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By Krista Charles

PIERRE ROYER/AFP via Getty Images

Microplastics are present at both the highest and deepest points on Earth. The tiny pieces of plastic had previously been discovered in the 11-kilometre-deep Mariana trench in the Pacific Ocean and have now been detected on Mount Everest.

This is the first time that microplastics, bits of plastic less than 5 millimetres across that can come from the breakdown of larger items, have been detected on Everest.

Imogen Napper at the University of Plymouth, UK, and colleagues collected eight 900-millilitre samples of stream water and 11 300-millilitre samples of snow from different points on the mountain. The team found microplastics in all of the snow samples and three of the stream samples.

“Even though the research on Mount Everest was really exciting and getting the samples was incredible, you are secretly hoping not to find any because you want the environment to be pristine,” says Napper.

The most polluted sample was from the Everest Base Camp in Nepal, where most human activity on the mountain is concentrated. It had 79 particles of microplastics per litre of snow. The highest sample, taken at 8440 metres above sea level, or 408 metres below the peak, had 12 microplastics per litre of snow.

Most microplastics found on Mount Everest came from synthetic fibres, including polyester and acrylic, which are used to make the clothes and gear that trekkers rely on.

Just walking around for 20 minutes, washing our clothes or opening a plastic bottle can release microplastics into the environment.

“What we don’t yet fully know is the potential problems these tiny pieces of plastic could be having to ecosystems, to organisms and even to our own health as well. We can’t afford plastics to be the asbestos of the 21^st century,” says Christian Dunn at Bangor University in the UK.

Because of their size, it is incredibly difficult to get rid of microplastics. According to Napper, the focus needs to be on technological advances to stop their further spread.

“At the moment, the problem is like an overfilling bath and rather than mopping up the floor continuously what we need to do is just turn off the tap. By turning off the tap, you stop plastic getting into the environment,” says Napper.

Journal reference: One Earth, DOI: 10.1016/j.oneear.2020.10.020