I think I heard a long time ago someone say like “every glass of water contains water molecules from the pee of benjamin franklin” or something to illustrate the scale of how many atoms there are in things. Is this true? Has so much pee hit all water sources that everything you drink from anywhere was once pee?
This is a silly joke question, and you’re right about the urea breaking down. Now for the water molecules (which are indistinguishable, so outside of pseudoscience the answer is meaningless), it becomes more interesting.
Assuming a person pees about 1l/day, over a lifetime you have on the order of 10^29 water molecules in your pee. There’s about 1.3 billion cubic kilometers of water on earth, or about 10^21 litres. So assuming the pee gets perfectly diluted, you get about 10^8 molecules that used to be in a specific person’s pee, per litre of water. In reality it will likely be more, since much water is deep in the ocean, where there is little convection, so it takes long to evenly mix the pee around.
Times that by 8 billions people and that many water molecules have been in any person pee currently alive.
Add in a another billion+ or so people for people who were alive before now and you’ve got even more waterolecules which have been in people’s pee.
Then add in all of the other mammals and vertebrates on earth and you’ve got MORE water molecules which have been in pee before.
That’s a lot of pee.