For the First Time, Nanoplastic Particles Have Contaminated Decades-Old Polar Ice

A team of scientists studying ice cores from Greenland and Antarctica have identified some types of nanoplastic particles, including particles from tires, in decades-old polar ice. As per the international team, sea ice cores in these polar regions are contaminated with more nanoparticle pollution than thought.

Although less influenced by human activities, it seems like both North and South polar ice are unable to evade contamination from the toxic effects of nanoplastics. These particles smaller than a micrometer in size are harmful to organisms. Due to it being hard to measure, the worldwide extent of nanoplastic pollution remained unclear until today.

Researchers from Utrecht University, the University of Copenhagen and the Université Libre de Bruxelles attempt to measure nanoplastics and identify nanoscale plastic particles derived from 14-meter-deep ice cores from Greenland and sea ice cores from Antarctica using new methods.

A far bigger, existing pollution problem than it seems

Due to size and weight, nanoplastics are easy to get carried along by wind and water currents. Nevertheless, the researchers are still surprised to see substantial quantities in their samples.

"Now we know that nanoplastics are transported to these corners of the Earth in these quantities. This indicates that nanoplastics is really a bigger pollution problem than we thought," said Dušan Materić, lead author of the study. His team used the same techniques in a previous study and were able to identify nanoplastic particles in samples the Alps.

In fact, Materić's team are the first to identify nanoplastics in polar ice. However, their results show that nanoplastic contamination has been taking place for decades. "Our data suggest that nanoplastics pollution is not a new problem," said Materić.

"We are only now becoming aware of it, because we have recently developed the right method to measure it. In the Greenland core, we see nanoplastics pollution happening all the way from 1960s. So organisms in that region, and likely all over the world, have been exposed to it for quite some time now."

Types and sources of nanoplastic particles

Among the several types of nanoplastic particles identified by the researchers is the polyethylene, the most prominent nanoplastic type and accounted for more than half of the particles. The team also identified significant amounts of nanoparticles originating from tire wear in the Greenland ice core, significant in the Northern but not in Southern polar site.

The North and South ice core samples seem to have big difference in terms of the amount of nanoplastic particles it contains. The Greenland ice contained 13.2 ng/mL on average, whereas the Antarctic Sea ice contained 52.3 ng/mL.

In addition, as far as the extent of the pollution is concerned, "we further discuss the possible sources of nanoplastics that we found at these remote locations, which likely involve complex processes of plastic circulation (emission from both land and sea surface, atmospheric and marine circulation)," the authors wrote.

This includes both atmospheric and marine transport, (re)emission, deposition and ice incorporation. "Further studies are clearly needed to better constrain the source of theses contaminants to the polar regions."