We love swimming pools. Many people know just how much water they use en masse, and the energy required to filter them regularly—but far fewer know about the chemical contaminants in them. The chemicals regularly used to disinfect pools, chlorine and bromine, are environmentally harmful at low levels, especially for organisms living in the water and soil where the pool water is disposed of. If stored incorrectly, the chemicals in pool water may release gaseous chlorine, which is extremely reactive, particularly with fluids often found in pools such as urine, and can cause major injuries. Other chemicals used to clarify the water and discourage algae growth can wreak havoc on ecosystems if drained carelessly, disrupting wildlife growth and adding toxins to the water supply.

The other major drawback of pool chemicals is their effects on the human body. Professionals have stated that it’s much safer to swim with pool disinfectants like chlorine and bromine than without swimming without them exposing you to a wide range of potentially harmful microbes. However, many of the greatest dangers come in practice. A study examining the presence of a synthetic sweetener (acesulfame-K), often used as a urinary marker due to its high consumption and therefore ubiquity in excretion, found that over 250 samples from 31 pools across Canada contained acesulfame-K. The interaction between chlorine and urine, or other body products like lotion, sunscreen, shampoo, and conditioner, forms organic compounds that can pose serious respiratory threats and irritation to the eyes. Proper ventilation can prevent these fumes from reaching dangerous levels, but it’s still important to be cognizant of the environmental and physical harm that pool chemicals can cause upon reaction.

So what can we really do about this? Well, there aren’t exactly environmentally-friendly substitutions for the construction and maintenance of a pool, but there are habits you can put in place to make sure your pool isn’t causing undue harm; and if you don’t own a pool, you can encourage people you know to do this. Using a pool cover to reduce evaporation and therefore water usage is the first. The second is to mix chlorine and bromine as pool chemicals to make sure you aren’t using too much of either. Consider how eco-friendly your garden or backyard landscaping is, too, and whether or not you’re letting the present ecosystem flourish or destroying parts (ripping up grass to put in turf, spraying pesticides, etc.) It’s still better to use pool chemicals than not to—but by installing a safe ventilation system, being careful about what you’re putting on your body before you swim, like lotion and sunscreen, and checking the chlorine levels regularly, you can reduce the pollutants and toxins in your swimming pool. And at the end of the day, the age-old advice still holds true: don’t pee in the pool.

Works Cited

“17 Ways To Make Your Pool More Eco-Friendly (Infographic).” Pool Care Guy. April 20,

2018. https://poolcareguy.com/eco-friendly-pools/.

“Swimming-related Illnesses – Healthy Swimming.” Centers for Disease Control and

Prevention. July 8, 2022,

https://www.cdc.gov/healthywater/swimming/swimmers/rwi.html.

Chemical Emergency Preparedness and Prevention Office. Chemical Emergency

Preparedness and Prevention Advisory SWIMMING POOL CHEMICALS: Chlorine.

United States Environmental Protection Agency, 8(1). July 1990.

Office of Solid Waste and Emergency Response. Safe Storage and Handling of Swimming

Pool Chemicals. United States Environmental Protection Agency, EPA

550-F-01-003. March 2001.

Teo, Tiffany, et al. Chemical contaminants in swimming pools: Occurrence, implications

and control. Environment International, 76:16-31. December 11, 2014,

https://pubmed.ncbi.nlm.nih.gov/25497109/.

Image credits: 

Responding to Pool Contamination | Healthy Swimming | CDC