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Bottled Water Can Contain Hundreds of Thousands of Previously Uncounted Tiny Plastic Bits, Study Finds

(Image by Naixin Qian)

In recent years, there has been rising concern that tiny particles known as microplastics are showing up basically everywhere on Earth, from polar ice to soil, drinking water and food. Formed when plastics break down into progressively smaller bits, these particles are being consumed by humans and other creatures, with unknown potential health and ecosystem effects. One big focus of research: bottled water, which has been shown to contain tens of thousands of identifiable fragments in each container.

Now, using newly refined technology, researchers have entered a whole new plastic world: the poorly known realm of nanoplastics, the spawn of microplastics that have broken down even further. For the first time, they counted and identified these minute particles in bottled water. They found that on average, a liter contained some 240,000 detectable plastic fragments—10 to 100 times greater than previous estimates, which were based mainly on larger sizes.

The study was just published in the journal Proceedings of the National Academy of Sciences.

Nanoplastics are so tiny that, unlike microplastics, they can pass through intestines and lungs directly into the bloodstream and travel from there to organs including the heart and brain. They can invade individual cells, and cross through the placenta to the bodies of unborn babies. Medical scientists are racing to study the possible effects on a wide variety of biological systems.

“Previously this was just a dark area, uncharted. Toxicity studies were just guessing what’s in there,” said study coauthor Beizhan Yan, an environmental chemist at  Columbia Climate School’s Lamont-Doherty Earth Observatory. “This opens a window where we can look into a world that was not exposed to us before.”

Worldwide plastic production is approaching 400 million metric tons a year. More than 30 million tons are dumped yearly in water or on land, and many products made with plastics including synthetic textiles shed particles while still in use. Unlike natural organic matter, most plastics do not break down into relatively benign substances; they simply divide and redivide into smaller and smaller particles of the same chemical composition. Beyond single molecules, there is no theoretical limit to how small they can get.

Microplastics are defined as fragments ranging from 5 millimeters (less than a quarter inch) down to 1 micrometer, which is 1 millionth of a meter, or 1/25,000th of an inch. (A human hair is about 70 micrometers across.) Nanoplastics, which are particles below 1 micrometer, are measured in billionths of a meter.

Plastics in bottled water became a public issue largely after a 2018 study detected an average of 325 particles per liter; later studies multiplied that number many times over. Scientists suspected there were even more than they had yet counted, but good estimates stopped at sizes below 1 micrometer—the boundary of the nano world.

A tiny particle of polystyrene plastic as imaged by a new microscopic technique. It is about 200 nanometers across, or 200 billionths of a meter. (Courtesy Naixin Qian)

“People developed methods to see nano particles, but they didn’t know what they were looking at,” said the new study’s lead author, Naixin Qian, a Columbia graduate student in chemistry. She noted that previous studies could provide bulk estimates of nano mass, but for the most part could not count individual particles, nor identify which were plastics or something else.

The new study uses a technique called stimulated Raman scattering microscopy, which was co-invented by study coauthor Wei Min, a Columbia biophysicist. This involves probing samples with two simultaneous lasers that are tuned to make specific molecules resonate. Targeting seven common plastics, the researchers created a data-driven algorithm to interpret the results. “It is one thing to detect, but another to know what you are detecting,” said Min.

The researchers tested three popular brands of bottled water sold in the United States (they declined to name which ones), analyzing plastic particles down to just 100 nanometers in size. They spotted 110,000 to 370,000 plastic fragment in each liter, 90% of which were nanoplastics; the rest were microplastics. They also determined which of the seven specific plastics they were, and charted their shapes—qualities that could be valuable in biomedical research.

One common one was polyethylene terephthalate or PET. This was not surprising, since that is what many water bottles are made of. (It is also used for bottled sodas, sports drinks and products such as ketchup and mayonnaise.) It probably gets into the water as bits slough off when the bottle is squeezed or gets exposed to heat. One recent study suggests that many particles enter the water when you repeatedly open or close the cap, and tiny bits abrade.

However, PET was outnumbered by polyamide, a type of nylon. Ironically, said Beizhan Yan, that probably comes from plastic filters used to supposedly purify the water before it is bottled. Other common plastics the researchers found: polystyrene, polyvinyl chloride and polymethyl methacrylate, all used in various industrial processes.

A somewhat disturbing thought: the seven plastic types the researchers searched for accounted for only about 10% of all the nanoparticles they found in samples; they have no idea what the rest are. If they are all nanoplastics, that means they could number in the tens of millions per liter. But they could be almost anything, “indicating the complicated particle composition inside the seemingly simple water sample,” the authors write. “The common existence of natural organic matter certainly requires prudent distinguishment.”

The researchers are now reaching beyond bottled water. “There is a huge world of nanoplastics to be studied,” said Min. He noted that by mass, nanoplastics comprise far less than microplastics, but “it’s not size that matters. It’s the numbers, because the smaller things are, the more easily they can get inside us.”

Among other things, the team plans to look at tap water, which also has been shown to contain microplastics, though far less than bottled water. Beizhan Yan is running a project to study microplastics and nanoplastics that end up in wastewater when people do laundry—by his count so far, millions per 10-pound load, coming off synthetic materials that comprise many items. (He and colleagues are designing filters to reduce the pollution from commercial and residential washing machines.) The team will soon identify particles in snow that British collaborators trekking by foot across western Antarctica are currently collecting. They also are collaborating with environmental health experts to measure nanoplastics in various human tissues and examine their developmental and neurologic effects.

“It is not totally unexpected to find so much of this stuff,” said Qian. “The idea is that the smaller things get, the more of them there are.”

The study was coauthored by Xin Gao and Xiaoqi Lang of the Columbia chemistry department; Huipeng Deng and Teodora Maria Bratu of Lamont-Doherty; Qixuan Chen of Columbia’s Mailman School of Public Health; and Phoebe Stapleton of Rutgers University.

Science for the Planet: In these short video explainers, discover how scientists and scholars across the Columbia Climate School are working to understand the effects of climate change and help solve the crisis.
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Jim
Jim
1 month ago

Not at all surprised. As research into the effects in living organisms continues I expect it to not end well. Always wondered why environmentalists never tried to legislate the end of plastic tarps, one of the most obvious degrading plastics.

Tom Zaccone
Tom Zaccone
1 month ago

What were the brands sampled and how do they compare?

Last edited 1 month ago by Tom Zaccone
Maureen Roy, MPH
Maureen Roy, MPH
Reply to  Tom Zaccone
1 month ago

All we know so far is that one of the authors said that common water brands were purchased for this study from Wal-Mart. You can look online to see what water brands are sold at Wal-Mart.

Maureen Roy, MPH
Maureen Roy, MPH
1 month ago

As a practical matter, be aware of French green clay, also known as montmorillonite; 1 teaspoon of that powder, mixed into approx. 1 gallon of drinking water, can adhere to particles in the water. Let settle 1 hour + pour off water into serving pitcher. It is sold in bulk herbal section of independent US natural food stores. Citation: https://www.sciencedirect.com/topics/materials-science/montmorillonite

Being
Being
Reply to  Maureen Roy, MPH
1 month ago

Excellent advice, Thank you!

beizhan yan
beizhan yan
Reply to  Maureen Roy, MPH
1 month ago

I would be cautious about this method since it may introduce more nano- montmorillonite particles than nanoplastics. We do not have data to support that montmorillonite is safer than nanoplastics.

Web Team
Admin
Reply to  Maureen Roy, MPH
1 month ago

Note: Dr Beizhan Yan is a co-author of the research study this article details.

Terry O'Malley
25 days ago

Well thank goodness for Nano-research.
It is obvious, from the picture and the description of the particle size. that even though plastic contains carbon, in its compound form, is not easily biodegradable. Like discarded tires, the organics are trapped in the mixture and requires a controlled thermal/pressure environment, to allow the separation/ and isolation in order to capture the minerals.

The other disturbing factor, is that non of the current filtration caption systems, can collect the Nano particle size materials. .

The oceans feed the aquatic life, the airborne material has free rain in its travel, inwhere all forms of animal and plant life, consumes and digests the waste stream in various sizes, meaning everything is available for consumption through indirect contact.

We have a lot of work to do.

AKcepted
AKcepted
Reply to  Terry O’Malley
19 days ago

If it important enough for you to mention three water brands then you should have done so. To refer us to walmarts website is a cop out!

Chata
Chata
Reply to  AKcepted
18 days ago

Thank you very much for your info…can you please tell me what brand of water is safe for us to drink? I use to drink fiji

Mark Tate
Mark Tate
20 days ago

In addition to plastic bottles, I suspect that medical plastic oxygen tubing, used my millions of people with breathing issues such as COPD, may be exacerbating their illness. These tubes, often up to fifty feet, are used at homes for extended periods, even 24 hours 7 days a week. New tubing in particular have obnoxious chemical smells. Micro and nanoplastics might be directly inhaled into the lungs. Studies have indicated that these particles can affect red blood cells’ ability to carry oxygen. Their disposal at hospitals and homes may well be creating additional problems. I urge Columbia scientists to study possible shedding of plastic particles from medical plastic oxygen tubing and their affects on the lungs for long term exposure.

Jim Rich
Jim Rich
19 days ago

Where’s the RESULTS? Big headlines no information

amato massimo
amato massimo
18 days ago

Some work remains to be done, particularly in establishing any potential consequence on human physiology. Public authorities should probably work harder to make tap water become a preference, should a link be established between certain pathologies and the nanoplastics in bottled water. But I am afraid that proving the correlation (let alone the causality) will be a tough task…

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