Climbing the Himalayas more safely

Mountains are attracting a steadily increasing number of visitors. Each year, about 40 million tourists visit the mountainous areas of the Alps, and more than 100 million travel to high altitude regions all over the world.1 For example, the number of trekkers in Nepal rose by 450% between 1994 and 2000, and a similar increase has been seen for climbers reaching summits higher than 6000 m.2 In the linked paper (doi:10.1136/bmj.e3782), Westhoff and colleagues show that the number of climbers taking part in “traditional” (non-commercial) expeditions to high Himalayan peaks has remained relatively consistent since the 1990s, whereas the number of participants in commercial expeditions has increased continuously.3

Westhoff and colleagues aimed to determine whether previous participation in Himalayan expeditions reduced the risk of death associated with the climb and whether commercial expeditions are safer than traditional ones.

Although mountaineering activities may contribute to the well established health benefits of physical activity and to the inverse and independent relation between physical activity and overall mortality,4 the study reports an extremely high risk of death for traditional climbers and those taking part in commercial expeditions who attempt to climb Nepalese Himalayan peaks.3 The unadjusted mortality during the 40 year observation period (1970-2010) was 1.63% on Himalayan peaks of 8000 m or higher; if we assume 30 days of exposure per climb this equals 544 deaths per one million days of exposure. The risk of death varied from 170 deaths per million days of exposure on a “low risk” 8000 m mountain (such as Cho Oyu) to 1334 on a “high risk” 8000 m mountain (such as Annapurna).3

Compared with downhill skiing, mountain hiking, rock and ice climbing in the Alps, or trekking in Nepal, climbing in the high regions of the Himalayas is associated with a huge increase in death (table⇓).5 6 7 8 Compared with downhill skiing, which is a relatively high risk sport,6 the risk of dying on Himalayan peaks of 8000 m or higher is increased on average by a factor of 495. Although Westhoff and colleagues found a trend towards a lower risk of death among those participating in commercial expeditions, the finding was not statistically significant.3 Especially with regard to commercial expeditions, two main questions arise: which types of preventive measure have the potential for reducing the extremely high risk of death and which level of risk can be considered acceptable?

Climbing on low risk 8000 m mountains (rather than higher risk ones), improved logistics, modern equipment, appropriate acclimatisation and medical advice, and optimised weather forecasting may all help reduce mortality. Westhoff and colleagues found a significant trend toward reduced odds of death from 1970 to 2010, suggesting that such innovations and preventive efforts are already at work.3 As reported by Huey and colleagues earlier,9 experience in the form of previous climbs in the Himalayas had no beneficial effects.3

Falls were the most common cause of death and are probably associated with insufficient fitness and mountaineering skills.9 10 Previous climbs in the Himalayas may not be a good enough indicator of these attributes, the acquisition of which requires planned and long lasting (months to years) preparatory training, so participation in a previous expedition alone is unlikely to reduce the risk of falling. Mountaineers and organisers of commercial expeditions do not always appreciate the importance of taking time to acquire fitness and skills. Better and long lasting advice during the preparatory phase and a more rigorous selection process for participating in expeditions would probably help to reduce the risk of death

As Westhoff and colleagues show, it is the duty of researchers to analyse and highlight various aspects of the risks of death associated with climbing in the Himalayas, and it is the responsibility of expedition organisers to provide all the facts about the risks to their customers. Ultimately, the informed mountaineer has to decide whether the risks are acceptable and whether or not to participate. Continuing joint efforts of scientists, expedition organisers, and mountaineers will, hopefully, help to make climbing in the Himalayas safer.