The ideal amount of pool water a person should drink is zero. While pools offer a refreshing respite, the water is not intended for consumption and is not potable. Accidental ingestion of small amounts is common and generally harmless, but the pool environment contains chemical and biological contaminants that pose health risks. The potential for sickness increases directly with the volume swallowed, meaning even a few large gulps can introduce hazards.
Accidental Swallowing vs. Intentional Drinking
Swimmers inevitably swallow small, incidental amounts of water while breathing or splashing, and the body can typically handle this minor exposure. This accidental ingestion usually does not lead to illness in healthy individuals, especially in a well-maintained pool. However, drinking a larger volume of water, such as a full mouth- or glass-full, significantly increases the risk of immediate symptoms.
The difference between a harmless splash and a harmful swallow is a matter of concentration and dose. Children are particularly susceptible because they tend to swallow more water unintentionally than adults. Ingesting larger amounts introduces more contaminants, which can overwhelm the body’s natural defenses and lead to gastrointestinal distress. Therefore, intentional consumption of pool water is discouraged due to the elevated risk of exposure.
Chemical Components and Immediate Health Effects
The immediate risk upon ingesting pool water is largely due to the chemicals used for disinfection and pH balance. Chlorine or bromine, while necessary to kill germs, can cause a burning sensation in the mouth and throat when swallowed in high concentrations. This chemical exposure can lead to acute digestive distress, including nausea, stomach discomfort, and vomiting.
Irritation is compounded by chloramines, which form when chlorine reacts with organic waste introduced by swimmers, such as sweat, urine, and dirt. Chloramines reduce the pool’s disinfection power and are responsible for the distinct “chlorine smell.” Swallowing water with high chloramine levels can exacerbate gastrointestinal upset, signaling high contamination. If a pool’s pH level is poorly maintained or if the pool has been recently “shocked” with disinfectant, ingesting even a moderate amount of water can result in severe chemical irritation.
Pathogens and Waterborne Illnesses
The most significant health concern from drinking pool water is the risk of contracting a Recreational Water Illness (RWI). These illnesses are caused by pathogens that enter the water, often through fecal matter from an infected swimmer. While chlorine is an effective disinfectant, it does not kill all germs instantly; it can take minutes to days to eliminate certain organisms.
The parasite Cryptosporidium is particularly concerning because it resists standard chlorine levels and can survive for more than ten days in pool water. An infected person can shed millions of these microscopic parasites, and swallowing as few as ten can cause illness. Other common pathogens, including Giardia, E. coli, and norovirus, also survive in pool water and cause gastrointestinal symptoms. These symptoms, such as diarrhea, vomiting, and stomach cramps, may appear days or weeks after exposure, depending on the specific pathogen ingested.
Minimizing Ingestion and Exposure
The best strategy for pool safety involves minimizing the amount of water swallowed and reducing the introduction of pathogens. Swimmers should always shower thoroughly with soap and water before entering the pool to wash off potential contaminants. Parents should teach children to avoid swallowing water and to spit out any water that enters their mouth while swimming.
Swimmers who have experienced diarrhea should not enter the pool for at least 14 days after symptoms have fully resolved to prevent the spread of resistant germs like Cryptosporidium. Regular bathroom breaks should be encouraged for children. Non-toilet-trained children should have their swim diapers checked frequently and changed away from the poolside. Observing these hygiene practices helps keep the water cleaner for everyone and reduces the risk of illness from accidental ingestion.