There is growing worry about tiny plastic particles, known as microplastics, appearing everywhere on Earth - Not only in the soil but also in our food and drinking water.
However, an even smaller classification of plastic exists: nanoplastics. These are tiny fragments that come from microplastics breaking down further. By leveraging cutting-edge technological improvements, scientists have been able to study these microscopic particles in bottled water. They found about 240,000 plastic fragments in a single liter of water, which is more than ten times the expected quantity..
The team published their findings in the peer-reviewed science journal Proceedings of the National Academy of Sciences.
In this article, we'll take a closer look at what researchers discovered.
Scientists have utilized laser technology to image hundreds of thousands of tiny plastic particles in bottled water, that have been invisible up until this point.
(Image Credit: Naixin Qian, Columbia University via Eurekalert)
Invisible Threat: Nanoplastics Travel Through Our Bodies Including the Heart and Brain
Unlike microplastics, nanoplastics have the capability to penetrate directly into the bloodstream through the intestines and lungs due to their extremely small size. Once in the bloodstream, they can then travel to various organs, including the heart and brain.
Every year, we produce almost 400 million metric tons of plastic. More than 30 million tons end up in the water or on land. Plastics don't break down into harmless materials; they just keep splitting into smaller pieces of the same harmful stuff. There's no limit to how small these pieces can get.
Microplastics are defined as being up to 5 millimeters (less than a quarter inch) down to 1 micrometer, which is really, really small. Nanoplastics are even smaller than that, they are measured in billionths of a meter (measurements below 1 micrometer).
Understanding the Scale: The Pervasiveness of Nanoplastics in Bottled Water
Bottled water and its plastic content became a big issue after a 2018 study found lots of microplastics in it. Scientists thought there were even more tiny plastics than they could count, but they had a hard time measuring anything smaller than 1 micrometer.
Naixin Qian, the study's lead author, stated that earlier studies could estimate how much tiny plastic was there but couldn't actually see the individual pieces or tell if they were plastic or something else.
For their study, the teams used a special microscope technique (stimulated Raman scattering microscopy) to identify small plastics. The team looked at three popular bottled water brands in the U.S. and found between 110,000 and 370,000 particles in each liter, with most of them being nanoplastics.
Image Credit: YAKOBCHUK VIACHESLAV via Shutterstock / HDR tune by Universal-Sci
Beyond Bottled Water: The Wider Impact and Future Studies on Nanoplastics
The researchers also found out what kind of plastics these were. One common type was Polyethylene terephthalate (better known as PET), the type of plastic that many water bottles are made of. But there were other types, too, like polyamide (a type of nylon), probably coming from the filters that are used to clean the water for consumption.
Disturbingly, the researchers stated that what they found is just a small part (approximately 10%) of what's really in the water. The team is uncertain about the composition of the remaining particles.
If they are indeed all nanoplastics, their quantity could be as high as tens of millions per liter. However, the particles could be almost anything, "indicating the complicated particle composition inside the seemingly simple water sample," the authors write.
The researchers are now looking at other sources of nanoplastics, like tap water, snow in Antarctica, and even human tissues, to understand how these tiny plastics affect us and our environment.
As mentioned in the introduction of this article, the scientists published their findings in the Proceedings of the National Academy of Sciences. For those interested, there's a link below this article.
Sources and further reading:
Rapid single-particle chemical imaging of nanoplastics by SRS microscopy - (Proceedings of the National Academy of Sciences)
Stimulated Raman scattering microscopy (Nature Methods)
Polyethylene terephthalate (Science Direct)
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