What is pulmonary oxygen toxicity?
Pulmonary oxygen toxicity goes by a variety of names; chronic toxicity, whole body toxicity or the Lorrain Smith Effect (see question [12]). High partial pressures of oxygen damage lung tissue over a period of time. The result is similar to flu or pneumonia symptoms; coughing, breathing difficulty, lack of co-ordination, sore throat and chest. Unless the exposure is extremely long recovery is not a problem. This is generally not considered to be a problem for sport divers. There is not the same risk of drowning as for CNS toxicity (see question [10]). If symptoms do become apparent they will probably do so after the dive. It is more of a problem for divers working in a saturation environment. For example, if the inspired PO2 is greater than 0.6 ATA for several days you will probably want to speak to a doctor. The oxygen clock (see question [12]) is used to track pulmonary oxygen toxicity. Taking air breaks can reduce the risk to virtually nil. The following table gives the NOAA normal
