A groundbreaking study by researchers from the Universitat Autònoma de Barcelona (UAB) has revealed that polymer-based commercial tea bags release billions of microplastics and nanoplastics (MNPLs) into tea infusions, posing potential health risks. The findings, published in the journal Chemosphere, also show for the first time that these particles can be absorbed by human intestinal cells and potentially spread throughout the body via the bloodstream.
The study characterized MNPLs from tea bags made of nylon-6, polypropylene, and cellulose. Researchers found that:
- Polypropylene released approximately 1.2 billion particles per milliliter, averaging 136.7 nanometers in size.
- Cellulose released about 135 million particles per milliliter, with an average size of 244 nanometers.
- Nylon-6 released 8.18 million particles per milliliter, averaging 138.4 nanometers.
The research team employed advanced techniques, including scanning and transmission electron microscopy (SEM and TEM) and infrared spectroscopy (ATR-FTIR), to identify and analyze the particles.
For the first time, MNPLs were stained and exposed to human intestinal cells in laboratory experiments. The results revealed that mucus-producing intestinal cells absorbed the highest number of particles, with some even entering the nucleus, which contains genetic material. This suggests that intestinal mucus plays a crucial role in the uptake of these contaminants.
The study emphasizes the urgent need for standardized testing methods to assess MNPL contamination from plastic food contact materials and calls for regulatory policies to mitigate risks. Researchers warned that as the use of plastics in food packaging rises, addressing MNPL contamination is vital for food safety and public health.
“Chronic exposure to these pollutants could have significant health implications, underscoring the need for further research and proactive measures to reduce contamination,” said Alba Garcia, a researcher at UAB.
As reported by medicalxpress, the findings highlight the pressing environmental and health challenges posed by plastic waste and its infiltration into daily life.