What can prolonged exposure to high PPO2 lead to in divers?

Prolonged exposure to high partial pressure of oxygen (PPO2) can lead to seizures or other central nervous system effects primarily due to the toxicity of oxygen at elevated pressures. As divers descend deeper, the pressure increases, causing the PPO2 to rise as well, especially when using Nitrox, which contains a higher percentage of oxygen than normal air.

When the PPO2 exceeds certain safe levels (typically above 1.4 ata for recreational diving), it can have neurotoxic effects, leading to symptoms such as visual disturbances, twitching, and in severe cases, seizures. This is known as oxygen toxicity, which can be particularly dangerous for divers, as a seizure underwater can result in drowning or other serious incidents.

Understanding the risks associated with high PPO2 is crucial for divers using Nitrox and for managing diving operations safely, ensuring that divers stay within safe exposure limits to prevent these severe central nervous system complications.