Isotonic Swimming Pool

If water comes contact with your eyes or nasal passages, it should be slightly salty. That's way contact lens solution and nasal spray are salty. Just saltly enough, but not too much. This is called "isotonic," apparently.

If water is hypertonic (too salty) it can make cells swell up and burst. If it's hypotonic (not salty enough), cells shrivel up (like your finger tips when you stay in the bath tub too long.)

I just went swimming in my parents' swimming pool. I went for a dive, and forgot to exhale, so water went up my nose. Ever have that happen to you? Kinda hurts.

If you've ever tried to wear contact lenses in the pool, you'll know an even greater pain: The contact lens shrinks, squeezes your eyeball, and maybe even pops out. (The contact lens pops out, I mean. Not your actual eyeball. That would be ... well, kinda cool actually.)

All this got me thinking: Why not add some salt to the pool? Add just the right amount so the pool water is isotonic. Instead of it irritating your nose and eyes, it might even feel kinda nice.

Of course, there's the issue of chlorine. Chlorine in pools has never really bothered me, but it probably isn't too healthy either. I wonder, have we thought about any alternatives to chlorine?

1 comment:

Losing M. Mind said...

Interestingly, when life evolved as bacteria (and Archaeans) in seas it had to evolve just the right balance. I remember that if there is more of certain kind of solute on one side of the cellular membrane, the ocean water would flow in to dilute the cell, or vice versa.

For instance Na+ ions. Fish had to evolve ways to deal with this also, I forget the details, but sharks have a salt gland that excretes concentrated salt. Water flows out their gills and so they drink water and the salt gland excretes the salt. Salt water fish have to drink because water flows out their gills to dilute the ocean.

With fresh water fish it's the opposite. Water flows into their gills to dilute their cells and so they urinate. Salmon and fish that spend some time in both fresh water and salt water have to actually change their biochemical function to adapt. Fish also evolved the kidney as the salt excretor.

I know that our kidneys regulate the balance of salt in our blood, and get rid of ammonia wastes, which is a byproduct of the breakdown or proteins (which are nitrogenous) in our cells. All life has to get rid of the ammonia. Our kidneys do that as well.

For both of these reasons that is why you die within a week after kidney failure without dialysis. ammonia builds up, and the balance of metal ions (salt) gets out of whack. My point being, that life has had to evolve in tricky ways to maintain a good osmotic balance. Our neurons use salt metal ions to create their electrical action potentials.