Posted 13th March
A pioneering study has found UK rivers are heavily contaminated with microplastics
Researchers from The University of Manchester are now calling for tighter regulations on waste flowing into urban waterways after a first of its kind study found microplastics from urban river channels are a major contributor to pollution in the oceans.
Microplastics are tiny pieces of plastic debris that include microbeads, microfibres and plastic fragments which enter river systems from multiple sources, such as industrial effluent, storm water drains and domestic wastewater.
These particles pollute the environment and threaten our ecosystem's health too - although around 90 per cent of microplastic contamination in the ocean is believed to originate from land, there isn't much known about their storage and the movements in river basins.
In what was the first detailed-catchment-wide study to be conducted anywhere in the world, Rachel Hurley, Jamie Woodward and James Rothwell from the Department of Geography at The University of Manchester analysed the microplastics in river sediments from 40 sites across Greater Manchester, including rural streams in the hills and urban rivers in the city centre.
Microplastic contamination was found in all parts of the network, including a site on the River Tame at Denton which had the highest levels so far to be recorded anywhere in the world.
After a period of major flooding, researchers have resampled at all the sites, with levels of contamination found to have fallen at the vast majority of them, while flooding had removed around 70 per cent of the microplastics stored on the river beds. This shows how flood events can lead to the transfer of larger quantities of microplastics from urban rivers to the ocean.
Professor Jamie Woodward, the University's Head of Geography, said: "Microplastics in the ocean have recently attracted a lot of attention, but until now science knew little about the major sources of this pollution and the transport processes involved. We decided to explore the contamination of urban river beds, as we began to think that they may be the main source of the problem."
"We are only beginning to understand the extent of the microplastic contamination problem in the world’s rivers. To tackle the problem in the oceans, we have to prevent microplastics entering river channels. We also need to reduce our use of plastics large and small. We welcome the microbead ban introduced by Michael Gove earlier this year, and we hope that improvements in wastewater management will be put in place in the future."
Photo courtesy of the University of Manchester