Abnormal Atmosphere

Abstract

A partial pressure of oxygen in the inspiratory air that is above normal can cause damage to the respiratory tract, the parenchyma of the lungs, the nervous system, and the eyes; the pressure and the duration of exposure to it are decisive. Bodily rest increases the tolerance, while physical effort reduces it. If pure oxygen is breathed at 1.0 bar, after 24 h there is an increase in the volume of interstitial fluid in the lungs together with a reduction of the compliance and impairment of the diffusion of gases. If the exposure is to last for days or weeks the inspiratory partial pressure of oxygen should not be more than 0.4–0.5 bar.