The lasting physical and mental health effects of long term very high altitude exposure appear to be remarkably similar to daily heavy smoking.

Very high altitude observatories are a known worker health hazard.

In high altitude astronomical facilities we routinely discharged large amounts of nitrogen gas into closed spaces. We were never informed by the astronomy management team about the abnormally low oxygen environments that the use of liquid nitrogen creates, how long term exposure to it manifests itself in human health and the resulting abnormal mental behaviors.

Industrial liquid gas containers were left open and venting gas into the indoor environment in high altitude astronomy. On reflection, I realized that I routinely observed mental and physical effects that match those of a low oxygen environment in staff that I supervised.

At the age of 46, forgetfulness & confusion had become a daily aspect of life.

Never trust a high altitude astronomer.