Which gas is primarily reduced in the body when using Nitrox?

When using Nitrox for diving, the primary gas that is reduced in the body is nitrogen. Under normal air breathing conditions, our bodies absorb nitrogen, which is inert at surface pressure. However, as the depth increases during a dive, the partial pressure of nitrogen also increases, which can lead to nitrogen narcosis and decompression sickness if a diver returns to the surface too quickly without allowing the necessary off-gassing of nitrogen.

Nitrox, being a blend of oxygen and nitrogen, typically reduces the amount of nitrogen absorbed by the body compared to breathing normal air, which contains approximately 78% nitrogen. By increasing the concentration of oxygen and decreasing the proportion of nitrogen in the breathing gas, Nitrox allows divers to minimize their nitrogen absorption, thereby reducing the potential for decompression sickness.

In contrast, carbon dioxide is a byproduct of respiration and is not primarily reduced by using Nitrox. Helium is used in specific diving situations, mainly for deep dives or to avoid narcosis, but it is not related to standard Nitrox use. Hydrogen does not play a significant role in diving gas mixtures because it is not an essential component of breathing gases for divers.

Thus, in the context of Nitrox diving, nitrogen is the gas that is primarily