"Defined as particles of plastic measuring between 100 nm and 5000 μm, the microplastics in our environment primarily derive from the laundering of synthetic clothing, the wear on automotive tires, and the exfoliants in personal care products. Though the degradation of plastic bags and bottles is considered to be a secondary source, it is blamed for the majority of microplastics found in the oceans." Editor´s note, Photonics Spectra mag, Oct 2023.
I note the 1st sentence of microplastic soures!