Swimming pools provide recreation and exercise for many different types of people. Unfortunately, some swimmers suffer allergic reactions from the chemical disinfection process needed to keep waters safe for bathers. Despite the drawbacks inherent in chlorine-based disinfection, it is effective in preventing diseases caused by E. coli and other bacteria, according to the Centers for Disease Control and Prevention. Problems occur when poor maintenance results in too much chlorine and unbalanced pool waters.
Levels and Adjustments
According to the Centers for Disease Control and Prevention, most local health departments mandate that chlorine levels in swimming pools fall between 1 and 3 ppm. Human error sometimes results in over-chlorination, and swimming in pool waters with too much chlorine results in health problems for pool patrons, including eye, lung and skin irritation.
When large numbers of bathers and accompanying large amounts of contaminants overburden existing chlorination, pool managers use superchlorination to "shock" the pool back into hygiene control. Superchlorination involves adding large amounts of chlorine at once to a pool. Because the amount of chlorine is so high, swimmers cannot enter the pool until the chlorine diminishes through evaporation and chemical interactions to return to safe and acceptable levels. Swimmers who enter superchlorinated pools risk severe lung irritation and reddened and irritated skin.
The pH balance of pool water is just as likely a culprit as disinfection by products regarding skin irritation in swimmers. Too much of certain chlorine substances make the waters too acidic or too alkaline for human comfort. Water that falls outside the 7.2 to 7.8 recommended pH scale can inflame and irritate skin, according to the CDC. Balancing the chemicals in the water helps avoid dermatitis or other allergic reactions.
Some people have more sensitivity to chlorine disinfection than others. Even at normal chlorine levels, they experience dermatitis from the exposure. The Mayo Clinic describes dermatitis or skin sensitivity as itchy, dry and red areas over the body. High levels of chlorine produce a range of symptoms from inflamed skin to blistered skin from direct contact with concentrated chlorine, according to the Centers for Disease Control and Prevention. Some dermatitis-type irritations result from poor pool maintenance, including adding too much chlorine.
Some people cannot stand the side effects of chemical treatment. Swimming outside is better because ventilation outside is superior to indoor pools. Swimmers might assume that their skin problems result from too much chlorine in the pool water, when in fact dry, itchy skin and eye irritation might be the result of too little disinfecting chlorine. According to Mary Pohlman, M.D. and member of the USMS sports medicine committee, when the by-products of the disinfection process build up in a pool, chloramines produce the bad smell and skin and lung irritation sometimes blamed on too much chlorine.
- Environmental Science and Technology: The Good, the Bad, and the Volatile: Can We Have Both Healthy Pools and Healthy People?
- CDC: Irritants (Chloramines) & Indoor Pool Air Quality
- CDC: Pool Chemical -- Associated Health Events in Public and Residential Settings -- United States, 1983-2007
- MayoClinic.com: Slide show: Common skin rashes
- CDC: Your Disinfection Team: Chlorine and pH
- U.S. Masters Swimming: The Healthy Swimmer: Readers Ask: Coping With Chlorine Reactions