What are the two types of oxygen toxicity that divers may encounter?

The correct answer identifies the two types of oxygen toxicity divers may encounter as CNS (Central Nervous System) and Pulmonary.

CNS oxygen toxicity occurs when divers breathe high concentrations of oxygen, typically at pressures greater than 1.6 ATA (atmospheres absolute), leading to symptoms such as visual disturbances, convulsions, and other neurological impairments. This condition can be particularly dangerous at depths where high partial pressures of oxygen are present, often associated with deeper dives and mixed gas diving.

Pulmonary oxygen toxicity relates to the effects of high concentrations of oxygen on the lungs. Prolonged exposure to elevated oxygen levels can lead to inflammation of lung tissue, leading to respiratory issues such as chest pain and difficulty breathing. This can occur during long dives at depths where breathing gas contains more oxygen than normal air, especially in cases where divers are breathing pure oxygen for extended periods.

Understanding these two types of oxygen toxicity is crucial for divers and dive supervisors, as it enables them to plan dives responsibly, monitor for symptoms, and take preventive measures, such as limiting the time spent at depths with high oxygen exposures. Awareness of these conditions enhances diver safety and ensures effective management of dive operations.