Scientists find about a quarter of a million invisible nanoplastic particles in a liter of bottled water
The average liter of bottled water contains nearly a quarter of a million invisible pieces of nanoplastic, first discovered and classified by a dual-laser microscope.
Scientists have long thought there were a lot of these microscopic pieces of plastic, but until researchers at Columbia and Rutgers University did their calculations, they never knew how many or what kind. Looking at five samples from each of three common bottled water brands, researchers found that particulate levels ranged from 110,000 to 400,000 per litre, with an average of about 240,000 according to a study published Monday. Proceedings of the National Academy of Sciences.
These are particles that are less than a micron in size. There are 25,400 microns — also called a micrometer because they are one-millionth of a meter — in an inch. a A human hair is about 83 microns wide.
Previous studies have looked at slightly larger microplastics ranging from a visible 5 millimeters, less than a quarter of an inch, to one micron. The study found that the amount of nanoplastics is approximately 10 to 100 times greater than microplastics in bottled water.
Much of the plastic appears to come from the bottle itself and from the reverse osmosis membrane filter used to block other pollutants, said the study’s lead author, Niexin Qian, a physical chemist at Columbia University. It did not reveal the three brands because the researchers wanted more samples before they identified a specific brand and wanted to study more brands. However, she said they were popular and purchased at Walmart.
Researchers still can’t answer the big question: Are these nanoplastic pieces harmful to health?
“This is currently under review. We don’t know if or how serious it is,” said study co-author Phoebe Stapleton, a toxicologist at Rutgers University. “We do know that it gets into (mammalian, including humans) tissues. “Current research is looking at what it does in cells.”
The International Bottled Water Association said in a statement: “There is currently a lack of standardized (measurement) methods and no scientific consensus on the potential health effects of nanoparticles and microplastics. Therefore, media reports about the presence of these particles in drinking water do nothing more than scare consumers.” Unnecessarily.
The American Chemistry Council, which represents plastics manufacturers, declined immediate comment.
The world is “sinking under the weight of plastic pollution, with more than 430 million tons of plastic produced annually” and microplastics present in the world. World oceans, food And drinking water Some of it comes from clothes and cigarette filters, according to what the British newspaper “The Independent” reported United Nations Environment Programme. Efforts to a Global Plastics Treaty Talks continue after talks stalled in November.
All four co-authors interviewed said they cut back on their use of bottled water after conducting the study.
Wei Min, a physical chemist at Columbia University who pioneered dual laser microscope technology, said he cut the use of bottled water in half. Stapleton said she now relies more on filtered water at her home in New Jersey.
But study co-author Bezan Yan, an environmental chemist in Colombia who has increased his use of tap water, pointed out that the filters themselves could be a problem by introducing plastics.
“There’s no winning,” Stapleton said.
Outside experts, who praised the study, agreed that there is public concern about the dangers of microplastics, but it is too early to say for sure.
“The danger of the plastics themselves remains an unanswered question. “For me, the additives are the most concerning,” said Jason Somarelli, MD, professor of medicine and director of the Comparative Oncology Group at Duke University, who was not part of the research. “We and others have shown “These nanoplastics can be internalized into cells, and we know that nanoplastics carry all kinds of chemical additives that can cause cell stress, DNA damage and change metabolism or cell function.”
Somarelli said his unpublished work found more than 100 “known cancer-causing chemicals in these plastics.”
What’s worrying is that “small molecules can show up in different organs and may cross membranes they’re not supposed to cross, such as the blood-brain barrier,” said Zoe Diana, a developmental biologist at the University of Toronto.
Diana, who was not part of the study, said the new tool the researchers used makes this an exciting development in the study of plastics in the environment and the body.
About 15 years ago, Min invented the dual laser microscopy technique that identifies certain compounds by their chemical properties and how they resonate when exposed to laser beams. Yan and Qian talked to him about using this technique to find and identify plastics that were too small for researchers to use established methods.
“The work could be an important advance in detecting nanoplastics,” said Cara Lavender Law, an oceanographer at the Marine Education Society, but said she would like to see other analytical chemists replicate the technique and results.
Denise Hardesty, an Australian government oceanographer who studies plastic waste, said context is needed. The total weight of the nanoplastic found is “roughly equivalent to the weight of a penny the size of two Olympic-size swimming pools.”
Hardesty is less concerned than others about nanoplastics in bottled water, noting that “I’m honored to live in a place where I can get ‘clean’ tap water and don’t have to buy drinking water in single-use containers.”
Yan said he has begun studying other municipal water supplies in Boston, St. Louis, Los Angeles and elsewhere to see how much plastic is in tap water. Previous studies Searching for microplastics Some early tests suggest there may be less nanoplastics in tap water than in bottled water.
Even with little-known information about human health, Yan said he has one recommendation for concerned people: Use reusable bottles instead of single-use plastics.
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