‘Forever chemicals,’ pollutants found near summit of Everest

From an elevation of 27,600 feet, just below the summit of Everest, researcher Mariusz Potocki could see one of the planet’s most dramatic scenes — the snow-capped Himalayas against a deep blue sky. He was on a mission to gather snow and ice samples at the summit, but just above him was another startling sight: a line of climbers so dense that a photo of it went viral.

His team had stopped at a resting spot climbers call “The Balcony,” and the snow there was littered with feces, oxygen bottles and other trash. But he wanted to gather what samples he could, so he ascended a short distance to find some cleaner snow off to the side of the trail. “I just pulled out the bottles and took samples,” he said.

And then another surprise: There, at the roof of the world, the snow samples showed traces of toxic chemicals known as PFAS, laboratory analyses done later showed. More notable results came from samples his colleagues gathered at lower elevation, which revealed these substances at levels far higher than at other mountains around the world.

“We were shocked,” said Kimberley Miner, an assistant research professor at the University of Maine Climate Change Institute, who coordinated the research remotely from the United States. “We retested everything like three times, because it was much higher than we expected.”

The study by Miner and colleagues, published in December, was part of the 2019 National Geographic and Rolex Perpetual Planet Everest Expedition, a large, interdisciplinary research project intended to understand the climate change threats facing mountain systems. It shows chemical fingerprints smudging even the world’s tallest peak in ways unseen and previously unstudied.

“The purpose of the expedition was to see if the highest parts of the planet are affected by human activity,” said Paul Mayewski, the expedition leader and director of the university’s Climate Change Institute.

Miner’s research has taken her all over the world to study chemicals in glaciers, especially persistent organic pollutants such as PFAS — shorthand for perand polyfluoroalkyl substances. Sometimes called “forever chemicals,” these are toxic compounds that break down slowly and accumulate over time in people and other animals.

Such pollutants are found in low concentrations in the atmosphere, and they are blown all over the globe. Then, when it rains or snows, they often are deposited on the ground. So Miner suspected the Everest samples would only show low levels of persistent chemicals from this sort of atmospheric deposition.

But when the Everest samples were shipped to an analytical lab, she learned about the PFAS levels that were particularly high in the samples from lower down on the mountain.

“I thought we’d screwed up, and we hadn’t,” Miner said. “We got consistently these very, very high levels.”

Miner’s samples showed two specific PFAS chemicals were especially high — perfluorooctanesulfonic acid and perfluorooctanoic acid. The chemicals have been used since the 1950s to repel stains and water in carpeting, upholstery and apparel; in nonstick cookware and food packaging; and in floor wax, textiles, firefighting foam and sealants. Neither is still manufactured in the United States, but they are made in other countries.

Both have been linked to health problems.