Microplastics in UK Rivers: the small particles pointing to a big problem

It’s getting harder and harder to avoid microplastics. They have been found at the bottom of the ocean and at the top of mountains. They’ve entered the food chain, the bottled water we drink, and even our bodies. Our rivers are a major harbour of microplastic pollution, and when examining UK rivers, physical geographers from The University of Manchester found shocking levels of microplastics.

The University of Manchester’s findings linked microplastics to another big problem - sewage discharges into rivers. Their findings had far-reaching implications, influencing policy and debate in the UK’s Parliament. We collaborated with Professor Jamie Woodward and The University of Manchester to share this important research through whiteboard animation and caught up again with Professor Woodward recently to talk more about the microplastics problem and how the whiteboard animation has been received.

 
 
I only get surprised now when somebody does a study and they don’t find microplastics, whether that’s in the environment or in the human body.
— Professor Jamie Woodward, The University of Manchester

Congratulations on your research and the impact it’s having. How has the animation been received?

It's had a great response and various people who are active in these campaigns, like Feargal Sharkey, have retweeted and commented on it, so that was good to see. I think we'll get a lot of mileage out of it in all sorts of avenues from teaching and outreach to campaigning online. We're really pleased with the way it has turned out. It captures the essence of the research, and its impact on policy, which is just as important.

Can you tell us more about the link between microplastics and sewage discharges?

We started this microplastics work back in 2015 with Dr Rachel Hurley (then a PhD student in Geography) and my colleague Professor James Rothwell. Our group at Manchester was the first to discover that UK riverbeds could be contaminated with microplastics. We just didn't know that before and it’s opened up all sorts of interesting research questions. Then we found that when you get flood events, those channel bed microplastics get washed away downstream. Now, the bad news is, obviously, ultimately, they end up in the ocean, but the good news is the rivers will clean themselves.

So, if flooding cleans the riverbeds of microplastics, how do the riverbeds become contaminated in the first place and why are they so regularly replenished with microplastics? It is well known that urban wastewater, including the wastewater from homes and industry that goes to wastewater treatment or sewage treatment plants, is heavily contaminated with microplastics. People have studied that for many years, and we joined up the dots on this. We realised that the only way that microplastics can accumulate on channel beds at such high concentrations is if untreated wastewater is being discharged into rivers when the rivers are at low flow. In essence that's an illegal activity. When we see microplastics on a river channel bed in very high concentrations, we now find it's a clear indicator of poor wastewater management.

 
 

Now, most of the media and campaigning attention has been focused on the disgusting discharges of sewage for obvious reasons. But, if you don’t treat the wastewater, not only are you discharging sewage, you’re also discharging microplastics and a whole host of other pollutants. These microplastics come from multiple sources including domestic wastewater, industry runoff and from roads. If the water companies treat that wastewater, not only of course are they treating the sewage and removing that problem, their processes are also very effective at removing the microplastics. The message we wanted to get across is, if you treat the wastewater, it should be a win-win, because you tackle the sewage problem and you help to tackle the microplastics problem at the same time.

How do microplastics impact our environment and health?

Microplastics are everywhere. I only get surprised now when somebody does a study and they don't find microplastics, whether that's in the environment or in the human body. The microplastics that we find in rivers are mostly less than one millimetre across and easily identifiable under a microscope. We don't have very much information yet about the tiny microplastics, what we call nanoplastic particles, which researchers are starting to explore now. Nanoplastic particles can move within the body, they can get into the bloodstream and end up in organs. We're only beginning to uncover the mobility of these very small plastic particles and where they can end up, not just in the environment, but also in humans and animals.

We have a lot of people on this island and our rivers are mostly rather small, so they have a limited capacity for transporting and coping with pollutants. It’s never been more important to take good care of them.
— Professor Jamie Woodward, The University of Manchester
 
 

In light of your research, how does policy and water company behaviour need to change?

What we’re asking is that the water companies should fully treat the wastewater. There's also a big government initiative to tackle problematic storm overflows, what we call ‘combined sewer overflows’. We know that they are important conduits for microplastics. Now, they're quite a thorny problem because tackling that requires significant investment. This research has also shone a light on the fact that the private water companies haven't been investing sufficiently over the last 30 years. It’s a big task, and they have failed to get the balance right between investment and profits.

When I see sewage discharge, I also think of microplastic discharges, because sewage discharges are basically untreated wastewater. Most water companies are performing very badly, so they need to do much better. The water companies should be regulated by Ofwat (the Water Services Regulation Authority) and their impact on the environment should be policed by the Environment Agency; both are under formal investigation by the Office for Environmental Protection because of their failure to prevent the water companies from polluting the environment. There's certainly political will now and widespread public anger to change the situation but there has been lots of talk and not much action. The water companies have been operating in an unregulated environment for too long and our river environments are in a sorry state.

 
 

The debate about the water companies has often been a left-right debate, but now the political pressure to get the water companies to improve their behaviour is coming from across the political spectrum. When you've got rivers in the Cotswolds being degraded with sewage, you've got true blue Tory constituencies, outraged about the demise of their environment. You've got the hunting, shooting, and fishing lobby now wanting things to change because they've seen their rivers deteriorate. Interestingly, most of the hard evidence for poor water company behaviour has come from citizen science groups and university research, and not from the Environment Agency.

So, it's pretty grim and our rivers in general have poor ecological status and we're having this very dry weather , when the rivers are at very low flow. We have a lot of people on this island and our rivers are relatively small, so they have a limited capacity for transporting and coping with pollutants. It's never been more important to take good care of them. We can now use microplastic contamination data to identify poor wastewater management and as a quantifiable measure to track changes and improvements.

The quality of your river environments, you know, the lifeblood of the nation, is a key indicator of how civilised your society is. We need to take good care of our rivers, but we've created a situation whereby water companies can make huge profits by dumping sewage and untreated wastewater into rivers and nobody has been holding them to account.

How has the animation helped you share your message?

Dr Julian Skyrme is the Director of Social Responsibility at The University of Manchester. He suggested we commission an animation because this research has been very powerful. As well as being an important piece of environmental research that has generated new insights into microplastics and related processes in rivers, it has generated widespread media coverage and is having a growing policy impact.

 
 

We have tried to capture all of this in a three-minute film, communicating the essence of what we've discovered, why it's important and the policy implications. The timing has been perfect because the new Environment Act was going through Parliament last year and the Environmental Audit Committee of the UK Parliament held an inquiry into river water quality across England. Our work has been cited multiple times in Parliament and we gave evidence to the EAC Inquiry.

So, when our paper was published in May 2021, there was immediately a lot of interest and there was also huge controversy about the behaviour of the water companies. Our research added significantly to that debate. It all happened very quickly, and the impact was very rapid. We thought an animation would be a powerful way of capturing that, you know, the essence of the discovery and its wider context, but also why it was important for policy and what it meant. I think the animation captures all of this really nicely.

 
 
It applies across Europe, North America and anywhere where they have wastewater treatment plants and problems with discharge of sewage, etc., and the production of microplastics. Wherever you’ve got people and industry you have plastic, this is a universal challenge.
— Professor Jamie Woodward, The University of Manchester

What are the key messages the world needs to hear when it comes to microplastics?

Clearly, the ultimate solution is to use much less plastic to create less plastic waste, otherwise it's just an end of pipe solution. But being completely pragmatic, we're not going to be using less plastic any time soon. The projections are really scary. So, in the here and now, one of the best strategies that we have available to us is to just treat that wastewater. We're not asking for any special techno-fix, the existing treatment practices will remove the microplastics from wastewater and keep them out of rivers.

What our research also found early on, and contributed to the debate, is that rivers are the main supplier of microplastics to the oceans, and it’s microplastics in the oceans that created the initial concern about microplastics. So, if you want to tackle the marine microplastic problem, the main thing is to keep microplastics out of rivers by treating wastewater and not dumping untreated wastewater in rivers.

 
 

Has illustration and animation helped you make your research more accessible and understandable for audiences?

What I really liked about the animation was the way it illustrated the geography of the contamination and the role of flooding in washing those microplastics away. Things like the contamination circles shrinking after the flooding, the wastewater treatment animation and the outfall processes. I think the animation is really effective at communicating some complex ideas. My take on the animation so far is that we've had lots of feedback saying, “oh, yes, an important message beautifully communicated. It's very simple. It's clear.” That's great.

Time will tell, you know. I think that we have about 10,000 views so far on the University Twitter feed. I gave a talk last week in the Czech Republic in Ostrava at the Melting Pot Ideas Festival. I talked about plastics and microplastics more generally. I showed the animation and, you know, the audience was predominantly Czech, it was a really good way in that context to communicate those ideas to a mixed audience of students and wider public, when English wasn't their first language.

Hopefully it will resonate beyond the UK, because the problem that we're talking about, it's not just a UK problem. It applies across Europe, North America and anywhere where they have wastewater treatment plants and problems with the discharge of sewage, etc., and the production of microplastics. Wherever you've got people and industry you have plastic, this is a universal challenge.

 
 
I gave a talk last week in the Czech Republic in Ostrava at the Melting Pot Ideas Festival ... [the animation] was a really good way in that context to communicate those ideas to a mixed audience, when English wasn’t their first language.
— Professor Jamie Woodward, The University of Manchester

The scale of the microplastics problem in our rivers is shocking, with a knock-on impact for our oceans. You can read more about the research of Professor Woodward and his colleagues in this Research Features article. We can all play our part in reducing the plastic waste we create, and we’ve put this poster together with some tips to help you do this.

We’re very proud of the reach our animation for Professor Woodward and The University of Manchester has had so far and we hope it keeps raising awareness about the problem of microplastics in rivers for a long time to come.  

If whiteboard animation could help you share research or ideas with new audiences, we’d love to talk to you. Book a free creative consultation to tell us about your project and ask us any questions.