ABSTRACT

Increasingly, large numbers of people are commuting to high altitude for commercial, scientific and other activities. Several mines are now situated at altitudes of 4000-6000 m. In some cases, the miners live at sea level and are bussed up to the mine where they spend a working period such as 7 days. They then return to their families at sea level for a further 7 days, and the cycle is repeated indefinitely. This pattern raises interesting questions about acclimatization and also how best to select people for this work. Telescopes are being sited at an altitude of 4200 m in Mauna Kea (Hawaii), and even higher at altitudes of 5000 m or more in Chajnantor in north Chile. In Mauna Kea, some of the workers commute daily from sea level. For the Chajnantor project, many workers will live at an altitude of about 2400 m and commute to the telescope though some will sleep at 5050 m. Military operations have now been conducted at altitudes up to 7000 m in the dispute between India and Pakistan with some soldiers moving rapidly to high altitudes and down again. A

Province, China reaches as high as 5000 m. Some athletes now commute to high altitude to improve their performance. An important innovation is the use of oxygen-enriched rooms at high altitude to relieve the hypoxia and reduce the equivalent altitude. Each 1% increase of oxygen concentration reduces the equivalent altitude by 300 m. Oxygen enrichment has been shown to improve neuropsychological function during the day and enhance sleep at night. The use of oxygen-enriched modules at the Chajnantor site shows great promise. The same technology is also being used at lower altitudes especially to improve sleeping.