Microplastic pollution found near summit of Mount Everest.

Humans now known to have polluted Earth from deepest ocean to highest peak.

Microplastic pollution has been discovered in snow close to the peak of Mount Everest, the world’s highest mountain. With plastic debris revealed in 2018 at the deepest point on Earth, the Mariana Trench, it is now clear that humanity’s litter has polluted the entire planet.

The tiny plastic fibres were found within a few hundred metres of the top of the 8,850-metre mountain, at a spot known as the balcony. Microplastics were found in all the snow samples collected from 11 locations on Everest, ranging from 5,300 metres to 8,440 metres high.

The highest concentrations of microplastics were found around Base Camp, where climbers and trekkers spend the most time. The fibres were most likely to have come from the clothing, tents and ropes used by mountaineers, the scientists said. Other recent discoveries of microplastic pollution in remote parts of the Swiss Alps and French Pyrenees indicate the particles can also be carried by the wind from further afield.

“It really surprised me to find microplastics in every single snow sample I analysed,” said Imogen Napper, at the University of Plymouth, who led the new research. “Mount Everest is somewhere I have always considered remote and pristine. To know we are polluting near the top of the tallest mountain is a real eye-opener.”

“With microplastics so ubiquitous in our environment, it’s time to focus on appropriate environmental solutions,” she said. “We need to protect and care for our planet.”

Reducing, reusing and recycling larger items of plastic waste is important, Napper said, as they can be broken down into microplastics when discarded into the environment. But many microplastics are shed from clothing made from synthetic fabrics, and she said a focus on better fabrics was needed, as well as using natural fibres such as cotton when possible.

Millions of tonnes of plastic are lost into the environment every year. It can contain toxic additives and carry harmful microbes and is known to injure wildlife that mistake it for food.

People also consume microplastics via food and water, and breathe them in, although the health impact is not yet known.

There have been longstanding concerns about litter on Everest, which was climbed by at least 880 people in 2019. But the new study is the first to assess microplastic pollution, which is less than 5mm in size and therefore too small to be picked up.

The study, published in the journal One Earth, analysed samples collected by a National Geographic expedition in 2019. The scientists found an average of 30 microplastic particles per litre of water in the snow samples and 119 particles per litre in the most contaminated sample. They also assessed stream water samples from eight locations, but only three had microplastics, perhaps as the streams were able to wash away contamination.

In her previous work, Napper has found that each cycle of a washing machine can release 700,000 microscopic plastic fibres, and that plastic bags that claim to be biodegradable were still intact after three years in the natural environment.

20 November 2020

The Guardian