Is high oxygen concentration good for humans?

High oxygen concentration is harmful to the human body. Generally, inhaling high-concentration oxygen under either hyperbaric or normal atmospheric pressure may cause functional or structural damage to the body when exposure reaches a certain level.

When oxygen concentration becomes excessively high, it can lead to oxygen toxicity. Specific symptoms include damage to the capillary barrier in the lungs, resulting in pulmonary edema, congestion, and hemorrhage. This severely impairs respiratory function, leading to organ hypoxia and subsequent damage. In particular, in a pure oxygen environment at one atmosphere of pressure, humans can survive for only about 24 hours, as prolonged exposure causes oxygen-induced pneumonia, eventually leading to respiratory failure and suffocation. Therefore, when high-concentration oxygen is frequently required for certain medical conditions, strict adherence to usage guidelines is essential to avoid prolonged or excessive oxygen inhalation that could trigger adverse health effects.

Thus, long-term inhalation of high-concentration oxygen is not beneficial. It may also accelerate aging. When excess oxygen reacts with oxidase enzymes in cells, it produces hydrogen peroxide, which can transform into lipofuscin—a harmful substance known to accelerate cellular aging. Lipofuscin is typically responsible for age spots and can contribute to the aging of organs and blood vessels, potentially causing hardening of the arteries. In the brain, it may lead to cognitive decline, memory loss, and other neurological impairments.