By Anna E. Mazzucco, Ph.D.
May 16, 2014
You might be surprised at how many people ignore that sign that says, “Do Not Urinate in the Swimming Pool.” Swimming is a healthful and fun activity that many people enjoy, but a few tips can make swimming safer and healthier for everyone.
While many people might be aware that it is considered “bad manners” to urinate in a swimming pool, kids and competitive swimmers alike may not always follow this rule. In fact, during the 2012 Summer Olympics, several athletes made headlines by admitting that this frequently happens. While this may seem merely unappealing, a recent study suggested that urine can actually combine with the chlorine disinfectant in swimming pool water to make potentially harmful chemicals.1 The researchers recommend that all swimmers avoid urinating in swimming pools to prevent these chemicals from forming.
The study found that a chemical in urine and sweat, called uric acid, undergoes a chemical reaction with chlorine to produce two substances– cyanogen chloride and trichloramine. These substances can be inhaled by swimmers, especially those who swim indoors. While it’s not clear if swimmers exposed to these chemicals are likely to develop health problems, one study found that teenagers who swim in chlorinated pools have a higher risk of getting asthma or hay fever.2 Another study found signs of lung irritation in children who swam frequently, but not in children who didn’t.3
In fact, several studies have shown that competitive swimmers tend to have higher rates of asthma and other respiratory health problems, although the reason for this wasn’t clear.4,5 But now some researchers think that these health problems could be caused by cyanogen chloride and trichloramine, which frequent swimmers are exposed to more than other people.
Do these health concerns mean we should stop swimming? Well, don’t throw in the towel just yet! Swimming has numerous health benefits, which outweigh any risks from these chemicals for most people, especially if you swim outdoors or only seasonally. But, if you or a family member swims regularly indoors, let your doctor know if you experience any wheezing or chest tightness.
There are many benefits to swimming. For example, swimming has been shown to help with arthritis and joint pain.6,7 It’s also considered excellent exercise during pregnancy and a beneficial social and physical activity for kids.8,9
Research shows that regular swimming can even reduce overall chances of death more than running or walking.10 For all these reasons, swimming is a great part of any exercise routine.
And, pool owners have found that there are other ways to disinfect pool water which do not use chlorine. These methods can use ozone, salt, silver and copper to reduce or completely replace chlorine, although these options tend to be more expensive than chlorine. If your neighborhood pool has an extremely strong chemical odor, ask the manager if the cleaning system can be checked out and air flow increased (for indoor pools). You shouldn’t be able to smell a clean and well-balanced pool all the way from the parking lot! And wherever you swim, follow our tips to make your experience as healthy as possible:
Healthy Swimming Tips:
- Use the restroom, not the pool. It’s a good idea to go before you get into the pool.
- Take a quick shower before swimming – this reduces the amount of sweat and other chemicals introduced into the pool.
- Use and re-apply sunscreen according to the instructions. For information on staying safe in the sun and choosing a sunscreen, read our article here.
- For other handy tips on swimming pool safety, see the Centers for Disease Control and Prevention healthy swimming tips here.
- Lian L, et al. Volatile Disinfection Byproducts Resulting from Chlorination of Uric Acid: Implications for Swimming Pools. Environ. Sci. Technol. 2014, 48, 3210−3217. ▲
- Bernard A, et al. Impact of Chlorinated Swimming Pool Attendance on the Respiratory Health of Adolescents. Pediatrics. 2009; 124(4): 1110–1118. ▲
- Lagerkvist B, et al. Pulmonary Epithelial Integrity in Children: Relationship to Ambient Ozone Exposure and Swimming Pool Attendance. Environ. Health Perspect. 2004: 112(17): 1768-1771. ▲
- Bernard A, et al. Chlorination products: emerging links with allergic diseases. Curr Med Chem. 2007;14(16):1771–1782. ▲
- Helenius I, et al. Respiratory symptoms, bronchial responsiveness, and cellular characteristics of induced sputum in elite swimmers. Allergy. 1998; 53(4):346 –352. ▲
- Hall J, Skevington SM, Maddison PJ, Chapman K. A randomized and controlled trial of hydrotherapy in rheumatoid arthritis. Arthritis Care Res. 1996;9(3):206-15. ▲
- Bartels EM, Lund H, Hagen KB, Dagfinrud H, Christensen R, Danneskiold-Samsøe B. Aquatic exercise for the treatment of knee and hip osteoarthritis. Cochrane Database Syst Rev. 2007;4:1-9. ▲
- Hartmann S. Bung P. Physical exercise during pregnancy—physiological considerations and recommendations. J Perinat Med. 1999;27(3):204-15. ▲
- Oriel KN, Marchese VG, Shirk A, Wagner L, Young E, Miller L. The psychosocial benefits of an inclusive community-based aquatics program. Pediatr Phys Ther. 2012;24(4):361-7. ▲
- Chase NL, Sui X, Blair SN. Swimming and all-cause mortality risk compared with running, walking, and sedentary habits in men. Int J of Aquatic Res and Educ. 2008;2(3):213-23. ▲