Tea Bags Release Billions Of Harmful Microplastics, Study Finds

Tea bags are popular for offering a convenient and comfortable tea-drinking experience, allowing users to easily dip and enjoy their brew. However, the material used for the outer layer of tea bags can actually have a negative impact on health.Commercial tea bags, which are made of polymer-based material, release millions of nanoplastics and microplastics when infused and release millions of microplastics when in use.

According to a study by the Autonomous University of Barcelona, food packaging is a major source of micro- and nanoplastic (MNPL) contamination, and inhalation and ingestion are the main routes of human exposure. The capacity of these nanoplastic and microplastic particles to be absorbed by human intestinal cells, and are thus able to reach the bloodstream and spread throughout the body.

Researcher have successfully obtained and characterised micro and nanoplastics derived from several types of commercially available tea bags. The UAB researchers observed that when these tea bags are used to prepare an infusion, huge amounts of nano-sized particles and nanofilamentous structures are released, which is an important source of exposure to MNPLs.

The tea bags used for the research were made from the polymers nylon-6, polypropylene and cellulose. The study shows that, when brewing tea, polypropylene releases approximately 1.2 billion particles per milliliter, with an average size of 136.7 nanometres; cellulose releases about 135 million particles per milliliter, with an average size of 244 nanometres; while nylon-6 releases 8.18 million particles per milliliter, with an average size of 138.4 nanometres.

"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 microbiologist Alba Garcia-Rodriguez, from UAB.