University of Canterbury researchers have discovered microplastic particles in all snow samples taken across the remote Ross Ice Shelf.
The driven snow of the world’s last untouched continent might not be so pure after all.
A world-first study by University of Canterbury researchers – published in science journal The Cryosphere on Wednesday – has confirmed the discovery of microplastics in freshly fallen Antarctic snow.
Microplastics are defined as any piece of plastic smaller than five millimetres in length.
PhD student Alex Aves collected snow samples from the remote Ross Ice Shelf in late 2019, as part of her postgraduate Antarctic studies.
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Once back in the lab, scientists found particles of microplastics in every sample – and it quickly became apparent her findings would be of global significance.
Aves said she was shocked by the discovery.
“It’s incredibly sad, but finding microplastics in fresh Antarctic snow highlights the extent of plastic pollution into even the most remote regions of the world.
“We collected snow samples from 19 sites across the Ross Island region of Antarctica and found microplastics in all of these.”
Glitter, beads, fibers and fragments – microplastics are everywhere.
Aves examined the samples using chemical analysis to determine what kind of plastic particles were present. She also looked at their colour, size and shape under a microscope.
They found an average of 29 tiny pieces of plastic per litre of melted snow, even higher than marine concentrations previously discovered in the surrounding Ross Sea, and in Antarctic sea ice.
Immediately next to the scientific bases on Ross Island, Scott Base, and McMurdo Station – the largest station in Antarctica – the density of microplastics was nearly three times higher, with similar concentrations to those found in Italian glacier debris.
There were 13 different types of plastic found, with the most common being PET, or polyethylene terephthalate, commonly used to make soft drink bottles and clothing.
Aves and her team also examined the possible sources of the microplastics.
Atmospheric modeling suggested they may have traveled thousands of kilometers through the air, but it was equally likely the presence of humans in Antarctica had established a microplastic “footprint”, the research said.
University of Canterbury atmospheric physics professor Laura Revell said when Aves first traveled to Antarctica they were “optimistic that she wouldn’t find any microplastics in such a pristine and remote location”.
“We [also] asked her to collect snow off the Scott Base and McMurdo Station roadways, so she’d have at least some microplastics to study.
“Looking back now, I’m not at all surprised … From the studies published in the last few years we’ve learned that everywhere we look for airborne microplastics, we find them.”
Antarctica New Zealand environmental adviser Natasha Gardiner said the research was “of huge value”.
“It improves our understanding of the extent of plastic pollution near to Scott Base and where it’s coming from,” she said. “We can use this information to reduce plastic pollution at its source and inform our broader environmental management practices.”
The research would help inform international policy, she said, and help all the Antarctic Treaty parties make evidence-based decisions on the urgent need to reduce plastic pollution going forward.
Gardiner said they had submitted a paper on Aves’ findings to the upcoming Antarctic Treaty Consultative Meeting.
Revell was part of a team who detected microplastics floating in New Zealand’s air for the first time in March last year.
She also led a world-first study which found airborne microplastics could have a direct impact on climate change.
In an as-yet unpublished study, one of her students has discovered New Zealanders are probably breathing in more tiny pieces of plastic in their own homes than they are outside – with microplastics concentrations as much as 10 times higher indoors.