Scientists have found microplastics—small plastic debris about the size of a sesame seed—in freshly fallen snow in Antarctica for the first time. They published their findings in The Cryosphere.
“It’s incredibly sad,” Alex Aves, lead author and researcher from the University of Canterbury in New Zealand, says in a statement. “But finding microplastics in fresh Antarctic snow highlights the extent of plastic pollution into even the most remote regions of the world.”
Microplastics have been found in almost every corner of the globe where researchers have looked, including on top of mountains and in remote ocean water. But scientists have not studied microplastics much in the Southern Hemisphere, particularly in Antarctica.
Working with coauthor Laura Revell, an associate professor in environmental physics also at Canterbury, Aves collected snow samples from sites across the Ross Island region of Antarctica, on the side closest to Oceania, including 13 remote locations with minimal human disturbance.
“We were optimistic that she wouldn’t find any microplastics in such a pristine and remote location,” Revell says in the statement. They also collected snow from six areas near research stations “so she’d have at least some microplastics to study.”
But all 19 of the samples they collected contained plastic, with an average of 29 microplastic particles per liter of melted snow. This is higher than concentrations previously found in the Ross Sea and in Antarctic sea ice, per the statement. The samples taken near the research stations, closer to human activity, yielded microplastic densities nearly three times higher than those in the remote areas. The team found a total of 13 different plastics in the snow samples, per the study. The most common was polyethylene terephthalate (PET), which is used to make soft drink bottles and clothes.
“We use synthetic textiles every day, and both daily wear and tear and frequent laundry processes can provide a direct route by which textile fibers can enter the environment,” Natalie Welden, a lecturer in environmental science and sustainability at the University of Glasgow, who was not involved in the study, tells Mongabay’s Elizabeth Claire Alberts. “Indeed, the authors highlight that, whilst some of the microplastics recovered could have traveled many thousands of miles, others could be from the various research stations on Ross Island itself.”
Microplastics can come from local sources, like human research activity on Antarctica. But it’s now known that plastic—like carbon and water—has its own cycle of movement across the globe, the plastic cycle. Microplastics found in Antarctica may have traveled as far as 6,000 kilometers (about 3,700 miles) to arrive in the Ross Island region, according to the team led by Aves.
Microplastics have been found in other remote areas of the Earth, including the top of Mount Everest and deep in the Mariana Trench. Earlier this year, researchers found evidence of the tiny plastics in human blood. Microplastic particles can be shed from almost any human use of plastic, including disposable bottles, clothes and packaging. Scientists are actively researching the health effects of microplastics, if ingested by humans, animals and organisms.
“Microplastics can have harmful substances stuck on to their surfaces such as heavy metals, algae,” Revell tells BBC News’ Navin Singh Khadka. “So they can provide a way in which harmful species can make it into some remote and sensitive areas that otherwise wouldn’t get there.”
Darker-colored microplastics may also help speed up melting because they can absorb more sunlight, per the study.
“Our results highlight the importance of further monitoring – both in Antarctica and in surrounding waters – to develop our understanding of the microplastic footprint in Antarctica and the threat it may pose to the Antarctic environment,” the authors conclude.