What is the equivalent CO2 value at a depth of 30 feet?

To determine the equivalent CO2 value at a depth of 30 feet, it’s essential to understand how pressure changes with depth and how those changes impact gas concentrations. In hyperbaric medicine, as a diver descends, the pressure increases, and this affects the solubility of gases in body fluids, including carbon dioxide (CO2).

At sea level, the pressure is 1 atmosphere (atm), which is the baseline for gas calculations. For every 33 feet of seawater depth, the pressure increases by another atmosphere. Therefore, at 30 feet, the pressure is approximately 1.9 atm (1 atm from the surface plus 0.9 atm from being 30 feet underwater).

The partial pressure of a gas in a mixture is influenced by the total pressure. The relationship of the partial pressures allows us to understand the concentration of gases, such as CO2. At increased pressure, the solubility of CO2 in blood also increases proportionally due to the principles of Henry’s Law.

Hence, the equivalent CO2 value at 30 feet is calculated such that it reflects this higher pressure environment. Given that the CO2 value is normalized to the pressure at sea level (1 atm), the correct value at increased pressure