In mice, immune cells carry microplastics — specks of plastic less than 5 millimetres long — through the bloodstream, where they eventually
. The plastic-packed cells appeared in the mice’s brains just hours after they were given polystyrene-laced water and piled up “like a car crash in the blood vessels”, says biomedical researcher and study author Haipeng Huang. The obstructions sometimes cleared eventually, but others stayed stuck for the entire month-long observation period and had effects including impairing the mice’s mobility. It’s not clear whether such blockages occur in people.
