The article specifically says micrometer so it would be right between millimeter and nano sized plastics. They will only get smaller as they degrade. > Our res

The article specifically says micrometer so it would be right between millimeter and nano sized plastics. They will only get smaller as they degrade. > Our results provide evidence in support of submicrometre- and micrometre-sized polystyrene and polymethylmethacrylate particles penetrating the stele of both species using the crack-entry mode at sites of lateral root emergence.