The water in the pool smells not because of chlorine, but because of... urine - a former NASA engineer found out why pools have such a pungent smell

The water in the pool smells not because of chlorine, but because
of... urine - a former NASA engineer found out why pools have such a
pungent smell
Mark Robert conducted an experiment: he took two buckets of water with
chlorine, left one �clean�, and added a little urine to the other,
closed the lid and left it for a day.
A day later he checked the buckets: the bucket that contained only
water and chlorine did not smell of anything. But the bucket to which
a little urine was added smelled of that same "nostalgic"
pungent smell of swimming pools.
This is explained by the fact that when chlorinated water and urine
come into contact, trichloramine is formed, which is the cause of the
pungent odor.
I won't set foot in a swimming pool again.