You may want to rethink that cup of tea. New research shows that some tea bags could be exposing you to dangerous microplastics so tiny they can travel from the intestine into the bloodstream and even the brain.
The presence of these tiny particles of plastic has been associated with a host of health problems. A 2023 study in Frontiers in Endocrinology linked microplastics to endocrine disruption1, and a new 2024 study in Life Sciences posited that they could even increase the risk of developing cancer2. In other words, your tea bag’s microplastic content should be taken seriously.
New Research on Your Tea Bag’s Microplastic Content
In this new study, researchers at the Independent University of Barcelona (Universitat Autònoma de Barcelona, UAB) were specifically looking into the microplastic content of tea bags made with three types of plastic: polypropylene, nylon-6, and cellulose. They found that tea bags containing polypropylene released a whopping 1.2 billion particles of plastic per milliliter drop of tea, as compared to 135 million particles per drop for cellulose teabags and 8.18 million particles per drop for nylon-6 teabags.
“Something as simple as [drinking] a cup of tea is enough to ingest […] millions or more nanoparticles or nanoplastics,” Ricardo Marcos Dauder, one of the study authors, told Newsweek3. And this is only the beginning of the problem. “We don’t need to be in special conditions, in special places, to be exposed,” he said.
What Are Microplastics?
Microplastics are exactly what they sound like: tiny pieces of plastic (less than five millimeters long, to be exact). But where do microplastics come from? Well, many come from larger pieces that break down over time. In the past, some were even manufactured intentionally, like microbeads, the plastic beads once used in certain beauty products like exfoliating facial scrubs. These have been illegal in the U.S. since 20154.
Are microplastics harmful? In short, yes. The size of these miniscule particles makes them a threat to our health and our environment, as they’re easily ingested or passed through water filtration systems into bodies of water. As more research comes to light, it’s important for consumers to be aware of the risks and exercise caution when it comes to potential sources of microplastics.
The Tiniest Plastics Have Big Repercussions on Human Health
While researchers have been exploring the effects of microplastics for several years, the specific microplastics Dauder and his team were studying have only recently come to light. According to an article from Columbia University’s Mailman School of Public Health, most microplastics measure between 5 millimeters and 1 micrometer5.
But Dauder and his team were looking specifically at the even smaller nanoplastics, which measure between 1 and 1000 nanometers. (For context, a single human hair is about 80,000 to 100,000 nanometers wide6.) And according to Dauder, these smaller plastics are even more hazardous for human health. “All the data shows that the smaller the size, the higher the uptake [of plastic] into the cells,” Dauder said. “The smaller the size, the higher the risk.”
Increased Absorption and Travel of Nanoplastics In the Human Body
Researchers were able to demonstrate this increased danger of nanoplastics by exposing the particles to various human intestine cells. They found that after just 24 hours, a specific type of mucus-producing intestinal cell had absorbed a significant amount of nanoplastics. The researchers even found these plastics in the nucleus of the cell, where genetic material is stored. The degradation of this DNA is one way in which the presence of these particles could contribute to increased cancer risk.
From the gut, tiny nanoplastics can easily pass through the intestinal walls and into the bloodstream, traveling to different organs including the heart and brain, or even into the placenta of an unborn fetus7.
In 2023, one research review in Frontiers had already begun exploring the endocrine disrupting risks of the presence of these plastics in the human body. Study coauthor Beizhan Yan, an environmental chemist at Columbia University’s Lamont-Doherty Earth Observatory, noted that, “Previously this was just a dark area, uncharted. Toxicity studies were just guessing what’s in there.” New attention and research, he continued, “opens a window where we can look into a world that was not exposed to us before8.”
Brewing Plastic-Free Tea
The source of most tea bags’ microplastic content comes from the glue used to seal them. Most tea companies have historically used a plastic-based glue, though some, like Clipper, have phased this out in favor of a plant cellulose “bioplastic” solution. However, despite being more sustainable in some respects than oil-based plastics, a 2020 study in Environment International found that bioplastics are “similarly toxic” to conventional plastics9.
To better eradicate plastics from your morning cuppa, instead seek out companies that use no plastic at all. For example, Bromley makes its teabag paper from wood pulp that is heat-sealed without glue10. Pukka’s plant-based tea bag paper is folded using a unique method that can be sealed with a simple stitch of organic cotton. Or if you’d rather choose your own tea without having to do research on plastic-free tea bags, brewing tea in a teapot is the best way to ensure there’s no plastic in your cup.
Avoiding Microplastics In Other Products
Unfortunately, tea bags are just one way consumers can come into contact with microplastics and nanoplastics. Bottled water is a commonly cited culprit. In a recent study published in Proceedings of the National Academy of Sciences, researchers from Columbia University discovered that a liter of bottled water contains an average of 240,000 detectable plastic fragments — far more than scientists had previously thought9.
Microplastics have even been found in the tap water we drink11 and the ocean water we swim in and source the seafood we eat12. And once there are microplastics in food and water, it becomes harder and harder for us to steer clear. So if there are already microplastics in bottled water and microplastics in tap water, what steps can we take to effectively avoid them?
Ways to Reduce Microplastic Ingestion
Despite the prevalence of microplastics, there are certainly still ways we can reduce our exposure. From finding solutions to eliminate microplastics to avoiding them by minimizing plastic use, here are some concrete things we can do as consumers.
Eliminating Microplastic Particles
To help combat this endemic problem, scientists at the University of Missouri have created a liquid-based solution made from natural ingredients that eliminates more than 98% of microplastic particles. It stands out from previous research in that it seems to work on five different sizes of polystyrene-based nanoplastics — as compared to previous studies, which focused on eradicating a single size of particle.
“These solvents are made from safe, non-toxic components, and their ability to repel water prevents additional contamination of water sources, making them a highly sustainable solution,” said Piyuni Ishtaweera, a recent alumna and current FDA employee who led the study while earning her doctorate in nano and materials chemistry at Mizzou.
Reducing Plastic Use
Reducing your own plastic use won’t just have a beneficial effect on the health of you and your family; it could also help to combat this endemic problem. Even little steps can make a difference — choose plastic-free laundry detergent (like the sheets from Smart Sheep) and bring your own mesh produce bags to the grocery store instead of using the plastic ones provided. Every small effort reduces not only the amount of plastic you’re coming into contact with, but also the amount that’s leached back out into the environment.
Sources:
- https://pmc.ncbi.nlm.nih.gov/articles/PMC9885170/
- https://www.sciencedirect.com/science/article/abs/pii/S0024320524005277
- https://www.newsweek.com/harmful-release-tea-bags-microplastics-nanoplastics-2005123
- https://www.fda.gov/cosmetics/cosmetics-laws-regulations/microbead-free-waters-act-faqs
- https://www.publichealth.columbia.edu/news/bottled-water-can-contain-hundreds-thousands-nanoplastics
- https://www.nano.gov/nanotech-101/what/nano-size
- https://www.publichealth.columbia.edu/news/bottled-water-can-contain-hundreds-thousands-nanoplastics
- https://www.frontiersin.org/journals/endocrinology/articles/10.3389/fendo.2022.1084236/full
- https://pubmed.ncbi.nlm.nih.gov/32951901/
- https://www.pnas.org/doi/10.1073/pnas.2300582121
- https://pmc.ncbi.nlm.nih.gov/articles/PMC9103198/
- https://news.nd.edu/news/engineers-unmask-nanoplastics-in-oceans-for-the-first-time-revealing-their-true-shapes-and-chemistry/
