Using stimulated Raman scattering microscopy, researchers analyzed bottles from three major U.S. brands and found particle counts far higher than previously estimated, mostly nanoplastics invisible to traditional tests.
These tiny particles, including PET, polyethylene, and polyamide, can cross cellular barriers, raising concerns about potential health impacts, though definitive long-term risks remain unclear.
No U.S. federal limits exist for micro- or nanoplastics in drinking water, prompting calls for industry transparency, improved manufacturing, and consumer precautions such as using reusable bottles and advanced filtration.