Scientists Tested Three Popular Brands of Bottled Water — Then They Found Some Tiny Particles

A century ago, plastic was created by humans for their convenience, but today, it has turned into a crisis that is strangling planet Earth, choking it to a slow death. And just when humans realized that they couldn’t control it, the plastic started making its way into everything from polar ice to ocean trenches, vegetables, into the stomachs of creatures like albatrosses, sea lions, manatees, and turtles, and even human blood. In a January 2024 study published in the Proceedings of the National Academy of Sciences, researchers focused on bottled water to examine whether it contained plastics.

To their horror, the water didn’t just contain micro-sized plastics, but rather “nanoplastics,” a kind of ultra-tiny and deadliest form of plastics. “Plastic” refers to a “polymeric material of non-natural origin,” according to a study published in Marine Pollution Bulletin. The term “microplastics” first appeared in 2004. Fast forward to today, humans generate about 400 million tonnes of plastic waste each year, per UNEP. In the aforementioned study, researchers from Columbia University examined bottled water from three brands, whose names were not revealed. Upon testing this water for plastic contamination, they discovered that the water not only contained microplastics, but thousands of tinier plastic particles called “nanoplastics.”

Microplastics are fragments ranging in size from about 5 millimeters down to 1 micrometer, meaning one particle could be as small as a human hair and as large as a pearl or a pencil-top eraser. The nanoplastic family is one step ahead of microplastics. As researchers described in a university press release, nanoplastic particles are below 1 micrometer and are measured in billionths of a meter. The nanoworld is so mysterious that it remains hidden from the human eye, lurking secretively in the dark, infesting everything with danger and death. It’s their tiddly size that makes nanoplastics even more lethal to humans and to life itself. 

Previously, scientists might have known about microplastics, but they weren’t aware of nanoplastics, mainly due to the lack of advanced instruments. For this study, however, they were able to develop a refined new technology and a powerful optical imaging technique that enabled them to study the bottled water from a more sophisticated lens. They employed a technique called “hyperspectral stimulated Raman scattering (SRS)” that featured an automated plastic identification algorithm, which allowed the scientists to analyze the micro-nano plastics at the single-particle level with high chemical specificity and throughput.

This was the first time that researchers were able to count and monitor these nano-sized villains lurking in bottled water, as they noted in the paper. Their analysis revealed that “on average, a liter contained some 240,000 detectable plastic fragments, 10 to 100 times greater than previous estimates, which were based mainly on larger sizes.” About 90% of these fragments were detected to be nanoplastics. They found seven types of plastics in these bottled water products, with the most common one being “polyethylene terephthalate or PET,” which is typically found in the packaging of soda bottles, sports drink cans, ketchup bottles, and mayonnaise containers.

No one would care about these invisible little specks in their water, but since nanoplastics are known to trigger deadly mechanisms in the human body, the evidence cannot be diminished or ignored. “If a plastic makes its way into us, it’s carrying those chemicals with it. And because the temperature of the body is higher than the outside, those chemicals are going to migrate out of that plastic and end up in our body,” Sherri Mason, the director of sustainability at Penn State Behrend in Erie, told CNN.