Tea bags can release a lot of microplastics
Microplastics, defined as tiny plastic fragments with a diameter of less than 5 mm, come from the decomposition of various plastic products, such as plastic bags, plastic takeaway boxes, plastic bottles, etc. Microplastics can enter water, soil and air, enter the food chain, and eventually enter the human body, which has a negative impact on our health.
Nanoplastics refer to plastic particles with a particle size between 1-100 nanometers, which may have a negative impact on the environment and organisms.
In daily life, micro/nanoplastics exist in bottled water, clothes, and even the air we breathe. Previous studies have shown that humans may inhale about 16.2 micro/nanoplastics per hour, and the amount of plastic particles inhaled per week is equivalent to a "bank card".
Recently, researchers from the Autonomous University of Barcelona published a research paper titled "Teabag-derived micro/nanoplastics (true-to-life MNPLs) as a surrogate for real-life exposure scenarios" in the journal "Chemosphere". Recently, researchers from the Autonomous University of Barcelona published a research paper titled "Tea bag-derived micro/nanoplastics (real-life MNPLs) as a surrogate for real-life exposure scenarios" in the journal "Chemosphere".
Studies have shown that when tea bags are used to make tea, tea bags release hundreds of millions of micro/nanoplastics, and these plastic particles can be absorbed by human intestinal cells, thereby entering the blood and spreading throughout the body.
In this study, the researchers analyzed tea bag filters with three different chemical compositions: nylon 6, polypropylene, and cellulose. Through a series of advanced scanning techniques, such as transmission electron microscopy, infrared spectroscopy, etc., they analyzed the release of microplastic particles from different tea bags and evaluated the absorption of these plastic particles by three different types of human intestinal cells.
The results showed that all three types of tea bags released a large amount of micro/nano plastic particles when brewing tea.
Specifically, polypropylene tea bags released about 1.2 billion particles per milliliter, with an average size of 136.7 nanometers; cellulose tea bags released about 135 million particles per milliliter, with an average size of 244.7 nanometers; and nylon 6 tea bags released about 8.18 million particles per milliliter, with an average size of 138.4 nanometers.
The researchers also analyzed the biological interactions of microplastic particles leached from tea bags in human intestinal cells, including three different types of human intestinal-derived cell types: Caco-2, HT29, and HT29-MTX. The main difference between these three cells is the amount of mucin secreted, which is HT29-MTX>HT29>Caco-2 (Caco-2 does not secrete).
The results showed that after 24 hours of exposure to 100 μg/mL plastic particles, HT29-MTX intestinal cells had the highest absorption rate of plastic particles, even entering the cell nucleus, indicating that mucus-producing cells may play a vital role in the absorption of micro/nano plastics.
All three polymer particles interacted with the cell nucleus, and HT29 and HT29-MTX cell clones showed the strongest overlapping responses compared to Caco-2 cells. These interactions may cause DNA damage, mutations, and interference with DNA repair, which require further experiments to confirm.
The study pointed out that it is crucial to evaluate the environmental and health risks associated with the ingestion of micro/nano plastics in the real world. The potential impacts of these plastic particles on human health may be multifaceted, including specific accumulation, toxicity characteristics, immune responses, and long-term health effects, such as genotoxicity and carcinogenicity.
The study showed that tea bags release a large amount of micro/nano plastics into the water, and these plastic particles can be absorbed by human intestinal cells, confirming the extent of plastic pollution in commonly used tea bags. The results provide more evidence for the prevalence of plastic pollution and its potential impact on human health.