Tiny pieces of plastic debris—“microplastics”—have been found in the deep ocean and even in human stool samples.
Now, for the first time, this form of pollution has been spotted on a glacier. By carefully sifting through natural debris atop a glacier in the Italian Alps, scientists collected polyester, polypropylene, and polyethylene fragments and fibers. These microplastics, likely transported to their remote location by the wind or hikers, are evidence of the widespread influence of plastic pollution, the researchers conclude.
Clogs on a Glacier
Roberto Sergio Azzoni, an environmental scientist at the University of Milan, and his collaborators focused their research on Forni Glacier. This glacier, located about 100 kilometers north of Milan, is one of the country’s longest and a popular site for hikers and climbers. The researchers collected supraglacial debris—bits of soil, rock, and dust—from the top of the glacier.
They wore cotton clothing and wooden clogs during the fieldwork to avoid inadvertently leaving plastic behind, a real concern because outdoor clothing and hiking equipment often contain plastics.
Back in the laboratory, Azzoni and his colleagues extracted tiny pieces of plastic, most smaller than 50 micrometers in diameter, from the debris on the basis of their density.
The scientists found that microplastics were numerous, about 75 pieces per kilogram of dried glacial debris, the team estimated.
“That’s very much in the range of variability of plastic contamination observed in marine and coastal sediments,” Azzoni said in a press conference last week at the General Assembly of the European Geosciences Union in Vienna, Austria, where these results were presented.
These microplastics were likely shed by hikers’ clothing and gear or transported by the wind from nearby cities, the researchers propose. All in all, between 131 million and 162 million pieces of microplastics are likely lurking within the lower part of Forni Glacier, the team estimated.
Glaciers aren’t so immaculate after all, the researchers concluded, and that’s potentially bad news: Microplastics released by melting glaciers can contaminate the glacial runoff water that’s used by local communities for drinking and irrigation.
These future effects should be investigated and monitored, said David Jones, an environmental scientist at the University of Portsmouth in the United Kingdom not involved in the research. Although it’s not at all surprising to find microplastics on glaciers, it’s critical to determine the consequences of these contaminants, said Jones. “The question is what the impact is going to be.”
—Katherine Kornei (@katherinekornei), Freelance Science Journalist