Plastic teabags release billions of microparticles and nanoparticles into tea
Hernandez LM, Xu EG, Larsson HCE, Tahara R, Maisuria VB, Tufenkji N (2019). Environmental Science & Technology.
What they found
Steeping one plastic teabag at 95 °C released about 11.6 billion microplastics and 3.1 billion nanoplastics into a cup, matched to the bag's nylon and PET by FTIR and XPS. The authors say this is several orders of magnitude above plastic loads reported in other foods. Water fleas exposed to the released particles showed dose-dependent behavioural and developmental effects.
Read this too
Busse et al. (Environmental Science & Technology 2020, doi 10.1021/acs.est.0c03182) published a comment questioning the particle counts; as summarised by Cella et al. 2022 (EU JRC), they concluded the material was partly soluble oligomers. The authors replied (doi 10.1021/acs.est.0c06422) that Busse et al. also found plastic teabags release particles but used different methods, so the numbers cannot be compared. We have not read the comment itself.
- Sample
- Commercial nylon and PET 'silken' teabags
- What it can't tell you
- Counts come from electron microscopy; not every particle was chemically confirmed as plastic. Critics argue much of the released material may be dissolved oligomers rather than solid particles. Few products tested. The toxicity test used water fleas at lab doses, not people.
- Funding
- Not checked (full text inaccessible). Europe PMC lists NSERC, Canada Research Chairs, Canada Foundation for Innovation and McGill Faculty of Engineering.
- Topics
- Food, Packaging
- Checked against
- Abstract (Europe PMC, PMID 31552738); critique as summarised in Cella 2022 (PMC8954753) via our tea bags article