It’s recently been reported that scientists have managed to create a test to measure how much urine is in a swimming pool. It seems that peeing in the pool has become commonplace, and even high-profile swimmers have admitted to doing it during rigorous training sessions, arguing that the chlorine “kills it”. Not only is this untrue, but the chemical reaction that occurs between your pee and the chlorine creates a chemical that has been linked to asthma and other respiratory issues.
Nitrogen trichloride, also known as trichloramine, is made when the urea in your pee reacts with chlorine – the disinfectant widely used in swimming pool water. Nitrogen trichloride is largely made by accident in pools these days, but this compound was originally made for interest in 1812 by Pierre Louis DuLong.
DuLong made the chemical by bubbling chlorine gas through a solution of ammonium chloride. But, despite his success, DuLong’s joy at having made it was probably short-lived – he hadn’t counted on the fact that it would be explosive – the chemical exploded without warning and cost him an eye and a finger. It’s extremely sensitive and will explode even under gentle shock or when exposed to sunlight.
Scientists Sir Humphry Davy and Michael Faraday also fell victim to the substance when they repeated DuLong’s work shortly after. An explosion also caused Davy to lose the use of an eye temporarily and Faraday did permanent damage to his fingers.
Luckily for professional swimmers, only pure nitrogen trichloride is explosive, and so the fact that it is mixed with water and other substances in a swimming pool should be reassuring. However, research suggests that nitrogen trichloride, among other products formed when you pee in chlorinated water, such as chloramine and dichloramine, is linked to eye and upper airway irritation.
It’s rather ironic that the chlorine that is used to kill bacteria and protect the health of swimmers, is linked to the creation of toxic chemicals. But also that the aroma that people associate with a clean pool, is actually the stench of nitrogen trichloride and an indicator of plenty of pee.
Occupational health hazard
It is a volatile chemical, meaning it easily turns into a gas and hangs around in the air around the pool. One study has shown that people who work in swimming pools or spend a lot of time around them, such as lifeguards, have a higher level of airway issue symptoms in comparison with the general population – poolside workers showed more frequent work-related upper respiratory issues than administrative staff.