Accidentally swallowing pool water is a common experience for many swimmers. While a small amount may not always cause immediate concern, the substances within it can sometimes lead to uncomfortable or, in less common instances, more serious health issues. Understanding what is in pool water and how it can affect the body can help swimmers make informed choices for a safer experience.
What’s In Pool Water?
Pool water contains various substances, broadly categorized into disinfectants and contaminants. Chlorine is the primary disinfectant used to kill harmful bacteria and viruses, helping keep the water safe for swimming. When chlorine interacts with organic matter introduced by swimmers, such as sweat, urine, skin cells, and cosmetics, it forms disinfection byproducts (DBPs) like chloramines, trihalomethanes (THMs), and haloacetic acids (HAAs). These byproducts contribute to the distinct “chlorine smell” often associated with pools, which actually indicates the presence of these compounds rather than free chlorine itself.
Beyond disinfectants and their byproducts, pool water can also harbor various contaminants. Pathogens like bacteria (E. coli, Shigella), viruses (Norovirus, Hepatitis A), and parasites (Cryptosporidium, Giardia) can enter the water from swimmers, particularly through fecal matter. Cryptosporidium and Giardia are especially concerning because they are highly resistant to standard chlorine levels and can survive in properly chlorinated pools for extended periods, even days or weeks.
Common Health Reactions
Ingesting pool water can lead to a range of health reactions, from mild discomfort to more significant illnesses. Mild reactions often include symptoms like stomach upset, nausea, vomiting, or diarrhea, which can result from irritation caused by chlorine or exposure to low levels of pathogens.
More serious health issues typically involve Recreational Water Illnesses (RWIs) caused by pathogens. Cryptosporidium (often called Crypto) is a common parasite that causes watery diarrhea, stomach cramps, nausea, vomiting, fever, and weight loss. Symptoms of cryptosporidiosis usually appear between 2 and 10 days after exposure, with an average incubation period of about seven days, and can last for several weeks. Another common RWI is giardiasis, caused by the Giardia parasite, which can lead to diarrhea, abdominal cramps, gas, nausea, weight loss, and dehydration, with symptoms often appearing 1 to 2 weeks after infection and potentially lasting for weeks or longer. While many people with healthy immune systems recover from these illnesses, young children, older adults, and individuals with weakened immune systems are at a higher risk for more severe or prolonged symptoms.
Immediate Steps After Ingestion
If a small amount of pool water is accidentally swallowed, it typically does not cause significant harm. However, it is always prudent to monitor for any developing symptoms.
For larger amounts of ingested water or if symptoms begin to appear, certain steps are recommended. Staying hydrated by drinking clean water is important, especially if vomiting or diarrhea occurs. If symptoms such as persistent vomiting or diarrhea, high fever, severe abdominal pain, or signs of dehydration (like dark yellow urine) develop, it is advisable to seek medical attention. This is particularly true for vulnerable individuals like infants, young children, or those with compromised immune systems, who may experience more severe reactions. If there is suspicion of severe chemical ingestion, contacting a poison control center can provide immediate guidance.
Minimizing Accidental Swallowing
Preventing accidental ingestion of pool water is key to reducing health risks. Swimmers, particularly children, should be taught not to drink pool water and to avoid games that encourage swallowing water, such as excessive splashing. Using nose plugs or holding one’s breath when going underwater can also help prevent water from entering the mouth and nasal passages.
Parents and guardians play an important role in minimizing exposure for children. Close supervision is essential, and children should be encouraged to take frequent bathroom breaks to reduce the introduction of contaminants into the pool. It is also important to ensure that children do not swim if they are experiencing diarrhea, as this is a primary way pathogens like Cryptosporidium spread. Additionally, showering before entering the pool helps to wash off sweat, dirt, and other substances that can react with chlorine and reduce its effectiveness.