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After the record cold winter of 2013-14, lots of folks are enjoying summertime by swimming in the pool. As you cool off, dazzle your fellow swimmers with the truth about these common swimming pool myths:
Myth #1: The heavy chemical smell around the pool is a reminder that chlorine is present in the water for killing germs.
Fact: A properly disinfected swimming pool has no strong chemical smell, despite the presence of chlorine disinfectant to destroy germs. That surprises most people. In fact, the odor we notice around pools arises from the presence of chloramines in pool water. Without turning this into a chemistry lesson, chloramines form when chlorine disinfectants react with contaminants brought into pools on the bodies of swimmers. These contaminants include perspiration, urine, body oils and cosmetics. Chloramines are irritants that can redden the eyes of swimmers and make their skin itchy. Ironically, while many people think a pool chemical smell means there is too much chlorine in the water, more chlorine disinfectant may actually be needed to destroy the irritating chloramines.
Myth #2: Chlorine in pool water turns your hair green.
Fact: Green hair is associated with swimming and blondes display this best, but don’t blame chlorine. The green color comes from metals, such as copper, in the water, which are added to control algae or may be leached from pool plumbing and fixtures. Hint: Wear a swim cap. If you hate that idea, experts recommend a thorough hair-rinsing as soon as you leave the pool, followed by a gentle shampoo.
Myth #3: Pool water is disinfected, so it’s alright if my children swallow some.
Fact: Teach your children to avoid getting pool water in their mouths. Chlorine does kill waterborne germs, but chlorine levels fluctuate in pools, especially busy, crowded pools. And germs are not equally susceptible to chlorine–some germs take longer to destroy than others. Pool staff are responsible for keeping chlorine levels within an acceptable range, but, unfortunately, not all pools are carefully maintained. It’s best to err on the side of caution and avoid swallowing pool water. But if this sounds like rather passive advice, please read on.
Myth #4: It’s up to pool operators to keep pools healthy.
Fact: There’s so much you can do too! To minimize irritating chloramines, shower before swimming and never pee in the pool. Take young swimmers on frequent bathroom breaks and make sure they wash their hands. Anyone with diarrhea must stay out of the water. Learn to recognize the signs of a Healthy Pool, and notify pool staff if those signs are missing. Finally, the Centers for Disease Control and Prevention (CDC) is encouraging swimmers to measure the pH and free chlorine level of pool water this year to make sure they are swimming in a Healthy Pool. It’s a simple test done with a color-coded plastic strip, and you can even order a free test kit at http://www.healthypools.org/order-pool-kit-form/. If you find unacceptable pool readings, inform pool staff, who should correct the pool chemistry. If this does not happen, CDC recommends you notify your local public health department. Finally, upload your results on the Healthy Pools site to see how your pool compares to others around the country.
Here’s to a great summer in only the healthiest of pools!
Swim lessons—compliments of the Step Into SwimTM Campaign—at a New York state park lake
Photo credit: New York State Parks Department
Learning to swim is an investment that can pay dividends in health, enjoyment and living a long life. Knowing how to swim can mean the difference between life and death, and opens up a world of other activities, like sailing, canoeing, fishing and water skiing, making them safer and more fun. This summer, the National Swimming Pool Foundation’s (NSPF’s) Step Into SwimTMCampaign will help up to 1,000 children become swimmers, including children living in rural areas with limited opportunities for swimming lessons.
The non-profit National Swimming Pool Foundation (NSPF) reports that four organizations received a total of $70,000 Step Into SwimTM gifts from the NSPF this year. Those gifts were funded by donations to the Campaign, which were matched dollar for dollar by the Foundation. According to a news release by the New York State Office of Parks, Recreation and Historic Preservation, one of those programs supported the American Red Cross and New York State Parks department. The collaboration, and the Step Into SwimTM gift, enabled the Red Cross to train over 15 new instructors this summer. The Parks Department made the swim lessons available for free in five New York state parks. New York state residents can check the schedule of swimming lessons for potential lessons in their areas. We applaud these groups and their efforts to share the gift of swimming.
Why Bother to Take Swimming Lessons?
A personal recollection from Bruce Bernard, PhD
Some families don’t think learning to swim is important, either because the parents don’t know how to swim, and they don’t view it as a problem, or because they don’t live near bodies of water. This reminds me of a very important memory from my childhood. My next door neighbor, Chuck, was the strongest man I have ever known. He was in his 30’s and would wrestle me and five of my friends, all of us about 16 – 17 years old. Chuck would throw us around like bales of straw. He could pick up three of us at a time (he owned a fence company and loaded railroad ties daily). No matter how many friends I had to wrestle with him, he always ended up putting us in a pile and sitting on us!
Several years after I finished college, I heard that Chuck had died. He had been in a small boat with his wife and had fallen overboard and DROWNED! INCONCEIVEABLE! Chuck? With his muscles? Save your child’s life: Give him or her swimming lessons.
Finding Swimming Lessons in Your Area
Summer is a great time to start your children soaring through the water as confident swimmers. In addition to the Step Into SwimTM Program, here are a few options for finding lessons:
- YMCA: The YMCA offers swimming lessons for all ages, family swim, competitive swimming and diving teams and adaptive swim programs for children with special needs. Find your local “Y” here.
- American Red Cross: The American Red Cross offers a six-level Learn-to-Swim program designed for children over six years of age and adults. Register for classes in your area here.
- Local Community Pools and Swim Clubs: Contact your local public or private swimming pool or club and inquire about swimming lessons. Lessons, either private or group, are often given on summer mornings before the pool opens for general use.
Are you a backyard pool owner? Do you sometimes wish you could have free expert advice on pool maintenance? Your wish just came true: check out the Water Quality & Health Council’s popular online “Ask a Pool Operator” feature.
The “Ask a Pool Operator” web page includes an extensive archive of questions and answers organized by category, including Chlorine, Cloudy-murky Water, Dealing with Animals in the Pool, Green Water and Algae, Inflatable Pools, pH , Salt Pools and more. Explore the site to learn from the already posted “Q’s and A’s,” and feel free to submit a new question.
Here is a sampling of questions submitted so far by pool owners and answered by an expert.
what is the right clorine level of a swiiming pool? if the test shows 9 should i close the pool ?
The ideal level of free chlorine in the swimming pool is 2 to 4 ppm. 1 to 5 ppm is acceptable and 9 ppm is on the high side. 9 ppm would likely be safe to swim, but could be more of an irritant. Ideally, the level would be alllowed to come down to 5 ppm before swimmers are allowed to swim.
Topic: Cloudy-murky Water
the pool is murky…looks like a pond…when i scoop out leaves the water that drains out from the net is clean. not grean or anything. i’m about to give up and drain the whole thing and start over..but I hate to do it its my last resort
Once the large debris is gone, top up the water and get it balanced and start adding algaecide if any green color to the water and chlorine (be carefull to follow instructions carefully for algaecide as it may go in particular order with your chlorine). The water balance and filtering should clear it up, but it is not a particularly quick process. It may take a few days to clear up from this point. If it is not improving daily, you should check the filter. It may need to be cleaned or not getting enough pressure, etc. Proper filtration along with the chemical treatments is the key to your recovery.
Topic: Green Water and Algae
ok i need help. I just bought a house with a inground 25k gal. pool. I dont know anything about the keep up on one. It has not been used for 2 years and is very green. I need help. Where do I even start?
The best thing that you can do is to learn about your swimming pool. There are many online resources and many local swimming pool retailers offer free or low cost “pool school” to help teach you about pool maintenance. First, a very green pool means algae. You will have to treat this, typically with chlorine and perhaps algaecide. I would suggest taking a water sample to a local retailer who will test the water for you and help you make a plan for opening your pool.
Topic: Inflatable Pools
We have a 900 gal. inflatable pool and frequently use shock, chlorine, clarifier, and anti-fungal conditioner. We find the water stays cloudy even after treating with clarifier every couple of days. We gauge the water treatment using the litmus tests every couple of days, and adjust the chemicals accordingly.
How often should we be treating the water, and how often should we drain and re-fill the pool? Thanks
You should be treating your water as often as the test says that it is out of balance. It is recommended to test 2 to 3 times per week. Just remember you will spend a lot less money making small adjustments than if you lwt it go for a while and have a problem that requires large dosages of treatment chemicals. Also, how often the pool is drained and refilled depends on several factors – bather load, amount of chemicals added, length of season, etc. Typically a partial drain and refill is all that is necessary to “refresh” the water (i.e. drain the water half way down and fill it back up). If you filled it when you started the season with fresh water, you should not need to drain and refill during the season.
how can i measure the ph level of my pool on a daily basis
There are several ways to be able to measure pH in your swimming pool on a daily basis. There are liquid kits, tablet kits, electronic meters and test strips. I would recommend the strips as they are easy to use and low cost if measuring that frequently. Also, you should only need to test the pool daily if it is getting used heavily or the conditions are extreme – heat, rain, dust, fertilizer overspray, etc. Testing 3 times a week should be sufficient under normal conditions (unless you are a public facility and more regular testing is required by regulation).
Topic: Salt Pools
I’ve heard about salt chlorination. Is it better than chlorine?
It is actually the same as chlorine, it is just introducing the chlorine in a different way. In a salt generator system, salt is added to the pool water and a cell installed that can convert this salt into free chlorine. It can be a very effective system and can cut down on maintenance due to the fact that it is constantly producing chlorine. However, it should be treated the same as any other chlorine system with regular testing and adjustment of balancing chemicals like pH and total alkalinity as well as the occasional shock treatment. One word of caution about these systems – the cell used to convert salt to chlorine will need to be replaced every 3 – 5 years and can be very costly. Before you purchase a salt system check to see what the replacement cell will cost you and factor that into your decision.
Topic: Dealing with Animals in the Pool
I have an above ground pool with a deck around it and we just opened the pool up.we are having a problem with the frogs hanging around on the side of the pool.how can i get them away from my pool (without harming my pool).
There are frog repelents available that would work to keep frogs away. There may be precautions necessary for use around the swimming pool. Follow manufacturer’s directions. Another trusted method is to spray a solution of vinegar onto the surface where you keep getting frogs. Frogs do not like the burning sensation this causes. However, the odor can obviously be mildly irritating. Last, make sure you do not leave lights on around or in the pool as this will attract insects which will also attract the frogs.
This poolside scenario will repeat itself many times this summer:
- Child emerges from swimming pool and approaches parent, rubbing his/her eyes.
- Parent takes one look at red-eyed child and exclaims, “There must be too much chlorine in the pool. Stay out of the water for a while.”
- Child agrees reluctantly.
The belief that swimmers’ red, irritated eyes are caused by “too much chlorine in the pool” is an urban legend. The irritation is real, but it is more likely linked to poor swimmer hygiene than to high chlorine levels, a fact that surprises many.
Peeing in the Pool Can be Bad for Swimmer Health
Why Add Chlorine to Pools Anyway?
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 irritated skin. You can check for healthy pH and chlorine levels in your pool this summer by ordering a free pool test kit. Place your order at www.healthypools.org.
The red eye myth is linked to another swimming pool fallacy, sometimes espoused by parents of young swimmers. That fallacy is that peeing in the pool is acceptable because “the chlorine takes care of it [it being the urine].” Peeing in the pool is not unusual: one in five American adults admit to “peeing in the pool,” according to our 2009 survey. The truth is that peeing in the pool can be bad for swimmer health because chlorine reacts with urine (and also feces, sweat, body oils and cosmetics, for that matter) to form products that are irritants and potentially worse. While researchers continue to probe the health effects of these substances–known as disinfection byproducts–they all agree that better swimmer hygiene can help prevent their formation.
Four Hygiene Tips for Showing a Little Kindness to Your Fellow Swimmer:
- Don’t pee in the pool! Take children on frequent bathroom breaks and make sure they know it is not alright to use the pool as a toilet.
- Check swim diapers of young children frequently and change diapers in facility restrooms, not poolside.
- Shower before swimming in the pool and help young children shower. Unshowered swimmers and hot tub users unwittingly contribute small amounts dirt, body oils, makeup, sweat and feces to the water, which add up in a crowded pool or spa.
- Encourage swim team coaches to permit swimmers to take bathroom breaks as needed.
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.
What is a hot tub? A stress-free, aqueous haven, or a water barrel brimming with bacteria? That was the essence of the question addressed in a recent Huffington Post interview with Centers for Disease Control and Prevention (CDC) epidemiologist Michele Hlavsa and University of Arizona Professor Charles Gerba. Although the headlines asserted, “This Will Make You Never, Ever Want to Get in a Hot Tub Again,” these two experts provide the kind of straight talk that can help you enjoy a healthy hot tub experience. As usual, knowledge is power.
Hot Tub Rash and More
In the interview, CDC epidemiologist Michele Hlavsa discussed “hot tub rash,” a condition that may result from using an inadequately disinfected hot tub. Levels of the bacterium
Pseudomonas aeruginosa1 may increase when hot tub disinfectant levels, such as chlorine and bromine, fall. Bacteria in water-soaked bathing suits can cause an infection of the hair follicles of the skin to which wet bathing suits cling. The infection is technically known as Pseudomonas folliculitis. Fortunately, hot tub rash—which may follow the shape of a person’s bathing suit—normally disappears within a week.
Another potential condition associated with inadequately disinfected hot tubs is Legionnaire’s disease, a severe type of pneumonia, and its milder counterpart, Pontiac Fever which according to Ms. Hlavsa, causes flu-like symptoms. These illnesses are transmitted by the inhalation of mists or tiny airborne droplets containing the Legionella bacterium. Senior citizens, smokers and those with weakened immune systems are most susceptible to these illnesses.
Download the following tip sheet for staying healthy in the hot tub:
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.
1Pseudomonas aeruginosa is the bacterium that is the common cause of swimmer’s ear. According to a 2011 CDC report, “swimmer’s ear” accounts for 2.4 million doctor visits and nearly $500 million in health care costs annually.
Cabin Fever Symptoms? Blame it on Frigid Winter, Late Spring and Delayed Opportunity to Swim in the Pool
Annual Pool Survey Find Americans Anxious to Shake Off Winter Blues and Dive In
WASHINGTON, D.C. – One in three Americans – and over half of Americans in the Northeast and Midwest regions – said the long, brutal winter of 2014 caused their worst cabin fever in at least a decade, and the “cure” many are looking forward to is jumping in a swimming pool, according to a national Ipsos survey released today.
Months of heavy snow fall, freezing temperatures and gray skies may be causing more pronounced symptoms of cabin fever. And the cure for the winter blues – that first dip in the pool – may be delayed by a cooler than usual spring.
“Swimming is a perfect cure for anyone suffering from an especially bad case of cabin fever this year,” said Chris Wiant, Ph.D., chair of the Water Quality and Health Council and president of the Caring for Colorado Foundation. “We stand to reap plenty of other health benefits from swimming, too.”
In the recent Healthy Pools public opinion survey, 37% of Americans ages 18-54 selected “swimming” as their favorite way to put the long, frigid winter behind them. “Gardening” was second at 24%, with “biking,” “hiking,” and “camping” each receiving 12-15%. Swimming was an especially popular choice among Americans ages 18-34, who selected it nearly three times as much as any other option.
The survey also found that many Americans were unaware of the many health benefits associated with swimming — and to a greater degree, held mistaken beliefs to the contrary. For example, one in five Americans incorrectly believes that swimming in properly chlorinated pools is bad for those with asthma.
“As long as the pool is properly maintained, swimming is a great activity for people with asthma. Swimming can also improve cardiovascular health, increase strength and flexibility, enhance motor skills, and help manage weight,” said Dr. Ralph Morris of the Water Quality and Health Council. “It’s fun and it opens up a whole world of safe, water-based recreation.”
Green Hair and Red Eyes: Debunking the Chlorine Myths
The new Healthy Pools survey also found that most Americans mistakenly think chlorine in the pool damages hair and makes our eyes red:
- 73% of Americans incorrectly believe chlorine causes red eyes while swimming. The eye-opening reality is that red, irritated eyes are actually caused by chloramines, a group of chemicals that forms when chlorine combines with substances brought into the pool by swimmers. These include body oils, sweat and urine.
- 2 in 5 Americans believe that chlorine turns hair green. This is a very common misconception. When swimmers’ hair takes on a greenish tint, copper is the real culprit. Copper is added to pool water when old brass fittings or gas-heater coils dissolve over time and chemicals to treat algae are used.
“Proper pool chemistry is key to healthy swimming. Swimmers can do their part to stop chloramines from forming in the first place by showering before swimming and not peeing in the pool,” said Michele Hlavsa, chief of the Healthy Swimming Program at the U.S. Centers for Disease Control (CDC). “We also encourage swimmers to check chlorine levels and pH with pool test strips before getting in the pool.”
As part of its award-winning summer Healthy Pools initiative, the Water Quality and Health Council is once again making free pool test strips available to the public this summer. To order a kit, visit www.healthypools.org.
Too Many Americans Are Missing Out on the Health Benefits of Swimming
In order to experience the many health benefits of swimming, people first need to know how to swim. But the Healthy Pools survey found that one in five Americans admit that they lack that skill.
“Becoming a swimmer is the first step to opening a spectrum of fun and healthy activities for the entire family – grandparents, grandkids and everyone in between,” said Thomas M. Lachocki, Ph.D., and CEO of the National Swimming Pool Foundation. “Our Step Into Swim program is just one way people can learn how to swim.”
To learn more about the Water Quality & Health Council and its efforts to raise awareness of the importance of disinfection for public health, please visit www.waterandhealth.org.
For healthy swimming information from CDC, visit www.cdc.gov/healthyswimming.
This Healthy Pools study was conducted among an online sample of 1,506 American adults by Ipsos on May 13, 2014. Margin of error of +/- 2.9 percentage points.
A new report1 by the US Centers for Disease Control and Prevention features statistics on pool chemical incidents during the period 2003-2012. The highlights include:
- An estimated 4,247 people2 per year went to emergency departments for injuries associated with pool chemicals; nearly half of these were younger than 18.
- The most frequent diagnosis was poisoning stemming from inhalation of vapors, fumes or gases.
- More than one-third of pool chemical related incidents occurred at a residence.
- Over 70 percent of incidents occurred over the summer swim season; over 40 percent of incidents occurred on a Saturday or Sunday, a time of increased pool use and decreased likelihood of a trained operator being on duty.
Chemicals are added to pools to maintain healthy conditions for swimming. Disinfectants, for example, inactivate waterborne germs that spread illnesses such as diarrhea, swimmers’ ear and skin infections. Many pool chemical incidents are preventable through operator training. In an attempt to help reduce pool chemical-related incidents, the American Chemistry Council and the Chlorine Institute collaborated to produce a training video featuring guidelines and recommended practices on the safe storage and use of pool chemicals. For example, to prevent chemical inhalation injuries, the video recommends, among other tips:
- Reading and following chemical manufacturers’ directions and relevant safety data sheets.
- Storing chemicals in a well-ventilated, dry and secure area, away from children and animals.
- Separating incompatible chemicals in storage.
- Never mixing acids and chlorine-based chemicals; avoiding cross-contaminating chemicals with common scoops or other equipment.
- Always adding pool chemical to water; never adding water to pool chemical.
- Using personal protective equipment such as goggles and plastic gloves when handling pool chemicals.
The video, available on YouTube and accessible to both commercial pool operators and backyard pool owners, includes safety messages based on information from the CDC.
As the pool season starts, share the video and help make a dent in pool chemical incident stats!
1 Hlavsa, M.C. et al., “Pool Chemical-Associated Health Events in Public and Residential Settings—United States, 2003-2012, and Minnesota, 2013,” Morbidity and Mortality Weekly Report, May 16, 2014/63(19);427-430.
2 (95% Confidence Interval = 2,821-6,930)
One 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.
The 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 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.