There are even nanoplastics at the North and South Poles - and they’re a bigger problem than we thought

From the top of Everest to the Arctic ice, there are traces of human-caused pollutants in even the most remote and pristine corners of our planet. And scientists have now discovered microscopic evidence of one of the most durable of all pollutants - plastic - at the North and South poles.

Nanoplastics - fragments of plastic smaller than a micrometre - have been found at both poles, and in even higher concentrations in Greenland ice. Our understanding of these tiny plastic particles remains limited, but their presence in such uninhabited, far-flung places suggests they may present a greater problem than we had anticipated.

“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.

To date, most of the studies about the effects of plastic pollution have centered around larger fragments - macro and microplastics. Nanoplastics are much harder to detect and have largely escaped attention. But several studies suggest they are widespread and make up a significant amount of our plastics debris. They have been traced in places including the North Atlantic, remote lakes in Sweden, Siberia and Russia, and snow in the Austrian alps, suggesting they are present everywhere.

Nanoplastics are formed by natural erosion of larger plastics, through physical, chemical or biological processes. And because they are so light, scientists studying nanoplastic distribution expect that they have been spread around the globe on air currents. They may also be re-emitted from secondary sources such as urban surfaces and soil, but more studies are needed to fully understand the sources, sinks and transport.

Although the research showing nanoplastics have reached the poles is new, their presence clearly isn’t. Nanoplastics from sources dating back to the 1960s have been found in ice samples, suggesting organisms have been exposed to their effects for decades.

Polyethylene - typically used for plastic bags and packaging - was the most common plastic type found. PET, or polyethylene terephthalate - the type of plastic used for bottles - was also regularly discovered. And plastics from dust created as tyres wear was another significant source.

We are only just starting to learn about the damage nanoplastics may cause us and other organisms. Humans are exposed to small plastic particles daily, by breathing them in and ingesting them from our food and drink. Microplastics have even been found in the placentas of unborn babies. It’s estimated we ingest tens of thousands to millions of microplastic particles annually. And although they were once thought of as inert, recent studies have suggested these particles are damaging our cells.

Nanoplastics have also been shown to have an adverse effect on marine life, affecting growth, delaying development, as well as causing larval malformations and subcellular changes.

“More research is clearly needed to focus on measuring environmental nanoplastics so that the risk of 'ecological surprise' can be timely minimized,” the study authors say.

With almost 400 million tonnes of plastics produced each year - and growing - the nanoplastics problem is not going away. More tiny pieces will be created as all these plastics break down - and at the moment we have no way of clearing them up.