Researchers have developed a new technique that can detect minute particles of plastic, leading to their discovery that bottled water contain far more plastic fragments than previously thought.
Nanoplastics — tiny fragments of plastic much smaller than microplastics — have been difficult for scientists to explore due to their small size. But a new microscopic technique, developed by researchers from Rutgers and Columbia universities, allows for the detection of these tiny particles of plastic for the very first time. According to their research, bottled water contains hundreds of thousands of them.
The study, published in the journal Proceedings of the National Academy of Sciences, found that, on average, one liter of water contained some 240,000 detectable plastic fragments. This amount is 10 to 100 times greater than previous estimates, which were based mainly on larger sizes of plastic.
Microplastics are created when plastics break down and get progressively smaller. New research is constantly emerging, demonstrating their prevalence, discovered everywhere from polar ice to soil to drinking water to food. Nanoplastics are much smaller than microplastics, with particles below 1 micrometer, and measured in billionths of a meter.
They’re so small that they can pass through environmental filters and biological barriers, including the lungs and intestines, and they can then travel to different organs, including the heart and brain. They can invade individual cells and even cross through the placenta, reaching a developing fetus.
"Previously this was just a dark area, uncharted. Toxicity studies were just guessing what’s in there," said study coauthor Beizhan Yan, an environmental chemist at Columbia University’s Lamont-Doherty Earth Observatory, in a news release. "This opens a window where we can look into a world that was not exposed to us before."
Researchers are working hard to assess the health impacts of consuming micro and nanoplastics, looking into how they may impact a variety of biological systems.
The issue is particularly relevant considering worldwide plastic production is approaching 400 million metric tons per year, with more than 30 million tons dumped yearly in water or on land.
To conduct the water bottle study, researchers used a brand new technique called stimulated Raman scattering microscopy, co-invented by Wei Min, a Columbia biophysicist and coauthor of the study. They tested three popular water bottle brands sold in the United States, analyzing plastic particles down to 100 nanometers in size, and found 110,000 to 370,000 particles in each liter. Ninety percent of these were nanoplastics, and the rest were microplastics.
They were also able to search for specific types of plastic, though the seven plastic types they looked for accounted for only about 10% of all the nanoparticles they found in samples. They were unable to identify the remaining 90%. If they are all nanoplastics, the actual number could stand in the tens of millions per liter.
The team of researchers is taking their deep dive into nanoplastics beyond bottled water, with plans to look into tapwater, wastewater from laundry, and snow while also working with environmental health experts to measure nanoplastics in various human tissues and examine their developmental and neurologic effects.
- Proceedings of the National Academy of Sciences. Rapid single-particle chemical imaging of nanoplastics by SRS microscopy.
- EurekAlert!. Bottled water can contain hundreds of thousands of previously uncounted tiny plastic bits, study finds.
- Frontiers in Endocrinology. A review of the endocrine disrupting effects of micro and nano plastic and their associated chemicals in mammals.
- Statista. Annual production of plastics worldwide from 1950 to 2021.