But some people pee in swimming pools and hot tubs.
When chlorine reacts with urine, it creates chemicals that can irritate eyes and lungs.
They’ve found a simple way to estimate the volume of urine in a pool.
(Have you ever heard that pool water has a chemical in it that will change color if you pee?
It makes a good marker for pee, says Blackstock.
Liter-sized samples of the city’s tap water contained between 12 and 20 nanograms of Ace-K. (Remember, Ace-K doesn’t decompose during water treatment.)
The smaller pool, though, had 156 nanograms of Ace-K per liter of water.
These pools probably aren’t unusual, says Blackstock.
Caffeine, for instance, can break down after it leaves the body.
Like Blackstock and her team, Escher suggests the best way to tackle urine is pools is prevention, not clean-up.