Damage during diving and when working in compressed air

In the United States, there are more than 1,000 damages per year associated with scuba diving, of which> 10% end fatal. Similar damage can occur to workers in tunnels or caissons in which compressed air is used to remove water from working areas. Many damages are associated with high pressure, which at depth or in caissons is created by a mass of water column plus atmospheric pressure on the surface. At a depth of 10 m (33 ft), sea water creates a pressure equal to the standard atmospheric pressure at sea level, which is 14.7 pounds per square inch, 760 mm Hg. Or 1 atm. (absolute atmosphere). Thus, the total pressure at this depth is 2 atm. For every additional 33 feet of depth, there is an additional 1 atm.

The volume of gases in the body cavities is inversely proportional to the external pressure. The increase or decrease in the volume of gas due to a change in pressure outside the body has a direct physical effect, which can destroy various body tissues (barotrauma). The amount of gas dissolved in the bloodstream increases with increasing pressure in the environment. An increased content of gases can cause both immediate (eg, nitrogen narcosis, O2 intoxication) and indirect damage during the ascent from depth, when decompression of the supersaturated gas causes the formation of nitrogen bubbles (caisson disease). Barotrauma or decompression can cause arterial gas embolism. Information on other diving related injuries (eg drowning, hypothermia, trauma) is presented in the relevant sections of the manual.

[1], [2]