29
Examination of witnesses
Professor Alistair Boxall, Professor Guy Woodward and Matthew Shardlow.
Q1 The Chair: Good morning and welcome to the Lords Committee on the Environment and Climate Change. Today is the first session of our inquiry into pet parasite medications. We will be hearing evidence from ENGOs and research institutes.
Before we start, I remind everyone that the session will be webcast live on parliamentlive.tv. A transcript will be taken and made public; witnesses will have an opportunity to review the transcript and make minor amendments if necessary.
Members are reminded that all relevant interests should be declared the first time they speak. This also applies to our witnesses. I should take this opportunity to say that I am a director of Peers for the Planet. Let me start by thanking our witnesses for taking the time to be with us today; it is much appreciated. I ask them to introduce themselves briefly.
Matthew Shardlow: I discovered this issue in the UK when I was doing some work on neonicotinoids a while ago. I am an independent consultant. I have just completed a major review of this topic for Wildlife and Countryside Link, in which I made 46 recommendations to fix the problem of flea treatment pollution in watercourses and the environment.
The Chair: May I ask you to lean into the mic? We will be able to hear you even more clearly then.
Professor Guy Woodward: I am a professor of ecology in the department of life sciences, which is in the faculty of natural sciences, at Imperial College London. I work primarily in aquatic ecosystems—mostly fresh waters and, in particular, running waters.
My research focuses on the understanding of biodiversity in these complex systems; the environmental and anthropogenic, or human-generated, constraints on those systems; and the role of environmental stressors, including how they interact. It involves things such as chemical pollution, of which parasiticides would be one, but also things such as climate change and acidification—a range of stressors, really. I have also been involved, along with co-authors from Imperial, in writing the written evidence that has been submitted ahead of this verbal presentation.
Professor Alistair Boxall: Good morning. I am based in the environment and geography department at the University of York. I am an environmental chemist, and I have been looking at veterinary medicines more generally in the environment for over 20 years. My early work fed into quite a lot of the European Medicines Agency’s guidance approaches. More recently, I have been looking at pet medicines, flea treatments and wormers. It is great to be here today.
Q2 The Chair: Thank you all very much, and thank you once again for joining us today. Let me start by asking each of you to give us a summary introduction to these chemicals of concern, which are found in pet parasite medications. Can you give us a very basic idiot’s guide to them? This area is new to many of us, I am sure, and to members of the public. Can you say what these chemicals are, what they are used for and why they are of concern? In addressing that, please give us some idea of their effect on the environment and on different species, including humans.
Matthew Shardlow: We are talking about flea treatments, which are more correctly referred to as flea and tick treatments because that is their purpose. They are used on pets—primarily dogs and cats, but potentially other pets. Horses, for instance, have some used on them as well. They are authorised by the Veterinary Medicines Directorate, which has responsibility for making sure that they are safe for pets, humans and the environment.
There are 22 authorised products in the UK at the moment. There are another 10 in other EU states. So there are a lot of products out there. The market is currently dominated by fipronil, which is a PFAS chemical and a highly toxic nerve agent for insects and other invertebrates, and imidacloprid, which is a neonicotinoid insecticide. It is also another nerve agent; it works in a slightly different way, but I will not go into that level of detail. Then there is fluralaner, which is another PFAS chemical, as well as a whole bunch of other ones that are used to a lesser extent.
These chemicals get into the environment. I discovered that in 2017, in looking at data on UK water quality that I had managed to get from the European Commission. I found that there was contamination of imidacloprid in rivers where there was no agriculture. It was the first indication that there was a problem with water pollution stemming not from agricultural use of these pesticides. They have now both been banned as agricultural pesticides because of the damage they were doing to wildlife.
There are also concerns around them getting into wild flowers. A recent study in the Netherlands found very high levels of not just those chemicals but some of the other flea treatments—including diazinon, which is an organophosphate, and permethrin, which is a pyrethroid—getting into flowers at levels that would be toxic to bees and other pollinators visiting those flowers.
The Chair: One of them is a neonicotinoid. Can you say a bit about that? It is a chemical with which we are more familiar.
Matthew Shardlow: Neonicotinoids were developed as agricultural pesticides in the early 2000s. After being introduced, they were used abundantly: imidacloprid was used to the extent of around 320 tonnes in agriculture in the UK. That is much more than fipronil, which was only ever used at 750 tonnes. So there is a big discrepancy between the neonicotinoid imidacloprid, in its previous agricultural use, and fipronil.
We know that most of the fipronil input is coming from flea treatments, because there is no other significant import or historical use, whereas there is slight uncertainty around the historical, legacy use of imidacloprid because these are persistent chemicals. There is probably still some imidacloprid coming out of agriculture, despite the fact that it was banned in 2018; seven or eight years later, there is probably still some coming through. Certainly, there will have been a declining amount of imidacloprid getting into the environment from agricultural use. With fipronil, it is much easier and clearer because fipronil is basically the flea treatment used in the UK, so we can be much more certain about the origin of the different levels that we are seeing in the environment.
Professor Guy Woodward: I shall add to some of those points. In the freshwater environment, in particular, a major concern is that many of these chemicals are highly water soluble—not so much fluralaner but certainly imidacloprid, which is the one that is been most studied. It enters the water, and that brings a whole range of biodiversity into contact with it, including things such as mayflies, dragonflies and caddisflies, which many of you may be familiar with—particularly if you fish, because they are widely used in fishing as they are a common prey source of species such as salmon and trout.
The invertebrates that are affected are critical in the food web. They are the core of the food web, linking the basal processes that allow energy to move through the food web to these higher trophic levels, such as fish and other species, including birds. So there are major concerns here around the direct impacts of the chemicals on insects in particular. Insects are extremely common in our freshwaters—particularly in the larval stage, where they spend most of their life cycle. They account for much of the biodiversity in those systems. They are highly sensitive and many of them are many hundreds, if not thousands, of times more sensitive than the common test species that has been used traditionally in the bodies that investigate toxicity: the water flea, or Daphnia magna. This is seen to be a pretty poor model for the sensitivity of most of the other species that seem to be many orders more sensitive to it.
There are also concerns around not just these direct toxic effects but species for which these toxins potentially do not act as such. They are majorly potent neurotoxins for mammals, for example, whereby their food sources are potentially removed. So direct toxic effects are seen for many species, but there are also these indirect effects that ripple through the food web. These are major sources of concern and are not really addressed in any depth at all in any of the regulatory build-up to the release of these chemicals, particularly in terms of their longer-term effects. Most of the studies that have been done in the laboratory tend to focus on fairly short-term trials. Chronic exposure and movement across different branches of the tree of life and through the food web are still poorly understood.
Professor Alistair Boxall: I would add a few things to what Mr Shardlow and Professor Woodward have said. This inquiry is about parasiticides. I highlight that they are actually part of a wider group of molecules. It includes flea treatments but also wormers, and it is a group about which we know much less. To take parasiticides as a whole, we are talking about more than 120 products and more than 30 active ingredients.
One thing to reiterate is that, if we took all the ecotoxicological data that we have on all the molecules where there is experimental data and ranked them, these would be some of the most toxic molecules ever assessed. Some of them are probably the most toxic that have ever been tested.
The Chair: Before you go on, could you just say a few words about ecotoxicology?
Professor Alistair Boxall: Ecotoxicology is the science of looking at the effects of chemicals on organisms in the environment. The way it is typically done is in a laboratory: we will take a chemical, make up a range of concentrations of that chemical, add an organism—perhaps a Daphnia, as Professor Woodward talked about, or a fish or an algae—then look at what effect that chemical causes at different concentrations. That could be a really bad effect—something like mortality—but it could also be a more subtle effect, such as an effect on growth or reproduction.
The Chair: Professor Woodward mentioned water fleas—Daphnia magna. What is the issue with using that as an indicator species for ecotoxicology?
Professor Alistair Boxall: I think it was Professor Woodward who mentioned that invertebrates are so diverse. Because of the way the regulations work, you are, in effect, using one species—the water flea—to represent all species in the environment. We know that species respond in very different ways to different chemicals, depending on their size, life cycle and biochemistry. For some chemicals, you can see maybe a 1,000-fold or 10,000-fold difference in the sensitivity of one species compared to another.
The Chair: We heard some evidence previously that the water flea may have some resistance to the chemicals that are used, and therefore that the impact on water fleas may be not as much as it is on other invertebrates found in the water environment. Is that the case?
Professor Alistair Boxall: Whether that is the case in the laboratory I am not sure, because most of the laboratory studies work with cultures, and these cultures have been maintained for a long time under fairly clean conditions. They will not have been exposed to these chemicals in the cultures, so they will not have seen them before.
It is different in the environment. It is possible that an organism in the environment can become more resistant to a chemical. That is why you occasionally find some species surviving in quite contaminated sites, because they are able to adapt and become less sensitive to the chemical. But we do not really understand—Professor Woodward might be able to expand on this much better than I can—what the implications on ecological health are of that happening. It is probably not a good thing.
The Chair: I am going to move on to Lord Krebs’s question, because it follows on quite well. Professor Boxall, if you have anything further to say—I know I interrupted your flow—please do so in response to Lord Krebs.
Q3 Lord Krebs: Thank you very much, Lord Chair, and thank you to our witnesses for joining us today. A lot of the questions that we will come to later in this session will build on what I am going to ask. It is really about the confidence that you have in the effects that you are describing and the strength of evidence. Matt, you said at the very beginning that these chemicals are approved by the Veterinary Medicines Directorate. That approval process, among other things, assesses the potential impacts on the environment and on human health. So clearly the regulator appears to disagree with you; you are painting quite a bleak picture of the environmental impacts. Could you briefly say why you think your interpretation of the evidence is not shared universally? Perhaps Professor Woodward would like to kick off, then Matt and Alistair.
Professor Guy Woodward: On the concentrations that we are seeing in the environment, in many cases, the more we see, the more we find. The concentrations that we find in urban areas are particularly high, which suggests that it is not solely an agricultural legacy. They are of a range well above the so-called predicted no-effect concentrations, just as a ballpark. This is a level below which you would expect them to cause no kinds of biological harmful responses, but, in many cases, we find that the chemical concentrations are orders of magnitude higher than that or certainly multiples of that in many sites. So there is certainly evidence that environmental concentrations are at or above the level that is known to cause toxic responses in a wide range of taxa in laboratory studies.
It is a little more complicated to link direct causality in the field, because there are many confounding effects, masking effects or amplifying effects when you move into more complex systems, because there are other pollutants in the environment that can blur the signal-to-noise ratio and other species that can affect how your focal species might respond. So there is a little more caveating around direct causality in the field, but the growing weight of evidence, from a range of field experiments, field observations et cetera, linking through to the laboratory, is suggesting consistent concern across all these different scales and levels.
I will give you an idea of the toxicity that Professor Boxall alluded to, as a rough rule of thumb. I was speaking to one of my environmental chemist colleagues the other day. In essence, if you took just two sugar cubes of concentrated active ingredient—for example, imidacloprid—it would be enough to exceed these predicted no-effect concentrations in about 400 Olympic-sized swimming pools.
These things are extremely toxic, as Professor Boxall said, in extremely small concentrations. In many cases, we have struggled to have the technology to spot them in the first place. We were largely ignoring them but then, when we started to look for them, we had the constraint that they are at such tiny concentrations, yet they are extremely toxic at those concentrations. It is only now that we are really starting to glimpse the full scale of the contamination.
Matthew Shardlow: In terms of more general chemical regulations, I have had a lot of involvement in and worked with pesticides in the past, and I was on the EFSA stakeholder group when we were in the EU. How this is supposed to work is that there is a risk assessment process of the pesticides before they are approved by the regulator and can be authorised for use. There have to be tests. If there is any hint that they might be toxic to the aquatic environment or to non-target invertebrates, tests have to be done and data is then presented. There is a problem with Daphnia, which is very resistant to some nerve agents in particular, so it is not a really good comparator.
What happens with pesticides is that, if they cannot resolve those concerns and get evidence that says that they will not cause harm when they are released into the environment, those chemicals will not get authorised. But sometimes they will authorise them with conditions. That is how we end up with chemicals that, we find out later, cause damage that we were not predicting and it is why things like fipronil and imidacloprid then get cancelled. That is not ideal because, by the time that has happened, damage has already been incurred in the environment.
So the whole principle is that you get ahead of the damage actually occurring in the environment, by looking in the laboratory and doing tests that you can extrapolate to make a prediction about what is happening in the environment. So you develop things like environmental quality standards for water, which have chronic and acute levels. They say that, if it goes above a certain level all the time, it will probably cause harm to wildlife; if it goes above the acute level for a short period of time, it will cause harm. You work that out from laboratory studies and then scale that up into what is going to happen in the field.
That is all absolutely clear with fipronil and imidacloprid, because we have the data from the pesticide work. For a lot of the other flea treatments, we have no data at all. That is because, in the veterinary medicines authorisation process, if it is to be used on a pet, it does not need a risk assessment. For most of the chemicals that we are currently using, unless they have been pesticides, we do not have any data about their environmental toxicity.
The Chair: Who makes that decision?
Matthew Shardlow: The VMD makes that decision. When we were in Europe, the European Medicines Agency had a committee which would make those decisions. It has done four risk assessments on flea treatments. They are not very good. We will not go into the detail here, but in my report, you can see they have used very unprotective levels and have used Daphnia only. Then they have drawn conclusions, and it is sometimes quite difficult to see how they think that that is not going to cause environmental damage.
Lord Krebs: Can I just be clear? Is what you are saying that the VMD approved the use of these insecticides without any risk assessment?
Matthew Shardlow: Correct.
Lord Krebs: Thank you; that is very clear.
Matthew Shardlow: There is what then happens in the environment. We can be more and increasingly confident. New evidence is the issue, in terms of people having different views, because there is a flourishing amount of evidence coming through. There is what I think of as the third tranche of scientific evidence. There is the initial tranche, when someone discovers something. There is the work that was done by Rose, Goulson et al—the initial work.
Now we are into tertiary science, and there is a lot of it going on. For instance, there was a really interesting study in Germany which looked only at streams which did not have sewage works on. Sewage is obviously the biggest input, but these streams had no sewage input—so there was no way that imidacloprid and fipronil were getting off people’s pets and hands, into the sewage system into these rivers. Yet, they found fipronil at high levels in those streams and at levels they then could directly correlate with damage to the populations of mayflies. The highest level in those rivers was lower than the average level in British rivers. That is why we can be absolutely confident that the levels we are seeing in British rivers will be impacting our fauna.
Similarly, we know that these chemicals are associated in the field with declines in bird populations, and we know that the more of these chemicals found in birds’ nests, the more dead birds you find.
The Chair: We are coming on to question 2 here. Can I just finish a point of clarification on this question? We have some written evidence from Johnsons Veterinary Products. It says that “the benefit-risk assessment for veterinary medicinal products must be made on its own merits and on complete, balanced evidence”. My question to all three of you is: has this benefit-risk assessment been carried out? I think we know the answer to that but can we hear that definitively? If not, whose responsibility is it to do this? Who would like to start on that?
Matthew Shardlow: The legislation is a bit more complex; I am sorry. There are three tests that have to be applied when a new product comes through for authorisation by the VMD. One is the balance test. The second test is an environmental test: will it cause environmental damage? The third test is: do we know whether it is going to cause environmental damage? The three tests are needed: the balance test—benefits versus risk—an environmental test but also a precautionary test of “Do we not know enough?” If either of those answers does not meet the risk-benefit analysis—it is going to cause unnecessary environmental damage, or we do not know enough to know whether it is going to cause environmental damage—in all three of those circumstances the approval should be withdrawn. It is not simply about the benefit-risk analysis; that is not what the legislation says should be considered at this point.
Benefit-risk analyses are done. As with much of this, though, they are entirely secret, so we cannot see any of that and we have no idea what information or data the VMD is using to make any of those assessments.
The Chair: Where is this information held? By whom?
Matthew Shardlow: I assume by the VMD. It is not in the public domain.
The Chair: I would like to bring in Professor Boxall and then Professor Woodward on this issue.
Professor Alistair Boxall: If I may, I would just like to add a little bit on how the process works. I sat on the Veterinary Products Committee for a long time, so I have experience of it. When you look at the European guidelines on these products, at the moment we do work to the European approach, so the drugs require an environmental assessment, strictly, but that assessment is done in two phases. Phase 1 is completely desk-based; there is no testing at all. Effectively what a market authorisation applier will do is work through a set of questions and, if they meet some of those questions, they stop. That is one of the issues with the pet medicines. When the guidelines were developed, it was assumed that environmental emissions would be low and therefore impacts would be low, but in the UK we have 22 million cats and dogs and we have prophylactic use of these molecules. We are in a situation where usage is no longer low, and it is not really appropriate to stop at that phase.
Now, really what should be happening is they should move to phase 2, where testing is done, but one of the problems is that the guidelines that are available from the European Medicines Agency have been developed for livestock medicines and agriculture medicines, so they do not actually have the procedures that are appropriate for assessing these medicines. They do perhaps in terms of some of the ecotoxicological effects but, in terms of the exposure pathways, they do not.
Then moving to your question about benefit-risk assessment and taking all of that together, I cannot see how, based on the information that people like the VMD and the industry have, they can actually factor in environmental risk to a benefit-risk analysis. I do not think they have the information to do that appropriately and accurately.
Professor Guy Woodward: I just want to add briefly to that. Yes, I agree that these assumptions really no longer hold. Part of the issue is that the procedure stops and then there is no kind of curiosity or reflection, looking back at the massive accrual of huge amounts of environmental and scientific evidence in the interim, which clearly shows that the proof is in the pudding here. These things are in high concentrations. They are leaking out into the environment. It seems to me that the only really credible source through which that can be happening at these levels would be pet and flea treatments. The issue, as Professor Boxall points out, is that with this prophylactic treatment we are not dosing on clinically diagnosed need; we are dosing just because we are on a regular subscription scheme, for instance, so there is massive overapplying.
The Chair: I will stop you there, because I think we will come on to that. Professor Lord Trees, would you ask your question? Do please make it short.
Q4 Lord Trees: Thanks for coming. The word “resistance” has been mentioned, and we do not deal with it later, so there are a couple of points I will quickly ask you to respond to. First of all, with regard to Daphnia, can you confirm that the resistance that has been talked about is an innate insusceptibility in that case to the drugs in question, right?
Professor Guy Woodward: Yes.
Lord Trees: That is distinct from acquired resistance. But I think there was a suggestion, maybe from Professor Boxall, that there might be acquired resistance amongst various invertebrate taxa to these compounds, and that would affect the apparent ecological effect. Is it a yes or no? Has any acquired resistance been demonstrated?
Matthew Shardlow: It has not, to my knowledge, in wildlife. In my experience, having looked at this from agricultural use, where you get these chemicals widely used in agriculture, the two—
The Chair: Just a short answer will do at this point.
Matthew Shardlow: The answer is fleas and ticks, yes—fipronil, particularly. There is lots of evidence of resistance and it not working very well at all for fipronil, but not on wild species that we are aware of.
The Chair: Thank you. I am sure we will return to that.
Q5 Baroness Whitaker: Good morning. I think there have been developments in our understanding of how these chemicals get into the water, particularly rivers, in the first place, so could you give me your views about how the chemicals from pet parasite medications do enter the environment? Which pathways contribute most to ecological exposure? Maybe this is initially for Professor Woodward.
Professor Guy Woodward: I can make a start on it, but will then defer to my colleagues, who are much more experienced in that area than I am. I have been involved in looking into this to some extent. It seems to me that there are multiple pathways. There is potentially—at least in the early days of the contamination—the scope for legacy contamination from agricultural fields, whereby the half-life can be relatively long. So there may still be leakage through that.
Baroness Whitaker: That is a residue, is it?
Professor Guy Woodward: Yes. In essence, it comes from things such as seed dressings, which there might still be in the soil. These chemicals can bind to the soil and stay there for some time. Eventually, they will leach out into water or groundwater, then they will appear in rivers.
The Chair: They were banned in 2016.
Professor Guy Woodward: Yes. It was 2017 for fipronil and 2018 for imidacloprid, although usage had already declined dramatically by that point. Basically, we have had a decade or so of no real outdoor or agricultural usage of either of them, so the fact that we are still seeing these very high concentrations now—we see them in urban areas in particular, and often see very high levels down stream of wastewater treatment plants—is pretty compelling evidence that this is no longer a solely agricultural issue. They are coming from elsewhere.
Most of the work that has been done to date—for example, trials and models where people have measured exposure and concentrations in different types of water moving in and out of the sewage system or into wastewater treatment plants—suggests that “down the drain” incidents, such as from domestic treatment of cats and dogs, are really key here. These residues can stay on the owner’s hands and on the fur of the animal for many weeks. They can still be found after a month or so on the animals, in bedding and so on.
Then, when the owners wash their hands, these chemicals enter the wastewater system. Wastewater treatment plants are designed to deal with sewage. They are not very effective at removing things like pesticides. So, in essence, these chemicals move in then straight out again with relatively little processing. There are other potential sources, but “down the drain” incidents associated with behaviour around looking after pets seem to account for most of it.
Matthew Shardlow: It is worth adding some of the terrestrial roots with which we are not quite so au fait. It is also worth adding that, once you move outside of imidacloprid and fipronil, you get into a bunch of chemicals that we are not monitoring at all in the environment. So we do not even know whether they are in the environment, let alone how they are getting into the environment.
A study in the Netherlands showed that there are high levels in flowers in parks. That is potentially another significant route: animals are rubbing the stuff off or peeing it out when they are in the environment. Dogs swimming in rivers and ponds is another really obvious way. There is a big study showing high levels in ponds on Hampstead Heath where dogs are allowed to swim.
Baroness Whitaker: Professor Boxall, is this in your field at all?
Professor Alistair Boxall: Yes; this is what I spend most of my day doing. We have covered a range of the main pathways, such as chemicals going down into the sewer system due to the washing of skin after application, the washing of bedding and the surface run-off.
I never thought I would say this to a Lords committee but, when the dog’s poo is on the pavement, it can get washed off. Then you have the poo bags, which are going to be disposed of somewhere, so there will be a route into landfill. We are recognising that dogs swimming is going to introduce these molecules.
An area that is probably important but where there is a lot less data is the terrestrial environment. One of the processes by which chemicals are removed in wastewater treatment is that they stick to sewage sludge. If you look at the ingredients in some of these products, some of them have properties that would mean they stick to sewage sludge quite extensively. I suspect that, for some of these molecules, that will be a very important route into the environment, and that will then expose the terrestrial environment.
Baroness Whitaker: Thank you very much. Have I got it right that the agricultural leachings are not measured?
Matthew Shardlow: No.
Baroness Whitaker: In any case, it is a declining source, is it not?
Matthew Shardlow: It is safe to conclude that they are declining.
Baroness Whitaker: Am I right in thinking that Professor Woodward said that these chemicals do not decay in the household? If they do not, why on earth do people keep on renewing them? We used to put a flea collar on our cat only when she took it off.
Professor Guy Woodward: They do decay, but much more slowly than you might imagine. If you look at the guidelines—I cannot remember this off the top of my head—the period during which you are advised not to let your dog swim in a river is fairly short. It is something like seven days—it is two days, in fact; there you go. It is very short. However, there have been studies showing that these things are persistent for 28 days or longer. In many cases, with monthly subscription schemes, you would be topping up immediately with another dose. So these things are potentially at high background levels all the time.
A very recent study by Collins et al came out last week. It is only pre-print; it has not yet been peer-reviewed. It looked at contamination levels in the home, such as in dust, and showed very concerning levels. Although they do degrade, because you are constantly topping them up, they are, in effect, what you might call “pseudo-persistent”.
Matthew Shardlow: I should add to that—I apologise; this is a complication—because this is a really complicated issue. We talk about forever chemicals, for instance. Some of them do not actually last for ever in their original form. They will break down but sometimes they break down into chemicals that are even more toxic, which we are then not monitoring.
I tried to map this, going down from use through to sewage treatments and into the river. The further down you go, the smaller the jigsaw puzzle bits get, because we are monitoring only part of the pollution. For instance, fipronil breaks down into around seven different compounds; those compounds are just as toxic as fipronil, on average, but we do not have measurements of all of them in the environment.
Baroness Whitaker: It would help us if you could write in identifying what they break down into.
The Chair: That is a very important point, actually. If we could better understand the longevity of these chemicals in the environment, that would be helpful. I turn to Lord Krebs.
Lord Krebs: I think that my question has been covered, actually.
The Chair: That is okay. Professor Boxall wants to come in before we move on.
Professor Alistair Boxall: I just want to make a comment on forever chemicals. One of the chemicals that these molecules are likely to break down into—the ultimate product—is trifluoroacetic acid, which you may have heard of. It is the new PFAS that is hitting the headlines because we are seeing it in very high concentrations in rivers, and concentrations appear to be going up. It is one of the molecules that is going to be a big regulatory concern.
The Chair: I am going to ask a supplementary question; this particular point has already been addressed but I want a definitive answer on it. A contrary view has been put forward to us by NOAH in written evidence. I will quote it; I will then ask each of you to address that quote. It says, “Modelling work indicates that veterinary medicinal products contribute only a small proportion of imidacloprid detected in UK surface waters”. That is contrary to what we have just heard from you all, so can you please address that point?
Matthew Shardlow: I have certainly seen no evidence of that nature.
The Chair: So is that evidence not in the public domain?
Matthew Shardlow: Not that I am aware of. A few years ago, a study was done, but there was an error in the calculations, which meant that they looked at only how much of the imidacloprid would get into the environment after one day of use, rather than across the whole two months in which the chemical was active. That paper came out a while ago and has largely been discredited.
I have seen no other models of information showing that a low level of this pollution is caused by these chemicals. In fact, for fipronil, it is absolutely obvious that it has to be from flea treatments because, even if all of the other potential sources—these might include, for instance, fipronil on cut plants that are imported from overseas, where they are still using fipronil as a pesticide—were taken into account, they would account for only 7% of river pollution, assuming that it all got into the river.
The Chair: That is lovely, thank you. Professor Boxall, can you answer that point directly and very briefly? We will then move on to Baroness McIntosh.
Professor Alistair Boxall: I will just mention some work that we have been doing modelling exposure of fipronil, imidacloprid and permethrin in Yorkshire. We have developed a model for the whole of Yorkshire based on veterinary usage. It is working quite well in estimating concentrations in the river, when we compare what we have come up with to what the Environment Agency measures. That definitely indicates to me that veterinary medicines are the major source. The only exception is permethrin, where I think other sources contribute to the inputs.
The Chair: What is an example of another source?
Professor Alistair Boxall: Permethrin is used in humans for head lice treatment and I think there are agricultural uses. It is also used as a treatment in things like walls and carpets to prevent moths eating away the material.
Q6 Baroness McIntosh of Pickering: We understand that the Environment Agency monitors only priority substances that are listed under the water framework directive. As many of these offending substances are not in that, it is under no mandatory obligation to monitor them, but voluntary sampling is undertaken. How do we actually know what the level of chemicals entering the environment and watercourses from these parasite medications actually is? What monitoring is being done to assess this and should more monitoring be done?
We heard from Buglife in our initial meeting, two weeks ago, that other countries such as Denmark not only monitor but go down a prescription-only route for these products. As I was an MP for North Yorkshire for 18 years, I am going to put all those questions, if I may, to Professor Boxall first.
Professor Alistair Boxall: First, I will talk a little about Environment Agency monitoring. The Environment Agency does do water framework directive substances, which is just over 40 substances, but it has locations across the country in which it screens for about 2,000 different substances, including some of these molecules.
It also has something called PEWS, which is an early warning system used to identify molecules that are coming up as concerns, and to add them to the monitoring list, if it can. It is actually proactive and it has quite a lot of data.
Alongside that, there is quite a lot of academic work going on in this area. Professor Woodward’s colleagues at Imperial have been doing work and we have been doing work. We are finding that these things are quite widespread; we are finding imidacloprid and fipronil, and we are starting to look at other molecules as well. I do not know if you want me to give you an idea of what we find.
Baroness McIntosh of Pickering: It is more to ask if it should be mandatory. From what you are indicating, it is very patchy.
Professor Alistair Boxall: I think the Environment Agency screening system is quite good. I mean, obviously it could be better; our overall monitoring of water could be better, because it is often done with grab samples and at set locations. There are exposure routes that are perhaps not well monitored. Going back to the swimming sites, for example, I do not think the Environment Agency has been doing a lot to target those types of exposure scenarios and the terrestrial environment is pretty much ignored.
The final thing missing from the monitoring is sediment. We know that some of these molecules move from the water phase into the bed sediment and that they stick in the bed sediment. That bed sediment is home to quite a lot of benthic invertebrates.
Baroness McIntosh of Pickering: The Environment Agency also comments on this being prescription-only. That is a fact now in Denmark. Should it be prescription-only here or is the monitoring not sufficient for that?
Professor Alistair Boxall: They probably should be prescription-only. I guess we will come to this later, but I think we should be trying to reduce the use of these molecules.
The Chair: We will come to whether they should be prescription-only in a later question.
Baroness McIntosh of Pickering: Professor Woodward, we understand that you are doing some of the work on this. Is there sufficient monitoring? Should there be more monitoring? Do we actually know what the level of damage is in the waters?
Professor Guy Woodward: I will just add to what Professor Boxall was saying. The Environment Agency is starting to step up and is paying much more attention to this. As I mentioned before, the technology and sensitivity of the instruments needed to detect this has only really come about recently, and the ability to monitor at scale is a cost as well as a logistics issue. There is an increase in effort there, but it can be patchy.
There are particular areas where we have poor knowledge—for instance in high-level temporal sampling, so repeated sampling through time not just through space, to understand the signature. That can be a little lacking. But when we look at the devolved agencies—for instance, in Wales and places like that, which the Environment Agency does not cover—concern has been raised.
As Professor Boxall mentioned, a lot of insights are also coming from the academic community independent of the Environment Agency and its equivalents. A very nice paper came out recently by Hadley et al characterising widespread contamination in Wales and particularly strong urban signatures in Cardiff, for instance. It is a national as well as local challenge.
Matthew Shardlow: The VMD, under the same regulations that we were talking about earlier for authorisation, also has to establish a system of pharmacovigilance. This system is supposed to be run and managed by the authorisation holder as a requirement of the authorisation to make sure that data gets reported back on impacts to pet health, impacts to human health and impacts to the environment. As part of that process of pharmacovigilance, there is no monitoring of the levels of these chemicals in the environment. The only reason that we have data is because imidacloprid and fipronil were added to the watch list. The watch list is part of the water framework directive, but it is not a compulsory part any more because we have left. At the time, it was the accepted thing and the watch list was a way to go through that process of working out whether you have the techniques in place to do the monitoring technically and get the data.
That means that we have the data for those two former pesticides. Of course they were pesticides, because they came through the pesticide process. Nothing that comes through the veterinary process ends up being monitored in the environment. So for most of the flea treatments, including fluralaner, which we use two tonnes of every year in the UK, there is no environmental monitoring. We do not know how much is out there. That is a real problem.
Baroness McIntosh of Pickering: So what would the process be to monitor?
Matthew Shardlow: The process is complex because the environment is a devolved issue. You have all the four countries, and there was a group of the environment agencies working together to look at what chemicals should be put on the list of water framework directive priority substances—the watch list. That group has stopped meeting because it does not have enough resources to meet, and there have been no updates to the list since we left the EU in 2020. As far as I can see, there is nothing happening in that regard so, in making progress by adding new chemicals to the water framework directive, we seem to be in a completely stuck policy position at the moment.
To add to Alistair’s point, it is not only sediments but also marine sediments and the marine environment where we do hardly any monitoring at all. In China, where they do monitoring of marine sediments, they are finding vast amounts of these chemicals now building up with all sorts of potential impacts on fisheries and our ability to feed ourselves in the future. Those sorts of things have happened: in Japan, we have seen entire fisheries collapse because of the ecological impact of these chemicals in rivers and lakes there.
Baroness McIntosh of Pickering: My concern is that it might be happening here, but you are saying that we do not know.
Matthew Shardlow: Yes.
Professor Alistair Boxall: I would like to build on the point that Professor Woodward mentioned around the analytical methods for many of these compounds. The methods that we have for fipronil and imidacloprid are okay; they are able to detect these molecules down to levels below the effect concentrations. But some of the other groups of molecules—an example would be something like moxidectin—are so toxic that the analytical methods that we have at the moment are not able to get down to that level of analysis, which is a major challenge. So even if we monitor, we might not be able to detect these things at levels that are toxic to the environment.
The Chair: Before we move on from monitoring, I have a couple of supplementary questions. We have talked a little about what the Environment Agency can and cannot do in terms of the water framework directive’s rulings on priority substances and water substances. Nevertheless, we hear that the Environment Agency carries out some voluntary testing and that this information is made available to various bodies, including academic research institutes. You receive that information. Is that information in the public domain? That is very helpful on the part of the Environment Agency.
Matthew Shardlow: Yes, but less so in Scotland and Northern Ireland. Their data is not publicly available.
The Chair: Do you know why?
Matthew Shardlow: No.
The Chair: I am a little puzzled about the role of the Chemical Investigations Programme, which also seems to be doing some very useful work. Can you tell us about its role and helpfulness in this?
Professor Guy Woodward: This is again one for Professor Boxall. I can chip in afterwards, but that is more his area.
Professor Alistair Boxall: The CIP is run jointly by the water companies, the Environment Agency and Defra.
The Chair: Who funds it?
Professor Alistair Boxall: I think it is jointly funded by all three. I think the bulk of the funding is from the water companies. Mr Shardlow may be able to give a bit more detail, but I think they included imidacloprid and fipronil in one phase of the CIP. It looks at a range of topical things that go down the sewer system. It involves a number of different projects looking at how well wastewater treatment systems do at removing these molecules and what the impact of the emission is on the levels of the chemicals at points downstream of the emission. It is a publicly available dataset: you can go to the CIP website and look at the data that is being generated in the phases to date.
Professor Guy Woodward: I am not overly familiar with the exact details, but one of the things that we have found when we have looked at some of these data is that there is not often a perfect line-up or strategic linking between what the Environment Agency is doing and what the CIP data are doing. Often, you have a bit of a frustrating disconnect where you cannot, for instance, look at patterns both through space and time in the same system. A bit more co-ordination and joined-up thinking would massively improve the quality and power of that dataset. It is useful but it is not quite as good as it could be in that regard.
Q7 Lord Jay of Ewelme: We have talked a lot today about imidacloprid and fipronil. Following on from the question from Baroness McIntosh, can you say a bit about other medications being developed that, as I understand it, are ingested rather than being applied on the skin and fur? What work has been done to consider the potential effects of those new chemicals on the environment, particularly in terrestrial ecosystems? I am conscious that—as I think Matthew Shardlow said earlier—there is almost no monitoring at all; but then he also said that there is possibly some monitoring going on in other countries in Europe and elsewhere. Can you give us a bit more of a picture of what is being done about alternative medicines?
Matthew Shardlow: There are 22 chemicals that are authorised. It should also be noted that quite a lot of other chemicals that are not authorised are used by people to control flea issues, particularly essential oils. The evidence is that some of these are highly effective but, because you cannot patent them, they do not get put through the authorisation process and so they do not get the label that states “this kills fleas” on them.
Lord Jay of Ewelme: Can you just go into a shop and buy them?
Matthew Shardlow: Yes. For instance, cedar oils have been shown to be quite effective, but they have not been through the authorisation process. That adds another level of risk in a way, because, as I said, we have hardly any information about the other ones.
I mentioned fluralaner earlier and how we use two tonnes of it every year. There have been one or two studies into that. One looked at birds and the amount of fluralaner in birds’ nests. The other looked at dogs swimming. Although it is an oral treatment—you might think that that means it is entirely safe—even swimming dogs, having taken oral fluralaner, will still emit the chemical into water.
I am not sure about other countries. I have not seen extensive data on this from other countries or even scientific studies for most of these chemicals—they just have no idea what is going on in the environment.
Lord Jay of Ewelme: Presumably it is going on. Do any of you have any links or contacts with what might be going on elsewhere outside the United Kingdom?
Baroness McIntosh of Pickering: If it is prescription-only, Chair, it would not—
The Chair: Please let the witnesses answer.
Professor Guy Woodward: I have one other concern about fluralaner in particular, which relates to a point that Professor Boxall alluded to. While things such as imidacloprid are very water soluble—they are a major issue in aquatic ecosystems, which is where there can be high exposure—fluralaner is much less soluble and, as he mentioned, it tends to bind with sediments and solids. If this comes bound up with sewage sludge, there is a risk here that we are almost back to square 1, because biosolids from sewage sludge are sprayed on agricultural land and then reintroducing pesticides into the agricultural system. That was the reason for the original ban on neonicotinoids and the concern about the pollution coming through the agricultural route in the first instance.
That is a potential cause for concern about what could happen with these. Isoxazolines are extremely toxic and can also be very persistent. These are worrying unknowns at the minute, but potential routes could be manifested. In a way, there could be a shift of the problem: maybe we lose on the swings and also lose on the roundabouts to some extent, with imidacloprid causing problems in the aquatic systems and then fluralaner—which is potentially starting to replace imidacloprid, as sales figures seem to suggest—potentially opening up new pollution and contamination pathways and intensifying impacts on land.
Professor Alistair Boxall: I can add a few insights into fluralaner; it is a molecule that we have been looking at. We have been running two monitoring projects. One was a PhD project looking at a range of these active ingredients, including fluralaner. The second is a large NERC-funded project in which we have been monitoring Yorkshire’s rivers continuously for a year.
The results on imidacloprid and fipronil are what we would expect based on what you have heard so far. We do not really detect fluralaner: in the continuous monitoring study, we detected it in only a couple of the hundreds of samples that we took. As Professor Woodward alluded to, that does not mean that fluralaner does not pose an environmental risk; it just suggests that something else is happening to it. It could well be that it is sticking to the sludge, and that sludge is then going on to the land and carrying the fluralaner with it. That really needs to be looked at.
For other molecules we have looked at, we have had occasional detections of moxidectin and pyriprole. We have also looked at dinotefuran—we did not detect that. We have also looked at permethrin, which we detected quite a lot across Yorkshire. As I alluded to earlier, we are not sure that the veterinary input is the major contribution to that, but it is a molecule that we detect quite widely.
Lord Jay of Ewelme: Am I right in thinking that, for other chemicals, very little research has been done and more needs to be done? Why is more not being done? We have slightly got the impression, throughout this inquiry, that there is an awful lot of research that needs to be done but, somehow or another, is not being done. I am quite sure why.
Professor Alistair Boxall: This work is technically quite challenging and very expensive. To look effectively at swimming sites, for example, you need to monitor these systems continuously. That is what we have been doing in Yorkshire. Looking more broadly, we have not been targeting swimming sites but that costs a lot of money and involves a lot of person time. Technically, some of these things are challenging. I mentioned the detection limit issue earlier as some of these molecules are so toxic that to develop the methods that get down to those levels is really tough. From a research perspective, some of this work is quite difficult.
Lord Jay of Ewelme: That is helpful.
Matthew Shardlow: Slightly tangential to that question is: who should pay for that? It costs money. If you are going to add more, it is not only the compounds—the 22 that are authorised, of which roughly 16 are not monitored in any way whatsoever in the environment—you also have to think about the breakdown compounds. That suddenly multiplies up quickly. You could end up with 50 new chemicals that you have to monitor.
The whole concept of pharmacovigilance is that it is part of the polluter pays principle, which means that if you are going to benefit financially from causing pollution, you should be the people paying for it. At the moment, that route through VMD insisting that the chemicals it is authorising have a proper pharmacovigilance regime is not being implemented and it is falling to the taxpayer, who are not then funding the work that is needed to ensure the pharmacovigilance is happening. If, through the authorisation process, we could get money out of the companies to cover some of these costs of this research that needs to happen, and then that research is done by independent scientists, and the monitoring done by the Environment Agency, that would seem to be a much more coherent, environmental principle-compliant approach to sorting this out.
Who should be doing it? Really it is the VMD and the authorisation holders who should be paying for and responsible for making sure these chemicals are monitored in the environment. They are the front line of environmental regulation in terms of these chemicals.
Lord Jay of Ewelme: Thank you, that was helpful.
Q8 Lord Trees: A quick declaration: I did work as a veterinary adviser to Elanco a long time ago, from 1977 to 1980, when none of these products that we are talking about was available. Elanco did not have any of them. The first part of the question I was given was: are existing environmental risk assessments for pet parasite mitigation medication sufficient? We have probably covered most of that. If you have anything to add, fine. I want to go a bit further and ask to what extent we can extrapolate from laboratory toxicity testing, and then finding these chemicals also in natural waterways, to proving there is ecological damage in those natural waterways.
It is a complex system, as you well know, happening in rivers and waterways. There are a lot of other chemicals there, and there are solids and bioavailability issues and so on. As an example, I am looking at a paper here from reputable authors in our own Centre for Ecology and Hydrology, and you will be aware of it. It is by Qu and Johnson as senior authors and entitled Significant Improvement in Freshwater Invertebrate Biodiversity in all Types of English Rivers over the Past 30 Years. This was published in 2023, so the 30 years covers exactly the lifespan of imidacloprid and fipronil. How do you square this? We are having to juggle these conflicting sources of evidence. Can you help us?
Matthew Shardlow: I will try. As you say, there are a lot of things going on in water. Historically, particularly downstream of sewerage works but other areas as well, we had high levels of ammonia and low levels of oxygen, which meant that our rivers were in a poor state. Over the last 30 years, that has improved massively, which meant that the oxygen is there, the ammonia is not there and species can move back in. We have seen a significant recovery from that issue. But what we are still seeing, and increasingly is becoming more detectable, is the depression downstream of sewerage works in precisely the groups that are most vulnerable to these flea treatments—things like mayflies, caddisflies, dragonflies and stoneflies—and that suppression of that population downstream of the sewerage works is exactly what we would expect to see and what we are seeing.
What we are seeing in the environment mirrors what we predict to be happening in terms of sewage. We cannot and will probably never be able to say, “It is this chemical in the sewage that is causing this impact”. Because, unlike when you are doing scientific experiments on whether a treatment is effective on the pet, where you can treat 10 dogs and then not treat them, you cannot treat 10 planets and then not treat 10 planets. That is the problem and it is happening everywhere. There is some monitoring of sewage stuff in a one-off study. We are talking about monitoring early. It occurred to me that you have not mentioned that. But again, we do not really know. We are not monitoring what is coming out of sewerage works regularly, either. We just have snap data on some of these things.
Lord Trees: In those effects, there will be a gradient from an outflow. How extensive is that gradient in a moving watercourse? Is it one kilometre or 50 kilometres? That is critical. What is the overall effect?
Matthew Shardlow: It is difficult to know. They did some study in Wales and the Roath Brook recently where they found a 90% decline in mayflies and associated that with imidacloprid levels in the rivers. There has been work done on the Test in Hampshire, again showing more than 90% decline in the invertebrate populations, and again associated with the levels of these flea treatments in the river. There has been work done in the Bure in Norfolk where Natural England suspects that the 90% decline in the dragonfly population is directly due to flea treatment populations, proving absolutely conclusively that one particular chemical is causing that damage in the environment. When those chemicals correlate with other ones, we will probably never get there.
We do not want to end up in a situation where we have lost all that top level in the most sensitive part of the environment, and then the system starts to flip into algae-dominated systems, which is what happens when you run these experiments in these systems. You get ecological flips, which would then be entirely destructive not only for the ecology but for the tourism in places like the Norfolk Broads, which is so heavily polluted with these chemicals.
Professor Guy Woodward: I will add a little bit to that. Once you get out into the field, some of the challenges are that this is where ecotoxicology meets the principles of epidemiology, to some extent. You are having to make strong inference when maybe you cannot pinpoint causality between one driver and one response, because that is simply not how the real world operates. We are drawing on multiple lines of evidence but, exactly as Matt has pointed out, they all seem to be pointing in a very similar direction. Certainly, the toxic effects we see in the laboratory and the sensitive groups that are vulnerable to these pesticides seem to be the ones that are then also showing the big declines against the backdrop of the point you opened with, the 30-year improvement in water quality.
Again, to echo what Matt has said, we are starting from a low baseline. In the 1970s, water quality in the UK rivers was terrible. What we have seen, essentially over many years, is much better improvement in water quality through removing sewage pollution in particular. It is not perfect, but there has been a general increase in biodiversity in Wales and England, for example. There seem to be these general trends. Essentially, what we might be seeing here is the peeling back of the layers of the onion of different stresses. We are moving things like sewage pollution, which is the overriding stressor in many urban areas. We have also largely fixed the problem of acid rain and acidification, which has been a big problem in upland areas.
We are now seeing these other stresses that have potentially been masked the whole time, and could still have been there, then appearing with things like the pesticides, for instance. In particular, if you look at those trends of recovery over time, although there has been a protracted period of biodiversity recovery, it seems, for many of these groups, more recently, concerns have been raised that this is in fact now levelling off or declining. There is potential here that there has been some masking by other confounding drivers present in the environment. As we pull these away, we start then to see other bottlenecks arising, which certainly seems to be strong correlational evidence that this is linked to things like pesticides.
Lord Trees: I am sorry, but I am still not getting an idea of a gradient and how extensive that is. We know, for example, that cooling water coming out of a nuclear power station warms water and you get a sort of microclimate in the aqueous environment, but it is limited. The outflows will cause certain effects, but are they quite local or are they generalised through a whole river system, for example?
Professor Guy Woodward: The problem that we see here, in many cases, is that there seem to be so many points of contamination that you do not really have any kind of clear controls any more. This is where you need to do field experiments, where you can actually control for the pesticides, for instance.
There are examples, however. There was a study that I was involved in a few years ago, which was looking at a different pesticide, chlorpyrifos, and a spill that happened in the sewage treatment works in Marlborough, just as an example. We traced the impact of that downstream in the River Kennet, the largest tributary of the Thames, and we saw widespread cascading effects on many species, beyond those that would be looked at in ecotoxicological terms. Even hundreds of metres away from the source of pollution, we see, for instance, suppression of key species by 90% or more in some cases. There can be really profound effects, but that was a case of, if you like, a natural experiment and a natural process of a spill that happened in a sewage treatment works, which then allows you to compare it with before-and-after data, et cetera. But the problem that we have is that because these things are coming out from so many multiple sources, there is potentially a constant drip feed of input. It is almost potentially pervasive—that is the challenge, I think.
Matthew Shardlow: I will just add that almost all the studies are based on Environment Agency data, which will only usually cover one point on a river, so you cannot really answer that question unless people do detailed studies like the one we have seen done in Wales. I think Alistair Boxall might want to add that he does some more detailed work, on a catchment, for instance. Then, you might start to find this, but most of our data is based on point sampling. Some of those points are upstream of the sewage works, so that does not tell you much about what is downstream of the sewage works. Some of them are in the estuary, and we know that 20% of samples in estuary are exceeding the limits for flea treatments as well. Although some of it has got bound up in the sediment—and that is not monitored, because that is underneath where the sampling is taken—we do know that these chemicals are extending down from sewage works right out to the sea. Work that has been done in China shows that they can then extend, in the sediments and the sea, out for many kilometres into the oceans.
Professor Guy Woodward: Even in the UK, there is a recent study which has shown high concentrations of this in seaweed in coastal areas around the UK, so it is a catchment-to-coast issue.
The Chair: If you would let our clerk’s team have a reference for that study, that would be very helpful.
Q9 Lord Lennie: What are the major evidence gaps that would improve our understanding of the ecological and human effects of pet parasite medications? We assume that VMD has a whole store of research information that is not available to anyone. Are there other areas where we should be doing research but are not, or places we should find research that is not released yet?
Matthew Shardlow: I will kick off, because I am not a scientist—or not employed as a scientist. For fipronil and imidacloprid, I am not sure we need much more evidence, frankly: I think there is plenty of evidence around those two. For me, the gaps are really around those other chemicals, where we have no idea what levels are in the environment. If they are going to have to step up to fill the gap if we remove imidacloprid and fipronil and start to rely on some of the alternatives, they might start to get used more prevalently and we will get into a situation where there is a risk. I am really relieved that Alistair is not finding fluralaner in the rivers and I am really hopeful that we might find a better product, but yes, it is really difficult.
It is mainly breakdown compounds and then what the other chemicals are going to do. There are all sorts of complex synergy effects that may be having a big impact. At the moment, we are treating each one separately and saying, “Oh, fipronil is at this level, imidacloprid is at this level, thiamethoxam is at this level, clothianidin is at this level”, but actually, they interact. When you put them into the environment, they do not have individual actions; they are actually cumulative and sometimes synergistic, so there are multiple interactions going on and that is an area we do not know much about. But my take-home message is that we know enough to act. We do not need more information for fipronil and imidacloprid; we have got absolutely all the evidence we need. They have been banned in agriculture, probably on less evidence than we currently have for the flea treatment issue here at the moment.
Lord Lennie: You would ban them now? Would you go for prescription or banning?
Matthew Shardlow: Well, we are jumping a bit to the end, but what I would say is that the VMD needs to follow the legislation, and that means revising the assessment reports. For each of the products, there is an assessment report; it should revise the assessment report—in fact, it must revise the assessment report, according to the legislation, whenever there is new evidence available, and it has to be the case that new evidence is available. Sometimes it feels like VMD only considers new evidence to be new evidence if it is provided to them by the manufacturer of the chemical, and does not take into consideration other evidence: that is the feeling you get when you work with VMD for a while. Basically, there is a load of new scientific evidence; it should go back through the process, undertake the assessment and assess whether there is a risk balance. As we have heard, it is hard to assess whether they are going to cause or are causing damage to the environment, and if VMD is not certain, basically, it still needs to take action and make sure that these chemicals are dealt with.
The problem is that the one bit of evidence that we did not have before my report that I think is really significant is: how much do we have to get this pollution problem controlled by? At the moment, for instance, the levels of fipronil sulfone, which is one of the breakdown products of fipronil, are 86 times higher than the proposed environmental quality standard—86 times higher. If we want to get the levels of fipronil and imidacloprid down to the levels where they are not going to be exceeding environmental damage limits, I have done the calculations based on the last 10 years of data and we need to reduce the amount of fipronil going into the environment by 98% and the amount of imidacloprid by 84%.
The question is: what is going to achieve that? It is not going to be a bit of advice or to get people to follow the label more accurately, which seems to be the only thing the Government are doing at the moment, because all the evidence is that it is following the label accurately, which is causing the current pollution issue: leaving only two days, when we know the chemical is coming off the dogs 28 days later. Why only no swimming after two days? Stroking pets, washing hands—all that is encouraged in the veterinary medicines guidance around these chemicals, and we know that that is what is causing this problem. At 98% and 84%, it is going to take some real radical action to get down to a level where the exceedances of the environmental quality standards become acceptable again.
The Chair: I think Professor Boxall has his hand up online.
Professor Alistair Boxall: Like Matt, I think that for imidacloprid and fipronil, we have a pretty good amount of data that if it was brought together could actually give us the answers that are needed. I think they already are—Matt alluded to that. For a lot of the molecules, there are really big data gaps, certainly in terms of the ecotoxicity. For some of these molecules, we have searched for data and it is just not there, so we have no idea. One of the bigger gaps, for me, is the fact that there is not yet a framework available for assessing the risks of these molecules, like there is for agriculture molecules and livestock molecules. I know that at the EU level, the Committee for Veterinary Medicinal Products is looking into this and discussing it, but at the moment there is no guidance on what you would need to do to do that risk assessment.
Then there is a whole range of other things: the lack of monitoring of some of these molecules, the terrestrial environment—the soil environment, the metabolites, the mixtures—and we also need to recognise that, for many of these substances, related substances are used in other product types. Permethrin is used in a range of different product types; there are other pyrethroids that are used in aquaculture; they are going to be working in the same way and they are going to be combined in the environment and impacting the ecology. Then you have the synergy, or the potential for synergy, that Matt alluded to.
There are a lot of gaps in the knowledge but, for imidacloprid and fipronil, we probably have enough information.
Q10 Baroness Whitaker: This is slightly out of your collective remits but is within our remit: are you aware of the human health reverberations of all these chemicals? You do not have to give any detail, but are you aware of any of this going on?
Professor Guy Woodward: It is not my area, so I cannot speak with any great authority on this at all, but I am at least aware of concerns around this. There have been papers that have raised a range of worrying potential pathways and impacts that have really not been considered to date. The one that I mentioned earlier on these pesticides entering the dust in the home and persisting there for a long time is a particular concern. There have been other studies that have raised potential links around things like endocrine disruption, fertility, neurodegenerative diseases and thyroid problems. Many of these are still up for further study, but the concerns have been raised.
One thing that is particularly concerning is that, if this is occurring in dust on the floors, in the home, and you have young children crawling around, their exposure rate could be much higher than in adults. So there is a potential long-term risk that might be present among humans in the house, but that is as much as I really know and it is speculative. At the moment, a lot of this work needs firming up.
The Chair: Professor Boxall, this is an important issue. We need to understand how it is impacting humans.
Professor Alistair Boxall: Like Guy, I am not a toxicologist, but I did sit on the Veterinary Products Committee for a few years and my understanding is that the human health risk is considered as part of the authorisation process for these molecules, as is the risk to the pet itself. The health risk to the owner is part of the assessment process, so the VMD will have information on that.
The pharmacovigilance scheme was mentioned earlier. As part of that, there is a way in which the human health impacts of medicines are reported to the VMD. So if there are effects being caused on humans from these medicines, the VMD will be monitoring that through their SARSS system.
Matthew Shardlow: My review was focused on the environmental pathways and environmental impacts. There were a couple of studies that jumped out while I was doing that, though. One was a review by the Environment Agency and CEH in 2023 of the levels of thousands of chemicals across British waterways, and fipronil was rated as the highest ecological toxicology risk and the highest human-intake toxicological risk. These chemicals are getting into groundwater, so they will be getting into water supplies. We have already heard that it is quite hard to get them out of the water, so that is an issue.
Another study that jumped out at me was about flea treatment use more generally, showing that it was associated with significantly lower cognitive and adaptive scores in children with autism spectrum disorder.
Q11 Lord Rooker: Morning and thanks for coming. You have scared the hell out of me, I must say. I declare an interest: I have never had a pet, but there was a family pet in my home for the weekend, for a few hours, and I asked the owner—because I have never asked before and never contemplated this—whether they do this, that and the other. I was gobsmacked at the regularity of the chemicals that were being used on this pet. It was so well organised—and that was just one pet, by the way. Some homes will have more than one. There is an issue there about the use of prophylactic treatments that may not be necessary, although I raised that and it was not acceptable.
I have a wind-up question but, before I ask it, could I just ask you this, Matt. You have mentioned the 22 chemicals more than once. Are they all manufactured in the UK or are any of them imported?
Matthew Shardlow: It is really difficult to find out where these things are manufactured.
Lord Rooker: Why is that?
Matthew Shardlow: Because it is not reported anywhere. For instance data about what is in the effluent that comes out of factories is not reported anywhere. If we knew what was in the effluent, we might be able to spot who was processing these chemicals but, as it is, we do not know. We know that China is by far the world’s biggest producer of imidacloprid and fipronil. I am not sure if it is producing all of it, but it is producing a very large amount of these chemicals. For the other ones, I am sorry; knowing where chemicals are made is just not in the public domain.
Lord Rooker: In some ways, you have more or less touched on this, but this is to give you a chance to spell out any changes that you would like to see the Government, the veterinary sector or the industry make to reduce risk, particularly to the environment. Is there a particular set of demands or actions that the Government could be responsible for, by using the tools that it has in the veterinary and animal health industry? This is a big industry; we have had a bit of evidence on it and we are talking about big money here. We are well aware of that and of the vested interests around, by the way. Are there factors that you could point to, because you are the first to give us evidence publicly, which we could use for questions to later witnesses?
Matthew Shardlow: There are levels of protection. I talked about the front-line defence being the management and regulation of these chemicals, and the VMD is effectively managing both the environmental risk and the market as it exists. As long as it continues not to take any action to protect the environment, it is effectively creating a marketplace that does not have any pressure on it to be environmentally better. So we need innovation in this marketplace, and that innovation can only come when the market authority, the VMD, starts to apply environmental pressure on that marketplace. That will drive the marketplace to find environmental solutions. As long as it can keep producing chemicals that are causing the levels of chemical pollution that we are seeing from these flea treatments, with no comeback on its profits, it will not be encouraged to move to a better system where there are more environmentally-friendly considerations when they are putting in these chemicals. That is about having a proper system with proper environmental risk assessments and then proper reappraisals whenever environmental information comes available.
The first thing that the Government can do is make sure that the VMD is doing the following: applying its own legislation, as it should do; reviewing the assessment reports; undertaking the three tests—not just the balance test that it keeps going on about but the environmental test—and seeing whether the environmental information is enough. That would be great.
If we decide not to do that, then this drops down to level 2, which is about asking: how are we managing these products getting into the environment? I am afraid that extending the guidance of not washing dogs from two days to four days will not result in a 98% reduction in pollution levels. The only way you could possibly get there is to convert all the sewage works into carbon-filter systems or other processes. There are other processes you can have with sewage works, and there are good environmental reasons for doing that because it reduces the amount of other chemicals that are going through the sewage from getting into the environment. However, at any estimate it will cost tens of billions of pounds to do that, and it will cost hundreds of millions of pounds every year afterwards to treat our sewage. As I said, there are benefits from doing that, but there are also costs. Those costs will not be borne by the people who are profiting from the flea treatments; they will be borne by the public.
As soon as you get out of properly regulating the chemicals at source, you then have to go downstream and put in place new trade effluent measures. The Government could monitor all the effluent coming out of pet hospitals, kennels and veterinary practices—all of that is likely to have high levels of these highly toxic compounds. The environment agencies in all four countries are mandated to protect us from environmental pollution. Despite what you might hear, that does not require that it is added to the water framework directive—that is just a mechanism for achieving the outcome, which is that we are protected from pollution. The Environment Agency would have to pull its finger out and start to monitor and record these chemicals in trade effluent, and then work out how it will treat that trade effluent in such a way that it gets the levels of chemicals down by 80% or 90% to levels where they might be acceptable to release into the environment.
Lord Rooker: That is very helpful.
Professor Guy Woodward: I have a vested interest in that I am an owner of two dogs; I probably have some dog hair on my suit as I sit here. We also need to bear in mind that we need to be able to treat our pets, and we do not want to remove chemicals that can provide useful protection for them.
The real issue is the scale of use and what I would call gratuitous overuse: carrying out prophylactic treatments when there is no clinically diagnosed need to treat the animals. There might be a suggestion that this then becomes expensive for people to go to the vet, but going to the vet when your dog or cat has fleas would be a lot cheaper than paying a monthly subscription to many of these schemes. Speaking from my own experience of owning dogs for 30 years, I can recall having only one flea infestation in that entire time. Maybe that is unusual, but I know from some of the discussions with my colleagues in the veterinary sector that relatively small percentages of cats and dogs present at vets with fleas. With dogs, I think it is one in 400.
Rather than the idea that you need to treat them on a monthly basis—and that, if you do not, you are not a caring owner—we need to move back to how it used to be, whereby you would go to the vet and treat them as you needed. That would go a long way to bringing down these concerning concentration levels to where they are not of such concern. More things might be needed on top of that, but that would be one obvious step—and it would also be a lot cheaper than trying to impose very costly technological solutions in wastewater treatment plants.
Professor Alistair Boxall: I have a list of five changes that I think are needed. I will list them in order.
The first is that we need a proper environmental risk assessment done on all flea treatments and wormers as part of the authorisation process. We should move them to phase 2 and we should test them for their safety. That testing needs to be done in a way that assesses organisms that are potentially sensitive to these molecules. That data should then be used to feed into the benefit-risk assessment. We should not authorise ingredients where the environmental risks outweigh the benefits that Guy has just talked about.
We should stop the prophylactic use of these molecules, and we should ban the advertising that happens at the moment. Almost daily, I get in my social media feed an advert trying to sell me a flea treatment. They are scaremongering.
For those that are approved, we need to develop environmental quality standards and have the monitoring programmes that test that those standards are being met. They need to focus on the media that these things are getting into.
We talked about treatment. If we see that there is a real health benefit for some of these molecules—and that they are needed even though they do pose a risk—there may be the need to mitigate them and the need for technological treatments. The proposals that are happening in Europe at the moment, with updating the urban wastewater treatment directive, provide an ideal opening, because that has an extended producer responsibility approach. That has focused on pharmaceutical manufacturers and personal care manufacturers, where they will pay 80% of the costs of the treatment. We could add the pet medicine manufacturers to those sectors, and there would be a mechanism there to fund the treatment without the public having to pay.
Finally, we should be working to promote the development of safer alternatives and innovating by looking at things that are less toxic and harmful to the environment. Those are my five recommendations.
The Chair: Excellent. We are five minutes over time. This has been a really helpful session to committee members. I say thank you very much again to all three of our expert witnesses for their evidence today. With that, I bring the public session of this meeting to a close.
