Manch­ester river has worst mi­croplas­tic pol­lu­tion ever recorded

Tehran Times - - SOCIETY -

A river in Greater Manch­ester has the worst level of mi­croplas­tic pol­lu­tion ever recorded any­where in the world, a study has dis­cov­ered.

The River Tame in Den­ton was one of sev­eral wa­ter­ways in north­west Eng­land found to have “ex­traor­di­nar­ily” high con­cen­tra­tions, with lev­els of plas­tic pol­lu­tion worse than in Hong Kong and South Korea.

Mi­croplas­tics from these ur­ban rivers and streams are a ma­jor con­trib­u­tor to fa­tal ocean pol­lu­tion when they flood, the study found.

Re­searchers from the Univer­sity of Manch­ester found mi­croplas­tics, tiny pieces of plas­tic de­bris such as mi­crobeads and mi­crofi­bres, are shifted into the seas, par­tic­u­larly af­ter flood­ing.

They are toxic to ecosys­tems in­clud­ing marine life. The re­searchers said their study showed reg­u­la­tions on waste wa­ter flow­ing into ur­ban rivers and streams should be tight­ened.

In the first de­tailed study of its kind any­where in the world, the team took sam­ples from river sed­i­ments at 40 sites across the north­west of Eng­land, in­clud­ing ru­ral streams in hills and ur­ban rivers in the city cen­ter.

It has long been known that such par­ti­cles en­ter rivers from var­i­ous sources, in­clud­ing in­dus­trial ef­flu­ent, storm wa­ter drains and do­mes­tic waste­water.

But the new study looked at how they set­tle in and move out of river basins.

The re­searchers found mi­croplas­tic con­tam­i­na­tion in all parts of the net­work, in­clud­ing a site on the River Tame, which had con­cen­tra­tions up to 517,000 plas­tic par­ti­cles per square me­ter.

The re­searchers took new sam­ples fol­low­ing se­vere flood­ing – and found lev­els of con­tam­i­na­tion fell. The flood­wa­ter had re­moved about 70 per cent of the mi­croplas­tics stored on the river beds.

“This demon­strates that flood events can trans­fer large quan­ti­ties of mi­croplas­tics from ur­ban river to the oceans,” the study con­cluded.

One of the study’s authors, Pro­fes­sor Jamie Wood­ward, the Univer­sity of Manch­ester’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 [the En­vi­ron­ment Sec­re­tary] ear­lier this year, and we hope that im­prove­ments in waste­water man­age­ment will be put in place in the fu­ture.”

House­hold sources of mi­croplas­tics in­clude straws and plas­tic bags as they slowly break down.

Sci­en­tists say they are a risk to all types of life in the sea, from zoo­plank­ton to grey seals and even sharks.

The study, pub­lished on­line in Na­ture Geo­science, said: “A key part of tack­ling the global mi­croplas­tic prob­lem is ef­fec­tive reg­u­la­tion to en­sure that, in all parts of the world, the mul­ti­ple sources of mi­croplas­tics in river catch­ments are brought un­der con­trol.”

Dis­carded fish­ing gear, which breaks down over hun­dreds of years, is an­other source of ocean plas­tics pol­lu­tion, killing crea­tures as large as whales, dol­phins, tur­tles and por­poises.

Newspapers in English

Newspapers from Iran

© PressReader. All rights reserved.