All moral rights asserted. Recolouring or alteration of the image is prohibited without permission. Coloured scanning electron micrograph (SEM) showing the surface of polystyrene plastic. The sample has been treated with sand and ultraviolet (UV) light to simulate environmental exposure. The surface at right clearly shows degradation. The particles released from it are mostly smaller than 1 micrometre. These microplastics will persist in the environment as pollutants. Magnification: x4000 when printed at 15 centimetres wide.