A chemical reaction between chlorine in pools and urine causes a byproduct that affects the human respiratory system.
University of South Carolina chemistry professor Susan Richardson has been studying the effects of a disinfection byproduct called trichloramine, which forms in pools whenever urine reacts with chlorine in pool water. She is concerned about the “statistically significant” number of professional swimmers who struggle with asthma.
“Trichloramine, once it’s formed, it goes immediately into the air,” she said. “Especially if you’re in an indoor pool, that classic pool odor-smell that you’re smelling is actually trichloramine.”
Richardson said the odor is the reaction of chlorine combining with urea, which comes from urine and human sweat.
“Trichloramine has been implicated as a possible cause in the incidences of asthma that they’ve seen. They see increased asthma in professional swimmers and Olympic swimmers — people that spend many hours per day in indoor pools,” she said. “Trichloramine can also be responsible for the red eyes that you can get when you swim in pools, chlorinated pools. Also, the phlegm in your throat and cold-like symptoms also induces those kinds of things, too. It’s known as a respiratory irritant.”
It’s not just trichloramine. Richardson said chlorine and other chemicals in pool water can react with lotions on a swimmer’s body, sunscreens, hair conditioners and perfume.
“You’re really a lot more exposed to that stuff in the air when you’re in an indoor pool versus outdoors,” Richardson said. “I do think outdoor pools are safer in that respect from breathing in a lot of these chemicals.”
When asked if there are methods to disinfect pools without using chlorine, Richardson said a Myrtle Beach company is using ionic technology with copper and silver electrodes to kill organisms. She said the technology is being studied. Ultraviolet disinfection also is under study.
She also notes the chemical reactions would not occur if people did not urinate in pools.
“Changing behaviors would go a long way,” she said. “If they know that they’re actually endangering themselves by peeing in the pool by forming these chemical by-products, maybe that can change.”
Richardson currently is focusing her research on new technologies that would reduce similar disinfection byproducts in drinking water.
“We are looking at these same kinds of chemicals . . . other chemical disinfection byproducts forming in drinking water as well from other precursors. Mostly just from natural organic matter,” she said. “In addition to trying to make pools safer, we’re also trying to make drinking water safer as well.”
Richardson is close to completing research using granular activated carbon to remove disinfection byproduct precursors in drinking water.