Microplastics have infiltrated every part of the planet. They have been found buried in Antarctic sea ice, within the guts of marine animals inhabiting the deepest ocean trenches, and in drinking water around the world. Plastic pollution has been found on beaches of remote, uninhabited islands and it shows up in sea water samples across the planet. One study estimated that there are around 24.4 trillion fragments of microplastics in the upper regions of the world's oceans.
https://www.bbc.com/future/article/20230103-how-plastic-is-getting-into-our-food