While chlorine has long been blamed for the discolouration in people’s eyes after a swim, we asked an expert to tell us what’s really going on.
According to Timothy Millard, Fraser Health’s manager of environmental health, the redness in your eyes after swimming is actually caused by everything else in the water that chlorine goes in to kill.
Millard explained that the ammonia in urine and human sweat reacts with chlorine to form chloramine. Chloramine causes red eyes and a distinctive odour when swimming.
“That pungent smell when you enter a pool is from the chloramine, not the chlorine,” said Millard. The former lifeguard said to address the issue of contaminants and chloramine formation, experts recommend managing chlorine levels carefully.
“To combat high chloramine, you actually put in more chlorine to burn it off,” said Millard.
He explained that the presence of chloramine reduces the effectiveness of chlorine. This means that more pee and dirt in the pool lead to more chloramine production, which in turn decreases chlorine’s effectiveness.
It’s essential to practice good pool etiquette to avoid excessive chloramine, which can cause red eyes. Most health authorities, such as Fraser Health, will also oversee this process, and noncompliance will force the facility to shut down.
Be sure to use the bathroom first and rinse off any sweat and dirt before hopping into the pool. These methods can help reduce the formation of chloramines and ensure a more pleasant swimming experience for everyone.
Chlorine tablet for swimming pools (Studio Nut/Shutterstock)
The presence of chloramine in the pool water is a clear indication that the chlorine is working to neutralize contaminants, but this process also produces eye and skin irritants.
“When the chlorine interacts with skin cells, body oils, lotion, shampoo, sunscreen, all that kind of stuff- it creates different chlorine compounds called chloramines, and that’s generally what you often smell,” said Millard.
Swimmers may also experience dry, itchy skin due to the high presence of chloramines.
Many people believe that a strong chlorine smell indicates a clean pool, but in reality, it signals the presence of chloramines. Millard said a well-maintained pool should have little to no odour.
The stronger the smell, the more contaminants are present, and the higher the likelihood of eye and skin irritation, Millard added.
The risks of swallowing unclean pool water
Chloramines not only cause red eyes but can also lead to other health issues.
As stated by the Virginia Department of Health, high amounts of chloramines are known to irritate the respiratory tract, which can be particularly problematic for individuals with asthma or other respiratory conditions. However, well-maintained pools should not see levels to that extent, researchers say.
Another important measure to take when swimming is to avoid swallowing the water itself.
While it’s far from toxic, it definitely is gross.
When people swallow a bit of pool water, they are likely consuming trace amounts of pee and bodily dirt.
According to a report from the Office for Science and Society at the University of McGill, “chloramines are safe at the levels used in drinking water, about 1 ppm, but higher concentrations are different.”
People who get into the water can carry in and spread germs. #SwimHealthy http://t.co/wsCJw3zWB0 pic.twitter.com/4A2liL48Zm
— CDC (@CDCgov) May 20, 2015
Although there isn’t a colour test to measure the urine content in swimming pool water, researchers from the University of Alberta (UoA) have discovered a sweet method to estimate the amount of urine present.
The secret lies in the artificial sweetener acesulfame potassium, which is present in numerous beverages and baked goods. Since no artificial sweetener is added to pool water, any amount that is found must come from people’s pee, as stated by the researchers at UoA.
Millard said this process is not applied to pools across the province.
“If we can confirm there’s that there’s an issue then we’ll go in and test the pools,” explained Millard. He said most commonly, Fraser Health would test for instances of pseudomonas in hot tubs, which can be cause for skin irritations.
Practice pool etiquette
It’s important to practice good pool etiquette to avoid excessive chloramine in a pool, which can cause red eyes.
Be sure to use the bathroom first and rinse off any sweat and dirt before hopping into the pool. Also, avoid the pool if you have an open wound or are feeling ill, as these can introduce bacteria into the water.
These methods can help reduce the formation of chloramines and ensure a more pleasant swimming experience for everyone.