What's Really in Our Swimming Pools?

Harrah’s Pool-Volleyball © 2010 Daryl Kenyon and made available on Flickr under the Attribution-NonCommercial-NoDerivs 2.0 Generic license

By Dr Lidiya Angelova-Duleva
 
Swimming pools are a favourite place amongst young and old, during summer and winter alike. We all know that they are full of water, but what else is in there?

​Swimming pools are actually a soup of water, bleach, human shedding and cosmetics, bacteria, and viruses and fungi. Sounds gross, right?!
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Well, it is not that bad. The water is circulated through filters so it can be refreshed. Of course that alone is not enough to keep the water clean, and so regents called disinfectants are added at minimal concentrations, which are sufficient to kill potential germs. All of you are probably familiar with the bleach-like smell of swimming pools. This smell is a result of using sodium hypochlorite (NaClO), which is also in bleach but at a more concentrated amount. NaClO reacts with water to form hypochlorous acid (HOCl), which has antimicrobial properties. Many people still don’t shower before they get into the pool, or don’t bother getting out when they need to urinate. This makes the disinfection process even more difficult to conduct. Swimming pool owners often use the highest safety approved concentration of the chemicals to prevent any outbreaks, but that can make the water unpleasant for people with sensitive skin. Sodium hypochlorite can react with the human urea, which results in the formation of  quite toxic substances. Fortunately these substances are produced at low levels and do not have any long term harmful effects.

The “bleach” in the pools, along with the other reagents, is important for keeping the water safe. The contents of our swimming pools are largely based on the quality of the water in it. However, it also depends on our personal hygiene. So, make sure you shower before you get into the pool and try not to pee in it!
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References:
http://www.compoundchem.com/2014/07/06/sodium-hypochlorite-bleach-swimming-pools-cleaning-products/
http://www.who.int/water_sanitation_health/bathing/srwe2full.pdf
http://standards.nsf.org/apps/group_public/download.php/17496/ANSI-APSP-11%202009-for-apsp-store.pdf

​About the Author
 
Lidiya’s curiosity about “how the life works” led her to complete a Masters degree in Biology and a PhD in Microbiology. Science gave her more questions than answers and after a few years as a postdoc at the National Institute of Health in Rockville, MD, USA, she decided to pursue her “first” love in writing. Not long after that, she became a mom of a wonderful girl, who is a very energetic toddler now. She loves to travel and has lived in many countries; she is still looking for a place to settle down. Lidiya is thrilled to be a part of the Scienista bloggers team, and loves being able to connect with lots of wonderful young, and already established female scientists, while writing about science, life and everything else.

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