In a trailblazing study, researchers have discovered bottled water sold in stores can contain 10 to 100 times more bits of plastic than previously estimated \u2014 nanoparticles so infinitesimally tiny they cannot be seen under a microscope.<\/p>\n\n\n\n
At 1,000th the average width of a human hair, nanoplastics are so teeny they can migrate through the tissues of the digestive tract or lungs into the bloodstream, distributing potentially harmful synthetic chemicals throughout the body and into cells, experts say.<\/p>\n\n\n\n
One liter of water \u2014 the equivalent of two standard-size bottled waters \u2014 contained an average of 240,000 plastic particles from seven types of plastics, of which 90% were identified as nanoplastics and the rest were microplastics, according to the study.<\/p>\n\n\n\n
Microplastics are polymer fragments that can range from less than 0.2 inch (5 millimeters) down to 1\/25,000th of an inch (1 micrometer). Anything smaller is a nanoplastic that must be measured in billionths of a meter.<\/p>\n\n\n\n
\u201cThis study, I have to say, is exceedingly impressive. The body of work that they put into this was really quite profound. \u2026 I would call it groundbreaking,\u201d said Sherri \u201cSam\u201d Mason, director of sustainability at Penn State Behrend in Erie, Pennsylvania, who was not involved in the study.<\/p>\n\n\n\n
The finding reinforces long-held expert advice to drink tap water from glass or stainless steel containers to reduce exposure, Mason said. That advice extends to other foods and drinks packaged in plastic<\/u><\/a> as well, she added.<\/p>\n\n\n\n \u201cPeople don\u2019t think of plastics as shedding but they do,\u201d she said. \u201cIn almost the same\u00a0<\/strong>way\u00a0<\/strong>we\u2019re constantly shedding skin cells, plastics are constantly shedding little bits that break off, such as when you open that plastic container for your store-bought salad or a cheese that\u2019s wrapped in plastic.\u201d<\/p>\n\n\n\n Mason was the coauthor of a 2018 study<\/u><\/a> that first detected the existence of micro- and nanoplastics in 93% of samples of bottled water sold by 11 different brands in nine countries.<\/p>\n\n\n\n In that past study, Mason found each tainted liter of water held an average of 10 plastic particles wider than a human hair, along with 300 smaller particles. Five years ago, however, there was no way to analyze those tiny flecks or discover if there were more.<\/p>\n\n\n\n \u201cIt\u2019s not that we didn\u2019t know nanoplastics existed. We just couldn\u2019t analyze them,\u201d Mason explained.<\/p>\n\n\n\n In the recent study, published in January 2024<\/u><\/a> in the journal Proceedings of the National Academy of Sciences, researchers from Columbia University presented a new technology that can see, count and analyze the chemical structure of nanoparticles in bottled water.<\/p>\n\n\n\n Instead of 300 per liter, the team behind the latest study found the actual number of plastic bits in three popular brands of water sold in the United States to be in between 110,000 and 370,000, if not higher. (The authors declined to mention which brands of bottled water they studied.)<\/p>\n\n\n\n However, the new technology was actually able to see millions of nanoparticles in the water, which could be \u201cinorganic nanoparticles, organic particles and some other plastic particles not among the seven major plastic types we studied,\u201d said coauthor and environmental chemist Beizhan Yan, an associate research professor at Columbia University\u2019s Lamont-Doherty Earth Observatory<\/u><\/a>.<\/p>\n\n\n\n The innovative new techniques presented in the study open the door for further research to better understand the potential risks to human health, said Jane Houlihan, research director for\u2002Healthy Babies, Bright Futures<\/u><\/a>, an alliance of nonprofits, scientists and donors committed to reducing babies\u2019 exposures to neurotoxic chemicals, who was not involved in the study.<\/p>\n\n\n\n \u201cThey suggest widespread human exposures to minuscule plastic particles posing largely unstudied risks,\u201d Houlihan said in an email. \u201cInfants and young children<\/u><\/a>\u00a0may face the greatest risks, as their developing brains and bodies are often more vulnerable to impacts from toxic exposures.\u201d<\/p>\n\n\n\n Nanoplastics are the most worrisome type of plastic pollution for human health, experts say. That\u2019s because the minuscule particles can invade individual cells and tissues in major organs, potentially interrupting cellular processes and depositing endocrine-disrupting chemicals<\/u><\/a> such as bisphenols<\/u><\/a>, phthalates<\/u><\/a>, flame retardants<\/u><\/a>, per- and polyfluorinated substances, or PFAS<\/u><\/a>, and heavy metals<\/u><\/a>.<\/p>\n\n\n\n \u201cAll of those chemicals are used in the manufacturing of plastic, so if a plastic makes its way into us, it\u2019s 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,\u201d Mason said.<\/p>\n\n\n\n \u201cThe chemicals can be carried to your liver and your kidney and your brain and even make their way across the placental boundary and end up in an unborn child,\u201d Mason said.<\/p>\n\n\n\n In studies of pregnant mice, researchers have found plastic chemicals in the brain, heart, liver, kidney and lungs of the developing baby 24 hours after the pregnant mother ingested or breathed in plastic particles, said study coauthor Phoebe Stapleton, associate professor of pharmacology and toxicology at Rutgers University\u2019s Ernest Mario School of Pharmacy in Piscataway, New Jersey.<\/p>\n\n\n\n \u201cMicro and nanoplastics have been found in the human placenta at this point, Stapleton said. \u201cThey\u2019ve been found in human lung tissues. They\u2019ve been found in human feces; they\u2019ve been found in human blood.\u201d<\/p>\n\n\n\n In addition to the chemicals and toxic metals plastics may carry, another relatively unstudied area is whether the plastic polymer itself is also harming the body.<\/p>\n\n\n\n \u201cThe new frontier in plastics is understanding the polymers \u2014 the plastic part of plastic,\u201d Mason said. \u201cWe\u2019ve been very limited in our ability to understand the potential impact of the polymers on human health because we have not been able to detect down to that level. Now, with this new approach, we will be able to start doing so.\u201d<\/p>\n\n\n\n CNN reached out to the International Bottled Water Association, which represents the industry, for a response to the study\u2019s findings.<\/p>\n\n\n\n \u201cThis new method needs to be fully reviewed by the scientific community and more research needs to be done to develop standardized methods for measuring and quantifying nanoplastics in our environment,\u201d a spokesperson for the association told CNN via email.<\/p>\n\n\n\n \u201cThere currently is both a lack of standardized methods and no scientific consensus on the potential health impacts of\u00a0nano- and\u00a0microplastic particles. Therefore, media reports about these particles in drinking water do nothing more than unnecessarily scare consumers.\u201d<\/p>\n\n\n\n The study\u2019s new method of identifying nanoparticles in bottled water relies on a modified version of Raman spectroscopy, a laser-based technique that can analyze the chemical composition of cells by measuring how molecules vibrate in response to light.<\/p>\n\n\n\n The altered version, called stimulated Raman scattering microscopy, or SRS, adds a second laser to \u201camplify the previous signal by several orders of magnitude, allowing the previously unseen nanoparticle to be detected,\u201d said senior author Wei Min, a professor of chemistry at Columbia University in New York City, who coinvented<\/u><\/a> SRS in 2008.<\/p>\n\n\n\n \u201cThis study is the first one to apply this microscopy to the nanoplastic world,\u201d Min said.<\/p>\n\n\n\n By dramatically boosting the image, SRS can clearly identify and capture images of nanoparticles in microseconds<\/u><\/a> rather than the hours needed by the older technique \u2014 and do so without harming the tissues being imaged.<\/p>\n\n\n\n \u201cBut seeing the particles is not good enough because how do you know this is plastic or not? To do that we developed a new machine-based learning technology that allows us to identify and classify which plastic it is,\u201d Yan said.<\/p>\n\n\n\n At the time of publication, the study\u2019s algorithm was able to identify seven types of plastics: polyamide, polypropylene, polyethylene, polymethyl methacrylate, polyvinyl chloride, polystyrene, and polyethylene terephthalate.<\/p>\n\n\n\n \u201cBased on other studies we expected most of the microplastics in bottled water would come from leakage of the plastic bottle itself, which is typically made of PET (polyethylene terephthalate) plastic,\u201d said lead author Naixin Qian, a doctoral student in chemistry at Columbia University.<\/p>\n\n\n\n \u201cHowever, we found there\u2019s actually many diverse types of plastics in a bottle of water, and that different plastic types have different size distributions,\u201d she said. \u201cThe PET particles were larger, while others were down to 200 nanometers, which is much, much smaller.\u201d<\/p>\n\n\n\n