Plastic Watch: Nanoplastics and Coffee Cups

Plastic Watch: Nanoplastics and Coffee Cups 1

By Jerri-Lynn Scofield, who has worked as a securities lawyer and a derivatives trader. She is currently writing a book about textile artisans.

Earlier this month,  Treehugger reported on a study published by the journal Environmental Science and Technology that provided yet another good reason for dispensing with disposable coffee cups:

When you drink hot tea or coffee from a plastic cup, you could be swallowing trillions of bits of plastic so small that 1,000 of them could fit on a human hair.

That’s one concerning finding from a study published in the journal Environmental Science and Technology this month, which tested how many nanoplastics—plastic bits smaller than 0.001 millimeters in size—are released when exposed to water.

“[T]he most important finding has been the measurement of particles below 100 nm [nanometers] in water from things that people use in their everyday lives,” study co-author and National Institute of Standards and Technology (NIST) chemist Christopher Zangmeister told Treehugger in an email. [citations omitted].

Another reason to avoid such cups is that they create large amounts of waste, and – despite efforts by Starbucks and other coffee retailers – largely thus far, can’t be recycled (see my 2021 post, Starbucks Launches Reusable Cup Program, which discusses these issues at greater length. so, if you wish to give both your environment and your body a break, make your own coffee, and serve it from a proper cup or mug. Or,  drink coffee the Italian way, at a coffee bar, where coffee is still served in cups. Or, take your own reusable coffee receptacle to your favorite  take-out coffee spot and have them fill ‘er up.

More on those nanoparticles. First off, what are they?  Most of us have heard of microplastics, tiny bits of plastics that have been found everywhere, from deep in oceans to otherwise pristine arctic environments. These fragments are typically a few millimetres in s ize. Nanoplatics are  comprised of the same plastics as microplastics, but they’re even smaller still in size, typically a couple of micrometers. Their size makes them very difficult to study.

The difficulty of so doing is partly what motivated the study team. Per Treehugger:

The NIST-based study team wanted to see what would happen if everyday plastic items were exposed to water at increasing temperatures. While the study authors actually tested several plastics—and found that all of them released nanoplastics—they chose to focus the study on two types: food-grade nylon bags and coffee cups lined with low-density polyethylene. Food grade nylon is frequently used in the food industry for both wrapping and cooking food, while coffee cups are “ubiquitous,” Zangmeister explains.

They exposed the materials to water at increasing temperatures and found that they released more nanoplastics as the water warmed.


A typical cup of coffee is served at between 160 and 185 degrees Fahrenheit, definitely hot enough to expose the average caffeine addict.3 And they could potentially be swallowing quite a lot. In hot water, the average coffee cup released more than a billion nanoplastic particles per milliliter.

“For reference, a small coffee cup is about 300 milliliters,” Zangmeister says. “So, that could lead to exposure to trillions of particles per cup.”

The types of nylon bags used in slow cookers released 10 times more nanoplastics than the coffee cups, meaning they could be an even greater source of exposure.[citations omitted]

One thing I find especially exasperating about the increasingly frequent reports about the ubiquity of microplastics (and now, apparently, nanoplastics): while it’s apparent they’re everywhere, what their presence implies for human health has not yet been well-studied. That fact, of course, is unsurprising, as detecting and curbing plastic fragments would undoubtedly require great sums of money, and in the short-term at least, no one will profit by undertaking such a project. Meaning, who will fund such research?

So, we continue to merrily ingest these plastics particles, oblivious to the specific health implications. Of course, that doesn’t mean what we don’t know won’t hurt us. Over to Treehugger:

How much of a problem is this? The truth is that scientists don’t yet know, but the size of the particles does make them potentially hazardous.

“It’s believed that particles this small can make their way into cells, which may impact cellular function,” Zangmeister says. “But we don’t know that yet.”

The concern over nanoplastics builds on the growing worry over the slightly larger microplastics–plastics less than 5 millimeters in size.

The tinier the particle, the greater its potential impact, because tiny particles can enter into the very fabric of living cells themselves. Per Treehuggger:

There is a growing body of research attempting to understand the spread and impact of nanoplastics as well. A recent study published in Environmental Research found them embedded in the ice in both the North and South poles, while a study published in iForest—Biogeosciences and Forestry this month discovered they could enter a tree through its roots. Another pair of studies published in Chemosphere and the Journal of Hazardous Materials found micro-and nano-tire particles were ending up in estuary and freshwater ecosystems respectively and harming some of the organisms that lived there.

“I think there is more interest in the release of plastics into water because we’re just starting to really understand that they’re everywhere we look,” Zangmeister tells Treehugger. “Microplastics in the Arctic, soils from deep lakes, the water on Capitol hill. So, it really makes you ask the question of how they get there, their sources, and how small do they get.”


Zangmeister says that more research needs to be done to understand the impact of nanoplastics both on human health and the environment. It isn’t clear how long they would remain in water or whether they would clump together over time. What is clear from his research is that plastics do continue to break down even past the microplastic level.

“As particles get smaller, more of their surface is exposed to the environment and more chemical reactions can occur to the exposed surface, leading to more pathways for these materials to breakdown into the environment,” he says. [citations omitted.]

Sounds like there’s ample cause for concern, and studying the impact of microplastics and nanoplastics on human health is a topic more than overdue for research. Will any such comprehensive program be undertaken? I doubt it. Instead, $40 billion  must be shipped, asap, to the Ukraine thetter, to be blown up or set on fire. Such priorities!

Back to the coffee conundrum. Those reusable coffee cups won’t protect you from the nanoparticles already present in the environment. But they will stop the creation of even more of these fragments. Not to mention, not end up in a landfill somewhere.

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