You know that water in swimming pools contain chlorine, but what you probably don’t know is why pools need them in the first place. Chlorine breaks down into two chemicals when it is added to water: one that almost instantly eliminates bacteria, and the other remains in the water to deal with new bacteria introduced by new bathers.
Chlorination is done in one of two ways. First, liquefied chlorine gas may be added directly to the water. The other way is by dissolving sodium hypochlorite in water. In both methods, a hypochlorite ion is produced which breaks up under sunlight and releases oxygen free radicals that responds to all organic matter that it encounters, killing the bacteria. During the chlorination process, it is not safe to enter the pool, for it can cause drying of the skin, and whitening and loss of hair.
While chlorine is necessary to kill bacteria, it has some side effects, albeit minor. It has a distinct smell that may be unpleasant. It can irritate some skin types and make the skin itch, and it can cause fabric to fade quickly if not rinsed immediately after bathing. None of these are enough to cause huge concerns. However, be wary of over-chlorinated pools which may amplify the effects.