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New Scientific Test Finds Up To 75 Liters of Urine In Public Pools (theguardian.com)
Scientists have developed a test designed to estimate how much urine has been covertly added to a large volume of water. "The test works by measuring the concentration of an artificial sweetener, acesulfame potassium (ACE), that is commonly found in processed food and passed through the body unaltered," reports The Guardian. The findings are published in the American Chemical Society journal. From the report: After tracking the levels of the sweetener in two public pools in Canada over a three-week period they calculated that swimmers had released 75 liters of urine -- enough to fill a medium-sized dustbin -- into a large pool (about 830,000 liters, one-third the size of an Olympic pool) and 30 liters into a second pool, around half the size of the first. Although the researchers were unable to confirm exactly what fraction of visitors were choosing to quietly relieve themselves in the water rather than making the shivery trip to the changing rooms, the results suggest that the urine content was being topped up several times each day. The findings make for unwelcome reading, but swimmers might find some comfort in the measurements from eight hot tubs, which were found to have far higher urine levels. One hotel Jacuzzi had more than three times the concentration of sweetener than in the worst swimming pool. In total, the team sampled 31 different pools and tubs in two Canadian cities and found ACE to be present in 100% of the samples, with concentrations up to 570 times the background level in tap water samples. They used the average ACE concentration in Canadian urine to convert their measurements into approximate volumes of urine.
..it's 5 hundredths of a percent of the water volume. And since urine is 95% water, you're talking about less than 4 liters out of nearly a million liters of water. It wouldn't surprise me if the mass of dead skin or even hair was greater than non-aqueous urine components.
And since our swimsuits aren't hermetically sealed against our bodies, I'd wager there's some measurable amount of fecal matter in the pool too. Maybe some vaginal discharge and/or menstrual fluid, too. And you can't discount the amount of mucus and other sinus discharges along with some saliva from the people who like all of the above so much they get water in their mouths.
But in spite of all this (assuming the filtration and chlorination systems are working), the water in the pool is still way cleaner than most other bodies of water people swim in.
I've seen pictures of the Ganges that make me retch and people *bathe* in that water.
Yep, I have renal insufficiency, and I was curious if sweating would help lower blood urea nitrogen, uric acid, and serum phosphorus, and sure enough, I found an NIH white paper that found that sweat has higher amounts of them (and creatinine, and potassium) than blood.
So, I deliberately spend relatively long periods in the hot tub to help excrete fluids and electrolytes. In other words, I pee in the hot tub just because of the fact that I'm sitting in it.
And my lab results turn out better, not to mention I get less edema in my legs, thus I can tolerate drinking more water.