What is defined as pulmonary oxygen toxicity?

Pulmonary oxygen toxicity refers to the adverse effects on the lungs caused by prolonged exposure to elevated partial pressures of oxygen (PPO2). When the body is exposed to increased levels of oxygen over an extended period, it can lead to inflammation and damage in the lung tissues, resulting in symptoms such as respiratory distress and pulmonary edema.

In this context, long exposure to increased PPO2 is the primary concern because the toxic effects accumulate over time, leading to more significant damage than short-term exposures, which may not produce the same level of harmful effects. This understanding is crucial for individuals, especially in diving or therapeutic contexts, where oxygen levels can fluctuate dramatically.

The other options do not accurately reflect the definition of pulmonary oxygen toxicity. While short exposure to high PPO2 can lead to some immediate effects, it is the long-term exposure that primarily contributes to toxicity. Exposure to high levels of CO2 is unrelated to oxygen toxicity, and rapid ascent from depths is typically more associated with decompression sickness rather than oxygen toxicity itself.