Why Do Swimming Pools Use So Much Chlorine?

Many people keep their eyes closed or wear goggles when they go swimming at the pool, in an attempt to prevent the burning and itching often blamed on chlorine. However, the truth about the cause of those stinging sensations is a real eye-opener -- and not in a particularly pleasant way. While chlorine is used to kill germs, the source of the eye pain is something known as chloramines, which are created when the chlorine binds with sweat, urine and other bodily fluids that end up in the pool. The chloramines form in the water, but they also rise into the air thanks to air circulation and people splashing around. So if the pool is located in an enclosed space with limited ventilation, the irritation can get worse, affecting not only the eyes and skin, but also breathing. Ideally, pool operators should take steps to limit the amount of chloramines that can build up by ensuring that plenty of fresh air is pumped into the pool area. As for the swimmers, they can help by wearing bathing caps, taking a shower before jumping in, and -- needless to say -- not turning the water around them yellow.

Dive into some swimming pool facts:

• The ancient city Mohenjo-daro, in present-day Pakistan, was home to the Great Bath, the world's oldest known pool. The structure dates to the third millennium BC.
• There is roughly one pool for every 31 Americans, including more than 300,000 public swimming places.
• Competitive swimmers shave their body hair not just to go faster but also to better "feel" the water around them.