2024-01-09 09:10:37
Updated Tuesday, January 9, 2024 – 08:10
Nanoplastics are a generation of microplastics that are appearing all over the Earth, which breaks down further and can go into the blood, cells and brain
Tourists refill plastic bottles with water in Milan.LUCA BRUNOAP
A team of researchers assures that a liter of bottled water contains on average more than 240,000 plastic fragments detectable, between 10 and 100 times more than previous estimates, based mainly on larger plastics.
This is stated in a study carried out by researchers from the Columbia and Rutgers universities (United States), and published this Monday in the journal ‘Proceedings of the National Academy of Sciences’.
In recent years, there has been growing concern that small particles known as microplastics appear everywhere in the world. Tierrafrom polar ice to soil, drinking water and food.
These particles, which form when plastics break down into smaller and smaller pieces, are being consumed by humans and other creatures, with possible unknown effects on health and the ecosystem.
A big focus of research is bottled water, which has been shown to contain tens of thousands of identifiable fragments in each container.
Now, with newly refined technology, researchers at Columbia and Rutgers universities have entered a whole new plastic world: the little-known realm of nanoplsticosthat is, a generation of microplastics that decomposes further and can go into the blood, cells and brain.
Nanoplastics are so small that, unlike microplastics, they can pass through the intestines and lungs directly into the bloodstream and from there travel to organs such as the heart and brain. They can invade individual cells and cross the placenta to the bodies of fetuses. Medical scientists are racing to study possible effects on a wide variety of biological systems.
“Before this was just a dark, unexplored area. Toxicity studies were just guessing what was there,” he says. Beizhan Yanan environmental chemist at Columbia University’s Lamont-Doherty Earth Observatory, who adds: “This opens a window where we can look at a world that was not exposed to us before.”
MILLIONS OF TONS
Global plastic production is approaching 400 million tons per year. More than 30 million tons are dumped into water or land annually, and many products made from plastics, including synthetic textiles, release particles while still in use.
Unlike natural organic matter, most plastics do not decompose into relatively benign substances; They simply split and split again into smaller and smaller particles of the same chemical composition. Beyond individual molecules, there is no theoretical limit to how small they can get.
Microplastics are defined as fragments ranging from five millimeters to one micrometer (a human hair is approximately 70 micrometers wide). Nanoplastics, which are particles smaller than one micrometer, are measured in billionths of a meter.
Plastics in bottled water largely became a public problem after a 2018 study detected an average of 325 particles per liter. Scientists suspected there were even more than they had counted so far, but good estimates were limited to sizes less than a micrometer, the limit of the nanomundo.
PLASTIC SIETE
The new study uses a technique called stimulated Raman scattering microscopy, co-invented by Wei Ming, biophysicist at Coliumbia University and co-author of the study. This involves probing samples with two simultaneous lasers that are tuned to resonate specific molecules.
Focusing on seven common plastics, the researchers created a data-driven algorithm to interpret the results. “It’s one thing to detect, but another to know what you’re detecting,” says Min.
The researchers tested three popular brands of bottled water sold in the United States (they declined to name which ones) and analyzed plastic particles up to 100 nanometers in size.
They detected between 110,000 and 370,000 particles in each liter90% of which were nanoplastics and the rest, microplastics.
They also determined which of the seven specific plastics they were and mapped their shapes, qualities that could be valuable in biomedical research. One of the most common was the polyethylene terephthalate or PET. This was not surprising, since that is what many water bottles are made of. It probably gets into the water when pieces break off when the bottle is squeezed or the bottle is exposed to heat.
However, PET was outnumbered by polyamide, a type of nylon that probably comes from plastic filters supposedly used to purify water before bottling.
Other common plastics the researchers found are polystyrene, polyvinyl chloride and polymethylmethacrylate, all used in various industrial processes.
A somewhat disturbing idea: the seven types of plastic that the researchers looked for represented only about 10% of all the nanoparticles found in the samples.
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