Using a glass or stainless steel containers is a safer way to consume water, experts say. Clara Margais/dpa/picture alliance/Getty Images
By Sandee LaMotte, CNN
CNN — In a trailblazing new study, researchers have discovered bottled water sold in stores can contain 10 to 100 times more bits of plastic than previously estimated — nanoparticles so infinitesimally tiny they cannot be seen under a microscope.
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.
One liter of water — the equivalent of two standard-size bottled waters — 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 new study.
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.
“This study, I have to say, is exceedingly impressive. The body of work that they put into this was really quite profound … I would call it groundbreaking,” said Sherri “Sam” Mason, director of sustainability at Penn State Behrend in Erie, Pennsylvania, who was not involved in the study.
The new 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 as well, she added.
“People don’t think of plastics as shedding but they do,” she said. “In almost the same way we’re 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’s wrapped in plastic.”
How many nanoplastics are there?
Mason was the coauthor of a 2018 study that first detected the existence of micro- and nanoplastics in 93% of samples of bottled water sold by 11 different brands in nine countries.
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.
“It’s not that we didn’t know nanoplastics existed. We just couldn’t analyze them,” Mason explained.
In the new study, published Monday 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.
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.)
However, the new technology was actually able to see millions of nanoparticles in the water, which could be “inorganic nanoparticles, organic particles and some other plastic particles not among the seven major plastic types we studied,” said coauthor and environmental chemist Beizhan Yan, an associate research professor at Columbia University’s Lamont-Doherty Earth Observatory.
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 Healthy Babies, Bright Futures, an alliance of nonprofits, scientists and donors committed to reducing babies’ exposures to neurotoxic chemicals, who was not involved in the study.
“They suggest widespread human exposures to minuscule plastic particles posing largely unstudied risks,” said Houlihan in an email. “Infants and young children may face the greatest risks, as their developing brains and bodies are often more vulnerable to impacts from toxic exposures.”
Dangers to human health
Nanoplastics are the most worrisome type of plastic pollution for human health, experts say. That’s because the minuscule particles can invade individual cells and tissues in major organs, potentially interrupting cellular processes and depositing endocrine-disrupting chemicals such as bisphenols, phthalates, flame retardants, per- and polyfluorinated substances, or PFAS, and heavy metals.
“All of those chemicals are used in the manufacturing of plastic, so 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,” Mason explained.
“The 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,” Mason said.
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’s Ernest Mario School of Pharmacy in Piscataway, New Jersey.
“Micro and nanoplastics have been found in the human placenta at this point, Stapleton said. “They’ve been found in human lung tissues. They’ve been found in human feces; they’ve been found in human blood.”
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.