We have been told plastic is chemically inert. A new study says that is wrong in water. Naixin Qian, Wei Min at Columbia and Teresa Head-Gordon at UC Berkeley tested six common plastics: polyethylene, polypropylene, polystyrene, PVC, PET and acrylic. All six generated reactive oxygen species at their surface in plain water, in the dark, with no light needed. Among them were hydroxyl radicals, some of the most destructive molecules in chemistry. The more water-repelling the plastic, the more active it was, with a tight correlation between radical output and surface wetting. Their calculations trace it to hydroxide ions near the surface giving up electrons. In the lab, proteins clumped on the reactive surfaces, and mouse red blood cells that touched polystyrene lost their shape and leaked hemoglobin. The authors are careful. They used model particles, not whole bodies, and have not shown this harms people. But it gives the microplastics worry a mechanism.
Source: Nature, 14 October 2026 (open-access copy)
