Contrary to popular belief, chlorine does not kill all germs instantly. There are germs today that are very tolerant to chlorine and were not known to cause human disease until recently. Once these germs get in the pool, it can take anywhere from minutes to days for chlorine to kill them. Recreational water illnesses (RWIs) are caused by germs spread by swallowing, breathing in mists or aerosols of, or having contact with contaminated water in swimming pools, hot tubs, water parks, water play areas, interactive fountains, lakes, rivers, or oceans. RWIs can also be caused by chemicals in the water or chemicals that evaporate from the water and cause indoor air quality problems.
RWIs include a wide variety of infections, such as gastrointestinal, skin, ear, respiratory, eye, neurologic, and wound infections. The most commonly reported RWI is diarrhea. Diarrheal illnesses are caused by germs such as Crypto (short for Cryptosporidium), Giardia, Shigella, norovirus and E. coli O157:H7. It is important for swimmers to learn the basic facts about RWIs so they can keep themselves and their family healthy every time they swim. Crypto, which can stay alive for days even in well-maintained pools, has become the leading cause of swimming pool-related outbreaks of diarrheal illness. From 2004 to 2008, reported Crypto cases increased over 200% in the USA. Although Crypto is tolerant to chlorine, most germs are not. Keeping chlorine at recommended levels is essential to maintain a healthy pool. Some illnesses, such as head lice, MRSA, and pinworm, are unlikely to be spread in recreational water. However, there is a potential risk for spreading them at recreational water facilities through contact with other people or contaminated objects and surfaces. Animals can be great companions, but if allowed in or near your pool, they can sometimes contaminate the water and spread germs that cause disease. Learn about keeping your pool clean and taking precautions when animals have been in or near the pool.
Keep the pee, poop, sweat, and dirt out of the water. Stay out of the water if you have diarrhea. Shower before you get in the water. Don’t swallow the water. Every hour—everyone out of the pool. Take kids on bathroom breaks. Check diapers, and change them in a bathroom or diaper-changing area–not poolside–to keep germs away from the pool. Reapply sunscreen. Drink plenty of fluids. Check the free chlorine level and pH before getting into the water. Pools: Proper free chlorine level (1–3 mg/L or parts per million [ppm]) and pH (7.2–7.8) maximize germ-killing power. Hot tubs/spas: Proper disinfectant level (chlorine [2–4 parts per million or ppm] or bromine [4–6 ppm] and pH [7.2–7.8]) maximize germ-killing power. Most superstores, hardware stores, and pool-supply stores sell pool test strips.
Credit: Centers for Disease Control and Prevention