What physiological changes occur due to diving with nitrox compared to air?

Diving with nitrox, which is a mixture of oxygen and nitrogen with a higher proportion of oxygen than regular air, leads to a significant decrease in nitrogen loading. This is primarily because nitrox contains less nitrogen than the standard air composition, which is about 78% nitrogen.

When divers use nitrox, the reduced nitrogen uptake at depth lowers the overall nitrogen exposure during the dive. As a result, there is a corresponding reduction in the amount of nitrogen that dissolves in body tissues. This decreases the risk of decompression sickness (DCS), also known as the bends, which can occur when divers surface too quickly after being exposed to high pressures.

By reducing the nitrogen load, divers using nitrox can typically extend their bottom times and/or reduce their surface interval times compared to diving with air, ultimately enhancing safety for the diver. Other options, such as an increase in carbon dioxide retention or stating that no significant changes occur, do not accurately reflect the biological effects that arise from using nitrox as a breathing gas. Similarly, while some divers may feel a perceived boost in energy levels, this is not a physiological change recognized in the same context as the reduction of nitrogen loading. Thus, the alteration in nitrogen levels leading to reduced risks is