Most of us just want to finish our business and dash away, but the humble stream of urine has a surprisingly adventurous side. From tracking swimmers’ secret contributions to pools, to powering tiny lights in remote villages, the 10 unusual urine discoveries highlighted below showcase science’s knack for turning the ordinary into the extraordinary.
10 The Pool Pee Test
10 Unusual Urine Insights
It’s a common, albeit frowned‑upon, habit: people relieving themselves in public swimming pools. The chemicals we add to keep the water clear react with the nitrogen‑rich compounds in urine, spawning by‑products that can be less than friendly to swimmers. Until recently, there was no straightforward way to gauge just how much “extra” liquid ends up in the chlorinated oasis.
In 2017, a team of toxicologists from Alberta devised a clever workaround. They zeroed in on a chemical that slips out in urine unchanged, even after the liquid mixes with pool water. Their candidate? The artificial sweetener acesulfame‑potassium, a staple in many packaged foods and drinks.
The researchers gathered water samples from 22 public swimming pools and eight hot tubs across two Canadian cities, while also collecting the tap water used to fill those venues. By measuring the sweetener’s concentration, they could infer how much urine had been introduced.
The findings were striking: the sweetener’s level in pool water was up to 571 times higher than in the source tap water. Using those numbers, the scientists estimated that the pools contained anywhere between 30 and 75 liters (roughly 7.9–19.8 gallons) of urine, depending on the pool’s size.
9 The Urine Database
Urine is nothing short of a chemical treasure chest. After seven years of painstaking analysis, a 2013 study finally catalogued the full spectrum of compounds that can appear in human urine. The result? An online database boasting over 3,000 distinct chemicals.
Of those, bacteria contributed the fewest—about 72 substances—while the human body itself produced 1,453. The lion’s share, roughly 2,282 compounds, originated from external sources such as medications, food additives, cosmetics, and environmental pollutants. Altogether, the identified chemicals spanned 230 separate chemical classes.
The sheer breadth of the inventory surprised the researchers. Moreover, the study uncovered more than 480 chemicals that appear exclusively in urine, overturning the long‑held belief that blood was the superior medium for comprehensive metabolic profiling.
8 The 21‑Second Rule
In 2014, a quirky team of zoologists and engineers set out to time how long mammals take to empty their bladders. By observing animals at Zoo Atlanta and combing through countless YouTube clips, they discovered a striking regularity: any mammal larger than a rat spends roughly 21 seconds urinating, regardless of its size.
This counter‑intuitive pattern makes sense when you examine the urethra—the tube that ferries urine from bladder to outside. Across species, the urethra maintains a constant length‑to‑width ratio of about 18, a geometry that dictates a similar discharge time. Whether it’s a tiny cat or a massive elephant, the fluid’s pressure and the tube’s dimensions balance out to produce that 21‑second window.
Engineers were fascinated by the implication that volume doesn’t dictate flow time; instead, the tube’s dimensions dominate. The researchers speculate that this principle could one day inform the design of large‑scale artificial water‑transport systems.
7 Full Bladders Create Better Lies
It turns out that a full bladder can be a liar’s best ally. In a 2015 experiment, 22 volunteers were given either a modest or a generous amount of liquid to drink and then asked to hold it for nearly an hour before completing a questionnaire. By the time they were interrogated, many participants were desperate for a bathroom break.
When the panel probed the volunteers on moral and social dilemmas, those with the most pressure in their bladders produced the most convincing falsehoods. Their stories were richer, more detailed, and they radiated a confidence that made listeners more likely to believe them.
The researchers attribute this phenomenon to what they call the “inhibitory spillover effect” (ISE). The intense self‑control required to suppress the urge to urinate appears to spill over into other cognitive domains, sharpening the ability to fabricate believable lies.
6 Pee Bales
At Wimpole Hall, a National Trust estate in Cambridgeshire, staff members have turned a quirky idea into a green initiative. Male workers are encouraged to relieve themselves directly onto straw bales that line the walled gardens after visiting hours, while female staff can pour collected urine from bottles onto the same stacks.
The rationale is straightforward: urine is a nitrogen‑rich “activator” for compost. By sprinkling it onto the straw before it reaches the compost heap, the decomposition process speeds up, producing richer soil for the gardens. The practice also conserves water by reducing the number of flushes needed in the estate’s restrooms.
To avoid startling tourists, the staff only perform the ritual when the gardens are closed to the public. One caretaker summed it up succinctly: “We don’t want to scare the public.”
5 Space Fertilizer
When humanity looks to colonize Mars, bringing fresh food from Earth isn’t a viable long‑term strategy. One inventive solution: turn astronaut urine into a plant‑boosting fertilizer. The German Aerospace Center (DLR) has been experimenting with tomato seedlings grown in tanks of human urine.
On the International Space Station, astronauts already recycle sweat and urine to reclaim water, but the DLR’s experiment goes a step further. Researchers added pumice—lightweight volcanic rock—into the urine, providing a porous habitat for bacteria. These microbes convert the urine’s ammonia into nitrites and nitrates, essential nutrients for plant growth.
The ultimate goal is to integrate such bio‑reactors into Martian greenhouses, where synthetic urine could sustain crops under simulated Martian gravity, paving the way for self‑sufficient off‑world agriculture.
4 Urination Electrocution
In 2013, a night‑owl named Matthew Zeno stepped onto a G‑train subway platform after a few drinks and decided to relieve himself on the electrified third rail. The tragic result: the current traveled up his urine stream, electrocuting him on the spot.
A similar case occurred earlier with Joseph Patrick O’Malley, whose autopsy revealed electrical burns on his genitals, thumb, and forefinger, suggesting a 600‑volt surge traveled through his urine as he peed on the rail. He likely succumbed before the train even arrived.
The TV show MythBusters tackled the myth, testing whether a pee stream can conduct enough electricity to cause death. Their experiments showed that urine typically breaks into droplets, preventing a continuous conductive path. However, they warned that peeing against a high‑voltage fence—where the stream has less distance to fragment—could be dangerous.
3 Pee Power
In 2015, scientists harnessed the energy of urine using microbial fuel cells (MFCs). These devices employ bacteria that feast on the organic compounds in urine, releasing a modest electric current as a by‑product of their metabolism.
The technology has already powered small devices such as mobile phones and LED lights, especially in off‑grid settings like refugee camps, disaster zones, and remote villages. Some fairs have even installed specially designed toilets that channel visitors’ urine straight into MFCs, turning a bathroom break into a power‑generating act.
Beyond electricity, the researchers discovered an added benefit: the microbial process also reduces harmful pathogens. When they introduced Salmonella into the system, the bacteria’s numbers dropped to levels deemed safe by conventional sanitation standards, showcasing a triple‑win of power generation, waste treatment, and disinfection.
2 Revenge Against People Who Urinate In Public
Hamburg’s St. Pauli district is famous for its nightlife—and, unfortunately, its rampant public urination. The constant stream of stray urine left on walls and alleyways was not only a nuisance but also a costly cleaning headache for the city.
In 2015, a clever solution emerged: the most frequently targeted walls were coated with a hydrophobic paint that repels liquids. When an unsuspecting reveler tries to splash the wall, the paint sends the urine right back onto their shoes, delivering an instant, personal reminder.
This low‑tech, high‑impact approach has dramatically cut cleaning expenses and turned the act of public peeing into a self‑inflicted embarrassment, encouraging better bathroom etiquette.
1 Pee And Get A Discount
When it comes to advertising ingenuity, few campaigns have been as bold as IKEA’s 2018 “Pee‑On‑This‑Page” promotion. The Swedish retailer placed a specially designed page in a popular women’s magazine, inviting female readers to urinate on it.
If the urine tested positive for the pregnancy hormone hCG—meaning the woman was pregnant—the page would magically reveal a discount on a crib. To pull this off, IKEA teamed up with creative agency Akestam Holst and Mercene Labs, adapting a conventional pregnancy test strip into a printed advertisement.
The result? A quirky, interactive ad that not only captured attention but also rewarded expectant mothers with a practical savings on baby furniture.