Xenon gas could speed Everest treks. There's concern it could also leave climbers dangerously unprepared

CBC

29-05-2025

When Canadian Chris Dare attempted to climb Mount Everest in 2019, one of the challenges he faced was a serious overcrowding problem.
There were so many people making the attempt that the final push to the summit of the world's highest mountain took twice as long as expected due to bottlenecks, which he says made the climb far more dangerous. Eleven people were killed on the mountain during that year's climbing season.
But after a team of British climbers who had inhaled xenon gas recently made headlines for reaching the summit in five days, the B.C. resident is worried the issue could be made significantly worse.
Making the mountain easier to summit, Dare told CBC News, will likely attract more climbers, "exacerbating the already serious overcrowding problem."
That potential problem is just one of many issues being raised around the use of the gas by mountain climbers.
5 days to climb Everest
Xenon is a colourless and odourless gas found in very small amounts in the Earth's atmosphere and is known to have some anaesthetic properties and medical uses, like helping to diagnose lung problems, according to the Mayo Clinic website.
Mountain guide Lukas Furtenbach said last week that he and a team of British climbers had inhaled xenon gas before embarking on an expedition where they climbed the 8,848 metre peak of Everest less than five days after departing London.
The climbers spent months preparing, Furtenbach told The Associated Press upon his return to Kathmandu. He said they slept in hypoxic tents that simulate high-altitude conditions, underwent a xenon gas treatment at a clinic in Germany just two weeks before heading to Nepal and used supplemental oxygen during their climb.
Climbers normally spend weeks at base camp to allow their bodies to adjust to the higher altitude. To prepare their bodies for the lower air pressure and lower level of oxygen available at the top of Everest, they make practice runs to the mountain's lower camps before beginning their final attempt to reach the peak.
"Climatization is a process in which the body adapts to a high-altitude environment and makes kind of physiological changes to allow you to function in a hypobaric, hypoxic environment," said Dr. Rob Casserley, a British doctor who works in Quebec and has scaled Mount Everest eight times.
Dare says he believes more studies are needed on the use of xenon to aid climbers.
"It just seems very, very risky at this onset, right at the beginning," he said. "It's really hard for me to think about ... using a new type of technique. What type of safety protocol is involved with that?"
He's also concerned that if climbers come to rely more on xenon gas, they'll forgo the training needed to make such climbs and discover too late that their pre-acclimatization efforts didn't necessarily work.
As a result, climbers' bodies may not be ready to deal with the lack of oxygen at high altitudes, which means they could develop altitude sickness and end up with fluid build-up in the lungs (pulmonary edema) and swelling of the brain (cerebral edema), he said.
"You're not training the traditional way of being on the mountain for a month and a half, two months to acclimatize in the natural environment."
'Great psychological risk'
Casserley says the advantage of a longer expedition is that it allows climbers to acclimatize over time. That means they become stronger and more "street-wise and savvy on the mountain," he said.
In 2015, he survived avalanches on Mount Everest that were triggered by an earthquake in Nepal. He says climbing Everest is about 90 per cent psychological and 10 per cent physical.
"You start putting in people who've just come cold turkey out of their normal environment, I think it will put them at great psychological risk of having some kind of meltdown and not having the skills necessarily to get themselves down in a kind of so-called disastrous situation," Casserley said, noting that this could endanger a lot of people.
He also questions the science around using xenon gas to aid climbers, noting that there's been some evidence that it can increase erythropoietin (EPO), the hormone that stimulates the production of red blood cells, which in turn increases the capacity of blood to carry oxygen in the body. And that could possibly lead to enhanced athletic ability that would allow people to scale a mountain at a faster rate.
But he says that so far, there's only anecdotal evidence that the gas is performance enhancing.
(In 2014, the World Anti-Doping Agency added xenon gas to its list of banned substances after claims surfaced that it can be used by athletes to help boost performance.)
Climbers' observations shouldn't be dismissed
Dr. Peter Hackett, a high-altitude researcher at the University of Colorado School of Medicine who has also scaled Mount Everest, says Furtenbach's observations shouldn't be dismissed.
"I trust observations of experienced and skilled climbers. They know their bodies. They know how they react to high altitude," Hackett said. "If they thought there was a difference with the xenon, then I think it's upon science to try to find out if that's really true."
But he says it's also important to stress that Furtenbach's crew slept in hypoxic tents for three months before they went to the mountain and also used oxygen on the mountain, two things that are already known to make a big difference.
To say xenon on its own was responsible for their quick ascent is "misinformation," he said.
Hackett noted that Ukrainian climber Andrew Ushakov claims to have recently climbed Everest from sea level to the summit in a record four days with supplemental oxygen and pre-acclimatization in a hypoxic tent, but without the use of xenon.
"He did even better than these other guys," Hackett said.
He says the idea that xenon gas might be useful in high altitudes because it could increase red blood cells and protect vital organs from low levels of oxygen hasn't been shown in studies.
"There's no science to say that this works at high altitudes for climbers, and there's no science to say that it doesn't."
Hackett says it's worth researching the effects of xenon, but not because it could be a way for climbers to scale mountains faster.