I am fortunate to have grandparents who own a swimming pool, and grew up swimming in their pool whenever I had an opportunity to do so. Additionally, I am a certified lifeguard, so swimming is an important activity to me. When one thinks of the dangers of swimming pools, often words like “drowning” and “running by the edge of the pool and slipping” come to mind. Interestingly enough, there are many other hazards that take place in the pool which even professional swimmers and lifeguards may not know about.
There are substances from the environment that can negatively and undesirably affect chromosomes and genes of frequent swimmers. Research indicates that chlorine can create DBPs (disinfection by products) – which can cause DNA damage and cancer. The World Health Organization (WHO) states that there are three ways for chemicals to enter the body: inhalation, digestion, and absorption. When it comes to swimming in a chlorinated pool, the possibilities exist for all three.
The addition of chlorine to swimming pools is foremost a crucial genotoxic matter. While one is swimming, swallowing water from the pool is a frequent occurrence. To put this into perspective, a swimmer who weighs around 50 kg may ingest around 100 mL of water, which contains 25 mg/L of cyanuric acid and 3.5 mg/L of trichloroisocyanuric acid. The swimmer in fact gets less than 1/100,000 of the lethal dosage of both acidic compounds so the good news is that an average swimmer is not expected to suffer the potential risks of chlorine to a life- threatening extent.
Most people know that chlorine cleans the pool water, but what is the actual mechanism by which it does so? When chlorine is added to pool water, chlorine breaks down into hypochlorous acid and hypochlorite ions which can attack the lipids in the cell wall and destroy enzyme function, thus rendering the oxidized cells harmless. A few examples of broken down microorganisms in pool water are skin cells, sunscreen, sweat, spit, oils, and lotions. After chlorine kills the microorganisms and bacteria in the water, chlorine is then neutralized by combining with ammonia and is deemed harmless. However, when chlorine combines with cyanuric acid (present in urine and sweat), cynogen chloride forms and poses a potential danger for frequent swimmers. Astonishingly, national team members have said that nearly one hundred percent of competitive swimmers urinate in the pool.
As one may know from experience, chlorine has a very distinct smell, which some people find unpleasant. However, chlorine in pool water is deemed mandatory as a disinfectant. Chlorine is generally used for such disinfection; gaseous chlorine or sodium hypochlorite and cartilage filters usually disinfect public pools, and home pools typically use stabilized chlorine. These methods produce a variety of disinfection byproducts (DBPs), such as trihalomethanes (THMs), which are regulated carcinogenic DBPs that have been detected in the blood and breath of swimmers and of non swimmers at indoor pools.
So why do we want to stay away from ingesting DBPs and THMs? Exposure to those DBPs can have elevated risks to human health. Chlorine produces DBPs and THMs, which are both linked to potential cancer, reproductive and developmental health risks from disinfection byproducts (DBPs) in water. DPBs in water form, when found in disinfectants like chlorine, are used to control microbial pathogens.
Additionally, chlorinated pool water is being blamed for causing a higher percentage of skin cancers each year. If you are exposed to chlorinated water for an extended period, the chemical will produce a toxic substance that can produce a rash or other infection on the body. Chlorine actually promotes the generation of free radicals within the body, and specifically the skin. Free radicals have been shown to cause cancer.
A much greater number of DBPs were found among indoor pools than outdoor pools. The reason this is due to sunlight, which helps to speed up the process in which chlorine is neutralized. By swimming in an indoor pool, the chlorine neutralization process is decreased and will therefore increase the potential for chlorine to react with other substances.
This paper is not meant to discourage anyone from participating in swimming, but rather to educate. There are many physical benefits to swimming. However, just like any action in life, everything has a consequence. Staying active by swimming is a great way to exercise. However, there are precautions that can be taken to avoid the hazards listed above such as: limiting swimming time, avoiding the ingestion of too much water and rinsing chlorinated pool water from your body after swimming.