Contaminated water in swimming pools can lead to a number of recreational water illnesses (RWI). These illnesses can lead to a number of unpleasant infections and side effects, so pool owners must take steps to keep water safe and sterile. Many pool owners add chlorine to the water to kill germs, but it's important to optimize the chemical content of the water. Learn more about the effects of chlorine in swimming pools, and how chlorinated water can affect your family's health.
How chlorine kills germs
Pool owners started using chlorine to disinfect pool water in the 1920s, and the chemical is available as a granular powder, liquid or gas. When you add these forms of chlorine to water, they create a substance called hypochlorous acid. This acid is really good at killing bacteria and viruses, including salmonella and E.coli.
Bacteria carry a net negative charge, which repels other negatively charged particles in the water. Hypochlorous acid is neutral, which allows the substance to invade and kill bacterial cells. Scientists don't fully understand how chlorine works against viruses. Indeed, some viruses have a protective shell, which makes chlorine less effective. As such, chlorine cannot kill every RWI in your water, but it is one of the best disinfectants you can use.
Recommended chlorine levels
In the United States, the health department recommends that chlorine in swimming pools stays between one and three parts per million. Owners should also measure the pH level of water in a pool, as this has a direct effect on chlorine. As acidity rises, chlorine's germ killing abilities decrease. The ideal pH range for effective chlorination is between 7.2 and 7.8.
The risk from disinfection by-products
When chlorine comes into contact with water-borne impurities like perspiration, body oil and urine, the reaction causes chemical by-products. One of these by-products, chloramine, is an irritant that can cause eye and skin irritation, as well as the strong chemical odor you often find in public swimming pools.
Many people believe that this smell occurs because there is too much chlorine in the water. In fact, according to the American Chemistry Council, this problem occurs because there is not enough chlorine in the water. Excess impurities in the water can lead to excess chloramines, so pool owners must install effective filtration systems.
Other potential health risks
Researchers continue to investigate links between chlorine in swimming pools and serious health conditions. From several animal studies, researchers have found that there is a possible link between pool chemicals and asthma and bladder cancer. One study found that swimmers exposed to chlorine were more likely to suffer from asthma because the chemical made it easier to penetrate the lining of the lungs. In another study, after forty minutes of swimming, people showed an increase in markers of DNA damage linked to cancer. That aside, long-term evidence remains inconclusive.
The New York University College of Dentistry published a report in 2011 that outlined the risks of tooth damage from swimming pool chlorine. Researchers found that ineffective pool chlorination can lead to rapid erosion of dental enamel. In one subject, excess acidity in the swimming pool caused severe tooth decay over a five-month period for one man who swam for ninety minutes each day.
How your behavior affects pool hygiene
Some people may mistakenly believe that chlorine deals with all water impurities, but this is not the case. Chlorine does not dissolve organic matter, and when the chemical reacts with these impurities, it disappears. Bad pool habits (like urination in the pool) use up available chlorine, and leave harmful impurities in the water that can encourage bacterial growth.
Chlorination is an effective way to make sure the water in your swimming pool stays safe, but it's important to monitor chlorine levels. Too much or too little chlorine can lead to harmful side effects for you and your family. Click here for more information.