Archive for the ‘Pools’ Category

Warning: Peeing in the Pool May Be Hazardous to Your Health

Friday, March 28th, 2014

We Don't Swim In Your Toilet So Don't Pee In Our PoolOne in five American adults admit to “peeing in the pool,” according to our 2009 survey. That news elicits a collective “Yuk!” from the public. Now, new research conducted by the China Agricultural University and Purdue University (Lian et. al, 2014) draws a direct connection between swimming pool urination and potential negative health effects for swimmers. The reasons to discourage peeing in the pool are adding up. Are swimmers listening?

The Problems with Peeing in the Pool

Most people correctly associate chlorine with pool chemical disinfection–destroying germs that can cause diarrhea, swimmer’s ear, and various types of skin and wound infections. There is no doubt that disinfectants, such as chlorine- and bromine-based products, UV, and ozone, help keep swimming pool water healthy and safe. Pool chemistry takes on a new level of complexity, however, when we add, of all things, swimmers.

Germs in Pee!

In addition to a chemical argument for not peeing in the pool, there is a biological one. Contrary to popular opinion, urine is not necessarily sterile. In fact, the urine of infected individuals can contain: norovirus; the parasitic worms that cause schistosomiasis; and the bacteria that causes leptospirosis, among other pathogens.

Swimmers introduce an assortment of organic chemicals to the pool, such as the compounds found in urine, perspiration, cosmetics and body oils. Many of these are nitrogen-based. When nitrogen-based organic compounds react with disinfectants, low levels of chemical byproducts are produced. These byproducts are the subject of much study. In some of the latest research, Lian et al. show that nitrogen-based organic compounds react with chlorine to form low levels of cyanogen chloride and trichloramine, compounds of potential health concern.

The researchers surmise that uric acid in pools, most of which originates from swimmer urination (the researchers call it “a voluntary action for most swimmers”), is a precursor to much of the cyanogen chloride present in pools. Cyanogen chloride potentially can affect the central nervous system, heart and lungs. Trichloramine is an irritant. Bottom line: peeing in the pool may be convenient, but it is not healthy.

Campaigns to End Peeing in the Pool

Public health and swimmer organizations are working hard to raise public awareness of the need for good swimmer hygiene. Notably, for the past several years, the Centers for Disease Control and Prevention, USA Swimming and the National Swimming Pool Foundation, and our Water Quality & Health Council have been encouraging good swimmer hygiene. We think all swimming lessons should include a hygiene component that instructs students to:

  • Use the toilet and shower before swimming
  • Refrain from peeing in the pool
  • Refrain from swimming when you have diarrhea

Teach them young, and they’ll remember.

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.

Chlorinated Pools and Eye Health

Friday, September 13th, 2013

Chlorinated Pools and Eye HealthThe recent Wall Street Journal article “Does Chlorine Affect Your Vision?” provides excellent advice to swimmers on avoiding inflammation and infections of the eye known as conjunctivitis. To elaborate a bit, conjunctivitis, also called “pink eye” can be caused by three main conditions:  infections, allergies, and exposures to chemicals. Chlorinating swimming pool water goes a long way toward preventing conjunctivitis caused by bacterial and viral infections, and proper swimming pool chemistry optimizes swimmer eye, skin and respiratory comfort.

Good pool chemistry plays a key role in maintaining healthy pools for swimmers. The US Centers for Disease Control and Prevention calls chlorine and pH “the first defense against germs that can make swimmers sick.” In fact, when trace levels of chlorine are maintained in swimming pool water at the right pH, chlorine is on “guard duty” against a wide range of bacteria and viruses introduced into pools by swimmers that can cause a host of problems besides conjunctivitis, including gastrointestinal upset, swimmer’s ear and skin infections.

Allergic conjunctivitis occurs more commonly with individuals who already have seasonal allergies. Additionally, some people may be sensitive to some chemicals in swimming pool waters. Wearing swimming goggles is a good idea for both of these types of inflammation of the eye. For pool water in the pH range of 7.2 to 7.8, and free chlorine levels between 1 – 3 parts per million, both germ destruction and swimmer comfort are optimized.  That’s why it is so important that pool managers monitor and maintain the pH and chlorine levels appropriately.

Getting the Swimmer Involved in Maintaining Healthy Pools

Swimmers may not realize that in addition to responsible swimming pool management, they too can play a key role in ensuring proper pool chemistry. By practicing good hygiene swimmers can help minimize the formation of irritating disinfection byproducts formed when urine, perspiration and cosmetics combine with chlorine. A recent survey showed that many swimmers don’t shower before swimming and one in five admit to having peed in a pool.  Swimmer hygiene matters when it comes to a healthy pool:  Shower before swimming and don’t pee in the pool!

The Water Quality & Health Council also encourages swimmers to test pool water with a free pool test kit before getting in the pool. Swimmers can measure the pH and free chlorine level of the pool to ensure readings are appropriate.  Our free offer is available until the end of summer. If readings are out of the acceptable range, we urge swimmers to direct their concerns to the pool manager. If the response is less than satisfactory, a complaint to the public health department should be the next step.

In short, healthy swimming—for good eye health and overall well-being—is a joint effort between pool managers and swimmers. We cordially invite you to participate.

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

Mineral Ionizers: Don’t Forget the Chlorine

Friday, September 6th, 2013

Mineral ionizers treat swimming pool water by releasing metals such as copper and silver into the water. These metals are known to have germ-destroying properties, but do they do the job adequately? While some marketers claim that their technology results in a chlorine-free pool, research suggests that mineral ionizers should, in fact, be used in conjunction with low levels of chlorine.

According to the US Environmental Protection Agency (EPA), mineral–or metal–ionizers are regulated “to kill algae and as an adjunct to the chlorination process.”i In other words, EPA recognizes that metal ionizers are effective against algae, but that they are to be used in conjunction with the chlorination process to destroy pathogens in pool water such as E. coli, which can cause swimmer’s diarrhea, and P. aeruginosa, which can cause swimmer’s ear.

Yu et al. (2002)ii tested the germicidal properties of copper, low levels of chlorine, and a combination of copper and low levelsiii of chlorine. The researchers found copper alone destroyed E. coli at an average rate of about 62 percent. Very low chlorine levels destroyed E. coli at an average rate of more than 93 percent. However, when copper and low levels of chlorine were combined, the average killing rate of E. coli approached 100%, indicating a significant synergistic effect between copper and chlorine. The results are presented in the table below. Several other scientific studies also found evidence for a synergistic effect between copper and chlorine.iv,v,vi How are pool owners to make sense of marketing information and make healthy choices?

Germicidal Test Results of Yu et al. (2002)


4 Hour Exposure of E. coli to Copper Ions Alone (1 mg/L) in Aqueous Solution

4 Hour Exposure of E. coli to Free Available Chlorine Alone (0.1 mg/L) in Aqueous Solution

4 Hour Exposure of E. coli to a Combination of 1.0 mg/L Copper Ions and 0.1 mg/L Free Available Chlorine in Aqueous Solution

Average Killing Rate of E. coli bacteria




Choosing a Pool Sanitizer

Swimming Pool Sanitizers and EPA

The word “pesticide” may seem out of place when discussing swimming pools, but EPA categorizes disinfectants used for drinking water and swimming pools as “antimicrobial pesticides” under the Federal Insecticide, Fungicide and Rodenticide Act (FIFRA).

Antimicrobial pesticides help to control microorganisms that can cause human disease; these substances are regulated by EPA under the statutory authority of FIFRA. Individual states are authorized to regulate pesticides under FIFRA and under state pesticide laws, which may be more restrictive than FIFRA.

According to the EPA Pesticides website, all pesticides must be registered both by EPA and the state before distribution. Furthermore, all pesticides must be distributed bearing their EPA-approved pesticide label. Additionally, it is unlawful to distribute an unregistered pesticide or a registered pesticide with claims that differ from those approved by EPA.

When it comes to choosing a pool sanitizer, pool owners have many options. Here are some tips for making an informed selection:

  • All companies that distribute pool sanitizers are required to register their product with EPA, but not all products advertised online, for example, are in fact registered. Check the product label for its EPA registration under the Federal Insecticide, Fungicide and Rodenticide Act (see sidebar). You can also search the Purdue University National Pesticide Information Retrieval System, which is a database of federally-registered pesticide products.
  • EPA registration is important because the registration process requires EPA to ensure that the pesticide, when used according to label directions, can be used with a reasonable certainty of no harm to human health and without posing unreasonable risks to the environment.
  • Always follow manufacturer’s directions carefully; we recommend this Pool Chemical Safety video for tips on the safe storage and handling of pool chemicals.

Fred Reiff, P.E., is a retired official from both the U.S. Public Health Service and the Pan American Health Organization, and lives in the Reno, Nevada area.

i September 21, 2007 Federal Register Notice
iiYu, P., An, Z., Ren, Z., Liang, X. (2002). Experimental observation on synergetic efficacy of available chlorine and copper ion in killing Escherichia coli. Chinese Journal of Disinfection, 19, 185-186.
iii0.1 mg/L of chlorine was used; typical recommended levels of chlorine for swimming pool sanitation are 1-3 mg/L.
ivZheng, Y., Lin, Q., Xie, L. (2004). Observation on synergetic efficacy of chlorine and metal ion in killing microorganisms in water. Zhongguo Xiaduxue Zazhi, 21, 204-207.
vBeer, C., Guilmartin, L., McLoughlin, T., White, T. (1999). Swimming pool disinfection efficacy of copper/silver ions with reduced chlorine levels. Journal of Environmental Health, 61, 9-12.
viYayha, M., Landeen, L., Kutz, S., Gerba, C. (1989). Swimming pool disinfection: An evaluation of the efficacy of copper/silver ions. Journal of Environmental Health, 51, 282-285.

Swimming Pool and Spa Safety and Maintenance Resources

Friday, August 23rd, 2013

Are you a backyard swimming pool owner looking to “bookmark” some online resources on pool and spa safety and maintenance? We searched the Internet and found the following sites that we hope will prove helpful:

  • Pools and Hot Tubs (US Centers for Disease Control and Prevention (CDC) website): What would you do if you found a dead animal in your swimming pool? How long does chlorine take to destroy E. coli in the water? How does one care for inflatable and plastic kiddie pools? Need some tips on protecting yourself and your family from recreational water illnesses transmitted in hot tubs? This CDC website has all this and more.
  • Did You Know? A well-chlorinated hot tub has little odor. A strong chemical smell indicates a maintenance problem.
  • Home Pool Essentials (an online training course for $19.95): The National Swimming Pool Foundation teamed up with the American Red Cross to offer this online training course on home pool safety and maintenance. Safety topics covered include preventing drowning, diving injuries, recreational water illnesses and suction entrapment. Maintenance topics include instruction on how a pool works, how to ensure good water quality and how to add chemicals to water. The cost of the course includes a 30-page resource guide.
  • Did You Know? You should always swim with a buddy; do not allow anyone to swim alone. Even at a public pool or a lifeguarded beach, use the buddy system!
  • Pool Safety (Consumer Product Safety Commission (CSPC) website): The CPSC Pool Safely campaign alerts consumers and industry professionals to the numerous water safety steps that can be adopted to significantly reduce child drowning deaths. The website includes information on the Virginia Graeme Baker Pool and Spa Safety Act designed to prevent drain entrapment in public pools and spas.
  • Did You Know? An average of 390 children ages 0-14 drown in pools and spas each year. If a child is missing, look for him or her in the pool first.
  • Ask a Pool Operator (Water Quality & Health Council’s Health Pools website): Have a question on pool care that’s bugging you? Get a personalized response from an experienced pool operator.
  • Did You Know? According to a 2012 survey, although nearly all respondent said they would never re-use someone else’s bath water, almost seven in 10 admit they do not always shower before getting in the pool. Failing to shower before swimming adds contaminants to the pool that can lead to unhealthy swimming conditions.

Olympic Medalist Mom Teams up with CDC to Promote Healthy Swimming

Friday, August 9th, 2013

Olympic champion Amanda Beard is teaching her son proper swimmer hygiene while he learns to swim.
Olympic champion Amanda Beard is teaching her son proper swimmer hygiene while he learns to swim.
(photo from

Swimming in a properly maintained pool is a healthy and rewarding activity for people of all ages, but very few of us have the perspective of seven-time Olympic medalist swimmer and mom Amanda Beard. Beard recently partnered with the US Centers for Disease Control and Prevention (CDC) to encourage swimmers to protect themselves and their family and friends while swimming by promoting the Steps of Healthy Swimming:

  • Keep the poop, germs and pee out of the water.
    • Don’t swim when you have diarrhea.
    • Shower with soap before swimming.
    • Take bathroom breaks every 60 minutes.
    • Wash your hands (include vigorous rubbing) after using the toilet or changing diapers.
  • Check the free chlorine level and pH before getting into the water.
    • The free chlorine levels should be between 1-3 parts per million and pH should be between 7.2 and 7.8.
    • This summer the Water Quality & Health Council is offering free pool test kits at
  • Don’t swallow the water you swim in.
  • Take children on bathroom breaks every 60 minutes or check diapers every 30-60 minutes.
    • Change diapers in the bathroom or diaper-changing area and not at poolside where germs can rinse into the water.

Do the Math!

Beard’s strong focus on hygiene comes from the fact that if a swimmer fails to shower before swimming and brings feces into the pool, the pool could be contaminated with germs that cause illness. We know from a recent CDC study that fecal bacteria are present in over half of swimming pools tested. Another study estimated that a person who swims without first showering sheds an average of 0.14 g of fecal matter into the water. (Multiply the number of showerless swimmers by 0.14 g to get an estimate of the amount of fecal matter in your pool. Ugh.) Pathogens from fecal matter can infect swimmers who inadvertently swallow pool water, making them sick. And while chlorine disinfectants kill most waterborne pathogens within seconds, the process is not instantaneous, so there’s a lag time during which infection can potentially occur.

Teach Hygiene as Part of Swimming Lessons

We applaud Amanda Beard for spreading the word about the importance of swimmer hygiene. Beard is giving her three-year-old son swimming lessons and teaching him to do his part to keep the pool water clean. Swimming lessons are a wonderful gift that we can give to children to enjoy and benefit from throughout their lives. The younger they are when they learn to swim, the better. And while they are learning this life-saving skill, we suggest that all organized and informal swimming lessons include a hygiene component to help keep swimming healthy for everyone in the pool.

Remember, showering is not just a courtesy to others, it also helps keep you
and your loved ones healthy!

A New Pool Chemical Safety Video

Friday, July 26th, 2013

Cooling off in the swimming pool is one of the great joys of summer. A well-maintained pool provides a healthy venue for exercise and fun for the entire family. Yet, each summer we hear news reports of illness and injury from the misuse of pool chemicals. According to a report from the US Centers for Disease Control and Prevention (CDC), there was an average of about 4,000 cases of pool chemical-related illnesses or injuries per year in the period 2002 – 2008. Most of these were associated with backyard swimming pools.

In an attempt to help reduce pool chemical-related incidents, the American Chemistry Council and The Chlorine Institute collaborated recently to produce a new video featuring guidelines and recommended practices on the safe storage and use of pool chemicals. The video, available on You Tube, includes safety messages based on information from the CDC.

Causes of Swimming Pool Chemical Illness and Injury

CDC notes the most common causes of swimming pool chemical-related illness and injury are:

  • Mixing incompatible chemicals
  • Splashes of pool chemicals
  • Failure to use personal protection equipment when working with pool chemicals
  • Lack of proper training and supervision
  • Dust clouds or fumes generated by opening a pool chemical container

The video, which addresses these important issues and more, may be viewed in its entirety (about 13 minutes) at, or in shorter sections by topic:

  • Intro to Pool Chemical Safety, includes an introduction to pool chemicals and to the topic areas covered by the video (2 minutes, 9 seconds).
  • Properties and Safe Storage of Pool Chemicals, including reminders to: read and follow manufacturers’ directions and safety data sheets; never mix pool chemicals; always separate incompatible chemicals for storage and never store liquid chemicals above dry chemicals to avoid mixing upon accidental spilling (5 minutes, 13 seconds).
  • Pool Chemical Handling, including information on: the appropriate use of personal protection equipment, such as safety gloves and goggles; avoiding cross-contaminating chemicals and if pre-dissolving is needed, adding chemical to water, but never adding water to chemical, as a violent reaction could occur (2 minutes, 7 seconds).
  • Pool Chemical Accident Prevention, including guidance on: the importance of immediately responding to an accident; flushing eyes and skin with water in the event of contact with pool chemicals and calling 911 or the Poison Control Center (1-800-222-1222) in the event of a pool chemical accident (2 minutes, 4 seconds).

Please share this video with pool owners and operators to help reduce pool chemical accidents!

Three Top Swimming Pool Myths

Friday, July 5th, 2013

If you spend time at the pool this summer you probably will hear conversations that reinforce a few persistent myths about swimming pools. We invite you to check out three of the most popular myths below and then get the facts so that you can dazzle your poolside companions with your knowledge!

Myth Fact
If you pee in the pool, a dye in the water is activated, coloring the water around you. Swimmers are on the honor system when it comes to peeing in the pool. There is no dye used to give them away, although based on a recent survey of 1,000 adults, about 52 percent think there is. Dye or no dye, peeing in the pool is a very unhygienic practice that uses up chlorine and produces nasty irritants. Taking the time to leave the pool and use the bathroom is a public health courtesy.
Chlorine turns blonde hair green. Chlorine gets the blame but copper plays the game. Copper in the water comes from compounds added to destroy algae; it is also leached from metal plumbing in the pool (see Bhat et al. study). Fair-haired swimmers might consider donning a bathing cap or using a use a shampoo formulated to help remove copper (more information).
Swimming is bad for people with asthma. Doctors actually recommendswimming for patients with asthma. Swimming in a properly maintained pool helps increase lung function in asthmatics and is a healthy form of exercise for people of all ages (more information).

One more fact: The Water Quality & Health Council wishes you
a safe and healthy summer in and out of the pool!

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.

Myth Busted! Poll Finds Most Parents Believe Pool Urine Detecting Dye Myth Is True

Tuesday, July 2nd, 2013

5 Swimming Pool Myths You Thought Were True That Aren’t

WASHINGTON, D.C. — It’s the most widely told pool myth of all time: Don’t pee in the pool or the water will change color and everyone will know. Parents have long used the story of a chemical that changes color in the presence of urine to keep their children from peeing in the pool, and a new poll shows they believe it’s true.

A recent Mason-Dixon survey found that 52 percent of people believe there is a chemical that is added to pools to turn a conspicuous color in the presence of urine. In reality, no such chemical is used.  But there are ways to make sure the pool you are swimming in is healthy.

Experts say you can use a pool test kit, such as the free kit offered compliments of the Water Quality and Health Council, or even use your five senses to know if the pool you’re swimming in is healthy and well-maintained.

That’s important because your pool may not be as healthy as you think:  A recent study performed by the U.S. Centers for Disease Control and Prevention identified E. coli, a bacterium commonly found in feces, in almost 60 percent of the public pool filters they sampled in the Atlanta area. This demonstrates swimmer hygiene is not what it should be.

And an earlier survey by the Water Quality and Health Council found that one in five Americans admit to peeing in the pool, 81 percent believe other people pee in the pool and 62 percent believe others fail to report that their infant or toddler pooped in their diaper/bathing suit in a public pool.

While the use of a urine-detecting chemical may be the biggest pool myth, other common aquatic urban legends include:

Myth – Swimming is not good for children with asthma.
Truth – Medical experts say swimming in a healthy, well-maintained pool is an excellent physical outlet for swimmers with asthma.  The Belgian Superior Health Council examined the relevant scientific studies and concluded that the available evidence does not support advising children against swimming in chlorinated pools.  The U.S. Centers for Disease Control and Prevention, the World Health Organization, and other public health experts have asserted that swimming in a well-maintained pool is a healthy form of exercise for people with asthma.

Myth – Chlorine turns hair green.
Truth – The survey by the Water Quality and Health Council discovered that nearly half of respondents believe that chorine is responsible for turning hair green. In fact, the presence of copper in swimming pool water is to blame. Copper may be introduced to pool water in several ways, including metal plumbing or algaecide.

Myth – Swimmer “red eye” is caused by too much chlorine in the pool.
Truth – 87 percent of respondents to the Water Quality and Health Council survey believed that chlorine in pools makes swimmers’ eyes red and irritated. In reality, when nitrogen, found in urine and sweat, is combined with chlorine, irritants called chloramines are formed. It is these chloramines, not the chlorine itself, that irritate the eyes, skin and respiratory system. In this case, more chlorine may actually need to be added to pool water in order to reduce the formation of chloramines.

Myth – When it comes to pool water, clarity means cleanliness.
Truth – Even when swimming pool water is clear, microorganisms too small to be seen with the naked eye can be present. While chlorine destroys bacteria that could put swimmers at risk for disease, it takes time to work. Most germs are killed within seconds in a properly treated pool, but some (such as Cryptosporidium) can survive for days and require more aggressive treatment.

Myth – The strong odor of chemicals indicates a clean, well-treated pool.
Truth – A faint smell is expected, but a strong scent of chemicals could mean trouble. When irritating chloramines are formed by the mixture of chlorine and pool contaminants, such as urine, body oils and other substances brought into the pool by swimmers, a strong smell is released. A healthy pool is one with little to no odor.

Test Your Pool

Even if swimming pool water looks clean, the water could be contaminated. Healthy Pools offers tips to use your senses to test the waters.

  • Sight – Make sure you can see clearly through the water to the floor of the pool.
  • Touch – Check for tiles that feel smooth and clean, not slimy.
  • Smell – Make sure there are no strong chemical odors.
  • Sound – Listen for the sound of the pool pump.
  • Taste – Avoid tasting and swallowing pool water!

To order a free pool test kit offered as part of the Water Quality and Health Council’s award-winning summer Healthy Pools awareness initiative, go to

The Question of Children, Swimming Pools and Asthma

Friday, June 21st, 2013

children swimming in a poolDoes swimming in chlorinated pools cause asthma in children? In 2003, a Belgian research team proposed the increased exposure of children to chlorinated swimming pools could be responsible for rising rates of asthma among children in developed nations. But many other scientists (see below) challenge the “pool chlorine hypothesis,” as it is called, and since we last wrote about this topic, there is more information to ponder.

Belgian Superior Health Council Conclusions

Based on the Belgian research, that government’s Superior Health Council (BSHC), a group of scientific experts, was asked by the Minister of Public Health in 2009 for detailed scientific advice on the matter of asthma development in children who swim. The BSHC responded in February, 2011 with a report stating that although a relationship between swimming pool attendance and childhood asthma has not been confirmed, it cannot be excluded. Importantly, the BSHC concluded that the available evidence does not support advising children against swimming in chlorinated pools. The BSHC underscored the advantages of physical exercise during swimming. They noted swimming is especially well-tolerated by asthmatics–and they concluded that there is no good reason to keep children out of properly managed chlorinated pools.

What Causes Childhood Asthma?

No one really knows why some children get asthma and others do not. According to the Mayo Clinic, it is probably caused by a combination of environmental and inherited factors.

There has been much research on the potential causes of asthma in children. In addition to the research on pool swimming, many other factors have been investigated including: respiratory infection in infancy, air pollution, maternal smoking, fast food ingestion, exposure to cockroaches and a lack of exposure to environmental microbes, aka the “hygiene hypothesis.”

The Belgian Minister of Public Health requested further information from the scientific body in 2011, this time asking for advice on baby swimming and different methods of swimming pool disinfection. That report found no real benefits to baby swimming from 0 to 12 months old as inter-limb coordination is not acquired before the ages of three to four. For older children, however, the BSHC concluded swimming remains highly advisable, even in the case of asthma. The BSHC said the advantages of swimming under good hygienic conditions in monitored pools outweigh any potential risk of toxicity linked to chlorinated swimming pools. Furthermore, the BSHC stated that chlorine is the best disinfectant available in a properly-managed pool.

Other Investigators’ Conclusions

In 2008, Goodman and Hays conducted a “meta-analysis” of scientific research examining the association of swimming and asthma. They found no consistent association between asthma development and swimming pool use during childhood. Last year a Spanish research team similarly concluded that: “the body of evidence in children indicates that asthma is not increased by swimming pool attendance.” Overall, “…the health benefits of swimming outweigh the potential health risks of chemical contamination. However, the positive effects of swimming should be enhanced by minimizing potential risks.”

The Common Thread: Swimmer Hygiene and Pool Maintenance

A common thread running through all expert opinions on the swimming pool and asthma question is this: Both swimmers and pool managers have important roles to play in maintaining healthy pools. Swimmers have a responsibility to shower before swimming and not treat the pool as a toilet. Poor swimmer hygiene uses up chlorine and contributes to the production of irritating byproducts. Pool managers have a responsibility to maintain appropriate treatment chemical levels so that germs will be destroyed and pool water will remain comfortable. When things go haywire—swimmers pee in the pool and pool managers neglect their duties—pools become unhealthy, raising the possibility of unintended health consequences. Whether childhood asthma is among those consequences is doubtful, given the weight of evidence from the scientific literature, but why not do all we can to keep the “healthy” in “healthy pools”?

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

Is There Good Chemistry in Your Pool?

Friday, June 14th, 2013

Pool with inflatable tubeThis summer many of us will spend some “down time” cooling off in a pool. Whether the pool is in your backyard, your community, or your vacation spot, chemistry is at your service to help ensure that your pool experience is a healthy one. Within seconds of application, chlorine-based pool sanitizers destroy most of the waterborne germs that can cause diarrhea, swimmer’s ear and skin infections in swimmers—maladies that threaten to turn your “down time” into “down and out” time.

For most pools, the fundamental chemistry that protects swimmers from germs is maintained when the pool water pH and the chlorine level are kept within prescribed ranges. Pool operators are obliged to monitor and maintain pH between 7.2 and 7.8 and the “free chlorine1” level between 1 and 3 parts per million. That’s good chemistry for a swimming pool—a chemistry that optimizes waterborne germ destruction while keeping swimmers comfortable.
water by swimmers.

You Be the Pool Inspector!

As pool season begins once again, the Water Quality & Health Council is happy to make free pool test kits available to the public. According to a 2010 report from the Centers for Disease Control and Prevention, about one in eight public pool inspections conducted in 13 states resulted in pools being closed immediately due to serious code violations. If that makes you wonder how your pool would fare, consider ordering a free test kit at Each kit includes an easy-to-use test strip to dip into the pool and a color chart to help determine the pool water pH and free chlorine level. The kits can be used at any pool that applies chlorine-based sanitizers, including saltwater pools.

If your pool’s chemistry is “off,” tell your pool operator. If you are not satisfied with his or her response and you don’t think that anything will be done to improve the chemistry of the pool, contact your local public health department.

Have a fantastic summer and remember to pack a trusty pool test kit when you go to the pool. Don’t get in the water unless there’s good chemistry in the pool.

Linda Golodner is President Emeritus of the National Consumers League and Vice Chair of the Water Quality & Health Council.

1 Free chlorine is technically defined as a combination of hypochlorous acid and hypochlorite ion that forms when chlorine-based sanitizers are added to pool water. Free chlorine destroys algae and most waterborne germs. It also reacts with small bits of organic debris and impurities, such as substances added to pool water by swimmers.

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