Microplastics found in every British river we tested

Microplastics have been found in the highest mountains, the deepest oceans and now in Britain's most iconic and remote rivers and lakes.
  Published:  07 Mar 2019    |      Last updated:  29 Jul 2021    |      2 minute read

It's been widely reported that tiny bits of plastic, invisible to the human eye, have been escaping into the environment.

But we wanted to know just how widespread the problem is. So our plastics campaigner Julian Kirby headed out with Dr Christian Dunn of Bangor University to test British waterways for these minuscule plastic pollutants.

Plastics campaigner Julian Kirby testing for microplastics in the River Thames with Dr Christian Dunn of Bangor University
Julian Kirby (left) and Dr Christian Dunn testing for microplastics in the River Thames.
Credit: Dr Christian Dunn

Every single river, lake, loch and reservoir they surveyed all tested positive for microplastics – including highland sources you would reasonably expect to be pristine.

The widespread contamination of our rivers and lakes with microplastic pollution is a major concern, and people will understandably want to know what impact this could have on their health and environment.

Julian Kirby, plastics campaigner at Friends of the Earth.

What are microplastics?

Microplastic pollutants are bits of plastic less than 5mm in size. 

Our study, which we think is the first of its kind, found plastic fragments, fibres and film – the sources for which are yet to be established.

Typically, microplastics are thought to come from a number of sources, such as: 

  • car tyres
  • paints on buildings and road markings
  • plastic pellets used to make plastic products
  • clothing

Vehicle tyres are made of a mixture of synthetic materials, including different types of plastic, that shed during driving. They are responsible for the greatest proportion of microplastic pollution entering EU surface waters, according to a report by Eunomia for Friends of the Earth.

Every time we wash our clothes, microplastics drain out with the water and slip through the sewage system into our streams and rivers. Read our article on how to limit the pollution your clothes cause.

The risks to human and environmental health are unknown and urgently need investigating. But we do know these microplastics are escaping into the sea and potentially entering the food chain. They've been found in seafood, drinking water and even human stools.

Finding microplastics in our lakes and rivers

In research that took place between June 2018 and February 2019, Julian and Dr Dunn took 4 litres of water from each of 10 sites.

It's the first time that multiple water samples from British lakes, rivers, lochs and reservoirs have been tested for microplastic pollution.

The sites included:

  • major rivers running through large urban areas
  • remote waterways in Loch Lomond and The Trossachs national park 
  • Ullswater Lake in the Lake District
  • a reservoir in north Wales.
Four full 1-litre bottles placed on a rock next to Ullswater Lake in the Lake District
Water samples taken from Ullswater Lake in the Lake District
Credit: Friends of the Earth

A team of scientists at Bangor University then used a fluorescence lighting system to count microplastic pollutants per litre of water.

Astonishingly, they found the presence of microplastics in all the samples they tested.

A scientist at Bangor University testing for microplastics using a fluorescence lighting system
A scientist testing for microplastics using a fluorescence lighting system.
Credit: Friends of the Earth

Out of the 10 test sites, the River Tame in Greater Manchester contained by far the most microplastic pollution. So much in fact that they had to stop counting when they got to 1,000 pollutants per litre.

The second highest on the list was the River Irwell – with an average of 84.8 pollutants – also in Greater Manchester. The River Thames came in third, registering an average of 84.1 microplastic pollutants per litre.

A map of Britain showing the waterways we tested for microplastics and the amount of pollutants per litre
The waterways we tested for microplastics and the average amount of pollutants per litre.
Credit: Friends of the Earth

Emerging contaminants

Dr Dunn believes that these initial findings show that we need to start taking microplastic pollution more seriously, particularly in our rivers and lakes.

He warns that microplastics should be considered as an emerging contaminant – like pollutants such as pharmaceutical waste, personal-care products and pesticides. And he is calling for routine monitoring of all of the UK's waterways to get a better picture of the problem.

As with all emerging contaminants we don’t yet fully know the dangers they present to wildlife and ecosystems, or even human health, and to what levels they occur in all our water systems.

Dr Christian Dunn, Bangor University