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BARCELONA, Spain — In a concerning discovery for tea lovers everywhere, scientists have found that a simple cup of tea might come with an unwanted extra ingredient: billions of microscopic plastic particles. A new study reveals that common tea bags can release substantial amounts of micro and nanoplastics (MNPLs) into your brew during the steeping process.
The research, conducted by a team of scientists from Spain, Egypt, and Germany, and published in Chemosphere, examined three different types of commercial tea bags: those made from nylon-6, polypropylene, and cellulose. What they found was startling. A single tea bag can release anywhere from 8 million to 1.2 billion nanoplastic particles into your cup, with polypropylene bags being the worst offenders.
These plastic particles are incredibly tiny – most are smaller than a human hair’s width – and can be readily absorbed by the cells in our digestive system. The researchers discovered that different types of intestinal cells interact with these particles in varying ways, with some cells taking up more particles than others. Of particular concern was the finding that these nanoplastics can interact with cell nuclei, where our genetic material is stored.
“We have managed to innovatively characterize these pollutants with a set of cutting-edge techniques, which is a very important tool to advance research on their possible impacts on human health,” says Universitat Autònoma de Barcelona researcher Alba Garcia in a media release.
The study’s findings add to growing concerns about our daily exposure to microplastics through food and beverages. While plastic tea bags have become increasingly popular due to their durability and convenience, this research suggests we might be paying an unexpected health price for this modern convenience.
When examining the tea bags under powerful microscopes, the researchers found various surface irregularities, including scales, spheres, and irregular particles. These imperfections, which can appear during the manufacturing process, may contribute to the release of plastic particles during steeping.
The study raises particular concerns about how these particles interact with our digestive system. The researchers tested three different types of human intestinal cells, including ones that produce protective mucus similar to our gut lining. Interestingly, cells that produced more mucus tended to accumulate more plastic particles, suggesting that our body’s natural defensive barriers might actually trap these unwanted materials.
While the immediate health implications of consuming these particles remain unclear, the research highlights an important source of plastic exposure that many people might not be aware of. With tea being one of the world’s most popular beverages, the cumulative exposure to these particles could be significant for regular tea drinkers.
“As the use of plastic in food packaging continues to increase, it is vital to address MNPLs contamination to ensure food safety and protect public health,” the researchers conclude.
Paper Summary
Methodology
The researchers simulated typical tea preparation conditions using 300 tea bags in hot water (95°C) for each type of bag tested. They collected and analyzed the released particles using various sophisticated microscopy and spectroscopy techniques. They then exposed human intestinal cells to these particles for 24 hours to observe how the cells interacted with them. The particles were stained with a fluorescent dye to track their movement and location within the cells.
Key Results
The study found that polypropylene tea bags released the most particles (1.2 billion per milliliter), followed by cellulose (135 million per milliliter) and nylon-6 (8.18 million per milliliter). The particles varied in size but were predominantly in the nanoscale range (100-300 nanometers). Different types of intestinal cells showed varying levels of particle uptake, with mucus-producing cells generally accumulating more particles.
Study Limitations
The researchers acknowledge that their laboratory conditions might not perfectly mirror real-world tea preparation. Additionally, they could only analyze particles that formed a visible pellet during centrifugation, meaning some smaller particles might have been missed. The study also focused on empty tea bags in two cases, which might not perfectly represent typical consumer use with tea leaves present.
Discussion & Takeaways
The study emphasizes the need for a better understanding of how food packaging materials might contribute to our daily plastic exposure. While the health implications of these findings require further research, the study suggests that alternative tea bag materials or traditional loose-leaf tea might be preferable for reducing plastic exposure. The research also highlights the importance of considering how different cell types in our body might interact with these particles differently.
Funding & Disclosures
The research received funding from multiple sources, including the European Union’s Horizon 2020 Research and Innovation Programme, the Spanish Ministry of Science and Innovation, and the Generalitat de Catalunya. Several researchers held fellowships from various institutions, and one researcher received an ICREA ACADEMIA award. The authors declared no competing financial interests or personal relationships that could have influenced the study’s results.
