A major study has concluded that diving is bad for the lungs, though the effect may not be significant.
The research was carried out by Marit Skogstad of Norway's National Institute of Occupational Health.
They tested a group of divers after one year, three years, and six years. Many only did recreational diving;
more than 60 percent of dives were to less than 60 feet.
They found that various measures of lung function, such as how much air you can blow out, fell by
nearly one percent a year in the divers. There is normally a gradual falloff in lung function as we age, but in
the divers the decline was more than three times as fast as that of a control group of nondivers. And the
more dives that people did, the faster the decline. There were also decreases in other measures of lung
function, such as how fast you can blow out and how quickly gases are exchanged. But, overall, the decline
was slight -- nowhere near as severe as that linked to the effects of smoking, for instance.
Skogstad says, "I don't think it is a serious problem for most divers." However, she thinks it reinforces
the argument that people with lung problems, such as exercise-induced asthma, should not dive, especially
in cold water.
Michael LePage, Dive Magazine