specifically: a piece of plastic that is five millimeters or smaller in size —usually plural
Indeed, a handful of sand or cup of seawater from nearly anywhere in the world will probably be peppered with microplastics—pieces that are tinier than a small pea and often invisible. Jennifer Ackerman… the Mariana Trench contains the highest levels of microplastics (most likely from clothing, bottles, packaging and fishing gear) yet found in the open ocean, offering irrefutable proof that plastics have penetrated even the most remote places on the planet. Rina Li