Does bathing in swimming-pools (e.g., at hotels or water parks), where chlorine is added to the water, brighten your skin?
I've heard from many different people that bathing in pools with chlorine water makes your tan go away, although my doctor friend undoubtedly says otherwise.
The claim is also made in this fake tan company's FAQ:
Yes. Frequent swimming will enhance your body's natural exfoliation. Chlorinated water also tends to lighten the skin, therefore fading your tan quicker.
Your tan will gradually fade in about a week to 10 days. Exfoliating, shaving, prolonged water exposure, (especially in chlorinated pools) and heavy sweating can lighten your tan, as all these things contribute to rapid dead skin-cell removal.