Microplastics were found for for the first time in fresh snow in Antarctica, which could accelerate the melting of snow and ice and pose a threat to “health” of the continent's unique ecosystems.
The tiny plastics - smaller than a grain of rice - had previously been found on Antarctic sea ice and in surface waters. This time, however, is the first time they have reported fresh snowfall, according to the researchers.
The study, conducted by Canterbury University PhD Alex Aves and supervised by Dr Laura Revell, was published in the scientific journal The Cryosphere.
Aves collected snow samples from the Ross Ice Shelf in late 2019 to determine if microplastics had been transported from the atmosphere to the snow. Until then, there were few studies on microplastics in Antarctica.
"We were optimistic that we would not find microplastics in such a pristine and remote area," Revell said.
He instructed Aves to also collect samples from Scott Base and the streets of McMurdo Station - where microplastics have been detected in the past - so "we will have at least some microplastics to study," Revell said.
But this was unnecessary because plastic particles were found in each of the 19 samples taken from the Ross Ice Shelf.
"It's incredibly sad, but the finding of microplastics in fresh Antarctic snow highlights the extent of pollutionof plastics even in the most remote areas of the world," said Aves.
Aves detected an average of 29 microplastic particles per liter of melted snow, which is higher than the marine concentrations we reported before the Ross Ice Shelf and the Antarctic ice sheet.
Samples taken from science bases on Ross Island, Scott Base and McMurdo Station showed higher concentrations - almost three times as much as those in remote areas.
13 different types of plastic were found, with the most common being PET – the plastic commonly used for construction of soft drink bottles and clothes.
Atmospheric modeling has shown that thousands may have traveled kilometers through the air, however it is just as likely that the presence of humans in Antarctica has created a microplastic "footprint", according to Revell.
