Mr. ThomasOh man, now I really need to go.

When you’re at the beach this summer, you don’t have to worry about pitting your anti-pollution beliefs against the demands of your bladder. Science says it’s all right to piss in the sea. What a relief!

Human urine, points out science writer Lauren Wolf, is mainly water and salt. That’s the same as the composition of seawater — in fact, the ocean is significantly more salty than your pee. What do you bring to the equation? Just creatinine and urea, compounds that carry excess nitrogen out of your body. And the creatinine is negligible — only 0.09 ounces per gallon.

What about the urea? Well, it’s present in urine in a much higher concentration — 1.2 ounces per gallon — and while seawater normally contains nitrogen, which is crucial for the growth of seagoing organisms, it is definitely possible to have too much of a good thing. But on the other hand, we are talking about the OCEAN here:

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According to Stuart Jones, a biochemist in the department of clinical biochemistry at King George Hospital, in East London, a person excretes 0.2-0.5 L of urine during a typical potty break. (And, yes, I consulted an expert). So a person, on average, pees out 3 grams of urea per go. There are 7 billion people on the planet. Let’s just say that all of them relieved themselves in the Atlantic Ocean at once (the Atlantic and its adjacent seas have a collective volume of 3.5 x 1020 L), there would be about 6 x 10-11 g/L of urea in that body of water. If you’re a chemist and you think in terms of moles, that’s about 1 picomolar urea, a pretty tiny concentration for a highly unlikely situation in only one of the oceans of the world.

Also, Wolf points out, everyone else is peeing in the ocean all the time. By which she doesn’t mean that kid with the swimmies and the suspicious look on his face, but whales and dolphins and sharks and the Kraken and stuff:

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Because I’m fairly certain whales and dolphins don’t have ocean outhouses that collect and process their waste, they’re also peeing in the ocean. And boy do they pee. According to a quick search and some papers I found here and here, a fin whale (slender body, found in the North Atlantic, 16 times the length of a human on average) pees at a rate of 970 L/day and excretes amounts of sodium and chloride 23 times as high as do humans. Please feel free to use these fun facts as a conversation starter at your next cocktail party.

In short, let it rip. But try to maintain a courteous distance from other swimmers when you do. “It’s OK to pee in the ocean” is a far cry from “it’s OK to pee directly on your buddy’s leg,” unless of course he has stepped on a jellyfish.