Differences between swimming in the ocean and swimming in a pool


Beware of the swimming cesspools: you have no idea what's in the water!

The main points of this article
  1. The water in Indian public pools is only changed a few times a year. It is never changed when dead rats are found in it.
  2. They never tell you how many pool-goers catch serious diseases as the chlorine levels are often too low when the pool is crowded or when the voltage fluctuates in the chlorine salt pools.
  3. The pool's "filters" do not actually filter the water: they only sanitize it to some extent by killing bacteria, so you swim in a toxic soup of dead bacteria. Chlorine does not kill most viruses, Protozoa, Helminths, Ammonium, Cryptosporidium, etc.
  4. The filters's capacity is too low to filter the pool's water: they only take out large particles (which makes the water transparent) and dilute the pool's dirty water with a little partially filtered water.
  5. All users occasionally sweat, sneeze, spit, pee and poo in the pool. The chemical reactions between these, cosmetics, sunscreens and chlorine create substances 10000 times more toxic than the chlorine itself. Your skin and your hair absorbs all this, you occasionally swallow the pool water, and inhale huge amounts of chlorine.
  6. 19% of drowning deaths in the US involving children occur with certified lifeguards present: there often are simply too many pool users per lifeguard, which is most often the case in India.
  7. The pool, due to the variations in depth and other factors, is less safe and less convenient for a learner swimmer than a shallow, calm beach.
  8. Learning how to swim in the pool will not help you avoid drowning in the sea.
  9. The crowded Indian pool is not a suitable place for those women who want to avoid being ogled at or touched by men there.

Why do people go to swimming pools?

The summer approaching, both adults and children, often sent away by their parents to "swimming camps", are trying to cool down in every possible way. Well, is it just the scorching sun that drives people to swimming pools? The pool has become quite a modern status symbol. Cannot swim? No problem, just stand and soak there. While the Indian middle class hurry to the crowded public swimming pools that are often found at upscale hotels, the well-to-do Indians can afford to have a private swimming pool that could be cleaner - if only slightly.

    Do you actually know what's in the water?

  • 1 in 8 routine pool inspections conducted during 2008 in the US identified serious violations that threatened public health and safety and resulted in an immediate closure. No swimming pools in India have been closed down. La Piscine, the largest pool in Bali, Phuket, Unawatuna, Auroville, is regularly shut down whenever incidents like these occur: "A big rat fell in the pool last night and drowned. We have to close the pool for 24 hours to shock the water", "Too many people are at risk of infection and it is a huge inconvenience to everyone to have to close the pool when your child pees and poops in the pool." While in Auroville cases like this are regularly publicly acknowledged, have you ever read a similar announcement at a Pondy pool?
  • However, one thing between La Piscine and other pools is common: they lie to you about what's there in the water. "This pool is not contaminated with chlorine or other chemicals like most public pools" is one of such practical jokes played on you.
  • A recent study links the application of disinfectants in recreational pools to health problems such as asthma and bladder cancer. "All sources of water possess organic matter that comes from decaying leaves, microbes and other dead life forms,” Michael Plewa, a professor of genetics at the University of Illinois says. “In addition to organic matter and disinfectants, pool waters contain sweat, hair, skin, urine, and consumer products such as cosmetics and sunscreens from swimmers.” These consumer products are often nitrogen-rich, causing concern that they may contribute to the generation of nitrogenous disinfection byproducts, Plewa adds.When mixed with disinfectants, these products may become chemically modified and converted into more toxic agents. These disinfection byproducts can mutate genes, induce birth defects, accelerate the aging process, cause respiratory ailments, and even induce cancer after long-term exposures. Results proved that all disinfected pool samples exhibited more genomic DNA damage than the source tap water, Plewa says.  The risk comes from disinfection byproducts (DBPs), which are formed when organic materials like hair, skin, sweat, dirt and urine react with the large amounts of chlorine used to sanitize the pool water. DBPs are over 10,000 times more toxic than the chlorine itself, and in the first study of its kind to examine exactly what kind of damage these toxins are doing to swimmers, the results were alarming. Researchers measured evidence of genotoxic (DNA damage that may lead to cancer) and respiratory effects on swimmers who swam in a chlorinated pool for 40 minutes. Already, it’s known that trihalomethanes (THMs), one of the most common DBPs, are Cancer Group B carcinogens, meaning they’ve been shown to cause cancer in laboratory animals. They’ve also been linked to reproductive problems in both animals and humans, such as spontaneous abortion, stillbirths, and congenital malformations, even at lower levels.  These types of DBPs can also:
    • Weaken your immune system
    • Disrupt your central nervous system
    • Damage your cardiovascular system
    • Disrupt your renal system
    • Cause respiratory problems
  • DBPs are also the likely culprits for the increased incidence of sinusitis and sore throats among swimming instructors, as well as the negative impact of chlorinated pools on the respiratory health of children and adolescents. In fact, one study found that in children with allergic sensitivities, swimming in chlorinated pools significantly increased the likelihood of asthma and respiratory allergies.
  • The vast majority of swimming pools use chlorination as the sanitizing method to maintain a "healthy" level of water hygiene. Chlorination is a dangerous but institutionalized and accepted method of pool sanitation. Chlorine concentrations in water decline very quickly under a variety of swimming pool and environmental conditions. To combat the decline in effectiveness problem, pool managers often over-chlorinate a pool (>3 ppm) to offset chlorine reduction and occasionally use even more as a "precautionary measure" to kill "missed" bacteria. A heightened concentration of chlorine often leads to excessive absorption through the skin and inspiration leading to breathing problems in many swimmers. There is considerable variation in chlorine concentrations in fresh and salt water pools with the latter usually being much higher (Beech et al., 1980). The general rule-of-thumb about an over-chlorinated pool is: If you can smell the chlorine in the pool environment, it is dangerously high. When chlorine escapes from pool water it is diluted in the available air space. The smaller the air volume, the greater the concentration of airborne chloramines (the nasty product of pool chlorination). Many modern pools are structured to not facilitate removal of escaping chlorine. It is possible, that an exercising swimmer could be exposed to 30 or more times the volume of escaping chlorine byproducts than that experienced by a passive onlooker. Many swimmers agitate the water through vigorous exercise which accelerates the release of chlorine into the atmosphere. When chlorine concentrations in the air are measured as part of pool maintenance, it is usually done when no swimmers are present and water is minimally disturbed. Thus, when a pool is deemed "safe" it is because of an arbitrary measure in rare conditions. It bears no relationship to what exists in a pool busy with competitive swimmers when the atmosphere of a "safe" chlorinated pool becomes toxic. Chlorine reacts with bodily proteins to form chloramines; the most volatile and prevalent in the air above the pool surface being nitrogen trichloride (NCl3) Regular attendance at chlorinated pools by young children was associated with an exposure-dependent increase in lung epithelium permeability and increase in the risk of developing asthma, especially in association with other risk factors. It is postulated that increased exposure of children to chlorination products in indoor pools might be an important cause of the rising incidence of childhood asthma and allergic diseases.
  • The toxic effects of chlorine products in swimmers training in indoor pools are greater in younger than older swimmers. Young swimmers are therefore at a greater health risk. The hypersensitivity of young children to pool chlorination was also emphasized by Wood, Colombo, and Benson.
  • Erosion of dental enamel was reported in competitive swimmers from the same club. Symptoms compatible with dental enamel erosion were reported by 3% of non-swimmers (9/295), 12% of swimmers who were not members of the swim team (46/393), and 39% of swim team members.
  • Zwick et al. (1990) compared competitive swimmers (N = 14) and matched control subjects (N = 14) for clinically manifest allergies, subclinical sensitization to aeroallergens, imbalance of the cellular immune system, and bronchial hyperresponsiveness. Conjunctival or respiratory symptoms were found in 11 swimmers and in 3 controls. Sensitization to aeroallergens was confirmed in 9 swimmers by a skin test and in 11 swimmers by a radioallergosorbent test. Control subjects recorded 4 and 5 respectively. An altered cellular immune system, (i.e., imbalance in T-cell system, B-cell system, or natural killer cells) was detected in 7 swimmers and 2 controls. Bronchial hyperresponsiveness to methacholine was seen in 11 swimmers and 5 controls. This higher incidence of allergic diseases and subclinical sensitization to aeroallergens, disorders of the cellular immune system, and bronchial hyperresponsiveness in competitive swimmers was attributed to repeated exposure to chlorine in swimming pools.
  • In 2008, almost 4,600 Americans visited an emergency department for pool chemical-associated injuries. The most common injury diagnoses were poisoning, which includes ingestion of pool chemicals as well as inhalation of vapor, fumes, or gases and dermatitis/conjunctivitis.
  • Greater toxin absorption occurs through the skin than through breathing.
  • Nelemans et al. (1994) reported a positive association between a history of swimming and melanoma risk even after adjusting for sun exposure history. This suggests that carcinogenic agents in water, possibly chlorination by products, may play a role in melanoma etiology. Helenius & Haahtela (2000) reported the risk of asthma is especially increased among competitive swimmers, of which 36% to 79% show bronchial hyperresponsiveness to methacholine or histamine.
  • Uric acid from human urine mixes with chlorine to create the cyanogen chloride (CNCI) and trichloramine (NCl3). CNCI is a toxic compound that can harm organs like the lungs, heart, and central nervous system. NCl3 has been linked with acute lung injury. So the next time you’re at the swimming pool, heed those warning signs but also be wary of your fellow swimmers. And it’s probably best to avoid the kiddie pool.
  • Why is there so much poop in swimming pools? A new report from the Centers for Disease Control and Prevention found that more than half of all public pools had tested positive for E. coli, the bacteria most commonly associated with fecal matter.
  • Heart disease was virtually unknown before 1900. It hasn't skyrocketed because we live longer, nor just because infectious diseases have been suppressed (source). It's certainly not due to saturated fat. And the main problem may not be trans fat either. There's one thing that we consume a whole lot more of, and that's water. Don't worry about cholesterol; worry about chlorination. Chlorine is extremely reactive. That's why it's so effective as both bleach and as a disinfectant, i.e., poison. And if it's going to kill things by reacting with organic compounds, it's certainly going to react with your organs. That's why drinking chlorinated water is such a problem. Worse than putting chlorinated water into you is putting yourself into it. For one, there's usually more chlorine in a spa or swimming pool than in tap water: specifically, 3 parts per million vs. 0.5-2 parts per million, respectively. For comparison, .2 ppm will quickly kill most fish. Most people can't smell chlorine in the air at levels under 3.5 parts per million (ppm). When you soak in a pool or spa, what you're usually smelling — the same thing that irritates your eyes, skin, and lungs — is "used" chlorine, i.e., the compounds created when chlorine combines with organic compounds in the water. These include human hair, skin, sweat, dead insects, mucus, and yes, pee: urine it. This odious detritus is not just nasty; it's unnatural. You may have heard not to mix bleach and ammonia (which is what stale urine turns into) because it creates a poisonous gas. That gas, a chloromine related to chloroform, an anaesthetic abandoned after it killed enough people, is a type of organochlorine. This class of compounds includes the most toxic substances known. The worst of these is TCDD, a.k.a., dioxin. Chlorination creates organochlorines that mimic human hormones and can cause "lower IQ, reduced fertility, genital deformities, breast cancer, prostate cancer, testicular cancer, dramatic reductions in human sperm counts, and abnormalities within the immune system" (Your Water, Your Health, 19). Chloromines specifically are known to cause or exacerbate asthma and emphysema and have other adverse health effects (see "Tap Water Toxins: Is Your Water Trying to Kill You?).

Aren't filters supposed to filter everything bad out?

  • Some facilities advertise "saltwater" pools. However, saltwater pools are not, in fact, chlorine-free. Do you remember the formula for salt? Sodium chloride. As we all know, salt dissolves in water. It dissolves because it separates into sodium and chloride. The chlorine liquid or tablets commonly used in conventional chlorination are the same thing saltwater pool systems generate from salt. The chlorine level in a saltwater pools is kept at 2-3 ppm. This is the same amount as is recommended for a regular pool. Why then do saltwater pools smell less and feel better? It's not, as some would have you believe, because the chlorine in public pools is kept at higher levels. It's because in conventional pools, the chlorine level often falls too low. If free chlorine levels are kept at 1 ppm or more, chloramines do not build up. If levels drop too low, however, it takes a "shock treatment" to correct the problem. A "shock" is a kind of deep cleaning. A mega dose of chlorine is commonly used. You're basically "dropping a bomb" and killing everything. Shocks are only necessary in big pools where it's not feasible, as it is with a hot tub, to simply change the water. Since shock treatments create chlorine levels considered unsafe even by conventional standards, you have to wait for levels to come back down through evaporation. Rather than have to wait, people often don't use a strong enough dose. They routinely add too little chlorine to the shock treatment, and this actually makes the problem worse. Apparently, with saltwater treatment, chlorine levels are more easily maintained at sufficient levels to prevent chloramine formation. There are other advantages to saltwater filtration as well: the pH is kept near neutral and the water is softer (less calcium). However, the same additional chemicals that are usually incorporated into chlorine tablets may still need to be added separately   Pools that use chlorine tablets (tri chlor), and pools that use salt (sodium chloride) are very similar. The first thing to understand is that both use chlorine. Both systems require sodium bicarbonate, calcium chloride, and muriatic acid to make chemistry adjustments. Salt chlorine systems require the addition of stabilizer (cyanuric acid) and salt which tablet pools do not. Stabilizer holds chlorine in the water. Chlorine tablets have this chemical in them already.
  • The salt never leaves your pool by evaporation NOR is it ever used up. You would NEVER want this level of cyanuric acid in your pool. Obviously this retailer has been misinformed by the propaganda laid out by the chemical companies. Yes, cyanuric acid helps in SMALL quantities. But as cyanuric acid increases, the effectiveness of chlorine decreases, which in turn requires more chlorine to achieve the desired effect. The tablets (unfortunately) contain MORE cyanuric acid, which now puts us in a dangerous cycle of adding more cyanuric acid with each tablet... and having to add more chlorine to keep up with the increased levels of chlorine. The chemical companies do not tell you this as it translates to more profits for them.
  • More filtration time and a little less chemicals? You would pay for it with electricity.  Chlorine tablets cannot and will not suffice for large pools with high bather loads the average tablet will only sanitize 10,000 liters. The UV lights also lose there effectiveness after around 7 months.
  • Contrary to popular belief, bromine, with just as many "disinfection byproducts" as chlorine, can be just as problematic. For one, it interferes with thyroid function. Ozone or UV treatment systems are far healthier but are pretty expensive.
  • All of the above "purification" systems only "sanitize" the water. They kill stuff. They don't remove contaminants. That's typically done with filtration. The question is the rate of filtration vs. the rate of contamination. If people get the pool dirty faster than you can clean it, you have a problem. Again, it may just be a matter of building a bigger and more powerful system.
  • On an average, around 150 people visited Sampourna daily, and on weekends the figure touches 400 a day
  • Somehow people prefer to imagine that a swimming pool is a pipe through which a current of clean water enters at one end and the dirty water exits through the other end. You can use carbon filters, but if you want to achieve a high rate of filtration, the water cannot be circulated fast, and you will have to change the filter very often.
  • Chlorine does not kill most viruses, most Protozoa, Helminths, Ammonium. Besides, Cryptosporidium (or Crypto), is an extremely chlorine-tolerant parasite that can survive in a properly chlorinated pool for 3.5–10.6 days.
  • Escherichia coli, a fecal indicator was found in 58% of pool samples in the US, the CDC informed. Fecal material (poop material) can get into a pool during a formed or diarrheal fecal incident in the water or washing off of swimmers bodies. In other words, pool water can become contaminated if people don't shower beforehand or poop while in the pool.
  • With most outdoor pools, chlorine concentrations at the surface are usually low because environmental breezes whisk the contaminant away and replace it with "fresh" air. However, when outdoor pool sides are high, the atmosphere is heavy with moisture, and there is no breeze, dangerous atmospheric chlorine conditions can be produced. The atmosphere acts as a "blanket" that holds the escaping chlorine down at the surface where swimmers breathe. That results in hyper-chlorination in outdoor pools. This condition happens quite frequently, particularly early in the morning when "serious" swimmers are training.
  • Alternative water treatments (e.g., ozone, bromine, ultra-violet light) have usually relied on a single chemical treatment. That focus on using one agent could be a limitation for devising an adequate substitute for the hyperchlorination of heavily used pools. The associated amount of combined chlorine was much lower when disinfection was by ozone/chlorine. This produced more acceptable bathing conditions (Wyatt & Wilson, 1979). Ozonation allows markedly reduced levels of chlorine in pool water.
  • Unlike the sea, the pool has no microorganisms to consume both organic and inorganic pollutants. Another distinction is how differently the dirty water is merely diluted with the cleaner or "filtered" water. Everybody understands how quickly very small quantities of the polluted water on the beach are very quickly diluted by the huge mass of the ocean water. What happens in a swimming pool, however, is a totally different story, where very small quantities of the "filtered" water are thrown back into the dirty water.
If you're a hotel or athletic club, protecting yourself from a lawsuit "is not always about doing the right thing, but rather about doing the typical thing." Sadly, what's typical in this age of antibacterial soap, is pathological biophobiathat, for example, lead to 30% of all younger generations Germans being diagnosed with allergies. People regard the ocean with a certain amount of awe mixed with fear as they don't have the skills to handle it.

Learning to swim in most swimming pools can be either dangerous or problematic for certain reasons.

  • First, the depth of most pools sharply increases in some areas, and the bottom is extremely slippery.
  • Secondly, the areas of uniform optimum depth suitable for a learner of a particular height, which is usually at chest level, is actually very small in most pools.
  • The bad habits of grabbing the ropes or the edges of the pool stands in the way of developing proper swimming habits and gaining confidence.
  • And the buoyancy of the water in the pool is much lower than the buoyancy of the seawater.

Aren't swimming pools a safer place than the ocean?

  • In the USA, if you both own a gun and have a swimming pool in the backyard, the swimming pool is about 100 times more likely to kill a child under 10 than the gun is. Public attitudes towards pools are much more cavalier because people simply do not know the facts.
  • In the US, 58% nonfatal (3,341 cases, many of which end up with very serious permanent injuries) and 17% (683) fatal drownings take place in swimming pools every year, while just 7% of nonfatal cases (412) happen in the ocean. There are 1 to 4 nonfatal submersions serious enough to result in hospitalization. An estimated 5,000 children ages 14 and under are hospitalized due to unintentional drowning-related incidents each year; 15 percent die in the hospital and as many as 20 percent suffer severe, permanent neurological disability. In the United States in 2009, there were approximately 301 million swimming (not merely "bathing") visits each year by persons over the age of six, and there are an average of 3,868 unintentional drowning deaths per year.
  • Compare it with Tamil Nadu, with its 1,837 drowning deaths in 2011. We do occasionally hear about cases like the one at a Dubai villa where playback singer KS Chithra's eight-year-old daughter Nandana died after falling into it. Extremely few pools have isolation fences around them, and still fewer lifeguards. There are 10.4 million residential swimming pools in the United States where, in 1997 alone, 550 children under the age of 10 drowned. There are also 309,000 public swimming pools there where 19% of drowning deaths involving children occur with certified lifeguards present. How well do Indian lifeguards monitor swimming pools in India is anybody's guess.
  • People like to believe that being able to swim in a pool somehow increases their chances of survival outside it. In the US, only 50% of fatal drownings occur in natural bodies of water. Of course, we do occasionally read stories like the one about the two NRI doctors who recently drowned off the coast in Tenerife. The Indian doctors tried to rescue their children who had been swept out to sea by a freak wave that hit the rock on which they were playing. The children were eventually rescued by a German -not by an Indian, of course - tourist who could swim very well in the ocean. After all, swimming classes are compulsory in Germany.
  • As long as it is mostly Europeans, Americans or Australians who continue to swim on the ocean beaches, the media will regularly keep informing us about incidents like the recent one when almost 300 Korean schoolchildren drowned after a ferry sank on its way to a holiday island of Jeju. Almost 300 mostly schoolchildren, most of whom had learnt to swim in a swimming pool, died. Had they learnt to swim in rough ocean, they could have easily survived.