Tiny bits of plastic are contaminating mussels from the European Arctic to China in a sign that the global spread of ocean pollution can end up on people's dinner plates.

Mussels in apparently pristine Arctic waters had the most plastic of any tested along the Norwegian coast, according to a study this month by the Norwegian Institute for Water Research (NIVA).

Plastics may be getting swept north by ocean currents and winds from Europe and America, before swirling around the Arctic Ocean, NIVA researcher Amy Lusher said.