Final answer:
The presence of unusual taste, smell, breathing difficulty, or symptoms of decompression sickness can indicate harmful air in a scuba cylinder. Divers must take care to ensure clean and appropriately composed breathing gas to prevent conditions such as oxygen toxicity, nitrogen narcosis, and DCS. Treatment for DCS includes hyperbaric oxygen therapy in decompression chambers.
Step-by-step explanation:
Indicators that the air in a scuba cylinder may be harmful to consume include unusual taste or smell, breathing difficulty, or symptoms of decompression sickness (DCS). Scuba tanks contain compressed air due to the compressibility of gases, which allows a large amount of gas to be stored in a small volume. However, if contaminants such as carbon monoxide or particulates are present, they can pose serious risks to divers. Consuming harmful air can lead to oxygen toxicity, nitrogen narcosis, and DCS, the latter being a result of rapid ascent without proper decompression stops.
DCS occurs due to the formation of gas bubbles in the blood, causing symptoms such as joint pain and rashes, and in severe cases, paralysis or death. To treat DCS, hyperbaric oxygen therapy in decompression chambers is used. Divers at considerable depths inhale air at high ambient pressure, which increases the concentration of dissolved gases in their blood. To manage these risks, divers should be aware of buoyancy, pressure equalization, and limit their time underwater.