How did tyre particles end up in Antarctic soil? Scientists point to the atmosphere

Tyre-wear particles have shown up somewhere no one expected to find them: buried in the soil of one of Antarctica’s driest, coldest regions. A new study has detected nanoplastics, including fragments from tyre wear, in soils from the McMurdo Dry Valleys, and researchers say the most likely explanation is that the particles travelled there through the atmosphere.

Published in Scientific Reports, the research points to a combination of local human activity and long-range atmospheric transport as likely sources of the contamination. Scientists have already detected nanoplastics in other remote locations such as Greenland and the Alps, findings that hinted these tiny particles could travel long distances through the air. Until now, Antarctic soils, particularly those far from the coastline, had remained one of the few places where nanoplastics had not been reported.

Nanoplastics are plastic particles measuring less than one micrometre across, making them small enough to remain suspended in the air more easily than larger microplastics, pass through cell membranes, and carry other pollutants on their surfaces — qualities that make them a growing concern beyond the more familiar issue of microplastic pollution.

The research team used a newly sensitive detection method, thermal desorption-proton transfer reaction-mass spectrometry, to identify nanoplastics at nanogram concentrations in soil samples collected from the Taylor and Wright valleys during January 2023. Nanoplastics were detected in 54 percent of the 13 topsoil samples analysed, with the highest concentration reaching 295 nanograms per gram of soil, and were also found in half of the deeper samples taken from more than 20 centimetres down.