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At the top French Pyrenees, not far from the border with Spain, is an almost virgin clearing, sheltering snow and a weather station, but mostly snow on the snow. The nearest road closes in winter. The largest city in a radius of 100 km has only 9,000 inhabitants.
Look closely at the landscape and see that the place is covered with plastic. Between November 2017 and March 2018, the researchers collected water from the meteorological collectors and searched for microplastics – pieces less than one-fifth of an inch – and found that 365 particles landed on a meter square each day. Source? Probable winds coming from big cities like Barcelona, 100 miles south.
With the discovery, the researchers revealed a new horror of plastic pollution. Scientists already knew that microplastics can be suspended in major cities like Paris and Dongguan, China, but no one has yet shown how far these things can go. It was a short-term pilot study that required additional research from other researchers, but the implications are shocking – for environments supposedly blank worldwide, for ecosystems and for human health.
Allen, et al., Nature Geoscience
As we all have heard, the central problem with plastic is that it takes a thousand years for the plastics to decompose, which in the meantime bounces back into the environment. And when something like a plastic bottle breaks down, it gets rid of small pieces of itself, microplastics that then make their way into the bodies. This is a particular problem at sea, which has been fairly well studied: a survey revealed that mussels were sampled around the United Kingdom. all had microplastics in them.
It is less well understood at this stage how different types of plastics (researchers have discovered a range of samples ranging from polystyrene to polyethylene to polypropylene) cross the atmosphere differently depending on their material properties. It is also difficult to understand how the shape of a microplastic, be it a film, a fiber or a fragment, affects its movement. You can assume that a larger film surface would travel farther than a fragment, but that simply has not been tested.
"One of the challenges ahead is to try to model how these plastics move in 3D in the air, so we can determine where they come from," says Deonie Allen, pollution scientist for the company. environment, the EcoLab, member of the Scientific Research for France, co-author of a new document in Nature Geoscience.
To a certain extent, it is perhaps not surprising that researchers discovered microplastics here in the Pyrenees, as they discovered another important clue: a fine orange dust. This is probably from the Sahara, a phenomenon recorded by this monitoring station for more than a century. (Even more incredible, the dust of the Sahara also crosses the Atlantic to fertilize the tropical forests of South America.)
"Winds do not distinguish between types of particles," says marine geologist Michele van der Does, who has studied the long-range transport of dust particles, but who has not participated in this new work. . "These plastic particles are much larger than the dust particles we find, although we also find these giant dust particles. But their density being much lower, they are also more easily transported over great distances. "
Another consideration is the unique nature of plastic decomposition. As microplastics separate, their properties change in theory. Thus, a single fiber can be divided into two fibers, creating new parts with new aerodynamics. As they are degraded, microplastics end up becoming even more ominous: nanoplastics, a piece less than a micron or a millionth of a meter.
These pieces of plastic, no matter how small, can be found just about anywhere, including in the tissues of an organism, as discovered by researchers when They introduced nanoplastics into scallops. "They showed that in the space of 6 hours, these nanoparticles were parading in the animal," says study co-author Steve Allen, a pollution scientist in the US. environment at the University of Strathclyde and EcoLab (and wife of Deonie Allen). "They are in all parts of the animal in 6 hours."
It is not just the plastic itself that preoccupies the organisms. "We know that these plastics absorb all the chemicals they cross into the environment, such as pesticides," says Allen. "We also know that they contain heavy metals. So if these particles get into your lungs and carry these chemicals, we do not know what's going to happen yet. "
Even more disturbing: nanoplastics are very similar to nanoparticles used in medicine to administer drugs in the human body. "So they can cross the blood-brain barrier in the same way, but with their toxins," says Deonie Allen. "And it's really disturbing." To be clear, however, this idea was not saved with data.
Researchers to haveHowever, explored another disturbing feature of the plastic in the oceans. "In some ecosystems, such as coral reefs, plastics act as disease vectors," says Luiz Rocha, a fish curator at the California Academy of Sciences, who did not participate in the study. "So, a piece of plastic is like a little petri dish for all kinds of bacteria, including pathogens. While walking along the reef, they touch one coral and another and transmit the disease. "
The question of whether microplastics could act as disease vectors on land is another issue that requires more research. But it's important to keep in mind that the microplastic and nanoplastic problem is not a land-sea dichotomy. The effect of plastic on marine creatures has been much more studied than its effects on terrestrial creatures like us, but there is also quite a lot of interaction between the two environments.
Take the laundry, for example. Washing clothes such as yoga pants and fleeces can release hundreds of thousands of synthetic fibers per wash cycle in the environment. "They are not completely eliminated by the filters, they are not completely eliminated by the wastewater treatment plants," says João Pinto da Costa, analytical chemist at the University of Aveiro, who studied plastic in the environment without participating. in this new research. The fibers are found in rivers and seas, but also in sediments, where they dry up and are picked up by the wind. "Also, when you put on your clothes to dry, it's easy to imagine that a lot of fiber will be carried by the wind."
This poses an incredibly complex problem. Plastics have made the world definitely a safer and healthier place: imagine what medicine would be like without technology. But the scale with which plastics contaminate this planet and its life forms is becoming clearer. Even if your country decides to ban all single-use plastic bags, your neighbors could still throw them away and, if this developing pattern of air contamination is true, the microplastics thus obtained could to make your way. In this sense, it is not so different from climate change: either we approach it all together, or we risk nothing.
"That means it's everyone's problem," says Deonie Allen. "But it also means that if you think about the amount of pollution present in places like China, where they wear masks, you might be able to deal with that because we do not manage our plastic. It's pretty scary and it could motivate people to do something. "
It should be noted again that this was a small pilot study. But it should also be noted that the researchers were so alarmed by the results that they wanted to get the message out quickly so that the scientific community could further examine how microplastics are blowing around the Earth.
"We breathe it," says Deonie Allen. "Look up, people. Do not look down.
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