Pool Hygiene Statistics: What U.S. Swimmers Admit, 2009 to 2025

At a glance

• 53% of respondents to the June 2025 U.S. Healthy Pools poll admitted peeing in a pool as an adult (PHTA and ACC, 2025); the release does not say whether that share covers all 2,000 adults or swimmers only.
• 17% of U.S. adults in 2009 and 19% in 2012 said they had ever peed in a public pool (Wiant, 2011; Wiant, 2012); later polls asked about any pool as an adult, so the series is not a clean trend.
• 48% of U.S. adults said in April 2019 that they do not shower at all before swimming, and 31% shower for at least the 1 minute CDC recommends (Sachs Media for WQHC, 2019; CDC).
• 24% of U.S. adults in 2019 said they would get in a pool within one hour of having diarrhea, and 9% would wait 2 weeks (Sachs Media for WQHC, 2019).
• E. coli, a fecal indicator, was found in 58% of 161 public pool filter backwash samples in metro-Atlanta, Georgia, in summer 2012 (CDC MMWR, 2013).
• A 2017 tracer study estimated 30 liters of urine in a 110,000-gallon pool and 75 liters in a 220,000-gallon pool in two Canadian cities (Jmaiff Blackstock et al., 2017).
• 77% of 2025 U.S. poll respondents blamed red, stinging eyes on too much chlorine (PHTA and ACC, 2025); CDC attributes red eyes to chloramines formed when chlorine binds to pee, sweat and dirt (CDC).

Pool hygiene statistics: what U.S. swimmers admit doing

Self-reported peeing in pools has risen in each published U.S. general-population poll wave since 2009, from 17% to 53%. Part of that rise coincides with changes in question wording, sponsor and possibly the respondent base, so the series shows direction more reliably than size.

In 2009, 17% of U.S. adults said they had ever peed in a public pool (Wiant, 2011). In 2012, 19% said the same, a change the survey author reported as not significant (Wiant, 2012). In 2018, 27% of swimmers admitted peeing in a pool as an adult (WQHC 2018 release). In April 2019, 40% of U.S. adults said they had peed in a pool as an adult (Sachs Media for WQHC, 2019). In June 2025, 53% of Healthy Pools respondents gave the same answer (PHTA and ACC, 2025).

The 2025 poll added behaviors not asked before. 48% of U.S. swimmers said they regularly rinse feet or sandals in the pool, 43% regularly eat or drink in the water, and 48% of respondents do not wash swimsuits with soap after every swim (PHTA and ACC, 2025). Among frequent swimmers (10 or more swims a year), 63% regularly eat or drink in the pool (PHTA and ACC, 2025).

For outbreak counts linked to pools, see the swimming pool illness outbreaks report. For inspection findings at public pools, see the public pool inspection violations report.

Pre-swim showers: how many U.S. adults rinse off and for how long

About half of U.S. adults say they skip the pre-swim shower, a share that has stayed between 48% and 52% in the 2017 to 2019 polls. Fewer than a third shower for the full minute CDC recommends.

In April 2019, 48% of U.S. adults did not shower before swimming, 8% showered for 15 seconds, 13% for 30 seconds, 11% for 1 minute and 20% for 2 minutes or more (Sachs Media for WQHC, 2019). CDC advises a shower of at least 1 minute before getting into the water (CDC). CDC says a one-minute shower removes most of the dirt, sweat and oils that use up pool chemicals (CDC).

The share of U.S. adults who had ever skipped the pre-swim shower rose from 35% in 2009 to 43% in 2012, a change the author reported as significant (Wiant, 2011; Wiant, 2012). In 2018, 52% of U.S. adults never showered before swimming (WQHC 2018 release). Dutch researchers defined a swimmer’s initial pollutant release as what comes off in the first 60 seconds of a standardized shower and found pre-swim showering reduces chemical and microbial pollutants (Keuten et al., 2012).

Italian studies report higher shower compliance than U.S. polls. In a 2013 study, 65% of 4,356 indoor pool users in five Italian cities always showered first (Pasquarella et al., 2013). In a 2016 study, 69% of 184 Italian adult pool users and 86% of child and adolescent users always showered first (Gallè et al., 2016). These are pool-site questionnaires, not national online polls, so they are not directly comparable with U.S. figures.

Swimming with diarrhea: stated intentions versus CDC guidance

Roughly one in four U.S. adults has told pollsters they would enter a pool within an hour of having diarrhea. CDC tells swimmers to stay out of the water when sick with diarrhea because some germs survive chlorine for days.

In April 2019, 24% of U.S. adults said they would go in a pool within one hour of having diarrhea, 34% would wait 1 day and 9% would wait 2 weeks (Sachs Media for WQHC, 2019). The within-an-hour share was 25% in 2017 (WQHC 2017 release) and 17% in 2018 (WQHC 2018 release). In 2020, 28% of U.S. residential pool owners said they would swim within an hour of diarrhea (WQHC 2020 release).

CDC says to stay out of the water when sick with diarrhea and sets a longer wait after a Crypto diagnosis (CDC). CDC lists the time to kill or inactivate germs at 1 ppm free chlorine, pH 7.5 or less and 77°F as less than 1 minute for E. coli O157:H7, about 16 minutes for hepatitis A, about 45 minutes for Giardia and about 10.6 days for Crypto (CDC).

The surveys measure intentions, not illness. Outbreak counts, causes and trends are covered in the swimming pool illness outbreaks report.

How much urine is in a pool: the sweetener tracer study

The only direct measurement found is a 2017 Canadian study that used an artificial sweetener as a urine tracer. It implies urine made up roughly 72 to 90 parts per million of the water in two large pools.

Acesulfame-K (ACE) is a stable artificial sweetener that is completely excreted in urine, which makes it a urine marker. In a 2017 study, researchers found ACE in every one of more than 250 samples from 31 pools and hot tubs in two Canadian cities, at 30 to 7,110 ng/L (Jmaiff Blackstock et al., 2017). Using 3 weeks of ACE readings, they estimated 30 liters of urine in a 110,000-gallon pool and 75 liters in a 220,000-gallon pool (Jmaiff Blackstock et al., 2017).

WHO (2006) cites average urine releases of 25 to 30 mL per bather and an estimate as high as 77.5 mL per bather (WHO, 2006). On those averages, 30 liters equals roughly 387 to 1,200 bather releases and 75 liters roughly 968 to 3,000 (PC&S calculation). This is a scale check, not a count of people.

Urine matters for pool chemistry because of nitrogen. WHO’s 2006 guidelines report that 84% of the nitrogen in urine is urea (WHO, 2006). In a 2014 lab study, chlorination of uric acid, which enters pools through urination, produced cyanogen chloride at molar yields up to 44% and trichloramine at yields up to 108% (Lian et al., 2014). A 2007 study measured roughly 0.1 mg/L of trichloramine in pool water samples (Li and Blatchley, 2007).

Chloramines: what the chlorine smell and red eyes actually signal

CDC says a strong chlorine smell at a pool probably means chloramines, irritants formed when chlorine binds to pee, sweat and dirt. Many U.S. poll respondents misread the smell, and most misread red eyes.

CDC states that if you smell chlorine where you swim, you are probably smelling chloramines, and that chloramines can cause red, itchy eyes, coughing and wheezing (CDC). In June 2025, 42% of U.S. poll respondents believed a strong chlorine smell means the pool is extra clean, and 77% thought red, stinging eyes come from too much chlorine (PHTA and ACC, 2025).

CDC says most city, county and state health departments limit combined chlorine to 0.4 ppm or less, and that operators can superchlorinate by raising free chlorine to 10 times the combined chlorine level (CDC). Chloramines build up in the air of indoor pools when ventilation brings in too little fresh air (CDC).

At one indoor waterpark in Mason, Ohio, NIOSH measured a mean trichloramine level of 0.44 mg/m3 on a high-occupancy day in 2007 and a peak of 1.06 mg/m3 (NIOSH, 2008). In 2007, 25% of samples on day 1 and 20% on day 2 there exceeded 0.5 mg/m3, the level at which irritation symptoms have been documented (NIOSH, 2008). In 2007, lifeguards there reported more work-related respiratory symptoms and eye and nose irritation than employees who did not work in the pool area (NIOSH, 2008).

Sweat is a second nitrogen source. A 2014 Dutch study measured sweat rates of 0.1 to 0.2 L per square meter of skin per hour in water below 29°C, rising to 0.8 at 35°C, and an average release of 77.3 mg of total nitrogen per bather in 30 minutes of exercise (Keuten et al., 2014).

Fecal contamination evidence from public pool filters

The clearest measured evidence of swimmer hygiene in U.S. pools comes from a 2012 CDC study of filter backwash in metro-Atlanta. More than half of the samples carried E. coli DNA, a marker of fecal material.

CDC and four county health departments sampled filter backwash at a convenience sample of public pools in Cobb, DeKalb, Fulton and Gwinnett counties, Georgia, in June to August 2012 (CDC MMWR, 2013). In that 2012 Georgia sample, E. coli was detected in 93 of 161 samples (58%), Giardia in 2 and Cryptosporidium in 1 (CDC MMWR, 2013). The MMWR editorial note cites an average of 0.14 grams of fecal material on a person’s perianal surface that can rinse into the water without a pre-swim shower (CDC MMWR, 2013).

What Americans believe about pool chemistry versus CDC facts

Most U.S. adults know chlorine is there to kill germs, but few understand how swimmer waste weakens it. The largest gaps concern chloramines, Crypto and urine.

In June 2025, 72% of U.S. respondents understood that chlorine’s main purpose is to kill germs, but only 16% recognized that urine, sweat, sunscreen and dirt all weaken it (PHTA and ACC, 2025). In 2019, 37% of U.S. adults believed a urine-detecting dye activates when a swimmer pees, and 28% said nothing happens (Sachs Media for WQHC, 2019). CDC says chlorine mixed with pee, sweat and dirt leaves less chlorine to kill germs (CDC).

Who funds and fields U.S. pool hygiene surveys

Every U.S. pool hygiene poll found for this report was paid for by chlorine or pool industry groups and run online. The polls are useful for direction and for misconceptions, less so for precise prevalence.

The Water Quality & Health Council, sponsored by the American Chemistry Council’s Chlorine Chemistry Division, commissioned the 2009 to 2020 polls (Wiant, 2011; Sachs Media for WQHC, 2019). The Pool & Hot Tub Alliance commissioned the 2021 and 2025 polls, with the American Chemistry Council’s Chlorine Panel as a 2025 campaign partner (PHTA and ACC, 2025).

Home pool owners: hygiene and water testing

The 2020 poll is the only one found that separated residential pool owners. Owners’ hygiene answers were close to the 2017 to 2019 general-population polls, and many tested water infrequently.

In April 2020, 30% of 675 U.S. residential pool owners admitted peeing in their own pool, 28% would swim within an hour of diarrhea and 54% did not shower before swimming (WQHC 2020 release). In the same 2020 U.S. poll, 16% of swimmers admitted peeing in someone else’s backyard pool (WQHC 2020 release). In 2020, 23% of U.S. owners who maintain their own pools tested chlorine and pH no more often than once every two weeks (WQHC 2020 release).

CDC advises home pool owners to check disinfectant and pH at least twice per day, keeping chlorine typically at 1 to 4 ppm and pH at 7.0 to 7.8 (CDC). Owners who hand off testing can compare pool cleaning service options and typical pool service costs.

Fifteen numbers that matter

1. In June 2025, 53% of U.S. Healthy Pools respondents admitted they had peed in a pool as an adult (online poll of 2,000 adults, PHTA and ACC, 2025).
2. In April 2019, 40% of U.S. adults said they had peed in a pool as an adult (online poll of 3,100 adults, Sachs Media for WQHC, 2019).
3. In 2018, 27% of U.S. swimmers admitted peeing in a pool as an adult (online poll of 3,000 adults, WQHC 2018 release).
4. In 2009, 17% of U.S. adults said they had ever peed in a public pool, and in 2012 the share was 19% (online polls of 1,000 adults each, Wiant, 2011; Wiant, 2012).
5. In April 2019, 48% of U.S. adults did not shower before swimming and the average pre-swim shower lasted 35 seconds (Sachs Media for WQHC, 2019).
6. In 2012, 68% of U.S. adults did not always shower before entering a pool, and 44% viewed a pre-swim shower as unnecessary (Wiant, 2012).
7. In 2017, 25% of U.S. adults said they would swim within one hour of having diarrhea; the share was 17% in 2018 and 24% in 2019 (WQHC 2017 release; WQHC 2018 release; Sachs Media for WQHC, 2019).
8. In 2020, 30% of U.S. residential pool owners admitted peeing in their own pool and 54% did not shower before swimming (675 owners, WQHC 2020 release).
9. In June 2025, 48% of U.S. swimmers said they regularly rinse dirt or sand off their feet or sandals in the pool (PHTA and ACC, 2025).
10. In June 2025, 23% of U.S. swimmers said they would not report fecal matter in a community or hotel pool, and 14% would remove it themselves to avoid a closure (PHTA and ACC, 2025).
11. In summer 2012, 75% of 161 public pool filter backwash samples in metro-Atlanta, Georgia, held at least one assayed microbe, and 58% held E. coli (CDC MMWR, 2013).
12. A 2017 study found the urine marker acesulfame-K in all of more than 250 samples from 31 pools and hot tubs in two Canadian cities, at up to 570 times tap water levels (Jmaiff Blackstock et al., 2017).
13. WHO (2006) cites average urine releases of 25 to 30 mL per bather and estimates as high as 77.5 mL per bather, while noting the area has not been well researched (WHO, 2006).
14. In 2017, 84% of U.S. adults were unaware that chlorine at CDC-recommended levels does not kill Crypto instantly (WQHC 2017 release); CDC lists about 10.6 days to kill Crypto at 1 ppm free chlorine (CDC).
15. At one Ohio indoor waterpark in 2007, 25% of trichloramine air samples on a high-occupancy day exceeded 0.5 mg/m3, the level at which irritation symptoms have been documented (NIOSH, 2008).

Rates, trends and severity we calculated

Download the calculation sheet (CSV)

New in this edition

• 2026-05CDC’s Healthy and Safe Swimming Week ran May 18 to 24, 2026, under the theme “Don’t let diarrhea sink the fun this summer!” (CDC).
• 2025-06The 2025 Healthy Pools poll (fieldwork June 26 to 30, 2025) is the latest U.S. swimmer hygiene survey found for this report; it is sponsored by the Pool & Hot Tub Alliance with the American Chemistry Council’s Chlorine Panel (PHTA and ACC, 2025).
• 2025-06CDC updated its Chloramines and Pool Operation page on June 23, 2025, which notes most health departments cap combined chlorine at 0.4 ppm or less (CDC).
• 2025-05CDC updated its swimmer guidance pages in May 2025, including the advice to shower for at least 1 minute before swimming (CDC) and its pages on eye irritation and diarrheal illness (CDC; CDC).
• 2021-04The 2021 Healthy Pools poll (2,000 U.S. adults) focused on COVID-19 and published no hygiene behavior items, which leaves a gap between the 2020 and 2025 waves (PHTA 2021 release).

What people ask

Common questions

Evidence tiers

Tier 1: primary and government sources (18)

• CDC Healthy Swimming: Guidelines for Keeping Your Pool Safe and Healthy
• CDC Healthy Swimming: Preventing Eye Irritation from Pool Chemicals
• CDC Healthy Swimming: Chloramines and Pool Operation
• CDC Healthy Swimming: Preventing Diarrheal Illnesses
• CDC Healthy Swimming: What to Do When There Is Poop in the Pool
• CDC: Healthy and Safe Swimming Week
• CDC: Microbes in Pool Filter Backwash as Evidence of the Need for Improved Swimmer Hygiene, Metro-Atlanta, Georgia, 2012 (MMWR 2013;62(19))
• American Chemical Society: Sweetened Swimming Pools and Hot Tubs (Environ Sci Technol Lett 2017;4(4):149-153)
• World Health Organization: Guidelines for Safe Recreational Water Environments, Volume 2: Swimming Pools and Similar Environments (2006)
• Elsevier: Quantification of continual anthropogenic pollutants released in swimming pools (Water Res 2014;53:259-270)
• Elsevier: Definition and quantification of initial anthropogenic pollutant release in swimming pools (Water Res 2012;46(11):3682-3692)
• American Chemical Society: Volatile disinfection byproducts resulting from chlorination of uric acid: implications for swimming pools (Environ Sci Technol 2014;48(6):3210-3217)
• American Chemical Society: Volatile disinfection byproduct formation resulting from chlorination of organic-nitrogen precursors in swimming pools (Environ Sci Technol 2007;41(19):6732-6739)
• MDPI: Health-Related Behaviors in Swimming Pool Users (Int J Environ Res Public Health 2016;13(5):513)
• Elsevier: Swimming pools and health-related behaviours: an Italian multicentre study on showering habits (Public Health 2013;127(7):614-619)
• CDC NIOSH: Health Hazard Evaluation Report HETA 2007-0163-3062: Indoor Waterpark, Mason, Ohio (2008)
• U.S. Census Bureau: Intercensal population estimates by single year of age and sex, 2010 to 2020
• U.S. Census Bureau: Vintage 2025 population estimates by single year of age and sex

Tier 2: trade bodies, public companies, market research (9)

• Pool & Hot Tub Alliance; American Chemistry Council Chlorine Panel: Half of Swimmers Admit to Using Pools as Foot Baths, New Survey Finds (2025 Healthy Pools survey)
• Sachs Media for the Water Quality & Health Council: Healthy Pools 2019: Survey Results
• Water Quality & Health Council (C. Wiant), via ScholarWorks@BGSU: A Snapshot of Swimmer Hygiene Behavior (2009 survey), Int J Aquatic Res Educ 5(3)
• Water Quality & Health Council (C. Wiant), via ScholarWorks@BGSU: New Public Survey Reveals Swimmer Hygiene Attitudes and Practices (2012 survey), Int J Aquatic Res Educ 6(3)
• Water Quality & Health Council, reposted by the Louisiana Department of Health: Survey: 1 in 4 Adults Would Swim with Diarrhea (2017 Healthy Pools survey)
• Water Quality & Health Council: Survey: 1 in 4 Adults Would Swim with Diarrhea (PR Newswire, May 16, 2017)
• Water Quality & Health Council release, reprinted by Swimmer's Daily: Many Swimmers Unaware of Potential Health Risks, Pool Survey Finds (2018 Healthy Pools survey)
• Water Quality & Health Council release, reprinted by Swimmer's Daily: Survey: 30% of Pool Owners Admit They Pee in the Pool (2020 Healthy Pools survey)
• Pool & Hot Tub Alliance release, reprinted by Pool Magazine: Worried about COVID-19 at the pool? Americans are split, survey finds (2021 Healthy Pools survey)

References

1. Pool & Hot Tub Alliance; American Chemistry Council Chlorine Panel. Half of Swimmers Admit to Using Pools as Foot Baths, New Survey Finds (2025 Healthy Pools survey). Accessed 2026-10-08.
2. Sachs Media for the Water Quality & Health Council. Healthy Pools 2019: Survey Results. Accessed 2026-10-08.
3. Water Quality & Health Council (C. Wiant), via ScholarWorks@BGSU. A Snapshot of Swimmer Hygiene Behavior (2009 survey), Int J Aquatic Res Educ 5(3). Accessed 2026-10-08.
4. Water Quality & Health Council (C. Wiant), via ScholarWorks@BGSU. New Public Survey Reveals Swimmer Hygiene Attitudes and Practices (2012 survey), Int J Aquatic Res Educ 6(3). Accessed 2026-10-08.
5. Water Quality & Health Council, reposted by the Louisiana Department of Health. Survey: 1 in 4 Adults Would Swim with Diarrhea (2017 Healthy Pools survey). Accessed 2026-10-08.
6. Water Quality & Health Council. Survey: 1 in 4 Adults Would Swim with Diarrhea (PR Newswire, May 16, 2017). Accessed 2026-10-08.
7. Water Quality & Health Council release, reprinted by Swimmer's Daily. Many Swimmers Unaware of Potential Health Risks, Pool Survey Finds (2018 Healthy Pools survey). Accessed 2026-10-08.
8. Water Quality & Health Council release, reprinted by Swimmer's Daily. Survey: 30% of Pool Owners Admit They Pee in the Pool (2020 Healthy Pools survey). Accessed 2026-10-08.
9. Pool & Hot Tub Alliance release, reprinted by Pool Magazine. Worried about COVID-19 at the pool? Americans are split, survey finds (2021 Healthy Pools survey). Accessed 2026-10-08.
10. CDC Healthy Swimming. Guidelines for Keeping Your Pool Safe and Healthy. Accessed 2026-10-08.
11. CDC Healthy Swimming. Preventing Eye Irritation from Pool Chemicals. Accessed 2026-10-08.
12. CDC Healthy Swimming. Chloramines and Pool Operation. Accessed 2026-10-08.
13. CDC Healthy Swimming. Preventing Diarrheal Illnesses. Accessed 2026-10-08.
14. CDC Healthy Swimming. What to Do When There Is Poop in the Pool. Accessed 2026-10-08.
15. CDC. Healthy and Safe Swimming Week. Accessed 2026-10-08.
16. CDC. Microbes in Pool Filter Backwash as Evidence of the Need for Improved Swimmer Hygiene, Metro-Atlanta, Georgia, 2012 (MMWR 2013;62(19)). Accessed 2026-10-08.
17. American Chemical Society. Sweetened Swimming Pools and Hot Tubs (Environ Sci Technol Lett 2017;4(4):149-153). Accessed 2026-10-08.
18. World Health Organization. Guidelines for Safe Recreational Water Environments, Volume 2: Swimming Pools and Similar Environments (2006). Accessed 2026-10-08.
19. Elsevier. Quantification of continual anthropogenic pollutants released in swimming pools (Water Res 2014;53:259-270). Accessed 2026-10-08.
20. Elsevier. Definition and quantification of initial anthropogenic pollutant release in swimming pools (Water Res 2012;46(11):3682-3692). Accessed 2026-10-08.
21. American Chemical Society. Volatile disinfection byproducts resulting from chlorination of uric acid: implications for swimming pools (Environ Sci Technol 2014;48(6):3210-3217). Accessed 2026-10-08.
22. American Chemical Society. Volatile disinfection byproduct formation resulting from chlorination of organic-nitrogen precursors in swimming pools (Environ Sci Technol 2007;41(19):6732-6739). Accessed 2026-10-08.
23. MDPI. Health-Related Behaviors in Swimming Pool Users (Int J Environ Res Public Health 2016;13(5):513). Accessed 2026-10-08.
24. Elsevier. Swimming pools and health-related behaviours: an Italian multicentre study on showering habits (Public Health 2013;127(7):614-619). Accessed 2026-10-08.
25. CDC NIOSH. Health Hazard Evaluation Report HETA 2007-0163-3062: Indoor Waterpark, Mason, Ohio (2008). Accessed 2026-10-08.
26. U.S. Census Bureau. Intercensal population estimates by single year of age and sex, 2010 to 2020. Accessed 2026-10-08.
27. U.S. Census Bureau. Vintage 2025 population estimates by single year of age and sex. Accessed 2026-10-08.