Microplastics have just been found in freshly fallen snow in Antarctica, which could accelerate the melting of snow and ice and pose a threat to the health of the continent’s unique ecosystems.
Small plastics, smaller than a grain of rice, have previously been found in sea ice and surface water in Antarctica, but this is the first time it has been reported in fresh snowfall, researchers say.
The research, conducted by Alex Aves, a doctoral student at the University of Canterbury, and supervised by Dr. Laura Revell, has been published in the scientific journal The Cryosphere.
Birds collected snow samples from the Ross ice shelf in late 2019 to determine if microplastics had been transferred from the atmosphere to the snow. Until then, there were few studies on this in Antarctica.
“We were optimistic I wouldn’t find any microplastics in such a pristine, remote location,” Revell said. He told Aves to also collect samples from Scott Base and McMurdo Station Roads, where microplastics had previously been detected, so “I would have at least some microplastics to study,” Revell said.
But that was an unnecessary precaution: plastic particles were found in each of the 19 samples on Ross’s ice shelf.
“It’s incredibly sad, but finding microplastics in the fresh snow of Antarctica shows the extent of plastic pollution even in the most remote regions of the world,” Aves said.
Plastic pollution has been found from the summit of Everest to the depths of the oceans. People are known to eat and breathe microplastics inadvertently, and another recent study found that particles cause damage to human cells. A study last year found that airborne microplastics are “spiraling around the world.”
Birds found an average of 29 microplastic particles per liter of melted snow, which is higher than the previously reported marine concentrations in the surrounding Ross Sea and Antarctic sea ice.
Samples taken immediately next to the science bases on Ross Island, Scott Base, and McMurdo Station produced larger concentrations, almost three times as many as in remote areas.
Researchers at the University of Canterbury are working on Antarctica in 2019. Photo: Lucy Howell
13 different types of plastic have been found, the most common being PET, the plastic commonly used to make bottles and soft drinks.
Atmospheric modeling suggested that they could have traveled thousands of miles through the air, but it is equally likely that the presence of humans in Antarctica has established a microplastic “footprint,” Revell said.
“There was a photo we found of some marker flags being put up to use to go around the base … these colors match the most common color microplastics we found in the environment.”
Previous research by Revell has shown that microplastics in the atmosphere can trap radiation emitted by the Earth and contribute to climate change. Dark microplastics on icy surfaces could absorb sunlight and cause localized warming, he said. Plastics can also be toxic to animals and plant life.
“We’re still learning a lot about the impacts, but from what we know so far, it’s not very good.”