In a groundbreaking new study, researchers discovered that bottled water sold in stores may contain 10 to 100 times more pieces of plastic than previously estimated; The nanoparticles were so small that they could not be seen under a microscope.
Experts say nanoplastics, which are one-1000th the width of an average human hair, are small enough that they can pass through tissues in the digestive tract or lungs into the bloodstream and deliver potentially harmful synthetic chemicals throughout the body and into cells.
According to the new study, one liter of water (equivalent to two standard-sized bottled waters) contained an average of 240,000 plastic particles from seven types of plastic; 90% of these were identified as nanoplastics and the remainder as microplastics.
Microplastics are pieces of polymer that can range from less than 0.2 inches (5 millimeters) to 1/25,000 of an inch (1 micrometer). Anything smaller is a nanoplastic, which should be measured in billionths of a metre.
“I have to say, this study is extremely impressive. “The work they put into this was really quite profound… I would call it groundbreaking,” said Sherri “Sam” Mason, director of sustainability at Penn State Behrend, Erie, Pennsylvania, who was not involved in the research.
Mason said the new finding reinforces long-standing expert advice to drink tap water from glass or stainless steel containers to reduce exposure. He added that this advice also extends to other foods and drinks packaged in plastic.
“People don’t think plastic is spillage, but they think it is,” he said. “Almost like we are constantly shedding skin cells, plastics are constantly shedding tiny pieces that break, such as when you open the plastic container for a store-bought salad or a plastic-wrapped cheese.”
How many nanoplastics are there?
Mason co-authored a 2018 study that first detected the presence of micro- and nanoplastics in 93% of bottled water samples sold by 11 different brands in nine countries.
In a recent study, Mason found that each liter of polluted water contained an average of 10 plastic particles larger than a human hair and 300 smaller particles. But five years ago there was no way to analyze these tiny spots or discover whether there were more.
“It’s not that we didn’t know nanoplastics existed. We couldn’t analyze them,” Mason explained.
In the new study, published Monday in the 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.
The team behind the latest study found that instead of 300 per liter, the actual number of plastic pieces in three popular water brands sold in the United States is between 110,000 and 370,000, if not higher. (The authors declined to specify which brand of bottled water they studied.)
However, the new technology can actually see millions of nanoparticles in the water, and these could be “inorganic nanoparticles, organic particles, and some other plastic particles that are not among the seven major types of plastics we studied,” study co-author and environmental chemist Beizhan Yan of Columbia University’s Lamont-Doherty Earth Observatory said. Associate research professor at.
The innovative new techniques presented in the study open the door to further research to better understand potential risks to human health, said Jane, director of research at Healthy Babies, Bright Futures, an alliance of nonprofit organizations, scientists and donors committed to reducing infant illness. Houlihan. Those exposed to neurotoxic chemicals who were not included in the study.
“They suggest that widespread human exposure to very small plastic particles poses largely unstudied risks,” Houlihan said in an email. “Infants and young children may face the greatest risks because their developing brains and bodies are often more vulnerable to the effects of toxic exposures.”
Dangers to human health
Experts say nanoplastics are the most worrisome type of plastic pollution for human health. This is because tiny particles can invade individual cells and tissues in large organs, potentially disrupting cellular processes and accumulating endocrine-disrupting chemicals such as bisphenols, phthalates, flame retardants, per- and polyfluorinated substances or PFAS, and heavy metals.
“All of these chemicals are used in the production of plastics, so if a plastic gets inside us, it’s carrying these chemicals with it. And because the temperature of the body is higher than outside, these chemicals will come out of the plastic and into our bodies,” Mason explained.
“Chemicals can move to your liver, kidney and brain and even cross the placental border, leading to an unborn child,” Mason said.
Phoebe Stapleton, Professor of Pharmacology and Pharmacology, said studies on pregnant mice found plastic chemicals in the developing baby’s brain, heart, liver, kidneys and lungs 24 hours after the pregnant mother swallowed or inhaled plastic particles. toxicology at Rutgers University’s Ernest Mario School of Pharmacy in Piscataway, New Jersey.
“At this point, micro- and nanoplastics have been found in the human placenta,” Stapleton said. “They’ve been found in human lung tissues. They have been found in human feces; found in human blood.”
Besides the chemicals and toxic metals that plastics can carry, another relatively unstudied area is whether the plastic polymer itself is harmful to the body.
“The new frontier in plastics is understanding polymers, the plastic part of plastic,” Mason said. “Our ability to understand the potential impact of polymers on human health has been very limited because we have not been able to detect it to this level. Now, with this new approach, we will be able to start doing that.”
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 fully reviewed by the scientific community, and further research is needed to develop standardized methods to quantify and quantify nanoplastics in our environment,” a spokesperson for the association told CNN in an emailed statement.
“There is currently a lack of standardized methods and a lack of scientific consensus regarding the possible health effects of nano- and microplastic particles. Therefore, media reports about these particles in drinking water only serve to unnecessarily scare consumers.”
What plastics are you swallowing?
The study’s new 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.
The modified version, called stimulated Raman scattering microscopy, or SRS, adds a second laser “to strengthen the previous signal by several orders of magnitude and enable detection of the previously unseen nanoparticle,” said senior author Wei Min, a professor of chemistry. Columbia University in New York City, which invented SRS in 2008.
“This study is the first to apply this microscopy to the world of nanoplastics,” Min said.
By significantly enhancing imaging, SRS can clearly identify and capture images of nanoparticles in microseconds rather than the hours required by older technique, and can do so without damaging the imaged tissues.
“But seeing the particles isn’t good enough because how do you know if it’s plastic? To do this, we developed a new machine-based learning technology that allows us to identify and classify what plastic it is,” Yan said.
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 expected that most of the microplastics in bottled water would result from leaching from the plastic bottle itself, which is typically made of PET (polyethylene terephthalate) plastic,” said lead author Naixin Qian, a doctoral student in chemistry at Columbia. University.
“However, we found that there are actually a wide variety of types of plastic in a bottle of water, and different types of plastic have different size distributions,” he said. “PET particles were larger, others were up to 200 nanometers, which were much, much smaller.”
Research has found that PET plastic particles can be broken by repeatedly opening and closing the bottle’s cap, crushing the bottle, or exposing it to heat, such as in a car.
There is much more research to be done
Now that nanoplastics can be identified and classified, it is possible to investigate the answers to all kinds of questions. For example, where did the nanoplastics floating in bottled water come from if not from the bottle itself? The Columbia team is exploring the hypothesis that other nanoplastics could come from spring water, perhaps tainted by some part of the manufacturing process.
Another important question: Which has less nanoplastic and chemical residues, bottled water or tap water?
“Many studies have reported lower levels of microplastics in tap water. Therefore, it is reasonable to expect lower levels of nanoplastics in tap water as well, given their common source,” Yan said. “We’re doing research on that right now.”
What happens when plastic polymer and endocrine disrupting chemicals enter the body’s cells? Do the invaders continue to wreak havoc by disrupting or damaging cellular processes, or does the body manage to expel them?
“We know that these microparticles enter the body, and we know that larger percentages of smaller nanoparticles enter cells, but we don’t know exactly where they go or what they do inside the cell,” Stapleton said. . “And we don’t know if or how they’ll get back out again.”
But Min said the new technology is well-suited for analyzing human tissue samples and will soon provide some answers.
“If you look at our raw data, it’s actually a series of images,” Min said. “We actually have a lot of data to show if a particle gets into a certain position in a certain type of cell, then we’ll be able to find it precisely in space.”
Houlihan of Bright Futures Healthy Babies said while science investigates these and other questions, there are things people can do to reduce their exposure to plastic.
“We can avoid consuming food and drinks in plastic containers. “We can wear clothing made from natural fabrics and purchase consumer products made from natural materials,” Houlihan said. “We can evaluate plastic in our daily lives and find alternatives whenever possible.”
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