How the plastic ended up in beer is an open question. The paper notes than some of the brands claim to use only spring water in their products, and sand particles often found around springs also showed up under the microscope. Malfunctioning equipment, unclean bottles, and even contaminated barley and hops are all possible sources. Beer may be filtered with activated charcoal, asbestos, wood chippings and other materials that could carry plastics.
The study only gets more shudder-worthy when it turns to the other debris they found.
"Workers in breweries lose, as any other people, the outer part of their epidermis," they write.
Scales of exfoliated skin were found in both small and larger chunks, along with bits of glass and even an "almost complete" dead insect.
source: popsci.com By Rafi Letzter