US-UK nuclear deal, and forensics for plastic pollution

0:12Hello,

0:19welcome to the Naked Scientist podcast. This is the programme that brings you the biggest breakthroughs and talks to the major movers and shakers in the worlds of science technology and medicine i'm chris smith and coming up the us and the uk have forged a long-term nuclear alliance but what will it really deliver we also examine a new study on whether smoking cannabis makes it harder to get pregnant and we'll be hearing from a forensic scientist who's using detective work to track where the microplastics are in our oceans

0:57First this week, the US President Donald Trump has been making a state visit to the UK and amid the pomp and ceremony, he also arrived with a number of high-ticket deal proposals between the US and the UK, including one centred on nuclear energy. Nuclear is regarded as a significant future player in helping the country to meet its net-zero ambitions. The US proposal sets out a vision for a fleet of advanced gas and small modular reactor technologies. UK Prime Minister Keir Starmer said it will usher in a golden age of nuclear. Supporters point to the clean energy and the new jobs this will provide.

1:34The critics, for their part, have warned of ballooning costs and safety issues. So is this agreement really all it's cracked up to be? Well, we asked Simon Taylor at Cambridge Judge Business School. He's the author of The Fall and Rise of Nuclear Power in Britain, a history to take us through it. The main part of the announcement is two deals for cooperation between American and British companies, in one case, small modular reactors, and in the other, advanced modular reactors, which are similar but slightly different. In each case, joint investments in the UK, you know, in the region of£10 billion or more.

2:11That's not a huge amount of money, though, is it? When we look at Hinkley, one power station costing double that, this is really a starting point, presumably. Well, both of these, I think, should be seen in the context of the British government's support for a lot more nuclear investment over the next few decades. And most of that investment likely to be in the form of small modular reactors or similar, as opposed to big reactors, the so-called gigawatt reactors, like Hinckley. The government is still, at least in principle, committed to one more big reactor. But I think the general emphasis of policy is around small modular reactors.

2:51And in that sense, yes, this is not a huge amount, but it could be the first of several investments that could build up over time to quite a substantial amount. Why does the UK need the US at all, given that we We have Rolls-Royce and they've already tabled a plan for small modular reactors and we're already building nuclear reactors. We point to Hinkley as an example, Sizewell has also been approved. Why do we need the involvement of the US? Why is this a big deal? Well, you're right to point to Rolls-Royce. Rolls-Royce has a so-called small modular reactor, but actually it's around 300 megawatts, which is actually not small according to the somewhat arbitrary definition of the International Atomic Energy Agency.

3:34but there isn't necessarily a single optimal size for reactors it depends what job you want them to do the reactors being proposed in the two deals one of which is with the british company centrica better known as british gas and the other with edf which is of course technically a french company parent company is actually the french government they're much smaller and there's also another deal third deal for so-called micro reactors so what this is bringing is a range of different designs of different sizes of reactors. And in the case of the Centrica proposal for so-called advanced modular reactors, they are designed to generate high temperature heat, which can be used for industrial processes, whereas an ordinary nuclear reactor doesn't generate that kind of heat.

4:16So, you know, there are different models for different purposes. In terms of the practicalities of actually doing this, building these things and running these things, let's start with the fuel, first of all. Where will that come from? The ultimate source of fuel is outside the UK, and that's not going to change. I mean, the UK does not have its own uranium sources, but you can get uranium from, let's call them friendly countries. There's quite a lot of uranium around the world. But some of the fuel fabrication and enrichment is done in the UK. And one of the other aspects of this deal is to increase the ability of the UK to do fuel enrichment and fabrication.

4:56In fact, to then export that to the United States. And the waste that arises, I mean, it's not going to be huge amounts compared with other ways of generating energy potentially. But waste is certainly a thing and a thing that people worry about with nuclear power. Well, there's no question that nuclear fission produces waste, some of it extremely toxic, some of it very long lived. And more modern reactors tend to produce a lot less volume of waste. Incrementally, the problem is not getting worse as much as people might think. And we're not talking about physically a very large amount of waste.

5:31But it is fair to point out that the UK currently doesn't have a clearly identified site for long term disposal. Now, that said, it's not urgent from a practical point of view. These reactors are designed to run for at least 40 years, some cases 60 years, and therefore there won't be any waste problem until the end of their lives. So we're talking well into the end of this century, if not the next century, which gives us plenty of time to come up with a practical solution. But obviously, some people think ethically it's dubious to create a problem which you haven't yet identified a definite solution.

6:07That's a very good point. What about also the proportion of energy we'll get from this? What's the bang for our buck in energy terms? If we go through with this, and this comes to fruition the way that everyone is saying it will, what does it look like in terms of the energy map of the country? I think the government's overall plan is to have nuclear contributing a significant share, so something in the region of 15 % to 20 % perhaps of total electricity supply over the medium or longer term. In the past, it's been as high as 20%. It's currently much lower and falling because the older reactors are closing.

6:42And although we have Hinkley coming online perhaps the end of this decade and then Sizewell 10 or so years from now, that together with Sizewell B, which is still operating, will not meet that target. The question of how many more reactors get built is partly an economic question. I mean, a lot of this hinges on these reactors turning out to be as claimed, namely that they are cheaper than existing big nuclear. but also there may be some special use cases there may be some niches as i say high temperature reactors are particularly suitable for a big industrial cluster where you have a need for for heat and there's a lot of attempts to try and find ways to use particularly very small reactors in ways that we would not have used reactors in the past so that it could be that the reactor share gets bigger but we're talking you know some decades away before that really happens Simon Taylor at the Judge Business School there.

7:34If you intend to get pregnant, it might be best to steer clear of cannabis. That is the finding of a new study which shows that THC, the main psychoactive component in the plant, can harm female fertility and reduce the success rates of IVF. The drug appears to accumulate in the fluid that surrounds developing oocytes, the egg cells, And this accumulation is associated with a greater chance of producing embryos that have the wrong numbers of chromosomes and therefore a lower rate of viability. The study was conducted by Cynthia Duval at Create Fertility Centre in Toronto, and I've been speaking with her.

8:12So we did two different studies. In the first one, we measured the cannabinoids levels, the cannabinoids coming from the plant, the cannabis. So we call them the phytocannabinoids. We measured these concentrations in the fluid that surround the oocyte. So during oocyte retrieval, we retrieved not only the oocyte for IVF treatment, but also this fluid that helped the oocyte growth. And we were able to measure the exact concentration of phytocannabinoids in this fluid. So this is in users of cannabis. You can show that in the fluid around their eggs, you are picking up cannabis-like chemicals. That doesn't, though, prove that it is affecting what the egg's doing, does it?

8:59So how do you then take that forward? For these patients, we looked at their IVF outcomes. We looked at how many oocytes we retrieved, how many of them fertilized, how many of them became an embryo, a blastocyst, and how many of them had the right number of chromosomes. And what did you see? For this particular part of the study, we saw that patients that were positive for cannabis consumption had lower number of embryos with the right number of chromosomes. So what we call the Eupleid rate was lower for patient positive for cannabis. Do you know that's down to the cannabis though? could it be that people who might be using cannabis might also be using more alcohol or eating a more deleterious diet and that might be doing this how do you know it is the cannabis that's that's likely to be linked to that we also did different correlation analysis especially with the ivf outcomes and the levels of cannabinoids so the more thc and its metabolites present in the follicle, the more the oocyte maturation rate was affected.

10:12So it's just adding another association with the level of THC in the follicles with the IVF outcomes. But we cannot for sure and be 100 % sure that it's only the THC. Like you said, it could be many different. Indeed, I mean, it could be multifactorial, couldn't it? But you've still got that strong association. How big is the effect though? Is it big enough to say there is a clinical impact on fertility or are we talking about something that is statistically significant and if you look in millions of people you're going to find it but really by and large there are other things that make a bigger difference on whether or not you're likely to get pregnant?

10:51I love that question especially when we talk about fertility and IVF settings. There's this inverted pyramids in IVF, where at each step of development, we're going to lose some of the starting material. So let's say we have 20 oocytes, and then 90 % of them will become mature, and then 70 % of them will progress to day three embryos, and then another 50 % of them will progress to blastocyst, which is the final stage of embryo development in vitro. Each time there's a decrease in one of these categories, it will be exacerbated for the following steps. So that's when we calculated the number of available embryo for transfer for patients that consume cannabis, they add lower embryo to transfer because of what we saw.

11:45What are the implications of this then? So if someone's used cannabis, does the fluid around their eggs remain laced with these chemicals for long periods of time? Or is there a washout and likely if they just stop, bearing in mind what you've now discovered, they can put their prospects of pregnancy back up to where it would be at baseline if they'd never touched cannabis? That's something we cannot answer in humans. We know that phytocannabinoids and products from cannabis will stay in the system approximately one month. So if you consume cannabis during your IVF treatment, we would be able to detect it in your follicular fluid.

12:25However, it's highly dependent on the amount you're consuming, the frequency and your whole metabolism. So that's something we could not address with this study. Can you speculate as to whether there are long-term indelible footprints stamped on your oocytes by using cannabis? Because of the difference between men and women. Men make sperm all the time, of course. Women are, when they're pregnant with a baby, if the baby's a girl, that's the grandchildren already in that pregnant woman, isn't it? So it's a lifetime of exposure to those eggs. So can you answer that question or is it just too early to say?

13:03Too early to say, but definitely a very interesting question. History has shown us that people that consume cannabis can have children and they're not completely infertile. So I don't necessarily want this study to be fear-mongering in any cases, but any exposure to pollution, drugs or plastic components, you have to be careful because yes, it has been shown to be transgenerational. So yeah, we have to be conscious about that without being scared of leaving the house. fascinating insights into the relationship between cannabis and reproduction that was cynthia duval at create fertility center in toronto that study has just come out in nature communications the naked scientists podcast is produced in association with spitfire cost-effective voice internet and ip engineering services for uk businesses find out how spitfire can empower your company at spitfire.co.uk

14:10Music in the programme is sponsored by Epidemic Sound, perfect music for audio and video productions. This is the Naked Scientist podcast with me, Chris Smith. Still to come, are you 6G ready? What does that even mean and do we really need it? But first, and on the subject of 5G and possibly 6G, we're going to explore how we can use our phones and other mobile devices to help clear up plastic pollution. The University of Staffordshire's Claire Gwinnett has been using her forensic science skills to track microplastics in the oceans and she's been developing an app that lets anyone sample water and then map pollution hotspots internationally.

14:49The goal is to build a big global database to monitor microplastic levels. There is a lot of work out there in trying to understand how much of these particles are in our environment but a lot of the time these are just in one place one time and for us to be able to understand trends and hot spots and really understand actually how much is there we do need more data and where citizen scientists have helped before that is in a sort of larger fragment size things that you can physically see with the naked eye so easier to identify and count but the big bit that's missing is in the smaller particulate sizes so we're talking about smaller than 300 micrometers and even down to sort of like 50 micrometres and less.

15:34And to give you kind of a context there, the average width of a human hair is 60 micrometres. So this project is about getting data at that smallest size range. Richard Thompson, who coined the term microplastics 20 years ago, we had him on the programme earlier in the year. The point that he was making is these things are very, very small. You need a lab like the one he runs to see them. So how do you propose to get the average man, woman and child in the street hitched up to this project? That's the real challenge, because absolutely you need microscopes at least to be able to see these tiny fragments.

16:10But what we've done is developed a process that is really simple and ends at the point where anyone with a mobile phone can attach a lens and be able to image their sample that ultimately ends up encased on a little microscope slide. and that image is automatically analysed because we're using machine learning to be able to auto detect these particles and also categorise them. Talk us through then, so say I'm at the beach and I'm thinking well this would be a really good place to take a sample for Claire's project, what would I do? You would have just the most simplest of kit, a glass water bottle or one of your metal water bottles if you wanted to take a sample and you would follow some protocols that are underpinned by forensic science so thinking about anti-contamination so you would wash your hands you'd make a note of what you're wearing and you'd make some documentation about where you are on that beach and then you'd be grabbing that sample now that sample you could if you wanted to filter right there and then on the beach because we've developed essentially a paper filter paper and from that you use a small little environmental tape that then presses over the top of it so you're literally lifting all of the particulates onto the sticky side of the tape which then you quickly put down onto a microscope slide so you've got a little sandwich then so tape your particulates and your slide at that point we want a nice place to be able to attach your lens onto your phone and then following just a little guideline really where you almost like mow the lawn as you as you're taking images along that slide those images then which are stored in your phone can then get uploaded and those will be uploaded with that information that you collected at the beach.

17:53You do need a few bits of kit then so you're going to have to have a lens that can turn the camera on your phone into a mini microscope you're going to need that slide and you're going to need that tape and the filter so what are you doing are you telling people where to get these things or are you actually making them available for people? When this officially gets launched in April we'll have like a little CSI for the ocean kit that if people would like to actually buy those and have it all together that's great but an alternative is also going to be available as in this is where you could buy these or this is also alternatives that you could use but might be in your own home as well the lens is important though Chris and it's a cool thing to have anyway because I tell you what become obsessed by looking at things under it but nevertheless that would be directed to where you could get one of those from.

18:42And all of the data, they converge on your web server, presumably. You're collecting all of this, so you'll have where the sample came from, who collected it and how, so some of the methodology. And critically, you'll have the image analysis, so you'll know what sorts of particles and in what sorts of numbers seem to arise from that particular venue that was sampled. Exactly. That data is placed onto a global map. so what that then allows is for that person who's just submitted that data or anybody else maybe if someone is just interested in looking in their local area can go and have a look at this map and start seeing what samples have been taken and start looking at the different characteristics that have been found there and also of course abundances and being able to connect as well with those other researchers because what we've seen over the years in microplastic research is that well there's and This is true in any discipline.

19:36There's some power in numbers and also in engaging with others to try and build more data and discuss this as an issue. That opportunity via that map and also linking with others will be possible through the mobile application. But you're a forensics specialist. So how did you end up in this space? The key here is forensic fibre examination or forensic trace evidence examination, which is what I am and I've been doing for many a year now. and that essentially is looking at tiny particles, analysing them in order to be able to find out what they are, how many are there, where did they come from, how long they've been there, but for the purposes of investigating crime, so actually taking those particles from a crime scene or from a suspect and the analysis techniques and the protocols and the processes and principles are exactly the same or we could apply them in the same way just for a different purpose, one for the courts and in this case for understanding our environment better.

20:35So CSI at the seaside. That was Claire Gwynnett from Staffordshire University and her project launches next year. We will look forward to catching up with her to hear how it's going. Scientists have taken a major step forward towards the next generation of mobile networks by developing a full spectrum chip that can transmit data up to 10 ,000 times faster than current 5G. The chip works across the entire range of radio waves too, from the very low bands which are used by today's phones up to ultra-high terahertz frequencies that we regard as the future. Experts say this could pave the way for 6G networks within the next decade, offering faster speeds, lower delays and the ability to connect far more devices.

21:20But is all that glitters not gold? Well, Richard Haas is an analyst at PolicyTracker and he's been following the story. Current mobile technology like 4G or 5G uses a variety of frequency bands on the radio spectrum, but they tend to be operated independently. So each of those bands requires its own chips and its own hardware. And what this paper does is it demonstrates a chip that, in theory, can access a wide range of spectrum bands from very low radio spectrum to very high and sort of combines them into bigger channels. And that allows you to, in theory, have really high data throughput, meaning you can download things very fast, basically.

21:57Does that enable you to shrink devices as well? Because if you've got to cater for all the other bands, if you can do all the jobs, one piece of kit in one place, that must mean you've got less technology to have to cram in. Yeah, I mean, that seems to be quite innovative in this paper, that they've managed to design this new chip that fundamentally works a bit differently and is able to do this, cramming all these bands into one chip. And that's very different to how current mobile phones work. We've only just got used to 5G. So what does 6G offer? How does it differ? It's sort of unclear at the moment what 6G will be, but the sort of obvious benefit of a technology like this is that you can achieve much higher speeds.

22:39I think another thing that's interesting about 6G is, in theory, you can do something called sensing, where you're sort of bouncing the signals off of objects. And because the radio waves are so small in these high frequencies, you have a much higher resolution, meaning you can see much more detail of objects. the similar sort of technology that we use at airports and you know and scanners and body scanners and so in theory that can let the network sort of know more about the environment that it lives in and that can be used to its benefit to improve the connection as well do we actually need this yet though because to be perfectly honest i cannot download data fast enough with my present fairly old device because the places I'm getting it from just can't serve it fast enough so I can be on the fastest connection that you can get but I can't get the data in any faster because it's being bottlenecked elsewhere so what will this do and are we really ready for this?

23:35It's a great question I think with mobile technology there's always the theoretical and the science and then there's the practical reality of what we all experience sort of day to day with our phones. And in reality, what most people experience today is speeds of around 20 megabits per second. And with that, you can pretty much do everything that you need to. You can watch Netflix, you can watch YouTube, you can upload videos and download videos. But there's not that much benefit that comes from increasing that speed. I think what most people actually complain about is you're deep inside of a shop, and you're trying to pull up your loyalty card, and it doesn't come up or something like that and that's sort of a reliability and also a coverage problem so there's this sort of theoretical speeds that you can get but those aren't always deployed equally across the whole country and that's sort of a different issue that i think some people hope 6g will also help with one of the constraints though and i've noticed this with my home wi-fi system i have dual band so five gigahertz but also we've got the original 2.4 gigahertz band the old-fashioned Wi-Fi and the range you get with 5 gig is much much lower so my devices have to be much closer to the access points in order to establish a good connection presumably as we make this even more powerful with 6g that problem becomes even more acute that's precisely the problem as we've sort of gone through the generations the mobile generations we've tended to use higher frequency bands, like you said, sort of above five gigahertz even.

25:08And the problem with that is they have what's called propagation. Basically, it means they don't travel as far. They bounce off of objects. And if you get into really high spectrum frequencies, they even bounce off of rain and clouds. So they just don't travel as far, basically. And that means if you wanted to make it work in a network setting, you'd have to install a lot of equipment, a lot of base stations, you know, on lampposts and sort of in the built environment in order for people to actually benefit from that because it has to be so close to the handset. This is where 6G is sort of, it's a scientific development, but it's also a commercial problem.

25:44Because if you're a mobile operator, how do you justify investing and putting it on every street corner to reach everybody if the added benefit is actually quite small? What can justify that investment? And how will governments implement it, use it? There was a huge rush about 20 years ago and governments made a fortune selling 3G bandwidth didn't they licenses so mobile operators there was a gold rush effectively for that what will they do with 6G and where will you see that coming down the tracks what sort of timeline yeah that's a really interesting question because we described there with the 3G spectrum auctions around the year 2000 they were very expensive a lot of spectrum was sold and we've had a few auctions since then so there was a big 4G auction in the 2010s, and then we had a big 5G auction sort of nearer to 2020.

26:34And the assumption I think everyone has is that there will be 6G auctions, right? The idea that you need new spectrum bands that you can give to the mobile operators so they can deploy this new technology. But at the moment, the issue is there isn't much spectrum left. So there's a lot of competition for these spectrum bands. And so that's a potential issue we're running into and regulators are running into is they need to find that spectrum for 6G. And there's even some people saying now that 6G might not need any new spectrum, and it might be fine to operate on the existing spectrum that it has, because you can do something which is called reforming, where you reuse the 5G spectrum bands, for example.

27:12And in terms of timeline? The mobile industry operates in these sort of 10-year cycles. So in 2020, starting in 2020, we were seeing the deployment of 5G. and I can say for you for sure that in 2030 there will be phones out there that support 6G. I can say that with some confidence because the whole industry operates in this cycle. The question then is once that happens and once we start having phones that say 6G in the corner in the top right, how different of an experience will that be to 5G? I think that is the key question and that all depends on how science develops, how the academic channels develop and also how the operators themselves want to invest in this technology.

27:53So there will be 6G in 2030. Will it be sort of completely different to 5G or will it be quite similar to 5G? That's yet to be seen. Richard Haass at PolicyTracker and that study has just been published in Nature. We know it's time for question of the week. And this time, James Titko is taking a leaf out of listener Trent's book. Autumn has arrived here in northern Canada where I live. it doesn't appear to be distributed evenly. I'll spot one yellow leaf on a green branch, a yellow branch on a green tree, or a single yellow tree in a forest. Question is, is this variation due to something in the trees or micro variations in temperature or other weather patterns?

28:35Thanks. Thanks Trent. It's a similar time of year here in the UK and you're right, the autumn can sometimes seem a bit chaotic. The first thing we're going to explore in answer to your question is, why are leaves green initially and what triggers them to change colour at all? To help, here's Charles Shee, botanical horticulturalist at the Royal Botanic Gardens Kew. Through the summer the leaves look green because of chlorophyll which helps with photosynthesis, the method that plants use to capture sunlight and to produce energy and that's the pigment that captures the sunlight for 30 senses. And chlorophyll, it's in a constant state of flux.

29:19It's being broken down and remade. In the autumn, as they shorten, the tree stops replacing that chlorophyll and begins to shut down. And that reveals some of these pigments. So for example, you have carotenoids, which give the oranges, also found in carrots, It's lavinals, which give yellows and have many medicinal properties. And in some species, the trees produce anthocyanins, which are the reds and the purples. Anthocyanins particularly protect from the cold and from pests, perhaps. But it also gives the tree a bit more time to draw nutrients back out of the leaf before it falls. So the autumnal pigments have always been in the leaves.

30:07they're just overpowered by the green pigment chlorophyll until the tree shuts down photosynthesis for the year. This gradual process will vary from tree to tree based on genetic factors. But why might it happen at a different rate even on leaves mere metres apart? Each leaf is slightly different. Older leaves, leaves placed in more sunnier environments or more stressed out leaves, will turn before more shaded ones. So that's why even a single tree can be a mosaic of green, yellow and red. The weather has a massive part to play to this. This year in the UK and also in parts of Canada, we've had some quite extreme conditions.