There is a lot of willful incompetence in high altitude astronomy that is in the process of coming to light.

When I worked in astronomy, I routinely observed young college and university students working with liquid nitrogen and breathing nitrogen gas as they discharged it into the indoor environment at high altitude.

At the W.M. Keck Observatory on the very high altitude summit of Mauna Kea, there was no routine monitoring of mental functioning, blood oxygen levels, blood pressure or heart rate of workers.

My memories of my time in high altitude astronomy indicate that there were no oxygen concentration monitors or alarms in the areas that liquid nitrogen was in use at the high altitude astronomical facilities where I had worked.

The toxicity of medical and industrial gas to the human depends on where it is used. A gas that is regarded as safe in a well ventilated environment at sea level may be a toxic gas in an indoor environment at high altitude.

Astronomy staff that routinely discharged industrial gas into the indoor environment at high altitudes did not wear oxygen deficiency monitors or protective breathing respirators.