Hidden Pollutants Panel - UK River Summit 2025
Panel Chair, Shosha Adie, Senior Reporter at ENDS Report
“Every single time I enter a river to do filming I will encounter some type of pollution. When I look back to when I first started filming in the late 80s it wasn’t uncommon for me to be in a shoal of grayling 400 strong. If I go back to that same area now I’m filming them in pockets of 20 to 30 with limited water clarity.”
Panel Introduction
Panel Members:
Panel Chair: Shosha Adie, Senior Reporter at ENDs Report
Professor Alistair Boxall - Environmental Science, University of York
Robert Bradburne - Chief Scientist, Environment Agency
Andrew Kelton - Fish Legal
Simon Pickstone - Deputy Editor, ENDS Europe
Professor Alistair Boxall - University of York
Hello everyone, it's fantastic to be here. I've been asked to tell you a little bit about what I do. I'm based at the University of York and my main area of interest is chemicals in rivers and it might surprise you that globally we use 350,000 different chemicals, that's how many chemicals are registered around the globe and that number is growing every year so we're adding 10,000 new chemicals to that list every year.
In a typical UK household the statistic is that there's 4,000 different chemicals so that'd be stuff in your medicines cabinet, under your sink, in your garage.
Professor Alistair Boxall
We have a few hundred pesticides approved, a few hundred veterinary medicines and if you drove here today your tyre will contain over 400 different additives which will probably leach as you come across. We talked a little bit about road runoff earlier and it's inevitable in the way that we use the products containing these chemicals that we are going to release into the environment so we'll be releasing down the sewer system. As we drive they'll be going onto the highways, applying them to farmland, applying them as sewage sludge to farmland and they get into the environment.
We've been doing monitoring in Yorkshire so over the past year we've been monitoring pretty intensively across Yorkshire. We've been using quite high tech methods to look at what chemicals are in Yorkshire's rivers and thinking of Mark's talk, Mark showed microplastics, plastics and wet wipes and things but he showed the River Wharf and the spot on the River Wharf. We see 4,000 different chemicals in the water where Mark swims on the River Wharf.
Many of those will be natural but a lot of them are synthetic yet the number of chemicals that we regulate is quite small, it's only less than 100 even though the Environment Agency are looking at this a little bit more broadly. So why does that matter? I think some of these chemicals could well be causing harm to our ecosystems. I do a lot of work on antidepressants and pharmaceuticals, there's data from laboratory studies showing that antidepressants affect fish behaviour at very, very low concentrations so they affect how male and female fish interact, they affect how fish migrate.
Tyre additives, there's data from the west coast of the US looking at one of the tyre additives which seems to be extremely toxic to salmon and we're detecting that in Yorkshire's rivers. The forever chemicals, so you might have caught some of the news more recently about forever chemicals in the rivers, a chemical called TFA.
We find TFA almost everywhere, it's not treatable by existing drinking water treatment methods so we will be drinking it in tap water and I think really we need to be much more clever about how we monitor and manage chemicals.
I think the way we are doing it at the moment, we're probably only looking at the tip of the iceberg and I think we need to be much more proactive and trying to identify things like TFA before they become a problem.
Dr Robert Bradburne - Chief Scientist, Environment Agency
Brilliant thank you, thank you everyone also for inviting me here today, this is a fascinating subject and a fascinating panel as well.
My name is Robert Bradburne, I'm the Chief Scientist at the Environment Agency and that means that I look after the science that the agency needs to do all of its functions. So water and chemicals are just one part of my life. I have to spend time thinking about climate adaptation, nature recovery, chemicals, flooding, nuclear installations, all sorts.
So this forms an important part of what I do. Why does the Environment Agency need science? We try to do our job based on the best available evidence that we have and so a really important part of the role that I play and the scientists that I look after play is to make sure that we are looking ahead to the future and trying to see what might be coming around the corner.
Dr Robert Bradburne, Chief Scientist, Environment Agency
So as Alistair was saying, get ahead of the game. We also use a lot of science and evidence to say, is what we are doing working? And it's a challenge that I often get as to how we can show how our interventions are having an effect on the environment that we're trying to look after.
And the last thing that science is so important for, for the agency is to innovate. You know, there are more and more chemicals coming online, we need to find new ways of looking for them, understanding them, measuring them, monitoring them. We can't keep using the equipment, the technology of the past, we've got to keep looking to the future.
So a large part of my job is also enabling the agency and all the people who are working tirelessly on the ground in the agency to have the best equipment, the best data analysis that they can to do their job pretty well. And so I was asked to think about what I think are some of the major issues that we're facing, these hidden issues that we're facing.
And my answer, I'm afraid, is a slightly complicated one, because I think the major issues that are facing water that is hidden from view is the fact that we have systematic change happening to our rivers and lakes and our groundwaters from all sorts of different angles at the same time now.
We have physical changes. You know, the weather, the driest spring, we keep hearing the something-ist month, the something-ist thing, there's always a new record, always a new superlative at the moment. That has a real impact on the physical nature of our rivers.
We've heard that the chemical landscape of our rivers is changing and is changing in unpredictable ways and it's changing in different ways across the country. And the biology of the rivers is changing as well. We've got new species which keep coming up into our rivers and challenging our ecology or changing our ecology.
And when you put all of that together, when as an environment agency we're there to try to improve the rivers, to try to improve nature for people and for nature, that becomes a real challenge to manage all of those changes happening at once, because they will all have an impact on whether that river is healthy.
So that's the real challenge that I see. Chemicals is part of it, but it's a much bigger picture of how we deal with the physical, chemical and biological changes that are happening out in our environment all the time.
Andrew Kelton - Fish Legal
My name is Andrew Kelton. I work for an organization called Fish Legal, which is a national membership association which basically represents anglers, angling clubs and owners throughout the country in legal disputes.
And the only reason I'm here today is, I think, because we recently took a case, a judicial review against the government, against DEFRA, basically, and the environment agency, specifically to do with a river in North Yorkshire called the Costa Beck, which Mark's film, I was just catching a bit of it just now, showed as the angling club there knows very well, it's highly polluted to the extent that it's covered in places up to three feet of silt in the top part of the river.
This is a river that used to be a superb grayling and trout fishery, and is now reduced to no fish of that kind at all. So Fish Legal were engaged, we've been engaged for about 20 years now at Costa Beck by the Pickering Fishery Association. And during all that time, we and the club have tried very hard to deal with what seems like really quite a simple issue of pollution from two fish farms and a sewage works.
And yet, after the best efforts of all involved, including the environment agency, we've done some very good science there, nothing in 20 years has improved.
So rather impatient after 20 years, I've only been doing it for seven years, I think, we brought a judicial review against the government and the Environment Agency using a specific mechanism, really, which is the Water Framework Directive, which sounds a bit technical, it doesn't have its name, but it was introduced in this country in 2003.
It was a 24-year plan to try and restore as many degraded rivers and lakes as was possible across the whole country. So you had a 24-year plan. So the judicial review really got into whether this planning process had been done effectively, and if not, what could be done to improve it.
And after 22 years now, with no improvement at all at Costa Beck, is a bit of an indication that it hasn't worked terribly well. So we brought the case to the High Court, the High Court agreed with us that the government was doing it, doing this planning wrong by saying that its measures to improve these water bodies, as they're called, should be at a very generic high level with no specific commitment to individual water bodies.
We said that that was wrong, the High Court agreed with us, interpreting the legislation very, very carefully. The government then took us to the Court of Appeal. The Court of Appeal then agreed with us as well that these river-based management plans should be applied specifically to individual rivers with specific committed actions at individual rivers like Costa Beck.
So we know that only 16% of surface water bodies across the country are at good ecological status. That basically hasn't improved since 2003, which is not a very good track record. Some things have been done that have improved the situation, but in the round not that many.
So that was a pretty poor start. But it's quite interesting what, to the court, the judges said about the government's approach. They talked about smoke and mirrors, sophistry is a rather nice word, and a fundamental misunderstanding of the legislation.
This is what very erudite and careful judges concluded. So anyway, the upshot is that the courts have decided that the river basin management planning process has been got wrong by the government.
This is DEFRA and the Environment Agency. And so they need to fundamentally reassess what they need to do. And it starts with looking at individual water bodies, assessing what the problems are there, and coming up with specific focused actions at each water body to get to good ecological status.
Simon Pickstone - Deputy Editor, ENDS Europe
My name's Simon Pickstone. I'm the Deputy Editor at ENDS Europe, which covers EU environmental policy. And I'll give you an extremely brief overview of what's been going on in the EU regarding water quality since Brexit.
Quite a lot. Not all that good. So on the kind of action side, in terms of improving chemical status of rivers, we've got to understand in the EU as well, we're starting from an extremely low base. So only 29% of the EU's surface water bodies are in good chemical status.
Latest assessment by the European Environment Agency from last year. Many of those are either poor or of unknown status and as a general shorthand, if it's unknown, it's likely not going to be great. So various things have been done legislatively to do something about this.
One of the most interesting is the revision of the sewage treatment rules, which is something called the Urban Wastewater Treatment Directive, which is an incredible name for a directive because the acronym is longer to pronounce than the actual name of the directive, UWWTD.
I think I put in too many Ws there, anyway. So under the revised Urban Wastewater Treatment Directive, member states have been tasked with upgrading sewage treatment plants serving large urban areas, so serving more than 10,000 people. They have an obligation now to fund fourth stage wastewater treatment, so that's cleaning wastewater of micropollutants, so that's pharmaceutical residues or metabolites or hormones or a range of cosmetic kind of residues that are left over from when you have your shower or whatever.
Simon Pickstone, ENDs Report
That's quite a cool, interesting thing that's modelled off an extremely successful campaign in Switzerland, where Switzerland really pioneered this treatment technology and has rolled it out pretty successfully already to a lot of its large urban areas.
That's funded by something called an Extended Producer Responsibility Scheme, so under that scheme member states have to require people selling pharmaceuticals and cosmetics to fund up to 80% of the costs of installing this technology. So that all sounds great.
What's happened since the directive came into force is that various pharmaceuticals and cosmetics industries have now gone to the European Court of Justice to try and overturn this requirement, and this is done on procedural grounds, and then you have also Poland and Italy specifically gunning for the directive as a whole, and they have enough support in the council now probably to force the commission to basically undo this directive.
So the chatter is that the commission is going to put forward a proposal to revise the directive to remove the requirement for pharma and cosmetics companies to pay for upgraded sewage treatment facilities, but that's all kind of like still rumours. So that's on the one side, we have one step forward, one step back.
Other things have been going on which are also quite interesting, so you may have heard of the universal PFAS restriction which is being discussed and lobbied about intensively in Brussels. This was first proposed by five competent authorities, so that's four EU member states, and Norway proposed a basically blanket ban on forever chemicals on PFAS, with a huge number of derogations and a huge number of very, very lengthy phase-out periods because a lot of these chemicals are simply too useful in a lot of industries to immediately phase them out.
So that's sitting with the European Chemicals Agency at the moment, and the European Chemicals Agency is under enormous pressure from the European Commission and from the member states to water down the scope of the revision of the restriction. So the European Commission is promising clarity on the issue in December, and it's very, very likely that we're going to see a much more limited ban on PFASs, and that's going to have a knock on effect with the amount of PFAS pollution that enters water bodies.
A second and related thing on PFASs was to do with firefighting foam, so this is going to happen now. There's a ban coming in on firefighting foams containing PFASs, and this is a huge deal because actually that contributes a huge amount of the overall pollution from PFAS.
That's now at the stage where there's a delegated act that's been published and that's going through a scrutiny period, so the European Parliament and the EU Council have until the end of the summer to basically reject it, and it seems unlikely that they will.
So that's going to happen.
Panel Discussion
Shosha: That's great. That's a lot of information, and that is a lot of information to unpack, isn't it? I hope we've brought you along with us, but I recognise that it's a lot to take in, and I think it's great we've also finished on PFAS.
Who here has actually heard about PFAS already? Oh, well, that's great, because otherwise that would have all been extremely complicated. But yes, PFAS Forever Chem, this is something we focus on our ends, and it's interesting to see what the EU is doing on this, because in the UK we're also in the process of nearly getting a restriction dossier, at least, on firefighting foams.
Chemical Prioritisation Discussion
Shosha: I think because there was a lot of information to digest there, I think maybe we can just talk about what do you think the priority chemicals should be? I know that Alistair, you mentioned there's sort of 10,000 new chemicals coming out each year. I mean, how do we sort of go through this process of deciding what to prioritise?
Professor Boxall: So I think, we have some quite powerful tools available now. So we have some very sort of clever analytical methods, and the Environment Agency are already using them, that can screen thousands of chemicals.
And I mean, we might hear about the PEWS system that the Environment Agency have got, which is, you know, I think that type of system is sort of the predictive early warning system.
The idea of that is to try and identify the chemicals either that we're using or coming on over the horizon that we should worry about. And there's quite a sort of systematic process of sort of going through that. And I think that type of approach, being more proactive, is the way to go.
So I think we do have some quite powerful tools. There's still quite a lot of data gaps. So in terms of effects of chemicals on organisms in the environment, we only know the effects of only a small proportion of the chemicals that we use. And I think there we're going to need to use models more.
So we have models that we can relate the structure of a chemical to the effect on a fish, or an invertebrate, or an algae.
And that then will allow us to begin to pinpoint, you know, which chemicals really matter. And just as an example, we're working with the pharmaceutical industry at the moment. So we're working on a large EU project. And the aim of that project is to do that, to think about how you can take information that the pharmaceutical companies would have on how a pharmaceutical interacts with us as humans, and then use that to extrapolate to a fish.
And we can do that, that will be a very powerful tool to then be able to identify the pharmaceuticals that we should be worried about, and which we should be, if we have to use them, what we should be treating in terms of tertiary treatment.
So I think it's that type of approach that we should be using.
Environment Agency Response on PFAS
Robert Bradburne: Yeah, and there's a number of things that we're trying to do to make sure we stay ahead of the game. So, one of the things that we can do is to keep, as Alistair said, keep upgrading our monitoring. We've just refitted our Leeds monitoring lab now with the latest kit.
We've spent about four million pounds putting in some very whizzy machines, which enable us to scan for a huge range of chemicals, because one of the issues is, we don't know sometimes what we're going to find, and actually being able to increase that range that you're looking for is really, really important.
So we're doing that. Of course, we can't sample everything everywhere, but we are looking out. And is PFAS in that?
So we routinely, we've actually been leading the world, I think, in some of our analytical methods for PFAS, because PFAS is a really difficult topic, because it's somewhere between 8,000 and 15,000 different chemicals. They all have this carbon-fluorine bond.
That is very, very strong, and that's why they hang around a long time. But that's pretty much all they've got in common. So when we say PFAS, we mean a huge range of things, from gases to non-stick-on saucepans to all sorts of other things. And that makes it quite tricky.
So what we're doing is we're trying to monitor both what we know is out there, so some of the legacy contamination chemicals that we already know are in the environment, and also a range of different ones to give us an idea of what's happening.
Q&A Session
Question from Surfers Against Sewage
Dani Jordan (Surfers Against Sewage): Our mission as an organisation is to end the pollution of rivers, lakes and seas, and we represent a community of water users. So, people who are immersing themselves in rivers, in the sea, but with very little protection usually. So, with that in mind, with talking about this chemical pollution, what should water users be most concerned about?
Professor Boxall: So, I think the first thing I would say to that is, in terms of chemical pollution, the levels of chemicals that we see in rivers, in terms of what I'd say is acute toxicity to humans. So, the levels are really low. So, it's not going to make you immediately ill.
I think it's more an issue of indirect effects of chemicals on human health, and also maybe some more long-term effects. So, if you swim in the river every day, every year, for the whole of your life, and you're exposed to some of these chemicals, then that could be causing you harm.
And then, in terms of the indirect effects, I think the group that I worry about most would be the antibiotics, which are widely used, and we detect them in rivers. And the concern there is that they are selecting for resistance in bacteria. And if you're swimming in that river, you could be acquiring those resistant bacteria.
So, if you get ill, and then you're admitted to hospital, and you need antibiotics, that could make the antibiotics less effective. So, I think that they would be my two worries.
Mark Barrow: Due to the nature of what I do, because I'm in rivers a lot, to be quite honest, I'm probably going to extreme safety measures, but I actually have to wear a full-face mask, dive tanks, dry suit, gloves, and everything, so that I'm fully contained, and nothing's really getting into, obviously, my system.
There have been occasions, odd occasions, where I have become ill, and I think probably the worst one was when I did the filming with Paul Whitehouse, and that was down to my own fault.
The camera crew were there, the water was too shallow to use dive tanks, and they used a snorkel in front of a combined sewer overflow. That then caught on a branch. I then digested a mouthful of CSO water and ended up off work for a week.
Question about PFAS in the Evenlode
Anne Miller (Evenlode Catchment Partnership): This is a specific question for Robert, actually, although others might want to jump in, because I'm Anne Miller, and I'm part of the Evenlode Catchment Partnership, and the Evenlode has the dubious privilege of being the most polluted river in terms of PFASs, almost from its source, thanks to the Fire Services Training College at Moreton and Marsh.
Having established that there's a problem with all this stuff, what the heck do we do about it?
Robert Bradburne: We might need a longer conversation, because they do hang around. You know, the most complete way of getting rid of a PFAS? Very easy. You burn it at something like 1,000 degrees. Okay? So, very easy to do with a river. Not a terribly...
And, you know, we've talked about whether wastewater treatment units are built to deal with some of these chemicals, not just PFAS.
So, on a serious note, there are some new innovations coming down the line. I was speaking to someone who's working with, I think, a Swiss company, actually, who have found a novel catalyst that can start to break down PFAS. So, there are things where people are starting to think about this.
I think a lot of this is generated by a lot of the legal cases in the US, if I'm honest, where they're very worried about levels in drinking water, and so they're looking for new solutions.
Question about AI and Unknown Toxicology
Trevor Loveday (The Water Report): A couple of questions, but they're both very short. One is, have you got an estimate of the number of PFAS or even generally chemicals in the system for which the toxicology is completely unknown? And when looking at sort of the identity, you were talking about identifying stuff in various sources. This sounds to me like a good task for AI. Is that being applied in this?
Professor Boxall: So, I think I can answer your first question. So, there is actually a very nice European Chemical Agency report that has looked at data availability for chemicals. And in that report, I think they work on 100,000 chemicals. Now, as I told you at the start, that's wrong. That's 350,000.
Of those, I think there's about maybe 500 that have very, very good datasets and probably a couple of thousand that have fair datasets. But the bulk of chemicals we use, we don't have much data at all yet.
Robert Bradburne: We are looking at AI, and I'm in fact going to a meeting only in a couple of days, looking at how we can use AI for water quality. I think the really key thing is, please think of AI, I hope there's no AI businesses here, please think of AI as a toddler.
You know, it is artificial intelligence, it's as good as the information it's got. And so what I'm really keen on doing, actually, is using AI where it's much better than human. So looking for some of these complicated links can be a good place for it.
Final Exchange - Riverkeeper Critique
Riverkeeper (45 years experience): I've been a riverkeeper my whole life, which is 45 years being a riverkeeper, and I've heard, I precede the Environment Agency guy up there, National Rivers, they were called.
And since the formation of the Environment Agency, it's been an unmitigated disaster. You've used the word innovation three or four times. If I was to say when I get home tonight, if I say to other riverkeepers, I've been in a tent with the Chief Scientific Officer for the Environment Agency, they'd all say, brilliant, did you punch him in the face?
You cannot regulate the water companies keeping human sewage out of our rivers. Where on earth do you go with all these chemicals? You're just confusing the matter.
It's not forever chemicals, it's human turds that we and Mark have to walk about in. He's just trying to confuse the issue and he hasn't answered the issue.
Professor Boxall: I would just push back a little bit on that. I think sewage is important, but I also think things like the forever chemicals are also very, very important. And we can't see them, we can't smell them. But these are things that we are being exposed to.
And also just to defend the EA a little bit. I think some of the stuff they do in my field actually is incredibly innovative. And actually, they are actually leading Europe in some of the methods they're using.
Shosha: I think the key thing here, and actually, it's great that you've raised this, because this is what the panel is about, is we can't just focus on one problem, because sewage pollution is one problem and it's really big.
But actually, if we don't tackle the chemical crisis, the forever chemical crisis, we're going to reach a point at which we've got another 100 years to go before we can even think about having good chemical health for our rivers as well. So, yes, all of these problems are extremely important.
Panel concluded with thanks to all participants and acknowledgment of the complexity of the issues facing UK rivers.
Listen to ENDS Report's podcast discussion of this panel: Hidden Pollutants Panel Podcast