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At this point, it’s common knowledge that bottled water contains microplastics—fragments of the insidious material that can be as small as a bacterial cell. But the problem is much worse than previously known: It turns out that bottled water harbors hundreds of thousands of even tinier pieces of the stuff.
A paper published Monday used a novel technique to analyze one-liter samples of bottled water for plastic granules, going down to just 50 to 100 nanometers in length—roughly the width of a virus. They found nearly a quarter of a million of these tiny particles per liter, about 10 to 100 times more than previously published estimates.
“We’ve opened up a whole new world,” Wei Min, one of the paper’s authors and a chemistry professor at Columbia University, told Grist. Until now, scientists lacked a quick and efficient way to identify nanoplastics, hindering research on their health and environmental impacts.
To conduct their analysis, researchers at Columbia and Rutgers universities filtered bottled water from three different brands through an ultrafine membrane. They then shone two lasers, calibrated to recognize the chemical bonds binding the nanoplastic particles, onto the membrane. Then it was a simple matter of counting all the different particles of plastic. They estimated that a typical one-liter bottle contains 240,000 of them.
Sherri Mason, an associate research professor at Penn State Erie who studies microplastics but was not involved in the new research, called the technique “groundbreaking.”
”I was blown away,” she told Grist. “It’s just really good.”
What’s more, the researchers were able to differentiate between types of nanoplastic. To their surprise, most of the particles were not polyethylene terephthalate, or PET—the material most water bottles are made of. Rather, they found more…
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