:21] Speaker D: Yeah. So a plastic is a really long molecule called a polymer. And the reason that we have different types of plastic is because we use different types of atoms in these molecules. And it might sound quite simple, but these can give plastics really drastically different process properties.
So all plastics have, you know, names. So the most widely used would be PET and polyethylene pe.
So that's things like plastic bottles that we see in when we get our. Yeah, plastic drinks bottles, shampoo bottles, and other kinds of hard plastic. And these are quite easy to recycle. You can imagine it really, if you want to melt something down and make it again, you can imagine that. But if you try and mix two different types of plastic together, you won't be able to get a material out.
The other problem is that you lose some of the desirable properties of plastics when you start the recycling process.
So like Catherine said, we have a lot of additives involved in making plastics and if we take loads of them together, you don't know what additives are involved. So you have kind of a mix of these in your final product.
So in order to get a nice, a nice looking plastic bottle that has some recycled content, you have to also incorporate new crude materials. So new materials that come from fossil fuels.
It's not very easy to make something that is 100% recycled.
[00:09:46] Speaker B: Before we started recording this, we went out and did a quick litter pick and I wonder if we might just have a look at a couple of things that we found just over the road in Tavistock Square. So, Carolina, what have we got here? The first item.
[00:10:03] Speaker E: So we have a lot of cigarette butts.
Those cigarette butts people don't know. But the filters contain plastic as well. So when you are smoking your cigarette, you are inhaling microplastics in your lungs. We have bottle leads, we have crisps, and those are packed packages are not recyclable at all.
[00:10:23] Speaker B: The shiny silver ones that look like they might be metal. Yes, they're plastic. Pure plastic.
[00:10:29] Speaker C: Yeah. And they last for a very long time in the environment.
They can take over a hundred years to break down. Really?
[00:10:37] Speaker B: What, a packet of Walker's Crisp?
[00:10:38] Speaker C: Yeah, yeah. If you just leave it and it can get into the oceans or like we saw just in the square over there, it will, it won't be the full plastic bag in 100 years time. It will have slowly broken down into smaller and smaller pieces. But you'll still see remnants of that original crisp packet after a very long period of time. And you can equate that to how long it takes you to eat a bag of crisps.
[00:11:01] Speaker D: You know, soft plastics are really challenging to recycle.
But a lot of supermarkets will have collection points. So if you want to save things like plastic bags and crisp packets, you can take these to supermarkets. But the products that we get out aren't necessarily as high quality. We can't make a plastic bag from a plastic bag. We'll have to make something else, something probably harder. And we don't have the recycling facilities, we don't have the infrastructure for this to be a sort of a roadside collection.
[00:11:28] Speaker B: Why Are they still making crisps in those bags that are so difficult to recycle?
[00:11:34] Speaker C: I think it goes back to that original point about plastics and they're just so cheap to produce. They already have the infrastructure for manufacturing. It's probably very expensive for a company like Walker's to upturn their whole manufacturing process and change it to a different type of plastic. So, you know, they might not have incentive within themselves from a financial point of view to change it.
[00:11:58] Speaker E: Well, yes and no. I think it's all about incentive and I think if the customer starts asking for it, the companies will change the policies. And if we start asking government to change it, they would start changing the policies regarding the plastic, the recycling. I think whoever produces the plastic should be responsible for the disposable of it. And it's a very simple process.
I understand the economical implications of it, but it's not impossible and it's quite straightforward. And I think that parts from the consumers saying, no, this is not okay, that's not the way we want it to be. And I think that nowadays we see a lot of things made of recyclable plastic or other items. There is even a company called are you mad? And we went visiting them with the volunteers to see what happens with the plastic, what is possible to be done. They collect plastic from the environment and they transform in other items. They are not a charity, they are doing it for North Face. They work with Selfridges, so they reuse it and do repurpose the plastic. They can use up to seven times the recyclable plastic so they can transform in seven different items. Is a process has a cost? Yes, it does, but is the way forward. And I think that we have to ask the government and the organizations and the corporations especially to be responsible for it. We can responsible for recycling and we should be more responsible for it. I think it will make much easier if, as I said before, all councils have the same method.
But I think that the companies have to be responsible for it.
[00:13:40] Speaker B: Government has in the past changed people's behaviours. For instance, the most famous thing is the charge for the plastic bags. It's either 5p or 10p. And fewer and fewer people actually take a new plastic bag from the supermarket because that tiny disincentive to the 10p disincentive just changes behaviors. On the other hand, in the old days we'd go to the green grocer and all the fruit and veg would all be on show, you know, in open containers and our, I don't know, our Fear of disease has meant that most of us now want to buy our fruit and veg wrapped in plastic so we can be sure no one else has touched it. We, we as consumers, we can change things. But also we've got to accept that a lot of the reasons for plastic is down to our own choices.
[00:14:38] Speaker C: A good example would be Coca Cola or Fanta, who now use recycled plastic bottles for their drinks. That incentive has definitely come from the consumer wanting a recycled material. It's not necessarily beneficial for them to recycle their products. Why would they do that if it wasn't just for us wanting something more sustainable?
[00:14:59] Speaker D: Yeah, it's a lot more expensive to make something from recycled material than it is to make something from, from new material. And it's also, again, you lose a lot of the properties. So whilst 20 years ago a company might not want to make a bottle out of recycled plastic because the bottle will look a bit dirty almost.
Nowadays you can instead put on them I made of recycled material and you can use that as a marketing tactic. So there is something consumer driven around companies making more sustainable choices.
[00:15:31] Speaker B: No, and that's great. At Imperial you're looking at new ways of manufacturing plastics, so some of these issues can be at least reduced. Catherine, tell us a little bit about your work.
[00:15:43] Speaker C: Yes. So I am a PhD student at Imperial College in the chemistry department and my research is focused on a plastic called polylactic acid, which is made from a chemical called lactic acid. You might know lactic acid is the chemical that builds up in your muscles after exercise, go off those marathons.
[00:16:01] Speaker B: Really?
[00:16:02] Speaker C: Yeah.
So it's actually a natural chemical. We can get it from plants, from things like corn or wheat. You can extract it and you can use this chemical to make plastic. And, and it's already commercialized. It's been around for about the last 20 or so years.
And examples of where people use it is in plastic cups. You might see a plastic cup that says I am a green cup on it. And if you look very carefully, it will often have an imprint which says PLA or polylactic acid. And this plastic is considered sustainable not just because it can come from natural materials, but it's also easier to break down in the environment chemically. Why that is, it has a lot of oxygen in it and the high level of oxygen in the chemical structure can make it break down faster.
So what I do is I look at improving the synthesis of this to make it more commercial. One of the problems is why not all plastic is polylactic acid. You might Be thinking, oh, that's great, why don't we have polylactic?
Yeah, exactly.
Well, as we've been saying, it's expensive to change a lot of infrastructure.
If you think of most plastic is made from oil. Shifting all of that to plastic made from corn is a big change in how you, where you get your materials from. But another issue about polylactic acid is it's almost as good as something like the plastic that makes a plastic bag. But often it's, it doesn't withstand heat as well, for example, and it can be quite brittle. So a lot of research is trying to improve its properties and trying to figure out how we can make it better, you know, so it can be applied maybe in industry more effectively.
[00:17:52] Speaker B: At the moment you mentioned cups. Perhaps if you're at a festival or somewhere, you might end up with a cup that says PLA on it. What are the other.
Are there any other significant commercial uses at the moment?
[00:18:05] Speaker C: Yeah. So one which is seeing a lot more use is in coffee cups. Because normal coffee cups, the takeaway coffee cups, last for a long time in the environment.
Some parts of them are often made of a plastic called polystyrene, which is very bad. And they're often black lids as well. And black plastic is very difficult to separate.
So you can use poly lactic acid as an alternative to, to plastic cup lids or as well the lining within a plastic cup or a coffee cup to make that more degradable. So you can make the rest of it out of paper and you can have a thin lining of a plastic to help keep it durable and withstand the temperatures of your hot drink.
But it's more degradable.
And yeah, another application of it is in yogurt pots. There are actually some yogurt pots that can be made from it.
[00:18:56] Speaker B: It does sound a little bit as though it's a niche product at the moment.
[00:19:01] Speaker C: I think I've seen online maybe PLA fibers used in clothing, but it still is very niche and it's not widespread. I think less than 1% of the plastic produced in Europe is bio based, the sort of polylactic acid type of plastic. So it's really a very small proportion of the plastic economy.
[00:19:21] Speaker B: Would it have the same relation to the rest of the plastics industry as say, biofuels do to the petroleum industry in terms of being a very small part, but growing?
[00:19:34] Speaker C: Yeah. I think PLA could hopefully one day be a bigger proportion of the plastic industry than biofuel is in. The fuel industry could be a more effective replacement within that context.
If we can improve the properties of it, you know, blend it with other types of plastics and you can diversify its applications.
So it's definitely a very feasible alternative to oil based plastic.
[00:20:00] Speaker B: Molly, so what work are you doing?
[00:20:03] Speaker D: Yeah, so I'm also a chemistry PhD student at Imperial in the White City campus.
So I look at the photo degradation of plastics. What this means is how plastics break down using so sunlight. So you might hear that the plastic in the environment takes hundreds or thousands of years to break down, but it does eventually break down. And the reason behind this is partially because of the irradiation from the sun.
I'm looking at designing additives for polyethylene, which is an existing plastic that will enhance the photo degradability of these plastics so that we can shorten the amount of time that they spend in the environment while maintaining the properties that make them so desirable. At the moment, I also look at the mechanisms behind why plastics photodegrade. And if we're able to fully understand these, then we can think about this when we design new plastics.
So these kinds of mechanisms will work in tandem with others. So in an ideal world, a plastic would have a kind of shelf life, a desired lifespan and then it would start to degrade. And the kind of molecular scale that I'm working at, this really will shorten the time between a microplastic and a, a plastic not existing anymore.
[00:21:14] Speaker B: Would you be able to incorporate them into the current production systems and supply chains or would it require starting again from scratch?
[00:21:24] Speaker D: So we already have obviously a very large scale production system for this.
There are.
The actual blending of additives is relatively simple. We wouldn't need to make a whole new polymerization mechanism.
[00:21:39] Speaker B: Carolina, this must be music to your ears.
[00:21:43] Speaker E: Definitely. I'm looking forward to it.
[00:21:46] Speaker B: You've been for the last nine months, you've been up and down the Grand Union picking stuff out of the canal. What are the ill effects you see?
[00:21:59] Speaker E: Well, I can see straight away into the wildlife.
It's very measurable because most of the. We have a lot of wildlife in the canal. You'll be surprised, but we see a lot of birds nesting on plastic.
[00:22:12] Speaker A: Wow.
[00:22:12] Speaker E: The nests sometimes are full, completely made of plastic. What's quite shocking and I wonder what is being fed to the chicks, for example. So it's something we see a lot of fish, not lots, but we see wildlife dead floating and we don't know, I don't know if that was affected by the consumption of plastic.
So we are waiting for the spring to go to end and we are Going to remove the plastic from the nests right now. We cannot do anything about it, but it is a real concern and it's quite palpable. And you can actually see it.
[00:22:52] Speaker B: Microplastics and what happens to plastics when they degrade is becoming a bigger and bigger issue as we're beginning to realize the effects. I mean, on the radio yesterday, they were talking about the fact that the biggest pollutant from roads is in fact the particulates that come off tires as they degrade. You've got stories about babies having plastics in their bloodstream, maybe even in their brain tissue. It's an issue that is growing and growing. You know, this is. We mentioned at the beginning of the show, this is only existed for 75 years. Is your research going to come soon enough?
[00:23:36] Speaker C: Oh, well, I think stemming the tide of plastic waste is the most important issue to tackle for which microplastics are a really growing part of. And so something to consider with microplastics is, as you said, plastics were first commercialized in the 1950s. Well, some of those plastics are known to not degrade for over 100 years. So the microplastics we're seeing now are from the 1950s, but we've been producing plastics year on year since then. So the amount that's going into the environment is exponentially increasing because it's just stuck around for 75 years.
So you would hope that research into new materials, new plastics, will help this issue. But I think really the key thing to change is consumption and production. We need to produce less plastic. That's sort of the base of it. We need to come up with alternatives because we rely so heavily on that as a material and it's so useful. But we really just need to produce less. So we put less into the environment.
[00:24:43] Speaker B: We're talking about consumers here. We've talked about consumers having the power to change things like the Coca Cola bottle. Are manufacturers doing enough to reduce the plastic they use?
[00:24:55] Speaker D: Yeah. So the problem is the scale of plastic production. It's millions of tons per year, hundreds of millions of tons.
And this isn't going to decrease while we continue to use as much as we do.
I think we know that consumers can drive changes. And whilst it is the responsibility of manufacturers, we need to make it clear that that is.
That is something that is viable. So as consumers, the. The most useful thing that we can do is reduce the amount of plastic that we use and dispose of it. Dispose of it responsibly.
[00:25:32] Speaker B: Yeah.
[00:25:32] Speaker A: I mean, there are simple things you.
[00:25:34] Speaker B: Can do, aren't there, for instance, buy a can of a fizzy drink because so much more. Was it 98% of aluminium?
[00:25:42] Speaker E: 98.
The most recyclable item in our system right now.
[00:25:47] Speaker A: Yeah.
[00:25:48] Speaker B: So buy a can rather than a bottle.
You will be highlighting this at the Great Exhibition Road Festival on the 7th and 8th of June in Exhibition Road. What will you guys be doing on the day?
[00:26:03] Speaker C: Yes. So our stand is focused on plastic waste, particularly plastic waste in the environment.
And we have a few different aspects to it. So one of the things we like to talk about is recycling and how people do their household recycling. As we were saying before, there's not one system in place, there's many different systems and in the past, a lot of people we've spoken to come to us saying they use different methods, they either put it all in one or where they're from, they have different bins for it. So we're trying to talk to people about what that means and what is being recycled. And part of this is talking about the different types of plastic that exist and not all plastics being the same.
Another thing we look at is how long plastics exist in the environment.
So we sort of play card games with the kids to see if they can guess how long a plastic lasts. And we also look at degradable plastics. So like the research I do on polylactic acid, I try. We've used some demonstrations to show how this can be used in plastic cups. But also isn't maybe the best material, as saying before, it can deform under high temperatures.
[00:27:12] Speaker D: Yeah. So it is our fourth year at the Great Exhibition Road Festival. We're really excited to return and I think the most important message that people get from our stand is learning how to tackle their household recycling better. So knowing what can and what can't be recycled, particularly if you're a plastic item.
[00:27:28] Speaker B: And where is the stand? Is it in?
[00:27:31] Speaker C: Our stand will be in the Green Futures Zone in the Sir Alexander and Fleming building.
[00:27:36] Speaker B: Carolina, you must be delighted that work is going on at one of our premium premier institutions to tackle the issue that you confront every weekend on the canal.
[00:27:50] Speaker E: Yes, I am.
I hope that will give people some views of what the issue is and maybe get more sensitive about how they dispose everything.
And I'm waiting for the carnival to arrive to have more volunteers because the amount of plastic will be immense.
[00:28:08] Speaker C: Is that something you saw last year, a lot of the plastic waste from Carnival particular?
[00:28:14] Speaker E: Yes. The good thing is people are not aware of how many people help actually and how many organizations work along the canal, the towpath to clean up the mess.
Of course we cannot rely on those good hearted volunteers all the time. If you think about Canal River Trust is the organization that looks after all the canals in England. We're talking about 2,200 miles of canals and waterways and they have a small crew to look after all of it and mostly volunteers.
So I think we need to to invest more on those organizations. On those organizations and people need to be more aware. Of course we have to reduce, that's for sure.
And let's see, we are working together to try to make a better world. Yeah, definitely.
[00:29:06] Speaker B: And Carolina, how do people volunteer for Urban Wise's initiative?
[00:29:11] Speaker E: So they can contact me on Carolina urbanwise.london or look at us in our website Urbanwise London www. Urbanwise London and they can just enroll. We every Wednesday afternoons we are doing the cleanups.
We do paddle and picks. If someone have a group of students or friends or corporation or anyone they want to participate, we can arrange a paddle and pick. We have experts, sport coaches that take us in the water with kayaks and bell boats. So if people don't feel very confident, they have the bell boat and they learn a little bit of paddling. We have all the equipment necessary for it and it's quite fun as well.
So I'm waiting for the emails to arrive.
[00:30:04] Speaker B: The Great Exhibition Road Festival takes place.
[00:30:06] Speaker A: This year on Saturday the 7th and Sunday the 8th of June.
[00:30:10] Speaker B: It's completely free.
[00:30:11] Speaker A: So come on down to Exhibition Road Road and discover an exciting range of events lined up from Imperial College London, the Natural History Museum, the Science Museum, the VA and all the other August institutions around South Kent. Portobello Radio is hosting the main stage.
[00:30:29] Speaker B: Where we have a spectacular lineup of artists.
[00:30:32] Speaker A: You can sign up via Eventbrite and be the first to find out about the free tickets for the most popular.
[00:30:37] Speaker B: Talks, workshops and shows.
[00:30:41] Speaker A: Thanks for listening. Great Exchanges is a collaboration between Imperial College London and Portobello Radio.
[00:30:48] Speaker C: Portobello.
