It’s a guilty little secret most of us share: peeing in the pool. It seems harmless enough, right?
After all, with all that water and chlorine, how much damage could a little urine really do? As it turns out, a lot more than you might think.
According to the American Chemical Society, the combination of urine and chlorine creates a hidden cocktail of harmful chemical reactions.
These reactions produce substances called disinfection byproducts (DBPs), which are linked to a range of health issues, including respiratory problems like asthma and those infamous stinging eyes.
To put it bluntly: that “classic pool smell” isn’t the smell of chlorine—it’s the scent of chlorine reacting with organic matter like dirt, sweat, and yes, urine.
And here’s the kicker: public pools contain an estimated 30 to 80 milliliters of urine per swimmer.
That might not sound like much, but when you multiply it by the number of people in the pool, the results are unsettling.
So, is peeing in the pool really harmless? Science says no—and it’s time to dive deeper into the facts.
What Happens When Chlorine Meets Urine?
Chlorine is a pool’s best defense against pathogens like Giardia and E. coli, making it essential for keeping the water safe.
However, chlorine doesn’t just eliminate bacteria; it reacts with nearly everything we bring into the pool, including sweat, sunscreen, and body oils.
When urine enters the mix, the resulting chemical reactions lead to the formation of DBPs.
One common DBP is trichloramine, a compound that contributes to the characteristic “pool smell” and is known to irritate the eyes, skin, and respiratory system.
In fact, professional swimmers who spend hours in the pool are at a higher risk of developing asthma due to prolonged exposure to DBPs.
“The more organic matter in the pool, the more DBPs are produced,” explains researchers in the American Chemical Society’s Reactions series.
And urine is one of the biggest culprits—responsible for up to half of all DBPs found in pool water.
Challenging the Myth of Harmless Pool Peeing
For years, many of us have operated under the assumption that a little urine in the pool is no big deal. After all, chlorine is there to clean things up, right?
But this belief is not only incorrect—it’s potentially harmful.
Unlike bacteria, urine is not something chlorine can “kill.” Instead, it reacts with the chlorine, creating harmful byproducts.
While these reactions happen with other organic matter as well, urine introduces a unique problem because of its urea content.
Urea, a nitrogen-rich compound in urine, reacts aggressively with chlorine, producing some of the most irritating DBPs.
This isn’t just a concern for those with sensitive skin or allergies.
Studies have shown that long-term exposure to DBPs can increase the risk of respiratory issues, particularly among competitive swimmers who are repeatedly exposed to high concentrations of these chemicals.
The Role of Medications and Other Factors
Here’s something you might not have considered: the medications you take can make the DBP problem even worse.
Certain drugs, when excreted through sweat or urine, introduce additional compounds that react with chlorine, leading to the formation of even more harmful byproducts.
Combine this with the fact that many people skip the shower before entering the pool, and you’ve got a recipe for chemical chaos.
Dirt, oils, and lotions all contribute to the DBP load, but urine remains the primary offender.
What Can You Do to Make Pools Safer?
The good news is that there are practical steps we can all take to reduce the formation of DBPs and make pools safer for everyone:
- Shower Before Swimming: A quick rinse can remove dirt, sweat, and oils, reducing the burden on chlorine.
- Use the Bathroom: It might seem obvious, but it’s worth repeating: avoid peeing in the pool. Encouraging kids to take bathroom breaks is especially important.
- Advocate for Proper Pool Maintenance: Regular water testing and proper ventilation can help minimize the concentration of DBPs.
By taking these simple steps, we can protect not only ourselves but also the health of those around us.
The Truth About That Pool Smell
Perhaps the most shocking revelation is the truth behind the familiar “pool smell.”
Many people associate it with cleanliness, but it’s actually a sign of a chemical reaction at work. The stronger the smell, the more DBPs are likely present in the water.
This means that a pool with little to no “chlorine smell” is actually cleaner and healthier than one with a strong odor.
So, the next time you catch a whiff of that unmistakable scent, remember—it’s not the chlorine itself, but what the chlorine is reacting with.
Why It’s Time to Rethink Pool Etiquette
Peeing in the pool isn’t just a harmless convenience; it’s a habit that can have real consequences for public health.
From respiratory issues to eye irritation, the effects of DBPs are far from trivial.
As the American Chemical Society puts it, “We’re much dirtier than we think.”
But by changing our habits and spreading awareness, we can help reduce the chemical load in pools and create a safer swimming environment for everyone.
So, the next time you’re tempted to “let it go” in the water, think twice. Your fellow swimmers—and your lungs—will thank you.
In the end, the science is clear: peeing in the pool is anything but harmless.
But with a little effort and a lot of awareness, we can tackle this problem head-on, ensuring that every dip in the water is as clean and refreshing as it should be.
