People are urinating in the swimming pool and we have the chemistry to prove it. That’s not chlorine that creates the distinctive pool smell; it’s chemicals that form when chlorine reacts with urine, sweat, and body oils. Researchers mixed chlorine with uric acid, a compound found in both sweat and urine, but with far more concentration in urine. The results were trichloroamine and Cyanogen chloride, which contribute to the pool smell, but even worse, it can irritate your eyes and lungs. So if you’re tired of getting all red-eyed after a swim and your pool smells like chlorine, you now know what to blame. That’s why chemists are asking people to please, please stop urinating in the pool.