What physiological effect can high partial pressures of oxygen have on divers?

High partial pressures of oxygen can lead to oxygen toxicity, a potentially serious condition that affects divers. When the partial pressure of oxygen in breathing gas exceeds certain levels, it can have toxic effects on the central nervous system and other tissues. The symptoms of oxygen toxicity may include visual disturbances, muscle twitching, nausea, and in severe cases, convulsions. This occurs because elevated levels of oxygen can induce hyperexcitability of the nervous system.

Understanding oxygen toxicity is crucial for divers, especially when using enriched air nitrox, as it typically has a greater percentage of oxygen than regular air. Managing this risk requires careful monitoring of depth and the mix of gases being used to ensure that the partial pressure of oxygen remains within safe limits, thereby preventing any adverse physiological effects related to oxygen exposure.