March 13, 2018
With the upcoming MI Swimming 12 & Under and 13 & Over State Championship meets around the corner I thought I would take a moment to send a quick note about air quality in pools, what causes poor air quality, and most importantly, what we can do to make a change for the better.
What’s that smell?
Often the odor detected in pools is incorrectly identified as chlorine. What you’re really smelling is trichloramine – a volatile reaction product of the chlorine in products used for disinfection and nitrogen containing compounds introduced into the water by swimmers.
What are the sources of nitrogen in water?
Sweat is the predominant source of nitrogen in water, but a significant percentage (roughly 40%!) of nitrogen containing compounds introduced into pool water comes from dead skin cells, chemicals on skin and in hair (lotions, soaps, moisturizers, shampoos/conditioners, etc.), and urine. Other sources of chloramines in pool water include the municipal water supply and nitrogen (e.g. ammonia) containing chemicals used for cleaning the pool deck.
Poor Air Quality is a direct result of Poor Water Quality
Water parameters such as pH, total and combined chlorine (and other disinfectants), temperature, etc. can be perfectly dialed-in and there can still be high concentrations of chloramines in pool water. Chloramines (trichloramine) is created – as stated above – when nitrogen compounds (sweat, skin products, urine) are infused into the water. If we are able to minimize formation of chloramines (trichloramine) we can dramatically improve air quality.
The weather is a significant complicating factor. Unfortunately, our championship meet season is held during the time of year when outdoor temperatures fluctuate dramatically. This makes it incredibly difficult to regulate HVAC systems.
How can we improve Air Quality in Pools?
- Showers – a 15-20 second shower (no soap needed!) has been shown to dramatically reduce the amount of nitrogen compounds available to water from the skin of athletes. So – please encourage athletes to take a shower prior to entering the pool and sing the Happy Birthday song twice.
- Use Bathrooms – encourage athletes to utilize bathrooms and to stop urinating in the pool. Many don’t realize that pool water is not changed out. Studies show that urine components remain within pools for years (!). Understanding that technical suits are difficult to put on/take off when wet, suggest utilizing showers if athletes have to urinate. Water from showers will not enter pool water.
- Don’t Block Exhaust Vents – Keep signs, banners, athletes, backpacks, towels, etc. away from exhaust vents. People tend to congregate in these areas as they are comfortable areas to stand due to the sensation of air moving.
Finally, recognize that HVAC systems in pools are not designed to remove airborne contaminants (e.g. trichloramine). They are generally designed to maintain temperature and humidity, primarily to prevent condensation and corrosion of structures/equipment. Anything that we can do to improve water quality in our pools will dramatically help to improve our air quality.