Tuesday, April 13, 2021

Roads produce 84 PER CENT of plastic dust in the atmosphere
Ryan Morrison For Mailonline
4/12/2021

© Provided by Daily Mail 

Roads and the vehicles using them are responsible for 84 per cent of microplastics found in the atmosphere, according to the results of a new study.

Researchers from Utah State University examined different sources of atmospheric microplastic pollution found in the western US over a 14 month period.

These microscopic pieces of plastic pollution are so pervasive they affect how plants grow, waft through the air we breath, infiltrate the oceans, are found in the guts of insects in Antarctica and even in the human bloodstream, study authors warned.

The US team found that 84 per cent of microplastics in the atmosphere came from road dust, mainly tires, 11 per cent from sea spray and five per cent from agricultural soil.© Provided by Daily Mail Study authors found the majority of atmospheric microplastics came from roads, with sea spray (as bottles and packaging breaks down) coming in second

© Provided by Daily Mail Researchers from Utah State University examined different sources of atmospheric microplastic pollution found in the western US over a 14 month period

WHAT ARE MICROPLASTICS?


Microplastics are plastic particles measuring less than five millimetres.

Tonnes of plastic waste fails to get recycled and dealt with correctly.

They end up in waterways, the soil, oceans and even the atmosphere, breaking down over time from larger pieces of plastic waste.

They can also come from tire rubber as cars drive on roadways, and micro beads used in washing and fabrics.

Plastics don't break down for thousands of years, instead forming smaller and smaller particles that enter the atmosphere and climate system.

Scientists warn microplastics are so small they could penetrate organs.

Creatures of all shapes and sizes have been found to have consumed the plastics, whether directly or indirectly.

Janice Brahney, Natalie Mahowald, and colleagues examined major sources of atmospheric microplastics as well as the locations where it is concentrated.

They found microplastics from the land on the surface of the ocean and plastic from the ocean on land - suggesting it spreads through the atmosphere.

Hotspots for terrestrial microplastic sources and accumulation included Europe, Eastern Asia, the Middle East, India, and the US, study authors explained.

Overall, the greatest concentration of atmospheric microplastics was estimated to be over the ocean.

Depending on size, microplastics remained in the atmosphere from approximately one hour to 6.5 days, the latter long enough to take them to another continent.

Even the most remote continent on the Earth, Antarctica, received microplastic pollution from the atmosphere, despite having zero microplastic emissions.

The findings suggest that even after atmospheric microplastics settle on land or in water, they may reenter the atmosphere.

Understanding how microplastics move through global systems is essential to fixing the problem, said Brahney.

'Plastics enter the atmosphere ... not directly from garbage cans or landfills as you might expect ... but from old, broken-down waste that makes its way into large-scale atmospheric patterns,' the team explained.

Roads are a big source of atmospheric plastics, where vehicle tires churn and launch skyward the tiny pieces through strong vehicle-created turbulence.

Ocean waves, too, are full of insoluble plastic particles that used to be food wrappers, soda bottles, and plastic bags.

These 'legacy plastic' particles bob to the top layer of water and are churned by waves and wind, and catapulted into the air.

Dust and agriculture sources for airborne plastics factor more prominently in northern Africa and Eurasia, while road-produced sources had a big impact in heavily populated regions the world over

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© Provided by Daily Mail These microscopic pieces of plastic pollution are so pervasive they affect how plants grow, waft through the air we breath, infiltrate the oceans, are found in the guts of insects in Antarctica and even in the human bloodstream, study authors warned

© Provided by Daily Mail The US team found that 84 per cent of microplastics in the atmosphere came from road dust, mainly tires, 11% from sea spray and five per cent from agricultural soil

This study is important, said Brahney, but it is just the beginning.

'Much more work is needed on this pressing problem to understand how different environments might influence the process - wet climates versus dry ones, mountainous regions versus flatlands,' she said.

'The world hasn't slowed its production or use of plastic, so these questions become more pressing every passing year.'

The findings have been published in the journal Proceedings of the National Academy of Sciences.


Microplastics in our air 'spiral the globe' in a cycle of pollution, study finds

By Jessie Yeung, CNN 
4/12/2021

Tiny bits of plastic from your packaging and soda bottles could be traveling in the atmosphere across entire continents, carried by winds, a new study found.

© Courtesy Janice Brahney, Natalie Mahowald A close-up image of microplastics, which researchers found cycle the globe through the atmosphere.

Most of our plastic waste gets buried in landfills, incinerated or recycled -- but up to 18% ends up in the environment. Since plastic isn't easily decomposable it instead fragments into smaller and smaller pieces until the microplastics are small enough to be swept into the air.


"Akin to global biogeochemical cycles, plastics now spiral around the globe," said the study, led by researchers from Utah State University and Cornell University, and published in the journal Proceedings of the National Academy of Sciences.

That means much of the plastic that gets dumped in the sea and across the land is broken down and spat back out, posing potential risks for our ecosystems. And though there has been some progress with the creation of biodegradable polymers, the researchers warned microplastics "will continue to cycle through the earth's systems."

"We found a lot of legacy plastic pollution everywhere we looked; it travels in the atmosphere and it deposits all over the world," said lead author Janice Brahney in a news release from Cornell. "This plastic is not new from this year. It's from what we've already dumped into the environment over several decades."

The research team collected atmospheric microplastic data from the western United States from 2017 to 2019, and found an estimated 22,000 tons of microplastics are being deposited across the US each year.

In the US, the main way plastics get tossed into the air is through road traffic. Car tires, brakes and even road surfaces contain plastic, which can be worn down into microplastics that enter the atmosphere. The turbulence of cars on the road -- the motion of tires, the braking process, the exhaust they emit -- all help churn up plastic on the ground and send it skyward, according to the study.

This happens in the ocean, too, where large clusters of waste form entire plastic islands. They are broken down into plastic particles that sit on the top layer of the water, where they are tossed into the air by waves and wind.

There are several other ways microplastics enter the atmosphere, in large cities through the wind, and in farms through soil dust during agricultural processes.

Once they enter the atmosphere, plastics can stay airborne for up to six and a half days, according to the study. Within this time, "under the right conditions, plastics can be transported across the major oceans and between continents, either in one trip or by resuspension over the oceans," the study said.

The US, Europe, Middle East, India and Eastern Asia are hotspots for land-based plastic deposition, said the study. Meanwhile, ocean sources of airborne plastic are more prominent along the coasts, including the US' West Coast, the Mediterranean, and southern Australia. Dust and agriculture sources for microplastics are more prevalent in northern Africa and Eurasia, while microplastics from road traffic are major contributors in "heavily populated regions" worldwide.

Microplastics are everywhere -- they influence soil and plant production, are consumed by flora and fauna, and "act as vectors for contaminants," said the study. Though previous studies have not found that microplastics pose a threat to human health, this study's researchers warned they "may have negative and as yet unknown consequences for ecosystems and human health."

"The inhalation of particles can be irritating to lung tissue and lead to serious diseases, but whether plastics are more or less toxic than other aerosols is not yet well understood," said the study. It added that further research is also needed to understand the impact of different factors including population density and ocean circulation.

The researchers also called for better plastic waste management.

"Our relative ignorance of the consequences despite rapidly rising plastic concentrations in our environment highlights the importance of improving plastic waste management or, indeed, capturing ocean plastics and removing them from the system," the study said.


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