Question

A scuba diver remaining at a depth of 50 meters for a significant amount of time needs to worry about the possible effects of which gas when he or she ascends?

oxygen

carbon dioxide

nitrogen

nitric oxide

Answer 1

The person needs to worry about the possible effects of nitrogen when he is ascending.

Decompression sickness or bends is caused by increased water pressure causing body's tissues to absorb more nitrogen. If that pressure is suddenly reduced , the extra nitrogen forms potentially harmfull bubbles . This occurs when he quickly ascends to surface and there is not enough time for nitrogen to leave blood and instead it forms bubbles. Thus bends occurs by rapid release of nitrogen from the blood. hence divers must return to the surface in carefully monitored stages , so as to control the rate at which absorbed nitrogen is released.