Joshua Wright, age 15, of Sarasota, Fla., for his question:
WHY DO DIVERS SOMETIMES GET THE BENDS?
Diving deep into the ocean is great adventure, but it is fraught with danger and peril. Great caution must be used by those using heavy diving gear and going down deep to do salvage work and also by skin divers who use light breathing gear and descend only to shallow depths to take pictures, fish or swim in the underwater mystery land.
When salvage work of other requirements call for a diver to go deeper than 60 feet into water, he must use heavy duty equipment that includes 15 pound weighted shoes and a belt designed to help the diver sink and stay upright in the water that can weigh anywhere from 40 to 140 pounds.
Going to the depths, the diver must take many precautions for his safety.
Air pressure can cause trouble inside the diver's body. An illness called the bends or caisson disease, because men working on bridge foundations inside caissons can also get it is feared by every diver.
When a diver breathes in air at much greater pressure than it is at sea level, the blood and tissues of his body take in much more oxygen and nitrogen, the two elements of which ordinary air is mostly made. The addition of these two gases does no harm while the diver stays at the same depth, but if the air pressure suddenly becomes less, the nitrogen especially forms bubbles in the body which interfere with blood circulation and heart action.
If a diver comes up from a great depth too fast, the bubbles are most likely to form in the veins, particularly around the joints and hence the name "the bends.''
Guarding against the bends is done by raising the diver to the surface of the water by easy stages while the air pressure is gradually lowered at the same time. This give his body time to get rid of the excess nitrogen before it can form the dangerous bubbles.
Air embolism is a similar illness in which a clot or a bubble can block a blood vessel. In this case, air could be forced into the small blood vessels of the lungs and bubbles formed. Following the path of circulation, the bubbles could enter the left side of the heart and then move out into the arteries.
A less serious problem to the diver caused by the pressures under water can be the rupturing of eardrums. Fortunately, these will heal soon.
The diver must always be on guard against exhaustion, for if he is suddenly tired, he cannot be as alert as deep sea diving requires. A diver must always be extremely alert and ready in both a physical and mental way to react to any danger he might encounter.