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According to several studies quoted here, chemicals can be absorbed by the skin transdermally, at least under certain conditions.

When it comes to elements in seawater like sodium, magnesium, potassium and iodine, is it possible for a human to absorb them transdermally in this instance?

If it depends on various conditions, (such as length of time spent in the ocean, physiological factors (e.g. intense swimming vs. gentle bathing), temperature of the water and their respective effects on skin porousness or other factors affecting transdermal absorption), what would be they be?

And if it can indeed be absorbed (e.g. from open water swimming), are the amounts significant to even measure alongside that of recommended levels for human dietary intake by advisory bodies such as FDA for those mentioned elements, or is it an extremely small amount much smaller than dietary levels of mineral intake?

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I found this article where swimming in the ocean reportedly cured a lady of psoriasis.… – The Last Word May 28 '14 at 6:26

There is not very much transport of ions or water through the upper layer of the skin, mainly responsible for that is the stratum corneum (SC). Through this layer you will get only with small lipids and also substances which are able to penetrate the lipid layer of the cells like chloroform or DMSO. I think therefore that it is pretty unlikely that you can take up noteworthy amounts of ions (which would have to pass through the lipid layer of the cells which is highly hygrophobic) through the skin. Have a look at these publications:

Interestingly this is different for other animals. The pacific hagfish is able to resorb organic nutients through his skin, see this article or this publication:

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I doubt it would be efficient. Your skin is a tight, water proof membrane designed to keep water and ions and other molecules inside while keeping the outside out. The molecules that are absorbed through the skin tend to be hydrophobic organic molecules. Ions, which any dissolved salt in water would become, do not easily pass through cellular membranes or your skin. If your skin is damaged, it may have tiny holes, which would allow ions into your blood. If the link provided in the comment can be trusted ( ), and I'm skeptical, the psoriasis could have caused the damaged needed to let ions in, but I AM HIGHLY SKEPTICAL OF THESE CLAIMS. There is nothing magical about the ions in seawater. You could dissolve the same salts in distilled water and fill a bath tub with it and achieve the same non-results.

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protected by Christiaan Oct 18 '15 at 13:37

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