Researchers warned Tuesday of a "troubling" accumulation of microplastics in sea ice floating in the Arctic ocean, a major potential source of water pollution as global warming melts the sheets of frozen water.
A team from the Alfred Wegener Institute for Polar and Marine Research (AWI) found 17 different plastic types in ice samples gathered during three Arctic expeditions on board the research icebreaker Polarstern in 2014 and 2015.
They included plastic from shopping bags and food packaging, from ship paint, fishing nets, nylon and polyester found in synthetic fabrics, and cigarette filters.
One sample contained the highest concentration of microplastics ever found in sea ice -- up to 12,000 particles per litre of frozen water.
This was two- to three times higher than any past measurement, the research team wrote in the journal Nature Communications.
The discovery suggests microplastics "are now ubiquitous within the surface waters of the world's ocean," sea ice physicist Jeremy Wilkinson of the British Antarctic Survey said in a comment on the study.