Nature paper shows microplastics are not chemically inert and generate radicals in water

16 October 2026

A paper published in Nature on 14 October 2026 reports that the surface of a microplastic particle in water is chemically active. Polystyrene microplastics degraded about 90 per cent of the dye methyl orange over ten days in water but not in other solvents, and electron spin resonance spectroscopy confirmed hydroxyl radical production at the particle-water interface. Six commodity plastics, namely polypropylene, polyethylene, polystyrene, polyvinyl chloride, polyethylene terephthalate and polymethyl methacrylate, all generated radicals, with more hydrophobic surfaces more active. Adding the surfactant Triton X-100 reduced radical generation, surface charge and the accumulation of a hydrophobic dye on the particle surface. Charged biomolecules such as proteins and DNA accumulated on the particle surfaces, the radicals promoted protein aggregation, and the particles damaged mouse red blood cells. The authors conclude that plastics in microplastic form are not chemically inert and that this reactivity may contribute to health and environmental harm.