We know that all single-use plastic products pose a growing threat to our environment as even disposable coffee cups are lined with plastic, automatically making them more difficult to recycle.
Now, a team of researchers from the National Institute of Standards and Technology has revealed that these disposable coffee or tea cups shed trillions of microscopic plastic particles into the drink. For their study, which has been published in the journal Environmental Science & Technology, the scientists analyzed single-use hot drink cups lined with low-density polyethylene (LDPE), a soft, flexible plastic film often used as waterproof coating.
We drink microplastics
They found that when these glasses are exposed to 100°C water or milk, they release trillions of nanoparticles per liter into the liquid that we then drink. “The main takeaway here is that there are plastic particles everywhere we look. There are many of them. Billions per litre. We do not know if they have negative effects on the health of people or animals. We just have great confidence that they’re there,” said Christopher Zangmeister, a NIST chemist and co-author of the paper.
During the experiment, after exposing the LDPE-coated coffee cups to boiling water for 20 minutes, they sprayed the water into a fine mist and dried the mist and whatever remained inside in solution to isolate the plastic nanoparticles. Using various state-of-the-art techniques such as scanning electron microscopy and Fourier transform infrared spectroscopy, the scientists managed not only to count the nanoparticles, but also to measure their size: the average size of the particles was between 30 and 80 nanometers – and a handful of over 200 nanometers – and the concentration of nanoparticles released in boiling water by food-grade nylon was seven times higher compared to that released by cups of coffee.
They have reached everywhere
Microplastics are generally considered to be less than 5 millimeters in length and can be seen with the naked eye, while nanoplastics are smaller than a millionth of a meter (a micrometer) and most cannot even be seen with a standard microscope. Previous studies have shown that certain consumer products, such as polypropylene (PP) baby bottles and nylon plastic tea bags, release these plastic particles into the surrounding water.
These findings are quite alarming to many scientists, who are concerned that repeated exposure to such contaminants could have long-term health effects. And it is that, although there are different types of plastic, they are all made of polymers, natural or artificial substances that consist of large molecules linked together and we have already found these microplastics not only in places as remote as Antarctica, but also in our lungs and in our blood.
“In the last decade, scientists have found plastics in any part of the environment that we look for. We’ve looked at them in the snow in Antarctica, at the bottom of glacial lakes, and they found microplastics larger than 100 nanometers, meaning they probably weren’t small enough to get into a cell and cause physical problems,” he said. Zangmeister. However, “our study is different because these nanoparticles are really small and a big problem because they could enter a cell, possibly disrupting its function,” concluded the expert.
Referencia: Christopher D. Zangmeister, James G. Radney, Kurt D. Benkstein, Berc Kalanyan. Common Single-Use Consumer Plastic Products Release Trillions of Sub-100 nm Nanoparticles per Liter into Water during Normal Use. Environmental Science & Technology, 2022; DOI: 10.1021/acs.est.1c06768
National Institute of Standards and Technology (NIST)
