Everest can be the mega-freezer for human germs

black and white mountain under white clouds

The exploration of Everest has left something more than an exciting chronicle, a good handful of feats and a trail of corpses of mountaineers that their predecessors have known how to take advantage of as gloomy “landmarks”. Ever since Edmund Hillary and Tenzing Norgay reached its summit in 1953, and even long before, the adventurers who have braved its slopes have sown a much more discreet, but just as enduring footprint: frozen microbes.

A group of scientists has just verified it.

That and the amazing ability of these germs to “sleep” for decades.

The other “footprint” on Everest. Demystify it. Its conditions may be suitable only for the best mountaineers, but Everest already has little of an inhospitable and lonely landscape. Today the mountain is such a popular tourist destination that it attracts a few hundred athletes and Sherpas each year. Before the pandemic we came to see long lines crowded in the rope that leads to its top.

The question that has been asked at the University of Colorado Boulder is: apart from the sad trail of feces and garbage that they throw in their path, are the mountaineers leaving any other footprint? What happens every time they sneeze or cough?

Hunting for a frozen…and tiny legacy. The researchers’ magnifying glass (or microscope) focused on the South Col, between Mount Everest and Lhotse, one of the highest mountains on the planet. Many of the adventurers who attempt to climb the highest peak on the planet from the southeast side set up their camps there, so… what better place to focus your search?

Scientists specialized in the study of life in the cryosphere have been in charge of the study with the help of Baker Perry, a professor of geography and National Geographic explorer who was able to collect the samples on Everest itself, material that they later analyzed at the university with next generation gene sequencing technology. As a climax they analyzed the DNA sequences.

And what did they find? Microbial DNA sequences similar to extremophile organisms detected in other remote, high-altitude locations, such as the Andes and Antarctica… and then some. Their search returned results associated with some organisms linked to humans, including staphylococci or streptococci, bacteria commonly found on our skin, nose, or mouth. Scientists have not before been able to clearly identify human-associated microbes in samples collected from more than 7,900 m.

“This study marks the first time that next-generation gene sequencing technology has been used to analyze soil from such a high elevation on Everest, allowing researchers to gain new insight into what’s in it.” celebrates the university, which goes further: adventurers “leave a frozen legacy of hardy microbes that can withstand harsh conditions at high altitudes and lie dormant in the ground for decades or even centuries.”

I was here (and my microbes too). “There is a frozen human signature in Everest’s microbiome, even at that altitude,” explains Steve Schmidt, professor of ecology and evolutionary biology and lead author of the study, published in the INSTAAR journal Arctic, Antarctic and Alpine Research : “If someone blew their nose or coughed, that’s the kind of thing that could show up.”

What most surprised the team was to see how microbes that have evolved to live in warm and humid environments, such as the one that our mouth or nose offers them, are able to “survive in a latent state” under the harsh conditions of Everest. The organism that was most abundant in the samples that they analyzed in the laboratory, yes, was a fungus of the genus Nahanishia capable of withstanding extreme levels of cold and ultraviolet radiation.

And why is it important? Because it represents a milestone, because it tells us about the impact of mass tourism and because it leaves some interesting readings that go beyond the great mountain. “It could lead to a better understanding of the environmental limits of life on Earth, as well as where life can exist on other planets or cold moons,” they detail from the North American university.

The researchers do not actually believe that this microscopic footprint on Everest could significantly affect its environment, but they do see implications for studying the potential for life beyond Earth. “We could find it on other cool planets and moons. We’ll have to be careful to make sure we don’t contaminate them with our own,” adds Professor Steve Schmidt.

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