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They say “the nose knows,” but I say the nose can be confused. Chlorine odors are a good example. Several different chlorine odors can arise from various chlorine-based substances and in different circumstances. They are not all simply due to “chlorine.” A prime example is the irritating smell commonly attributed to chlorine around some poorly managed swimming pools. That smell is from a couple of chemical compounds in the chloramine family. Some chloramines form when chlorine disinfectants react chemically with nitrogen-based substances from the bodies of swimmers, including urine. The poolside pronouncement of “too much chlorine in the pool” may be more aptly described as “too much peeing in the pool.” Ironically, the odor could signal that more chlorine is needed in the pool.
Not One Chloramine
Chloramines start out as ammonia— NH3— which looks like a three-legged stool with the nitrogen atom as the “seat” and a hydrogen atom at the end of each “leg.” Ammonia is common in the environment, and although household ammonia has a very sharp odor, ammonia has no odor at the very dilute levels typically found in water. When chlorine is added to water in sufficient amounts, it breaks ammonia down into nitrogen (N2) gas and hydrogen (as water or H2O). But if the amount of nitrogen increases (from peeing in the pool, for example), the balance between chorine and nitrogen is disturbed and the ammonia is only partially deconstructed.
When three chlorine atoms replace the hydrogen atoms on the ammonia molecule, the resulting compound is trichloramine, a pungent, irritating compound that is often mistaken for “too much chlorine” in the pool, even at very low concentrations. Trichloramine and its sister chemical dichloramine (with two chlorine atoms and one hydrogen forming the “legs”) are responsible for the odor you might smell when you enter an enclosed pool area in which there is poor airflow through the building. Besides just smelling bad, these same two chemicals can also turn swimmers’ eyes red.
The problem with trichloramine and dichloramine goes beyond that irritating smell. When trichloramine is present in the pool, the level of “free chlorine” available to disinfect the water and protect swimmers from microbial disease is greatly diminished. That’s why it’s important to check pool water regularly for the pH and the presence of free chlorine1. Pool managers are obliged to do just that, and pool patrons can do the same with easy-to-use pool test strips.
Trichloramine and dichloramine have a third sister – monochloramine. As the name suggests, in this compound, only one of the hydrogen atoms on the ammonia has been replaced with chlorine. This chemical, however, carries no odor and is an effective disinfectant that has been used successfully by many water treatment plants for many decades. What a difference a minor change in a chemical formula can make!
Monochloramine is typically formed in source water by first adding chlorine to break down any ammonia (into nitrogen and water) and then adding back trace amounts of ammonia in carefully monitored amounts to produce only monochloramine.
Unlike the chloramine family of compounds, chlorine bleach is a solution of water and sodium hypochlorite with the chemical formula NaOCl [bleach contains sodium (Na), oxygen (O) and chlorine (Cl)]. The odor of bleach (bleach that is not infused with a fragrance) is not nearly as pungent as that of di- and trichloramines. When the chlorine in bleach combines with nitrogen-based substances, however, smelly di- and trichloramines can form by chemical reaction. This could happen in the swimming pool environment, for example.
Chlorine is a common, naturally occurring element, but due to its reactivity, it usually occurs in nature combined with other elements, such as sodium in common table salt, NaCl. It is also produced industrially as part of the “chlor-alkali” process in which both chlorine and sodium hydroxide (NaOH) are generated by applying electricity to salty water. In that process, chlorine is produced as a gas consisting of twin atoms chemically bound together, and is represented by chemists as “Cl2.” Both chlorine and sodium hydroxide are used to help produce hundreds of everyday products, including water treatment chemicals, PVC pipes, pharmaceuticals, paper, aluminum, silicon chips for computers and even the titanium metal used in joint replacements.
Chlorine gas is a respiratory irritant that the human nose can detect at very low levels (0.2-0.4 parts per million in air; just for reference, one part per million is equivalent to four drops of ink in a 55-gallon barrel of water). At these low concentrations, chlorine gas smells very much like household bleach. When levels rise to the range of 1-3 ppm, however, mild mucous membrane irritation is noted and higher level exposure becomes increasingly dangerous.2 That is why the chlor-alkali industry takes extensive measures to ensure the safe production, handling and transportation of chlorine gas and even the less reactive sodium hypochlorite and calcium hypochlorite.
Not Just One Chlorine Compound
Chlorine is a reactive element that is found in many different compounds exhibiting different but sometimes similar properties, including odor. It is credited to have dramatically improved public health over the past 100 years through its ability to disinfect water. I hope this discussion helps to clarify “the smell of chlorine.” Now your nose knows!
Stephan A. Hubbs retired from water treatment operations at the Louisville Water Company in 2004. He was involved in the development of the first chlorine by-products regulation in 1975-1979 and remains an active volunteer in the drinking water community today.
1 Hypochlorous acid, or HOCl, for you chemists!
2 The Chlorine Institute, Inc., Pamphlet 63: First Aid, Medical Management/Surveillance and Occupational Hygiene Monitoring Practices for Chlorine, Edition 8, June, 2011.
Looking for a fun way to stay fit this winter? Consider swimming in an indoor pool. Swimming provides a great workout for the whole body—core (including abdomen), arms, legs, glutes and back, according to WebMD. It helps increase flexibility and strength without taxing the joints, a welcome advantage for people with arthritis. And feeling buoyant in the water can be both relaxing and soothing, reducing mental stress.
Indoor Pool Air Quality
One potential deterrent to indoor pool swimming is the strong chemical odor around some indoor pools. We have addressed the phenomenon popularly known as “too much chlorine in the pool” numerous times, but it bears repeating here: The irritating chemical odor around some pools is not due to chlorine, but to certain substances formed when chlorine disinfectant combines with nitrogen-containing contaminants brought into the pool by swimmers.
To compound matters, inadequate air exchange over the pool contributes to the build-up of irritants in the indoor pool space. If your indoor pool air is irritating, speak to the pool manager about air flow in the room, but consider your own personal “swimmer hygiene” as well.
Why is chlorine added to pool water anyway? Chlorine-based disinfectants are needed to control waterborne germs, helping to keep pool water safe for swimmers. Chlorine’s presence is non-negotiable (it’s even present in “salt” pools), so to minimize irritants forming, swimmer hygiene must be addressed. Many swimmers do not realize how much influence their hygiene has on pool water quality. Swimmers should shower before entering the pool and refrain from “peeing in the pool.” Showering thoroughly with soap removes body oils, perspiration, makeup, lotions and traces of urine and fecal matter from the skin. When chlorine combines with these substances, there is less of it available to destroy the germs in the water that can make swimmers sick. Inadequate pool chlorine levels can lead to swimmer’s diarrhea and swimmer’s ear, for example. And peeing in the pool, no matter how stealthily it can be done, is not cool!
A Family Affair
Swimming can be a family affair. Parents, swimming is an “electronic gadget-free” activity! The pool is a unique environment in which to connect family members across the generations. The buoyancy of pool water is a great equalizer as older swimmers are able to avoid high impact to their aching joints. Older family members can help teach younger ones to swim and then race them across the pool.
Ensuring that each family member can swim is an investment that can pay dividends over a lifetime. In addition to being a life-saving skill, swimming can enhance the quality of life. A variety of outdoor recreational activities in and around the water, including boating, fishing, water-skiing and more, become available and enjoyable for confident swimmers.
So, as counter-intuitive as it may seem to locate your swim suit and goggles and head for the pool when the weather forecast includes ice and snow, consider the benefits and the fun of winter indoor swimming.
Why Cryptosporidium is Responsible for over 80% of Swimming Pool Illness Outbreaks, and What Can be Done about It
Cryptosporidium is a microscopic parasite that is responsible for the majority of swimming pool illness outbreaks in the US with symptoms ranging from diarrhea to death. An outbreak this summer in Ohio sickened hundreds of swimmers. With that level of notoriety, it should come as no surprise that “Crypto” was the subject of much discussion at the recent National Swimming Pool Foundation’s annual World Aquatic Health Conference in Nashville (October 19-21). The figure at right illustrates the dominant role of “Crypto” in 35 reported recreational water illness outbreaks between 2005 and 2006.
Crypto lives in the intestines of mammals and is what is known as an enteric pathogen, spread through the feces of infected people and animals. According to the Centers for Disease Control and Prevention (CDC), Crypto can cause diarrheal disease in people two to ten days after they become infected. Swimming pool Crypto outbreaks start when fecal matter from an infected swimmer or animal contaminates pool water. Given that a single fecal event can release over one billion organisms into the water and ingesting as few as 10 or fewer organisms can cause infection in a healthy person,1 the disease potential of Crypto is both extremely high and easily observed once an outbreak begins. Symptoms usually last from one to two weeks, but may last longer in people with weakened immune systems. Infectious oocysts can be excreted for up to 60 days after gastrointestinal symptoms have ended. Death can result when the immunocompromised (e.g., young children, the elderly and the chronically ill) are infected.
Unlike the other waterborne pathogens represented in the pie chart above, Crypto is chlorine-resistant. This unique characteristic explains why it is the most common cause of illness in pool swimmers. Most waterborne pathogens are destroyed by chlorine, and many pools are adequately chlorinated to achieve that level of protection. In its infectious form, however, Crypto sports a thick, protective, outer shell known as an “oocyst.”
In this year’s World Aquatic Health Conference’s “Advanced Filtration Science” symposium, University of North Carolina at Charlotte researcher and professor Dr. James Amburgey provided helpful perspective around the Crypto issue by noting that analytical testing for Crypto is expensive, and that often the pool management is unaware of its Crypto problem until there is an outbreak. His experiments show Crypto oocysts escape swim diapers within five minutes of a diapered child being in the pool. Additionally, research shows 8.3% of noninstitutionalized adults are fecally incontinent.2 Just one fecal “event” in a pool can release over one billion oocysts into the water!
Because chlorine disinfection is ineffective against Crypto at normal swimming pool levels, oocysts must be removed through filtration (or exposed to advanced disinfection units employing ozone or UV light). Dr. Amburgey stated that a typical swimming pool sand filter removes only about 25 percent of oocysts each time the water is filtered (typically every 4-6 hours). Fortunately, there are several chemical and design factors that can be tweaked to achieve much greater removal rates. For this, the researcher recommended all three of the following techniques already employed by the drinking water industry:
- Slowing the rate of filtration (≤ 10 gallons per minute per square foot of filter area)
- Increasing the filter depth (≥ 24 inches of 0.5 mm effective size sand)
- Using coagulants (0.1 mg aluminum per liter of water with alum or polyaluminum chloride)
The first two factors make intuitive sense: Slowing the rate of pool water filtration and increasing the filter depth increase the odds of oocysts being caught in the matrix of a pool filter. Most importantly, however, Dr. Amburgey emphasized that coagulants dramatically enhance filtration. As filter media and oocysts are both negatively charged, there are no electrical attractions between them to enhance filtration. Positively charged coagulants added to swimming pool water, however, can effectively promote oocysts sticking to filter media. It is important to note that optimizing coagulation for Crypto removal can be complicated and is best left to researchers.
Other options suggested to enhance filtration include replacing sand with at least 18” of Ceraflow-70 (an ultrafine granular ceramic media), ceramic membrane filters, and the use of “precoat filters” where a woven material is precoated with at least 0.15 pound of diatomaceous earth (a fine powder) per square foot of filter area (forming a layer that is roughly 1/8” thick) that has pores small enough to trap Crypto particles. With pore sizes in the range of 1 micron (0.001 millimeter), diatomaceous earth can remove 99.99% of oocysts of diameter 4 microns in pool water.
Time will tell if swimming pool filtration is more widely optimized to help prevent future US Crypto outbreaks. As the recent World Aquatic Health Conference demonstrates, one thing is for sure: The right discussions are taking place.
1 Yoder, J.S, Wallace, R.M., Collier, S.A., Beach, M.J. and Hlavsa, M.C., “Cryptosporidiosis Surveillance-United States, 2009-2010,” Morbidity and Mortality Weekly Report, September 7, 2012. On line, available: http://www.cdc.gov/mmwr/preview/mmwrhtml/ss6105a1.htm
2 Whitehead, W.E., Borrud, L., Goode, P.S., Meikle, S., Mueller, E.R., Tuteja, A., Weidner, A., Weinstein, M., Ye, W., (2009). “Fecal incontinence in US adults: epidemiology and risk factors,” Gastroenterology, 137(2): 512-7.
Over 250 people in central Ohio and over 100 in Arizona have been sickened in summer outbreaks of cryptosporidiosis, a diarrheal illness caused by the microscopic parasite Cryptosporidium, or “Crypto.” These parasites are found throughout the US and abroad, and settle in the intestines of infected humans and animals, making Crypto one of the most well-known zoonotic diseases. According to the Centers for Disease Control & Prevention (CDC), millions can be released in the feces of an infected person. Only 10 to 30 are needed, however, to cause infection in a healthy person, according to Yoder and Beach (2010).1
Crypto spreads in aquatic facilities when people inadvertently swallow water contaminated with the feces of infected individuals. Understanding Crypto and how to avoid infection can help your family enjoy the fun and health benefits of swimming pools and other aquatic facilities.
Crypto is the leading cause of recreational water outbreaks in the US. You may be wondering why chlorine, a mainstay of swimming pool treatment, doesn’t destroy Crypto. The gold standard for disinfectants, chlorine helps reduce the public’s exposure to a wide array of waterborne bacteria, viruses and parasites. Crypto, however, is chlorine-resistant as a result of the protective shell of the parasite’s “oocyst” stage, the stage at which it is shed in the feces of those infected (see photo above). Crypto can survive in water at CDC-recommended chlorine levels (1–3 mg/L) and pH (7.2–7.8) for over 10 days, according to Shields et al. (2008)2 . The protective shell also allows Crypto to survive outside the body for long periods of time.
Temporarily elevating chlorine levels in Crypto-contaminated swimming pools—a process known as super-chlorination—can destroy the parasite, but it must be done when the facility is closed to swimmers.3 Crypto infections may spread regionally when infected swimmers who are unwilling to wait for a pool to reopen following super-chlorination visit neighboring pools. Pool water filtration is another strategy for removing Crypto. The factors affecting the efficiency of removal of Crypto and other parasites by filtration is an important subject of ongoing study. According to CDC’s Model Aquatic Health Code, UV (ultraviolet) radiation (light sanitization) following filtration may be the most cost-effective disinfection strategy (see the Code’s Annex, p. 131). UV inactivates Crypto so that it can no longer reproduce.
Symptoms of cryptosporidiosis include: watery diarrhea, stomach cramps or pain, dehydration, nausea, vomiting, fever and weight loss. Some people with cryptosporidiosis have no symptoms at all, and may unknowingly spread the illness in aquatic facilities. Symptoms are likely to last from one to two weeks, but can persist sporadically for up to 30 days. Immunocompromised persons may develop “serious, chronic, and sometimes fatal illness,” according to CDC. Such people include people with AIDS, those with inherited diseases that affect the immune system, and cancer and transplant patients who are taking certain immunosuppressive drugs.
Most people with healthy immune systems recover from cryptosporidiosis without treatment. CDC reports Nitazoxanide may be prescribed for treatment of diarrhea caused by Crypto in people with healthy immune systems. Nitazoxanide is not approved for treatment of immunodeficient individuals because it has not been shown to be effective for that population.
Tips for Reducing Your Risk of Cryptosporidiosis at Aquatic Facilities
Remember the saying, “When Swimming, Don’t Discount Sanitary Conditions”
- Wash hands thoroughly after using the bathroom, and instruct children to do the same.
- Shower with soap and water (especially the perianal area) before entering the aquatic facility.
- Diarrhea: Do not use aquatic facilities if you are experiencing diarrhea; if you were diagnosed with cryptosporidiosis, do not use aquatic facilities until two weeks after diarrhea has stopped.
- Diaper Changing: Do not change diapers poolside; use designated facilities, and wash hands thoroughly afterwards.
- Swallowing water: Avoid swallowing water while in the aquatic facility.
- Children: Take young children on frequent bathroom breaks (every hour); check diapers frequently (every 30–60 minutes).
The tips above are important, not only for the residents of Ohio and Arizona who are experiencing Crypto outbreaks currently, but for everyone who frequents aquatic facilities. Don’t wait for an outbreak—help avoid one!
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.
1 Yoder, J.S. and Beach, M.J. (2010). Cryptosporidium surveillance and risk factors in the United States. Experimental Parasitology 124:31–39.
2 Shields, J.M., Hill, V.R., Arrowood, M.J., and Beach, M.J. (2008). Inactivation of Cryptosporidium parvum under chlorinated recreational water conditions. Journal of Water and Health 6:513–520.
3 A recent update to the Model Aquatic Health Code recommends that for Crypto inactivation in pools (that use cyanuric acid stabilizer), a dosage of 20 ppm free chlorine is needed for 28 hours, representing a doubling of the previous concentration x time, or “CxT” recommendation.
The swimmers at the summer games inspired awe in all who viewed those exciting events, including the littlest backyard pool athlete who has dreams of winning gold. Recently, the sparkling blue of the dive pool in Rio was transformed into a deep green, sparking fears of algae. In fact, the color change was blamed on a decline in alkalinity, caused by insufficient levels of chemicals that buffer pool water pH. A significant drop in pH can make the water corrosive to metal fixtures and equipment, which could cause metal leaching and discoloration of the water.
If you are maintaining a backyard pool for your family, you may be wondering about the appearance of stains in your pool – not only in the water, but on pool surfaces. What causes them and how should they be treated? A recent article1 by Terry Arko in The IPSSAN (The Independent Pool & Spa Service Association, Inc., July, 2016) newsletter provides many helpful answers.
As Arko notes, “Not all stains are the same, so it’s important to diagnose the stain before providing a broad-spectrum treatment.” Arko also makes the point that when addressing a pool stain, the first thing to do is to ensure the water chemistry is balanced. He notes, “A lot of staining in pools is from the pH dropping down and aggressively dissolving the metals into solution.” Regarding pool surfaces, vinyl and fiberglass pools usually respond better to stain treatment than plaster pools, which are more porous. The quality of paint on plaster, concrete or cement plastered pools also affects how easily stains are removed. Arko recommends brushing pool walls regularly and adding a sequestering agent (to prevent metal staining) at a frequency (e.g., weekly, biweekly, or monthly) that fits your needs.
The table below is based on Arko’s recommendations for specific pool stain removal:
|Stain Color||Likely Source||Treatment||Notes|
|Blue-green stain on pool surfaces or in water (but water is not cloudy)||Copper from algaecides, heat exchangers, fill water, older copper plumbing||Granular treatments, such as citric acid and ascorbic acid used directly on the stain; an additional sequestering agent can help the filtration system trap removed metals. If treatment includes phosphoric and/or phosphonic acid, these must be removed at a later time. Generally, non-phosphate treatments are only effective on stains that have not yet set into the surface.||If water is blue-green and also cloudy, the likely source of the stain is algae, in which case an algaecide is needed; algae will also be evident by slimy walls and floor.
In the Rio dive pool example, the alkalinity of the pool water had to be restored with chemicals such as sodium bicarbonate and sodium carbonate.
|Purple precipitate on pool water surface, tile line, skimmers and pool cleaner||Copper cyanurate when the cyanuric acid level is over 100 ppm||Reduce cyanuric acid level to about 50 ppm by draining water.||Draining water also addresses copper in the water, but it is important to test the water for any remaining copper.|
|Brown stain on pool surfaces or in water||The most common source is well water that contains dissolved iron or manganese; other potential sources are pool heater headers or lawn fertilizers||Same as for copper; if the source of iron is well water, begin a maintenance program of adding a sequestering agent weekly; use a non-phosphate sequestering agent to preclude elevating phosphate levels.|
|Brown stains, some of which may be shaped like leaves and other organic debris||Leaves and other natural materials that settle to the pool bottom; often found after uncovering the pool at the start of pool season||Stains may disappear as pool chlorine levels are established or shock treatment is applied; alternatively, citric acid or ascorbic acid work well to lift these stains.|
|Metal corrosion||Salt generators corrode metals, such as pool ladders and light rings||Add a sacrificial anode, such as zinc; use a non-phosphate sequestering agent.|
Bruce Bernard, PhD, is President of SRA Consulting, Inc., and Associate Editor of the International Journal of Toxicology, and lives in Cambridge, MD.
1 “Pool staining—identify before you treat,” by Terry Arko, The IPSSAN, July, 2016, p. 9, 13, and 17.
Pool chlorine levels are easily measured by dipping a test strip in the pool for a few seconds and then matching the resulting color of the strip to a chart linked to “parts per million” chlorine levels. Here’s the rub: Some pool test kits measure “free chlorine,” whereas others measure both “free chlorine” and “total chlorine.” There is a difference between “free” and “total” chlorine. That may be breaking news to an investigative reporter who recently confused the two in a news segment about possible contaminants in swimming pools.
Why Measure Chlorine?
This summer, the Centers for Disease Control and Prevention (CDC) is recommending the public check the chlorine level and pH of pool water before enjoying a refreshing swim. Why? A new CDC report finds that one in five pools in five states in 2013 had to be closed due to serious safety violations, including improper pH or chlorine readings. That prompted an investigative reporter for NBC News and the Today show, to measure pathogen and chlorine levels at several public aquatic facilities. At one pool, the reporter described a “sky-high” total chlorine reading of 10 parts per million. He compared the reading to the appropriate range of free chlorine levels (1-3 parts per million), saying, “Three is ideal, so it is way over.” Needless to say, that created consternation in the news room, not to mention fear and confusion among the viewing public.
There’s Chlorine, and Then, There’s Chlorine!
Without getting too technical, the reading that is a measure of how much chlorine is available in pool water to destroy germs is known as the free chlorine level. But not all chlorine in the pool is available to destroy germs. As the Water Quality and Health Council discussed in its article of May 27, 2016, some chlorine may be unavailable because it has chemically reacted with impurities brought into the pool on the bodies of swimmers. Chlorine that reacts with swimmer perspiration, urine, body oils and cosmetics produces “combined chlorine,” which is mostly unavailable to destroy germs.
The total chlorine level is the sum of the free chlorine and combined chlorine levels in the pool. Reporting a total chlorine level of 10 parts per million, as the reporter did, only tells us that the free chlorine level is likely less than that.
Total Chlorine = Free Chlorine + Combined Chlorine.
I hope this explanation helps you interpret chlorine level reports! This summer, you can order a free pool test kit—that measures pool water free chlorine and pH—at www.healthypools.org.
Linda F. Golodner is President Emeritus of the National Consumers League and Vice Chair of the Water Quality & Health Council.
Each summer, parents of toddlers and young children delight in introducing their offspring to the kiddie pool. With its shallow water, plastic pails and inflatable toys, the kiddie pool is a haven of fun, discovery and social interaction for the youngest pool patrons. Spending time in the kiddie pool to acclimate a toddler to the water could be the first step in cultivating a life-long swimmer. All terrific!
Now for the disturbing news: According to a new report from the Centers for Disease Control and Prevention (CDC), of all the aquatic venues that were closed because of serious health and safety violations in 2013, kiddie and wading pools lead the pack. Specifically, in the five US states with the most public pools, one in five wading pools (20 percent) had to be closed immediately upon inspection due to serious health and safety violations.
The Diaper Set
It probably comes as no surprise that the diaper set provides specific challenges to pool water quality. CDC reports, “Young children are more likely to experience acute gastrointestinal illnesses…and are more likely to contaminate the water because they either are incontinent or have inadequate toileting and hygiene skills.” Unfortunately, there is no such thing as a leak-proof diaper, and they do leak. CDC also notes that “as much as 10 grams of fecal material can rinse off a young child’s perianal surface and into the water.” Add to this the fact that discovery for toddlers is often linked to tasting, or in this case, drinking pool water, and we have a potentially risky combination of factors.
Better Water Quality in the Kiddie Pool
The most frequently reported violations in wading pools in 2013 involved disinfectant level, pH and automated chemical feeder violations. Given the water quality challenges associated with kiddie pools, this is a significant finding that can help inform solutions. Here’s our best advice to parents and care-givers of young children at the kiddie pool:
- Don’t allow your child into the pool unless you have checked the pool water quality. Some pools post inspection results online. Alternatively, you can be your own pool inspector and obtain instant readings. Use a pool test kit to ensure the pH and free chlorine level of the water are within acceptable ranges. If readings are outside of the acceptable range, lose no time in approaching the pool manager. This summer you can order a free pool test kit at healthypools.org.
- Keep sick children and those experiencing diarrhea out of the pool.
- Change swim diapers frequently in the restroom, and take children who are newly potty-trained to the restroom at frequent intervals.
- Teach children not to drink pool water.
Water play in the kiddie pool is a fun, social activity for very young children. Rather than discouraging parents and care-givers from visiting these venues, we recommend reaping the benefits of the kiddie pool by actively managing the risks.
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 new Centers for Disease Control and Prevention (CDC) report states that one in eight swimming pool inspections in five states in 2013 resulted in immediate closure due to serious health and safety violations. Is it any wonder that officials with CDC are asking swimmers to be their own pool inspectors this summer? The agency adds that only 68 percent of US local public health agencies regulate, inspect, or license public aquatic facilities. CDC’s response is to turn swimmers into their own pool inspectors by providing them with an inspection checklist:
- Is the pool chemistry correct? Use a simple pool test kit to check the water’s pH and free chlorine level. (Get a free pool test kit at www.healthypools.org.)
- Is the drain at the bottom of the deep end visible?
- Do the drain covers at the bottom appear to be secured and in good repair?
- Is a lifeguard on duty? If not, is safety equipment available (e.g., rescue ring or pole)?
Getting the pool chemistry right (the first item on the checklist) contributes to a healthy and comfortable swim. Confirming the next three items on the checklist can be a matter of life and death. I speak from experience, the memory of which came flooding back to me while reading the checklist.
Saved in the Deep End of the Pool
Following my high school graduation in 1966, I worked as a lifeguard at a local community pool in Texas. One late afternoon in August I was seated in a lifeguard chair near the deep end of the pool, when I glanced down into the water and saw a girl lying on the bottom. Instantly considering and dismissing the possibility of a prank, I plunged in and pulled out the unconscious 15-year old from a depth of about eight feet. After boosting the girl’s limp form onto the pool deck, I heard someone yell, “There’s another one down there.” Back I went into the water and brought up a 12-year old girl.
Once on the pool deck, I administered mouth-to-mouth resucitation to the younger girl. She was revived quickly, but the 15-year old was turning blue despite the life-saving efforts of my fellow lifeguards. Finally, the older girl was revived by a fire department unit that was called. Both girls survived the ordeal, and as I indicated to a newspaper reporter who later interviewed me, at the end of the day, I was grateful that I had been trained in Red Cross senior life-saving. This near double drowning also points out the importance of learning how to swim to prevent drowning.
I am convinced that my story might have had a diffent ending if the pool water had been murky. Being able to see to the floor drain at the deep end of the pool is the ultimate test of pool clarity—clear vision through the greatest depth of water in the pool. Remember: If swimmers in trouble can’t be seen, they can’t be saved. CDC’s swimmer checklist is a significant tool that can help save lives this summer.
Ralph Morris, MD, MPH, is a Physician and Preventive Medicine and Public Health official living in Bemidji, MN.
This summer when you don your bathing suit and walk out onto the pool deck, you may be in for a sensory experience that conjures up happy memories of summers past—warm sunshine, sparkling pool water and the smell of chlorine. If the chlorine smell is very strong, however, you may soon spot “red-eyed” swimmers emerging from the pool. That’s when the pool water is assumed to have “too much chlorine” in it. Ironically, a strong chemical smell around the pool and “swimmer red eye” may be signs that there is not enough chlorine in the water. Sound confusing? It’s time to set the record straight about chlorine and swimming pools.
Chlorine helps protect swimmers from waterborne germs
Most swimmers understand that chlorine is added to pools to kill germs that can make swimmers sick. Chlorine-based pool sanitizers help reduce swimmers’ risk of waterborne illnesses, such as diarrhea, swimmer’s ear, and various skin infections. The great advantage of chlorine over other sanitizers, such as ozone and UV is that it keeps working long after it is added to pool water; chlorine provides a “residual” level of protection against germs in the water. Chlorine is not the only “game in town” when it comes to pool sanitizers, but of the common products, only chlorine- and bromine-based disinfectants provide significant residual protection. Salt-water pools, by the way, are chlorinated pools in which the chlorine is generated on site from sodium chloride.
It’s important to get the pool chemistry right
Pool managers strive to keep the “free chlorine” level of pool water between about one and three parts per million. Maintaining the chlorine level in that range depends on several factors, including the pH of the water (it should be between 7.2 and 7.8), and the presence of unwanted substances in the pool, such as urine, perspiration, body oils and lotions, which compete with chlorine and react with it. These substances add to what is known as the “chlorine demand.”
Products of chemical reactions between chlorine and substances added by swimmers are irritants known as chloramines. It is chloramines, not chlorine, that are responsible for swimmer red eye. Unshowered and unhygienic swimmers (read: those who pee in the pool), add to the “chlorine demand” and are often the real cause of swimmer red eye. Unfortunately, as chlorine reacts with impurities brought into the pool by swimmers, there is less of it available to kill germs. So, not only do unhygienic swimmers promote irritants forming in swimming pools, they may also inadvertently raise the risk of waterborne illnesses. More chlorine may be needed to chemically destroy the chloramines formed and restore a free chlorine residual.
Swimmers can help keep swimming healthy
This comes as a surprise to many swimmers. The fact is that swimmer hygiene affects the chemistry of the pool and the comfort of swimmers. Last summer we made the point that swimmer “red eye” is an indicator that someone might have peed in the pool. That raised awareness and quite a few eyebrows. This year, we join our efforts to those of the Centers for Disease Control and Prevention and ask swimmers to shower before swimming and never pee in the pool. When you walk out to the pool this summer, sniff the air and decide whether or not you are about to jump into a healthy pool!
Want to know if you have adequate chlorine in the pool? Order a free pool test kit at www.healthypools.org today!
For America’s Most Fun Form of Summer Exercise, Experts Urge Swimmers to Use Senses to Stay Healthy at the Pool
As Americans jump into another fun-filled summer of swimming, a new survey finds that most don’t know the real reason why some pools have a strong chemical smell. A survey conducted on behalf of the Water Quality and Health Council found that three-quarters of Americans incorrectly believe that the chemical odor they smell at pools is a sign that there’s too much chlorine in the water.
Experts at the Water Quality and Health Council, U.S. Centers for Disease Control and Prevention (CDC), and the National Swimming Pool Foundation® (NSPF®) said properly treated swimming pools do not have a strong chemical smell. However, when chlorine in pool water combines with pee, poop, sweat, and dirt from swimmers’ bodies, chemical irritants called chloramines1 are produced. These chloramines give off a chemical odor, cause eyes to get red and sting, and use up the chlorine, meaning there is less to kill germs.
“It’s understandable why most people think that a chemical smell means there is too much chlorine in the pool, but the truth could be the opposite,” said Chris Wiant, Chair of the Water Quality and Health Council. “To help prevent chloramines from forming where you swim, shower before swimming and take little swimmers on regular bathroom breaks.”
Experts from the Water Quality and Health Council, CDC, and the NSPF are advising swimmers to use a “Sensible Checklist” to ensure a fun and healthy swimming experience:
- Are the pH and chlorine level correct? Use a test strip to check.
- Standing at the edge of the pool, can you see the drain in the bottom of the deep end?
- Do drain covers on the bottom of the pool appear to be secure and in good repair?
- Is a lifeguard on duty? If a lifeguard is not on duty, is safety equipment (for example, a rescue ring or pole) available?
- Is the area around the pool free of strong chemical odors?
“Swimming is proof that exercise can be fun if you just add water,” said Thomas M. Lachocki, Ph. D., CEO of NSPF. “It’s not just a form of fun exercise though. Swimming is a lifetime survival skill. Learning to swim should become a priority for all parents and adults, not only could their children become healthier for it, but they could also save someone’s life someday.”
Getting the Word Out
The Water Quality and Health Council is once again making free test kits available this summer through their Healthy Pools campaign. Swimmers can test their backyard or community pool to ensure it has proper pH and chlorine level. To order a free test kit offered as part of the Water Quality and Health Council’s award winning summer Healthy Pools campaign, please go to www.healthypools.org.
The National Swimming Pool Foundation would like to encourage adults to find swimming classes for themselves and their children through swimtoday.org. Learning to swim today, can improve your health and save a life tomorrow.
To learn more about healthy and safe swimming, check out CDC’s new Healthy Swimming website at www.cdc.gov/healthyswimming.
The survey was conducted online by Survata, an independent research firm in San Francisco. Survata interviewed 1,500 adults May 12-13, 2016 and has a margin of error of 2.5%.
1 These chloramines are different from the type of chloramine that is sometimes used to treat drinking water.
2 The survey was conducted by Survata, an independent research firm in San Francisco. Survata interviewed 1,500 online respondents between (TBD) and (TBD). The margin of error for the survey is 2.53%.