“Swimmers shouldn’t have to flip a coin to determine if the pool they are swimming in is healthy”. These words, from Chris Wiant, PhD, Chair of the Water Quality and Health Council, reflect the results of the Council’s 2011 Healthy Pools Campaign in which swimmers tested their pool waters for pH and free chlorine values. About half of the results uploaded to the Healthy Pools website this summer by 1,500 swimmers showed improper pH and free chlorine values. According to Wiant, “too many of the pools tested were out of the optimum range for protection against waterborne germs and swimmer comfort.”

With a generous contribution from the Hach Company, the Water Quality & Health Council distributed over 32,000 free pool test kits to the public. Swimmers used the kits to test for pH and chlorine levels in pools across the country.

The majority of data (78%) were submitted by backyard pool owners, pointing to a need for better public education on proper pool chemistry. In addition, data were submitted by swimmers at community adult pools (18%), community kiddie pools (3%), and hotel and motel pools (1%).

According to the Center for Disease Control (CDC), chlorine and pH represent the front line of defense against waterborne illnesses. Routine chlorination kills harmful microorganisms that can cause health-related problems, such as gastroenteritis and swimmer’s ear. A new study by CDC found that swimmer’s ear infections are responsible for 2.4 million health care visits every year and nearly half a billion dollars in health care costs.

In an effort to assist backyard pool owners with pool-related questions, this summer the Water Quality & Health Council included a popular “Ask a Pool Operator” feature on its Healthy Pools website. The public was treated to free expert advice on technical problems dealing with swimming pool maintenance. The Council also works to improve pool management education through its Healthy Pools blog series.

Chris Wiant, M.P.H., Ph.D., is president and CEO of the Caring for Colorado Foundation. He is also chair of the Water Quality & Health Council.

As summer draws to a close, a recent Wall Street Journal article examines the popularity, costs and sales of various swimming pool disinfection technologies. The article compares traditional swimming pool chlorination with alternative germ-destruction technologies, including “saltwater pools,” ozone gas and ultraviolet radiation.

Some swimmers interviewed for the article expressed a preference for pools that use saltwater to generate chlorine over the traditional method of disinfection by the direct addition of chlorine products to the pool. These swimmers implied the two methods were vastly different. In effect, whether a pool is a “saltwater” pool or is treated with traditional chlorine disinfectants, germ destruction is achieved using the same chemistry—chlorine chemistry.

Chlorine is chlorine

Saltwater pools effectively generate chlorine on site from common sodium chloride salt.  A saltwater pool features a generator that applies electricity to salt, releasing dissolved sodium and gaseous chlorine. Chlorine then goes to work killing germs just as it does when chlorinated disinfectants are added to pools. Unfortunately, the Wall Street Journal article mistakenly asserts that chlorine from saltwater generators “…doesn’t allow the formation of itch- and stink-producing byproducts that conventional chlorine pools produce.” That is neither true nor possible.

In addition to killing germs, chlorine can react with low levels of impurities in the pool, including perspiration, body oils, urine and feces, to form “disinfection byproducts” such as chloramines, the irritants responsible for swimmers’ red eyes and itchy skin.  These can be minimized, however, by a combination of proper pool management and good swimmer hygiene.

Maintaining pool water quality

According to the Centers for Disease Control and Prevention (CDC), there should be no harsh chemical odor to a well-managed pool—public or private–in which pH and chlorine levels are maintained within appropriate ranges. In addition, CDC encourages swimmers to shower before swimming and avoid “peeing” in the pool; good swimmer hygiene helps reduce the presence of irritating chloramines in pool water.

Does a saltwater pool feel better on the skin? That might be attributed to the water softening effect of sodium in the saltwater pool.  Additionally, backyard pool owners particularly pleased with saltwater pools may be dealing with fewer swimmers and lower levels of impurities in the water than in the typical public pool, easing the task of pool maintenance. Nevertheless, whether it is added in the form of chlorinated pool disinfectants or generated in a saltwater pool, chlorine is chlorine and its chemistry does not waiver between conventional and alternative swimming pool applications!

Chris Wiant, M.P.H., Ph.D., is president and CEO of the Caring for Colorado Foundation. He is also chair of the Water Quality & Health Council.

How cute is that? Little Jake over there is undergoing aquatic rehabilitation in an underwater treadmill after paralyzing his rear limbs in an unfortunate accident. One veterinarian’s initial prognosis was that Jake would not be able to walk again. But after physical therapy and the underwater treadmill, Jake is back on his feet and happier than ever.

Canines are not the only species that can benefit from aquatic therapy. Whether it is used to help people recover from acute injuries or to maintain health in the face of chronic disease, hydrotherapy is regarded as having “broad rehabilitative potential” that is relatively underused (Becker, 2009).

Water: An ideal medium for exercise.

Swimming is widely recommended by medical experts for its healthful benefits*. According to the American Red Cross, the buoyancy of water results in less stress on the joints, helping to reduce swelling and tissue damage. Warm water can increase circulation, decrease pain, and increase muscle relaxation and soft tissue flexibility.

Patients (and puppies) looking to strengthen muscles should exercise in pools with some turbulence.
Aquatic exercise: Benefits galore

• Lower risk of death In a 2009 Washington State University study of over 40,000 men, exercise swimmers had less than half the mortality risk of sedentary men, and exercise swimmers had half the mortality risk of exercise walkers and runners.
• Aids patients with COPD A 2009 study of patients with chronic obstructive pulmonary disease (COPD) found the swimming pool a “feasible and positive alternative venue for pulmonary rehabilitation”.
• Asthma Many studies have found swimming improves asthma symptoms; LaKind et al. cite Welsh et al. ¹, who reviewed the relevant scientific literature. According to LaKind et al., Welsh et al. note that most studies find “positive effects of swim training on fitness as measured by improved aerobic efficiency, physical working performance, and recovery heart rates.”
• Heart healthy Aquatic exercise strengthens the heart muscle and improves oxygen delivery to the muscles.
• Reduces water and sodium retention Animal data collected in Brazil ² indicate exercise in water might be prescriptive for patients with hypertension, obesity and/or mild renal disease as it reduces water and sodium retention.
• Hand eye coordination and balance According to a study done in Taiwan, swimming can improve hand eye coordination and balance in the elderly, which could lower a senior’s risk of a falling-related injury.
• Bone health Aquatic exercise can maintain or improve bone health in post-menopausal women.
• Better flexibility and range of motion According to the American Red Cross, when accompanied by good stretching habits, aquatic exercise can greatly improve flexibility and aid range of motion.
• Improved mood Swimming can improve the mental state of both men and women, the elderly and women with fibromyalgia, mothers, and parents of children with developmental disabilities.

Swimming may be the BEST and most enjoyable form of exercise, so give it a try!

*The American Red Cross recommends a health assessment from your health care provider before you begin an exercise program.

Ralph Morris, MD, MPH, is a Physician and Preventive Medicine and Public Health official living in Bemidji, MN.

². Fabri et al.,(2010). Aquatic and Land Exercise Training Affects Renal Function in Rats Under Isosmotic Volume Expansion, Journal of Exercise Physiology, vol. 13, no. 2.

With high temperatures plaguing much of the country, the pool seems like the best bet to beat the heat. This blog highlights two interesting and entertaining resources recently found in the media that can help keep swimming healthy and enjoyable.

1. CDC’s Healthy Swimming 2011 Video Contest Winner’s Video!

This summer, the Centers for Disease Control and Prevention (CDC) challenged the public to create a short video to help educate swimmers about pool safety.  The winners, David and Aaron Mathews, worked with friends and family to develop “Recreational Water Illness Police,” a clip that uses humor to inform viewers about the most common recreational water illness—diarrhea. Roger that.

2. Quiz:  Is It Safe To Pee In The Pool … And Other Water Safety Questions

Want to test your water safety knowledge? A Huffington Post online quiz emphasizes key swimming safety issues, some of which are often overlooked, such as showering before entering the pool.  It is important that swimmers shower with soap (especially swimmer “bottoms”) before swimming so they do not introduce harmful bacteria into the pool.  This fact is lost on all but 25 percent of parents according to a recent report.  And no, it is not safe to pee in the pool.



It’s no secret that swimming pools, although fun and refreshing, are essentially communal bath tubs. To help keep water clean and safe, pool operators must adjust pool chemical levels. Maintaining proper pool chemistry can be a challenging task, especially in community pools where the number of swimmers fluctuates wildly from hour to hour.  Add to that the fact that many swimmers are unaware of the role of personal hygiene in keeping waters safe, and one begins to understand the magnitude of the pool operator’s responsibilities.

Chlorine and pH Get it Done

Chlorine is strongly associated with swimming in popular culture.  Although there are persistent myths about chlorine in swimming pools, chlorine is used as a disinfectant in the majority of pools to help prevent waterborne illnesses such as diarrhea, swimmer’s ear and skin infections.  Alternative sanitizers have been introduced in the marketplace over the last several years, but chlorine continues to offer the most effective and economical option to helping maintain safe pools.

Chlorine actually serves two purposes: it destroys algae and most waterborne germs, and it reacts with—oxidizes—small bits of organic debris and impurities introduced into pool water by swimmers.  Chlorine does this work in the form known as free chlorine, a combination of hypochlorous acid and hypochlorite ion.  Free chlorine is produced in pool water when chlorine disinfectant is added.  When free chlorine reacts with nitrogen-bearing or organic substances, the product is known as combined chlorine, a much weaker disinfectant and oxidant. The World Health Organization recommends free chlorine levels up to 3 mg/l be maintained in swimming pools.

As pool operators know, hypochlorous acid¹ is a more effective disinfectant and oxidant than the hypochlorite ion ², and their relative proportions fluctuate with the pH (acidity) of the water in the pool (low pH is more acidic and high pH is more basic).   To maintain optimal levels of hypochlorous acid for germ and algae destruction while at the same time keeping the water comfortable for swimmers, pool operators should maintain pH in the slightly basic range of 7.2 to 7.8.

Monitoring, Monitoring, Monitoring

One of the most important tasks of the swimming pool operator is vigilantly monitoring the pH and free chlorine level of pool water to ensure germs are being destroyed.  This is critical because chlorine may be depleted, for example, by a heavy “bather load”.  A crowded swimming pool adds more organic debris (e.g., perspiration, body oils, trace urine and fecal matter), which can lower the chlorine level or even deplete it, leaving little or no protection against waterborne germs.

A 2010 report from the Centers for Disease Control and Prevention (CDC) found one in eight public pool inspections conducted in 13 states in 2008 resulted in pools being closed immediately due to serious code violations, including insufficient disinfectant.  That is why CDC encourages swimmers to take matters into their own hands and (1) shower and thoroughly wash their bottoms before entering the pool and (2) use portable pool test strips to monitor for adequate free chlorine and pH.  As a public service, the Water Quality and Health Council is making these strips available free to the public this summer at www.healthypools.org/freeteststrips.  Swimmers will have to wash their own bottoms.

Fred Reiff, P.E., is a retired official of the Pan American Health Organization.

¹Hypochlorous acid is HClO.

²An ion is an atom or molecule with a net electric charge due to the loss or gain of one or more electrons. Hypochlorite ion is OCl-.

You are heading off to your community pool. The mental check list goes…

Sunscreen?  Yes.

Bathing suit?  Of course.

Shower?  Probably not.

Although the “shower before you swim” rule is consistently posted at community pools, a new University of Michigan report shows parents of young children do not appreciate the role showering plays in keeping swimming pools safe for the community (see video).  Whereas 64 percent of parents understand it is very important for children to avoid swallowing pool water, only 26 percent believe it very important to shower before swimming.  This study highlights the need to educate parents on swimmer hygiene.

The researchers polled 865 parents of elementary school children, aged 5 to 12 years old.  More than twice as many parents surveyed believe drowning at a water park is a significant risk compared to those who perceive a high potential risk of getting sick from the water in these settings.

Showering before swimming or visiting a water park is a must because it helps remove trace levels of fecal matter and associated pathogens on human skin.  Put bluntly, the most critical area of the body to wash is your bottom. Not surprisingly, young children and babies in diapers are very likely to contribute fecal matter to pools.  An ongoing shigellosis outbreak in northern Kentucky pools has caused the local health department to prohibit children who are not yet potty-trained from accessing pools (see blog).  Shigellosis causes diarrhea and is transmitted through inadvertent contact with fecal matter of infected individuals.

According to the Centers for Disease Control and Prevention (CDC), recreational water illnesses (RWIs) are on the rise. RWIs are caused by germs spread by swallowing, breathing in mists or aerosols or having contact with contaminated water in swimming pools, hot tubs, water parks, water play areas, interactive fountains, lakes, rivers, or oceans. More than 10,000 Americans are sickened annually by RWIs, which can cause diarrhea, vomiting, abdominal cramps and fever or skin, ear, respiratory and eye infections.

Sixty-five percent of parents polled agree that preventing RWIs is a shared responsibility between parents and pool staff; 28 percent believe that preventing infections is the sole responsibility of the water park staff. Chlorine and proper pool chemistry kill most of the germs that cause recreational water illnesses within an hour, and are essential to good pool management, but Cryptosporidium, a parasite that causes abdominal cramping, diarrhea and nausea, can survive for days even in properly disinfected pool.

The solution to preventing RWIs is a collaborative effort between park and pool operators and swimmers. The following simple preventive measures require the cooperation of informed parents:

• Shower or wash all parts of your body thoroughly with soap and water before swimming, paying special attention to the diaper areas of young children.
• Take children on bathroom breaks and check infant diapers often.
• Remind children to avoid swallowing water or getting water in their mouths.
• Do not swim if ill with diarrhea.

Healthy pools are a shared responsibility.  Parents, teach your children well:  Shower before swimming!

Joan Rose, PhD, is the Homer Nowlin Chair in Water Research at Michigan State University and a member of the Water Quality and Health Council.

The health department’s response to the outbreak has been appropriately aggressive, including arming environmental inspectors with waterborne disease prevention messages.  In contrast, a similar outbreak in a state such as New Hampshire, which is currently entertaining the notion of eliminating pool inspections to save state dollars, could be much worse.

According to the Centers for Disease Control and Prevention (CDC) website, Shigella is a group of bacteria that can cause diarrhea (often bloody), fever and stomach cramps within a day or two of exposure.  The bacterial infection that results from exposure to this organism, shigellosis, is spread via contact with the stool of an infected person through contaminated hands, food and water.  It is especially common in toddler childcare environments.

Swimming pools in Kentucky likely became contaminated when swimmers with shigellosis shed fecal matter into the water, which uninfected swimmers inadvertently ingested.  In a June 2 press release, District Director of Health, Lynne M. Saddler, MD, MPH, said, “…the bacteria spread easily through water— infection can occur between the time a person with Shigella has an accident in a pool and the bacteria is killed by the chemicals in the pool water. Shigella can be spread after the symptoms end, so people who have had diarrhea recently should not swim, even if they feel better and the diarrhea has ended….Even if children are in plastic diaper pants or diapers designed for use in water, commonly called swimmies, you can’t guarantee that fecal matter will not escape into the pool water.”  Since April of this year, the number of shigellosis cases in Boone, Campbell, Grant and Kenton Counties in Kentucky are more than triple the annual average.

The operators of 350 pools have been given information and educational materials, including instructions to pool operators on the proper response (e.g., “hyperchlorinating” the swimming pool) to fecal accidents.  Tips from the CDC and the health department include a warning to swimmers to: avoid swallowing pool or water playground water; shower before swimming; wash hands after using the toilet and changing diapers; take children on frequent bathroom breaks; and change diapers in bathrooms, not poolside.

CDC’s website notes the past two decades have brought a substantial increase in the number of recreational water illness outbreaks associated with swimming.  New Hampshire, take a good look at Kentucky for evidence that de-funding pool inspections is simply penny wise and pound foolish for public health.

Chris Wiant, M.P.H., Ph.D., is president and CEO of the Caring for Colorado Foundation. He is also chair of the Water Quality & Health Council.

A Guest Blog by Mom and Swimmer Kristen Swope

I grew up believing some pool-related myths that I realize rather belatedly were my parents’ bizarre, yet caring way to keep me from drowning or getting injured during unsupervised swims.  A few childhood pool story-swapping moments with friends revealed other gems that were also considered truths at the time. I’ve decided to compile the top three ones I believe are worth correcting even if some of them seem downright funny.

1. If you urinate in a swimming pool, the chlorine will turn the water around you blue.

My childhood friends and I actually fell for this one hook, line and sinker!  What can I say?  It was an effective tool to make us use the toilet instead of just hoping our bladders wouldn’t betray us as we relieved our childhood selves in the pool. So finally, the truth:  No “special” chlorine makes the water blue (or green, if we were to go by primary color combinations) when urine mixes with pool water.  It would be great if someone came up with a formula to make this possible.  How quickly we would correct this unhygienic practice!

2. Chlorine in pool water causes rashes and eye irritation.

Research and personal experience as an adult would tell me that properly chlorinated pool water will do no such thing, and that kiddie rash, red eyes, and other forms of skin and eye irritation are usually due to irritants formed when disinfectants combine with pool water contaminants, such as urine, perspiration and body oils. This can be remedied by making sure the pool water pH is in the right range (7.2-7.8), and appropriate chlorine levels (1 – 4 parts per million).

3. You should not swim right after eating.

If you grew up in a family like mine, chances are you know how frustrating it was during those times when the pool seemed to be calling out your name and you just want to jump in, but couldn’t…because you’d just eaten a sandwich. Unfortunately, this old wives’ tale stayed with me right until adolescence, when I hemmed and hawed at a swimming party because I had eaten two slices of pizza and was terrified that cramps would cause me to drown in the pool. My friends laughed at my apprehension and plunged right into the pool water, their bellies full of pizza.

Several interviews with competitive swimmers revealed that they, in fact, eat normal-sized meals (definitely not just one sandwich or a couple of slices of pizza) before going about their fitness routines in the pool. While more complex swimming styles such as the butterfly stroke admittedly are harder to execute on a full stomach, none of the athletic swimmers I talked to ever experienced cramping because they ate something prior to casual swimming.

I am now the mom of an inquisitive and swimming pool-crazy little girl named Isabel.  I realize that telling her tall tales about the pool is silly, and that it’s best to communicate tried-and-tested and fact-based rules to ensure her safety whenever she’s in or near a swimming pool.

Kristen Swope is a freelance writer based in Fremont, California, who has a five year old daughter and is a swimming enthusiast.

CDC’s Healthy Swimming Program provides information to the public, health professionals, and pool operators on a variety of topics to promote healthy and safe swimming experiences.  As the summer pool season begins, we are excited to announce…
CDC’s First-Ever Healthy Swimming Video Contest

This year, to help prevent the spread of germs in swimming pools, hot tubs, interactive fountains, lakes, or oceans, the CDC’s Healthy Swimming Program is asking the public to help them educate swimmers by making a short, creative video describing the simple steps everyone can take to ensure healthy swimming experiences. This video contest is being launched in conjunction with Recreational Water Illness and Injury Prevention Week (RWIIPW), May 23–29, 2011. RWIIPW is a national observance that focuses on educating swimmers and pool operators about healthy and safe swimming and is currently celebrating its 7th year.
Grand Prize

The 2011 Healthy Swimming Video Contest winner will receive:

–$1,000, provided by the CDC Foundation through support from a public-private partnership.

–The chance for their video to be seen by thousands on CDC’s Healthy Swimming Website and CDC’s YouTube Channel.

We encourage you to spread the word about the contest through your networks, membership, partners, subscribers, or community members. If you would like marketing material to help promote the contest please click here, and we will e-mail you resources to help engage your community in the contest. Entering the contest requires just a few simple steps and more contest information is available at CDC’s Healthy Swimming 2011 Video Contest page.
Contest Timeline

• May 16, 2011: Healthy Swimming Video Contest begins
• July 4, 2011 (11:59 PM, EDT): Deadline for all video submissions
• July 18-22, 2011: Public voting on top videos takes place online
• July 25, 2011: Winner announced

More Information

• Learn more about CDC’s Healthy Swimming Program
• Learn more about CDC’s Healthy Swimming Video Contest
• Learn more about the CDC Foundation

We appreciate your support and hope you will join us in this effort to promote healthy swimming. Please do not hesitate to contact us at healthyswimming@cdc.gov with any questions.

Michele Hlavsa is Chief of CDC’s Healthy Swimming Program.

But before diving in, it may be a good idea to know just what you are diving into.  Most pools are properly maintained, allowing swimmers to simply enjoy the water.  However, last summer, the Centers for Disease Control and Prevention (CDC) reported pool inspection data from 13 states indicated about one in eight public pool inspections resulted in pools being closed immediately due to serious code violations.

Dip before You Dive!

How do you know if a pool is properly maintained? There are hardly enough pool inspectors to go around, so CDC recommends swimmers take matters into their own hands and test pool water before getting in the pool.  It’s easy and free and will only take you a minute. Before swimming, dip a color-coded test strip into the water and check to see if the pH and chlorine readings are at appropriate levels. The pH should register between 7.2 and 7.8, and the free chlorine level should be between 1.0 and 4.0 parts per million (ppm).  If levels are out of those ranges, pool staff should be notified immediately. Pool staff should ascertain and correct the problem; if swimmers are unsatisfied with the pool staff response, CDC recommends they contact their local health department.

Swimmer’s Ear:  Listen up

New “swimmer’s ear” statistics provide a good reason to check pools for adequate pH and chlorine levels.  The May 20 Morbidity and Mortality Weekly Report (MMWR) notes that “swimmer’s ear” accounts for 2.4 million doctor visits and nearly $500 million in health care costs annually.  According to CDC, pools with proper pH and chlorine levels are less likely to harbor the bacteria that can cause “swimmer’s ear” and other germs that cause recreational water illnesses, including diarrhea and various skin infections.

Free Pool Test Kit Offer

This summer, the Water Quality & Health Council is offering free pool test kits to swimmers across the country. These can be requested online at http://www.healthypools.org/freeteststrips. Kits include three pool test strips and a pamphlet of information, including CDC’s tips for preventing “Swimmer’s Ear.”  We are asking swimmers to return to www.healthypools.org/freeteststrips to upload their pool chemistry results, contributing to an informal survey of pool health across the country.  We’ve even developed a convenient smart-phone application on that webpage to enable swimmers to upload data poolside.

What We Did Last Summer

Last summer, the Water Quality & Health Council provided more than 43,000 free pool test strips to individuals who requested them via the Healthy Pools website.  Data submitted last summer by close to 800 swimmers who had requested the strips indicated that 40 percent of pools had either unacceptable pH or chlorine readings.  We look forward to this summer’s results and further raising awareness of the importance of proper pool chemistry.

Check www.healthypools.org for more summer swimming tips.

For more information on preventing recreational water illnesses, please visit the CDC website at http://www.cdc.gov/healthywater/swimming/.

Chris Wiant, M.P.H., Ph.D., is president and CEO of the Caring for Colorado Foundation. He is also chair of the Water Quality & Health Council.