"We expected the opposite result," Ph.D. student Iseline Chaib, who conducted the research, told AFP.
"We then noticed that in the glass, the particles emerging from the samples were the same shape, color and polymer composition—so therefore the same plastic—as the paint on the outside of the caps that seal the glass bottles," she said.
The paint on the caps also had "tiny scratches, invisible to the naked eye, probably due to friction between the caps when there were stored," the agency said in a statement.
This could then "release particles onto the surface of the caps," it added.
OK, so maybe a minor change in how these bottles are filled and sealed could end up fixing the issue. There's clearly some issues with soft drink assembly lines, and if these can be addressed, then the overall amount of microplastics can be mitigated. Seems like we need to start phasing plastics out of every step of manufacturing if we want to end microplastics in food and drink.