Tech & Science: The sun can help break down ocean plastic, but there’s a catch - - PressFrom - United Kingdom
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Tech & Science The sun can help break down ocean plastic, but there’s a catch

17:45  19 november  2019
17:45  19 november  2019 Source:   popsci.com

Tea drinkers urged to avoid plastic tea bags after tests found bags shed billions of particles of microplastic

  Tea drinkers urged to avoid plastic tea bags after tests found bags shed billions of particles of microplastic Billions of particles of microplastic are being shed into every cuppa that is made using plastic tea bags, experts have found. A team of scientists from McGill University in Canada say the a plastic tea bag brewing in 95C temperatures releases a staggering 11.6 billion microplastics into one single cup. These tiny microplastics - at levels higher than other foods and drinks - are then consumed. Nathalie Tufenkji, from the university, told NewBillions of particles of microplastic are being shed into every cuppa that is made using plastic tea bags, experts have found.

The sun can help break down ocean plastic , but there ’ s a catch .

But there are big questions, including whether the systems will survive the ocean 's forces, harm marine life, and collect plastic . Ocean fish that humans eat have plastic in them. Yet there ' s still debate about where exactly the plastic is. Some scientists believe most of it is already too broken down and

a bird sitting on top of a sandy beach: As of 2014, 5 trillion plastic pieces are floating around the planet's oceans. © DepositPhotos As of 2014, 5 trillion plastic pieces are floating around the planet's oceans.

What if the plastic in the ocean could burn itself up?

This thought might not be too far from the truth. A recent study in the Journal of Hazardous Materials found that when four different types of post-consumer microplastics collected from the waters of the North Pacific Gyre were placed under a solar simulator, they dissolved into organic carbon.

Currently, scientists predict that 5 trillion plastic items, most of which are teensy microplastics, are currently floating around in the world’s oceans, weighing over 250,000 tons. Still, researchers have estimated that the plastic found at the surface of the sea is only around one percent of the plastic that has gone into the oceans.

Tiny turtle found dead with 104 pieces of plastic in its intestines

  Tiny turtle found dead with 104 pieces of plastic in its intestines A tiny turtle that washed up dead on a beach in Florida was found to have eaten 104 pieces of plastic, campaigners said. The Gumbo Limbo Nature Center in Boca Raton shared the plight of the tiny creature on its Facebook page, along with the picture of the turtle and the pieces of plastic found inside it. The centre wrote: “Not such a happy #TurtleTuesday this week. It's washback season at Gumbo Limbo and weak, tiny turtles are washing up along the coastline needing our help.

A lot of plastic debris in the ocean breaks down into smaller pieces and is ingested by marine life, and it is thought that a significant amount sinks to the sea A bottle dropped off the Mexican coast, near Acapulco, is likely to be caught in the same gyre. Some of the plastic waste drifts south, but a huge

Digestion of plastic into much smaller fragments ‘doesn’t necessarily help pollution’, Australian researchers say.

However, the plastics on the surface are unique in that they are exposed to sunlight. And, since plastics are made of polymers of carbon, that sunlight breaks down larger plastics into carbon over time, says Aron Stubbins, an author of the study and professor of marine sciences and engineering at Northeastern University.

This dissolved organic carbon was then, for the most part, munched up by marine bacteria in the water, which then likely converting it to carbon dioxide.

“They just see it as another food source,” Stubbins says.

To Stubbins, it looks like the way plastic can do the most harm is with large pieces, since they can end up in the stomachs of marine life and seagulls far before the sun can convert them into carbon.

The trouble, he says, is not so much on what they might release into the ecosystem but rather their physical presence in the water. “It’s more that they’re a physical nuisance, whether that’s to us as an eyesore and a reminder of the damage that they are doing to the planet, and to other organisms that might mistakenly eat them,” Stubbins says. “It’s more that they are a physical pollutant, in that sense, rather than a chemical pollutant.”

NHS is cutting single-use plastic by more than 1 million pieces a year

  NHS is cutting single-use plastic by more than 1 million pieces a year The NHS bought 163 million plastic cups, 16 million pieces of plastic cutlery, 15 million straws and two million plastic stirrers last year , NHS data shows.Staff and patients © Provided by Johnston Publishing Ltd NHS England chief executive Simon Stevens said: "It's right that the NHS and our suppliers should join the national campaign to turn the tide on plastic waste."Doing so will be good for our environment, for patients and for taxpayers who fund our NHS.

Normally, plastics break down with exposure to sunlight in a process called photocatalytic oxidation, but that can take many years. That membrane is made up of nanoscale wires coated in a semiconductor material that can absorb visible light from the sun and use it to break down plastic

GARBAGE BREAKDOWN . Some types of trash break down quickly . But other types , like plastic A lot of plastic waste caught in ocean currents eventually washes up on beaches ( see SwirlingPlastic ). Ocean pollution can seem overwhelming , but it’ s something everyone can help address .

Collin Ward, a chemist with the Woods Hole Oceanographic Institution who was not involved in the study, says this study adds to the growing knowledge that plastics may not be as persistent in the environment as we first thought. Right now, we just assume that plastic in the environment just hangs out forever, he says, but this study shows that might not be the case.

It might be a bit of a jump to start thinking about how this new knowledge might impact cleaning up the ocean in the future, Ward says.

“But going down this path, once more and more work is done, and we find out how general these findings are, we ultimately can think about incorporating this kind of information into models that would optimize clean-up operations,” Ward says.

While most of the dissolved microplastics just meant more food for microbes, one of the four plastics tested in the study actually harmed the bacteria. Stubbins says he’s not sure if it killed them off or inhibited their growth. Still, they definitely were knocked off their track compared to the same bacteria in plain seawater.

The Ocean Cleanup expands to polluted rivers

  The Ocean Cleanup expands to polluted rivers Watch The Ocean Cleanup unveil its new automated system The Interceptor, which will be deployed to catch plastic debris in rivers before it reaches our oceans.The Interceptor is a large scalable device that'll be anchored to riverbeds to autonomously catch plastic as it flows along. The group says the Interceptor can extract 50,000 kilograms (about 110,000 pounds) of trash per day and could potentially collect up to "100,000 kg per day under optimized conditions." The device is designed to be environmentally friendly. It's solar powered, and lithium-ion batteries let it work day and night without producing noise or exhaust fumes, the group says.

There are many products directly linked to harming endangered or threatened species, unsustainable fishing methods and pollution. But there ’ s more to be done! Become an Oceana Wavemaker and continue your efforts to help save the oceans . As a Wavemaker, you’ll receive a monthly update on

Once plastic is in our oceans , it flows on ocean currents all across the world – so even uninhabited islands in the Pacific and the Arctic are But there ’ s action you can take here in New Zealand, too. We’re calling on the NZ Government to take comprehensive action to eliminate pointless plastics .

There are lots of different ways to make plastic, so of course, there is potential for some types to cause harm in their dissolved form. It’ll take a bit more investigation to see how prevalent this unpleasant side effect is, Stubbins says.

“In some ways, it’s a relief that certain materials don’t last forever in the environment, but on the flip side, we have to exercise caution about the impacts of these transformation products,” Ward says.

Still, even if most of the microbes in this study were okay with dissolved carbon from plastic, we don’t really know how the dissolved carbon affects larger organisms’ health.

Not to mention, there’s a lot of plastic in the world, say the bits that end up a river, that exist in more significant concentrations than the ocean, Stubbins says. The ocean is enormous. So when sunlight breaks down the plastic, the byproducts of those chemical reactions are far more diluted in the sea than they would be in smaller water sources, such as rivers or streams.

“In those places, it may be of more concern if there are contaminants being released as they degrade,” Stubbins says. “The greater concentrations of plastic that there are, the greater the concentration of pollutants there would be. A greater concentration could cause more harm locally.”

Some next steps for Stubbins are looking deeper into the timeline of the breakdown of plastics—how long it takes, what the drivers are, and how chemistry and the size of the materials each play a role.

Sir David Attenborough offers words of wisdom to climate strike activists .
Sir David and Julian Hector, head of BBC Studios Natural History Unit, were awarded the 2019 Chatham House prize for Blue Planet II.The naturalist, now 93, made the comments after accepting the 2019 Chatham House Prize presented to him by the Queen at the policy institute’s London headquarters.

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