Drinking pool water can cause diarrhea, a common health concern associated with recreational swimming. The risk stems from two primary sources: infectious pathogens that survive standard disinfection and non-infectious causes related to the pool’s chemical composition. Swallowing contaminated water, even in small amounts, introduces foreign agents into the digestive system. This can trigger a range of gastrointestinal symptoms.
Pathogens That Resist Pool Sanitizers
The most significant infectious risk comes from microscopic organisms that are highly resilient to the chlorine levels typically maintained in pools. These germs are introduced into the water through swimmers who have had a recent diarrheal illness or residual fecal matter. The most frequent culprit in waterborne illness outbreaks is the parasite Cryptosporidium, often called “Crypto.” Protected by a tough outer shell (oocyst), Cryptosporidium can survive for many days, sometimes more than a week, even in properly chlorinated water. It takes only a tiny amount of contaminated water to cause infection, leading to cryptosporidiosis. Another common parasitic agent is Giardia, which is also chlorine-resistant.
Non-Infectious Causes of Gastrointestinal Upset
Gastrointestinal upset can occur without a live pathogen, primarily due to the chemical components of the pool water itself. Sanitizing chemicals, such as chlorine or bromine, can irritate the sensitive lining of the digestive tract if ingested in high concentrations. This chemical irritation can result in symptoms like nausea, vomiting, stomach cramps, and diarrhea. Another source of non-infectious irritation is the formation of disinfection byproducts, particularly chloramines. Chloramines are created when chlorine reacts with organic waste that swimmers bring into the pool, and swallowing water containing these byproducts can cause mild to moderate digestive distress.
Practical Steps for Preventing Water Ingestion
Minimizing the risk of illness requires both personal responsibility from swimmers and diligent maintenance from pool operators. Swimmers should strictly adhere to “Healthy Swimming Behaviors,” which include not swimming when experiencing diarrhea and refraining for two weeks after symptoms have resolved to prevent contamination. Teaching children to avoid swallowing the water is an important preventative measure. All swimmers should shower thoroughly with soap before entering the pool to remove dirt and organic matter that consumes the sanitizer. Pool operators must regularly test and maintain the water chemistry, ensuring the free chlorine concentration and pH levels are within recommended ranges.
Recognizing Signs of Waterborne Illness
Symptoms of a waterborne illness contracted from a pool are primarily focused on the digestive system. The most common manifestations include watery diarrhea, abdominal cramping, nausea, and vomiting; a mild fever may also accompany these symptoms. The time it takes for symptoms to appear, known as the incubation period, varies depending on the specific pathogen involved. For Cryptosporidium, symptoms typically begin two to ten days after exposure, though the illness can last for several weeks. During recovery, staying hydrated by consuming plenty of fluids is important to replace those lost. Individuals should seek medical attention if they experience signs of severe dehydration, bloody diarrhea, or if symptoms persist for more than a few days.