From the Thames to the Lake District, Britain’s iconic waterways are full of plastic pollution, according to a new analysis.

In recent years, scientists have found plastic scattered throughout the ocean, as far down as the Mariana Trench and even embedded in Arctic ice.

But the new research shows the problem also exists closer to home, with up to 1,000 tiny pieces of plastic found per litre in the worst-polluted rivers.

The team behind the study say their results show microplastics should be considered an “emergency contaminant” like pharmaceutical waste and pesticides.

“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,” said Dr Christian Dunn, a wetlands researcher at Bangor University.

Plastic waste across the world: in pictures Show all 15 1 /15 Plastic waste across the world: in pictures Plastic waste across the world: in pictures A father and son on a makeshift boat made from styrofoam paddle through a garbage filled river as they collect plastic bottles that they can sell in junkshops in Manila. The father and son team earn some three US dollars a day retrieving recyclables from the river. AFP/Getty Plastic waste across the world: in pictures A composite image of items found on the shore of the Thames Estuary in Rainham, Kent. Tons of plastic and other waste lines areas along the Thames Estuary shoreline, an important feeding ground for wading birds and other marine wildlife. Getty Images Plastic waste across the world: in pictures Children collect plastic water bottles among the garbage washed ashore at the Manila Bay. According to the United Nations Environment Programme, at current rates of pollution, there will likely be more plastic in the sea than fish by 2050. AFP/Getty Plastic waste across the world: in pictures Plastics and other detritus line the shore of the Thames Estuary. In December 2017 Britain joined the other 193 UN countries and signed up to a resolution to help eliminate marine litter and microplastics in the sea. It is estimated that about eight million metric tons of plastic find their way into the world's oceans every year. Once in the Ocean plastic can take hundreds of years to degrade, all the while breaking down into smaller and smaller 'microplastics,' which can be consumed by marine animals, and find their way into the human food chain. Getty Plastic waste across the world: in pictures A dump site in Manila in 2013. The Philippines financial capital banned disposable plastic shopping bags and styrofoam food containers, as part of escalating efforts across the nation's capital to curb rubbish that exacerbates deadly flooding. AFP/Getty Images Plastic waste across the world: in pictures Children swims in the sea full of garbage in North Jakarta, Indonesia. Getty Plastic waste across the world: in pictures An Indian woman holds a jar filled with Yamuna river water polluted with froth and toxic foam to be used for rituals at the river bank in New Delhi, India. The Yamuna River, like all other holy rivers in India, has been massively polluted for decades now. The river that originates in a glacier in the pristine and unpolluted Himalayas, and flows through Haryana, Delhi and Uttar Pradesh before merging with the Ganges River in Allahabad, once used to be the lifeline of the Indian capital. Currently, it is no more than a large, open sewer that is choking with industrial and domestic discharge that includes plastic, flowers and debris and has virtually no aquatic life. EPA Plastic waste across the world: in pictures Plastic waste is washed up on South Troon beach in Scotland. Recent reports by scientists have confirmed, plastics dumped in the world oceans are reaching a dangerous level with micro plastic particles now being found inside filter feeding animals and amongst sand grains on our beaches. Getty Plastic waste across the world: in pictures Children collect plastic to be sold and recycled, in a polluted river in suburban Manila. The city's trash disposal agency traps solid waste floating down waterways that was thrown into the water by residents of slums along riverbanks upstream. AFP/Getty Plastic waste across the world: in pictures View of the Carpayo Beach in La Punta, Callao, some 15 km of Lima. In 2013, the NGO VIDA labeled the Carpayo Beach as the most polluted in the country - 40 tons of trash on each 500m2. AFP/Getty Plastic waste across the world: in pictures Trash from Kamilo Beach in Hawaii. Gabriella Levine/Flickr Plastic waste across the world: in pictures A scavenger collects plastic cups for recycling in a river covered with rubbish near Pluit dam in Jakarta. Reuters Plastic waste across the world: in pictures Rubbish fills Omoa beach in Honduras. Floating masses of garbage offshore from some of the Caribbean's pristine beaches are testimony to a vast and growing problem of plastic pollution heedlessly dumped in our oceans, locals, activists and experts say. AFP/Getty Plastic waste across the world: in pictures A man climbs down to a garbage filled river in Manila. Plastic rubbish will outweigh fish in the oceans by 2050 unless the world takes drastic action to recycle the material, a report warned in 2016. AFP/Getty Plastic waste across the world: in pictures Garbage on East Beach, Henderson Island (Pitcairn Islands), in the south Pacific Ocean. The uninhabited island has been found to have the world's highest density of waste plastic, with more than 3,500 additional pieces of litter washing ashore daily at just one of its beaches. EPA

“But it’s now clear that microplastics should be considered a serious emerging contaminant and there needs to be a concerted effort to regularly monitor all our inland waters for them.

Preliminary results were gathered by Dr Dunn from 10 sites including Ullswater in the Lake District and Loch Lomond in Scotland.

It is thought to be the first study of its kind to use a fluorescence lighting system on water samples to identify and count tiny shards of plastic less than 5mm in size.

These pollutants include tiny fibres from clothing, scraps of tyre rubber and plastic pellets used in manufacturing.

The worst-polluted stretches were urban rivers like the Tame in Greater Manchester, but even remote lochs and reedbeds contained traces of plastic.

The results gathered were preliminary, and will now form part of a scientific paper.

“It was more than a little startling to discover microplastics were present in even the most remote sites we tested, and quite depressing they were there in some of our country’s most iconic locations.

Waterways containing plastic (pieces per litre of water) River Thames, London (84.1) Chester reedbed (7.6) Ullswater, Lake District (29.5) River Irwell, Salford, Greater Manchester (84.8) River Tame, Tameside, Greater Manchester (>1,000) River Blackwater, Essex (15.1) Falls of Dochart, Loch Lomond & Trossachs National Park (3.3) Loch Lomond, Loch Lomond & Trossachs National Park (2.4) Afon Cegin – river, North Wales (76.9) Llyn Cefni – reservoir, Anglesey, Wales (43.2 )

“I’m sure Wordsworth would not be happy to discover his beloved Ullswater in the Lake District was polluted with plastic.”

The research was carried out in collaboration with Friends of the Earth, which has been pushing for stronger legislation to curb the tide of plastic pollution and stop microplastics ending up in water.

Support free-thinking journalism and attend Independent events

Specifically, they are calling for an end to all non-essential single-use plastic by 2025.

“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,” said Julian Kirby, plastics campaigner at Friends of the Earth.