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Clearing up a cloudy issue concerning pool water

BATHER LOAD BACTERIAL SLOUGHING EXPLANATION
How_Swimmers_Affect_Water_Clarity
Whenever a person swims in a pool, bacterium and viruses from their skin and hair (not to mention any incontinent accidents) are left behind.

Whenever a person swims in a pool, bacterium and viruses from their skin and hair (not to mention any incontinent accidents) are left behind and the vast majority of these microbes will be eradicated by the chlorine (Cl) in the pool. The bacteria, which live on the skin of healthy people, are not necessarily harmful unless the person already has lowered immune defenses. Those who typically fall into this category include young children, seniors, pregnant women, AIDS patients, and those on immunosuppressant medication.
It is not unusual for DNA probes of swimming pool filters to find bacteria as common as P. aeruginosa or Escherichia coli (E. coli) given the former lives on most surfaces in civilization, while the latter is present in microscopic amounts on everything one would touch after going to the washroom.
It should also be made clear that there is a small sub-group of E. coli that is responsible for severe illness, resulting in vomiting and diarrhea, called E. coli O157:H7. These bacteria make people sick, and, if found in a pool filter, it would indicate a swimmer(s) was sick with the above symptoms when they went swimming. Almost any other E. coli contamination would simply indicate swimmers were not cleaning themselves thoroughly before using the pool, and while this is unsanitary, it is not a cause for alarm if the pool is properly chlorinated and maintained.
Knowing the difference between each strain, it can be considered that the Centers for Disease Control and Prevention (CDC) report on “Microbes in Pool Filter Backwash,” did not find any traces of E. coli O157:H7 with the DNA probe, but did find other non-specific E. coli. This shows the contamination in most pool filter samples was the result of dirty swimmers—not because severely sick people contaminated the entire pool, thus making it dangerous for all other swimmers.
Further, in the case of either E. coli strain, chlorine will kill whatever is floating in the pool as long as the sanitizer levels are kept appropriately high. Proper chlorine use is vital to keeping pool water clean, safe, and free of infectious microbial contaminants.

Use all the tools available

Encouraging a multipronged approach to pool water sanitation, with proper attention to disinfection, clarification, and filtration, as well as emphasizing the role of personal hygiene measures for all bathers, will likely lead to more enjoyable recreational water experiences. Properly implemented, these pool water management practices work; the aquatics industry strives to achieve the safest environment and this is how it should be perceived.

 

 

Williams_Headshot_2Dr. Jeff Williams is the chief technology officer and senior vice-president of R & D for Halosource Inc., a clean water technology company based in Bothell, Wash. He is an emeritus professor of microbiology and molecular genetics at Michigan State University, where he was a teacher and biomedical researcher for almost 30 years before founding Halosource in 1998. Williams can be reached via e-mail at jwilliams@halosource.com.

 

 

._DSCN0557_2Nathan Kenney is a water microbiology specialist for Halosource’s product development division. He joined the company in 2012 and is involved in development and testing. He received his bachelor of science (B.Sc.) in microbiology from the University of Washington. He can be reached via e-mail at nkenney@halosource.com.

 

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