At what level would a person experience adverse health effects due to low oxygen?

A person would experience adverse health effects due to low oxygen primarily at a level of 16% oxygen concentration in the air. Normal atmospheric oxygen levels are approximately 20.9%. When oxygen levels drop to 19.5%, most individuals can typically function without serious effects, though some may start to feel mild symptoms like shortness of breath or fatigue.

At 16%, the oxygen concentration is significantly below normal, leading to more pronounced health issues. Individuals may experience impaired cognitive function, decreased coordination, and other serious symptoms as the body struggles to obtain sufficient oxygen. Furthermore, as the concentration decreases further to 14% and below, the risk of unconsciousness or even death increases dramatically.

This understanding is vital for safety in environments where oxygen levels might be compromised, such as in confined spaces or areas with poor ventilation, highlighting the importance of monitoring oxygen levels to ensure safety.