Each year, hundreds of climbers tackle the ascent of the highest mountain in the world. While most go home boasting of their exploits, ScienceAlert explain that they leave behind tenacious microbes capable of surviving on icy surfaces.
Despite the extreme conditions that Everest offers, researchers have indeed discovered bacteria (including streptococci and staphylococci) in the sediments of the mountain. Even though these organisms are mostly inactive, it is believed that they may have been moved up there from less extreme areas, by the climbers themselves.
The highest point of this mountain rises to 8,849 meters, which explains the surprise of scientists when they discovered that certain viruses usually nestled warm, deep in our throats, could survive such extreme temperatures. “There are human traces frozen in the microbiota of Everest”microbial ecologist Steven Schmidt tells ScienceAlert. “If someone is blowing their nose, or coughing, it could show up.”
Stubborn microorganisms
Previously, researchers have studied soil samples from the Himalayas, for example, but this is the first time that samples taken at such high altitudes confirm the presence of human microorganisms. A high concentration of ultraviolet rays, low temperatures and lack of water contribute to the death of bacteria at altitude. Only the hardiest organisms can survive in such a hostile climate.
The samples were taken about 170 meters from the human settlements. As ScienceAlert indicates, the researchers believe that by observing samples directly at the camps, the number of human microorganisms present would be even higher. Most microbes, such as those carried by high altitude climbers, become inactive or die when exposed to extreme conditions. However, some organisms manage to develop during short periods in the presence of a water point.
The air temperature of the South Col – where many climbers camp before the ascent – rarely exceeds -10°C. Thus, it is difficult to know if the little water from melting ice is able to support the development of microorganisms.
However, temperatures are increasing by about 0.33°C per year. In July 2022, a record temperature of -1.4°C was recorded on the South Col. This warming could lead to the release of hitherto inactive organisms.
Such a discovery suggests that other forms of life remain to be observed. “We could discover signs of life on other planets and on cold moons”says Steven Schmidt.
