Bottled water contains thousands of nanoplastics that can invade body cells, study says

(CNN) — In a groundbreaking new study, researchers have found that bottled water sold in stores may contain 10 to 100 times more plastic particles than previously estimated: nanoparticles so small they cannot be seen with a microscope.

At one-thousandth the width of an average human hair, nanoplastics are so small that they can migrate through the digestive tract or lung tissue into the bloodstream, delivering potentially harmful synthetic chemicals throughout the body and into cells. , experts say.

According to a new study, one liter of water (equivalent to two standard-sized bottles of water) contains an average of 240,000 plastic particles of seven types, 90% of which are identified as nanoplastics and the rest as microplastics.

Microplastics are polymer fragments that can range from less than 5 millimeters to 1 micrometer. Anything small is a nanoplastic that must be measured in billionths of a meter.

“I must say that this study is extremely impressive. The work they put into this was really profound… I would call it innovative,” said Sherry “Sam” Mason, director of sustainability at Penn State Behrend in Pennsylvania, who was not involved in the study.

The new finding reinforces longstanding expert advice to drink tap water from glass or stainless steel containers to reduce exposure, Mason said. That advice also extends to other foods and drinks packaged in plastic, he added.

“People don’t think that plastics go off, but they do,” he said. “Just as we are constantly shedding skin cells, plastic is constantly shedding little pieces that break, like when you open that plastic container for your store-bought salad or plastic-wrapped cheese.”

How many nanoplastics are there?

Mason co-authored a 2018 study that found for the first time the presence of micro- and nanoplastics in 93% of samples of bottled water sold by 11 different brands in nine countries.

In that earlier study, Mason found that each liter of contaminated water contained an average of 10 plastic particles wider than a human hair with 300 smaller particles. However, five years ago there was no way to analyze those small specs or find out if there were more.

“It’s not that we didn’t know nanoplastics existed. We just couldn’t analyze them,” Mason explained.

In a new study published this Monday in the Journal of the National Academy of Sciences, Columbia University researchers have introduced a new technology that can see, count and analyze the chemical composition of nanoparticles in bottled water.

Instead of 300 per liter, the team behind the latest study found that the actual number of plastic pieces in three popular brands of water sold in the United States is between 110,000 and 370,000, if not more. (The authors declined to specify which brand of bottled water they studied.)

However, the new technology was able to see millions of nanoparticles in the water, which could be “inorganic nanoparticles, organic particles and some other plastic particles that are not among the seven main types of plastic we study,” said the co-author. and environmental chemist Beizhan Yan, associate research professor at Columbia University’s Lamont-Doherty Earth Observatory.

The innovative new technologies presented in the study open the door to future research to better understand the potential risks to human health, said Jane Houlihan, director of research for Healthy Babies, Bright Futures, a coalition of nonprofit organizations, scientists and donors committed to reducing children. Exposure to neurotoxic chemicals. She did not participate in the study.

“They suggest widespread human exposure to small plastic particles that pose largely unanticipated risks,” Houlihan said in an email. “Infants and young children may face the greatest risks, as their developing brains and bodies are often most vulnerable to the effects of toxic exposure.”

Hazards to human health

Experts say nanoplastics are the type of plastic pollution most relevant to human health. This is because small particles can invade individual cells and tissues in vital organs, potentially disrupting cellular processes and containing endocrine-disruptors such as bisphenols, phthalates, flame retardants, perfluorinated and polyfluorinated substances, or PFAS and heavy metals. Chemicals can accumulate.

“All those chemicals are used in the production of plastic, so if the plastic reaches us, it takes those chemicals with it. And because the body temperature is higher than the outside temperature, those chemicals will migrate from that plastic and end up in our bodies,” Mason explained.

“Chemicals can reach the liver, kidneys and brain and even cross the placental boundary and end up in the fetus,” Mason said.

In studies with pregnant rats, researchers have detected plastic chemicals in the developing baby’s brain, heart, liver, kidneys and lungs 24 hours after the pregnant mother ingested or inhaled plastic particles, said study co-author Phoebe Stapleton. Associate Professor of Pharmacology and Toxicology at Rutgers University Ernest Mario School of Pharmacy, Piscataway, New Jersey.

“Micro- and nanoplastics have now been found in the human placenta,” said Stapleton. “They have been found in human lung tissue. They have been found in human feces; Found in human blood.

Besides the toxic chemicals and metals contained in plastics, another relatively understudied question is whether the plastic polymers themselves harm the body.

“The new frontier in plastics is understanding polymers, the plastic part of plastics,” Mason said. “Our ability to understand the potential impact of polymers on human health is very limited because we haven’t been able to detect that level. Now, with this new approach, we can begin to do so.

CNN reached out to the International Bottled Water Association, which represents the industry, for a response to the study’s findings.

“This new method needs to be thoroughly reviewed by the scientific community and further research is needed to develop standardized methods for measuring and quantifying nanoplastics in our environment,” a spokesperson for the association told CNN via email.

“Standard methods are currently lacking and there is no scientific consensus on the potential health effects of nano- and microplastic particles. Therefore, media reports about these particles in drinking water do nothing but unnecessarily scare consumers.”

What plastics are you swallowing?

A new study method for identifying nanoparticles in bottled water is based 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.

A modified version, called stimulated Raman scattering microscopy, or SRS, “adds a second laser to amplify the previous signal by several orders of magnitude, allowing for the detection of never-before-seen nanoparticles,” said senior author Wei Min. of chemistry at Columbia University in New York City, who co-discovered SRS in 2008.

“This study is the first to apply this microscopy to the world of nanoplastics,” Min said.

Dramatically improving imaging, SRS can clearly identify and capture images of nanoparticles in microseconds instead of the hours required in previous techniques, and can do so without damaging the tissue being imaged.

“But looking at the particles is not enough because how do you know if it’s plastic or not? To do this, we developed a new machine learning technology that allows us to identify and classify that it is plastic,” said Yan.

At the time of publication, the study’s algorithm was able to identify seven types of plastic: polyamide, polypropylene, polyethylene, polymethyl methacrylate, polyvinyl chloride, polystyrene and polyethylene terephthalate.

“Based on other studies, we expect that most of the microplastics in bottled water leak from the plastic bottles themselves, which are usually made of PET (polyethylene terephthalate) plastic,” said lead author Nixin Qian. Chemistry at Columbia University.

“However, we found that water bottles actually contain many different types of plastic, and different types of plastic have different size distributions,” he said. “The PET particles were larger, while the others were up to 200 nanometers, which is much, much smaller.”

Studies have found that PET plastic particles can be broken down by repeatedly opening and closing bottle caps, crushing them, or subjecting them to heat, such as in cars.

There is still a lot of research to be done

Now that nanoplastics can be identified and classified, it is possible to investigate the answers to all sorts of questions. For example, if nanoplastics floating in bottled water did not come from the bottle itself, where did it come from? The Columbia team is investigating the hypothesis that other nanoplastics may come from water, perhaps contaminated by some part of the manufacturing process.

Another important question: Which has less nanoplastics and chemical residues, bottled or tap water?

“Several studies have reported low levels of microplastics in tap water. Therefore, given their common sources, it is plausible to expect low levels of nanoplastics in tap water as well,” Yan said. “We are researching that right now.”

What happens once plastic polymers and endocrine-disrupting chemicals enter the body’s cells? Do the invaders stay, wreaking havoc by disrupting or damaging cellular processes, or does the body manage to flush them out?

“We know that these microparticles enter the body and we know that a high percentage of small nanoparticles also enter cells, but we don’t know exactly where they go inside the cell or what they’re doing,” Stapleton said. “And we don’t know if they will come back. To get out or how.”

However, the new technology is suitable for analyzing human tissue samples and should provide some answers soon, Min said.

“If you look at our raw data, it’s actually a series of images,” Min said. In fact, we have a lot of data that shows that if a particle has entered a specific type of cell at a specific location, we can detect it precisely in space.”

As science explores these and other questions, there are things people can do to reduce their exposure to plastic, said Houlihan of Healthy Babies, Bright Futures.

“We can avoid taking food and drinks in plastic containers. We can wear clothes made from natural fabrics and buy consumer products made from natural materials,” Houlihan said. “We can take stock of the plastic in our daily lives and find alternatives where possible.”