This may not seem like a very important question to you. And you’d be right.

This question came up, and I assumed yes. Cells do, generally. Cells absorb O2 and produce C02 … even plant cells do this … through passive systems. But I wondered if the fact that the epidermis is adapted to be a barrier might mean that it would not. But then I realized that the epidermis absorbs water. O2 and H2O both diffuse freely across cell membranes. So of course some of the cellular respiration in mammals is surface diffusion. It must be. (Warning: I don’t know this to be a fact. If you do, state so in the comments and provide a reference that you’ve actually read recently and can verify, please!)

The problem is that when you “google it” … ask the Internet if humans or mammals absorb any oxygen through their skin, you get an interesting result, an oft repeated phrase: “No. Human beings cannot usefully absorb oxygen through their skin.” Which is not really an answer to that question, is it? I wasn’t asking about “usefully.” Jeesh.

I’m pretty sure that the answer to the question “do humans absorb Oxygen through their skin” — which is clearly a yes or no question — is “yes.” But perhaps this leads to concerns that some of the dumb-ass humans will misuse this information thinking that we actually breathe through our skin in any meaningful way. Imagine the stupid Darwin-Award wining tricks people might think up to do with this factoid. Nonetheless, while “the widely held mis-belief” that humans “breathe through their skin” is a potentially dangerous concept, it is also simply true that all typical normal living eukaryotic cells respirate. Even plant cells “breathe” in O2 and “breathe” out CO2. So the answer “no” isn’t really acceptable.

In truth, the best answer to the question “do humans breathe through their skin?” is probably something like “Please re-phrase that question so I know what strange and inappropriate things will happen in your brain depending on the answer”

Comments

  1. #1 Boris Legradic
    May 17, 2010

    A quick search on google scholar resulted in this paper: The cutaneous uptake of atmospheric oxygen contributes significantly to the oxygen supply of human dermis and epidermis
    From the article: “It has been known since 1851 that atmospheric oxygen is taken up by the human epidermis. The contribution to total respiration is negligible.” and “In this study it has been shown that under normal conditions, atmospheric oxygen can supply the upper skin layers to a depth of 0.25–0.40 mm. This is 3–10 times deeper than has been calculated previously (Fitzgerald, 1957; Baumgärtl et al. 1987). The whole epidermis and the upper corium can therefore be supplied with oxygen from the atmosphere. ”

    So there. Have fun with the strange and inappropriate thhings in your brain ;)

  2. #2 Greg Laden
    May 17, 2010

    Boris, thank you, my quick search did not get me that reference!

    The real use I was hoping to put this to is pedagogic.

    To the students in the AP cellular respiration lab: When you breathe, it is your cells breathing, and the plant over there in the corner of the room is also breathing. And, in turn, you are breathing in way that is similar to what the plant is doing, both via your lungs and even your skin surface, though that contribution is negligible….

  3. #3 Jeremy
    May 17, 2010

    If I recall correctly, in the James Bond movie Goldfinger a woman is killed by having her entire body painted gold, meaning that her skin can’t “breathe” and she dies. It’s a while since I’ve seen it so I don’t if I’m remembering it correctly – but if it happens in a Hollywood movie then it must be true right?

  4. #4 Stephanie Z
    May 17, 2010

    And Jeremy’s obligatory Goldfinger reference requires a reference to the two Mythbusters episodes in which they painted people gold.

    Don’t worry about your skin breathing. However, do worry about overheating, since controlling temperature is one of the things we use our skins for.

  5. #5 Art
    May 17, 2010

    Seems to me that oxygen would diffuse into the skin, CO2 out?, to some extent. Impermeability is one of those things we get misinformed about when we are young. Things get oversimplified and nobody makes any effort to clarify things. So we buy that the balloon ‘holds air’. That the cup holds water.

    That in electrical terms there are insulators and conductors. Later we get semiconductors. Later, if we stay with it, we find out everything conducts electricity to some extent. That water vapor penetrates things we thing it shouldn’t and that tiny amounts of gases diffuse across seemingly impermeable barriers. Why should skin be special.

    Which relates to another assumed fact – that the human urinary bladder is simply an impermeable bag. I suspect that when dehydration becomes an issue it helps conserve water by reabsorbing water to some extent. It would be interesting to find out if anyone has done any experiments.

  6. #6 daedalus2u
    May 17, 2010

    I was going to cite the paper that Boris did. There are a few others. This is actually quite important in NO physiology, and why the skin is the organ that sets the basal NO level.

    Because the external skin gets O2 from the external air, there is no hemoglobin in the external skin (obvious because the external skin is transparent) except when it is hyperemic. Hemoglobin is the sink for NO, so with the external skin hemoglobin-free, NO can diffuse into the plasma (the external skin is perfused by plasma) and attach to albumin forming S-nitrosoalbumin, the most abundant S-nitrosothiol in the blood.

    In at least some mammals, the response to hypoxia is partially mediated through O2 sensing in the skin.

    http://www.ncbi.nlm.nih.gov/pubmed/18423195

    This actually makes a lot of sense. The skin is actually the tissue compartment that has the lowest O2 level. This can be seen in the graph of O2 levels in the paper Boris cited. Because it is close to the external atmosphere and is large in area, there is a big signal to trigger responses to hypoxia. This global hypoxia signal can be integrated over a large area and over a long time without subjecting critical tissue compartments (supplied by the heart and lungs) to low O2 levels. It decouples hypoxic sensing from O2 delivery and utilization.

    The one thing I don’t like about this paper is that nitroglycerine really isn’t a “NO donor”. It does have NO/NOx effects, but those are complex and not fully understood, but it is understood that they are not through prompt NO release.

  7. #7 Greg Laden
    May 17, 2010

    The fact that in order to avoid asphyxiation, Shirley Eaton’s body was not 100% covered (a patch of bare skin remained on her stomach) belies a faulty understanding of the premise. In the faulty understanding, the surface of our skin is roughly equivalent to our nostrils. Everything will be OK if we have a bit of space for at least part of the skin to “breath through.”

    Skin surface respiration would be because the skin is in direct contact with O2 bearing air.

    The fact that the Mythbuster guy exhibited the early signs of asphyxia (e.g. change in pulse) yet the Mythbusters concluded that covering one’s body in gold paint can’t (eventually) kill you speaks to the nature of modern skepticism …. specifically, it is quite possible to call one’s self a skeptic but reject ideas because one believes they should be rejected.

    If it does turn out that the epidermis gets, say, half of its O2 from the air, then it would turn out that the largest organ in the human body gets only half its needed oxygen from breathing. And no matter what, it is clear that this is … interesting. It is quite possible that this skin breathing issue can make it to my list of falsehoods (http://tinyurl.com/294cpjy).

    Beyond that, I have one more comment for now: If it is true that the skin gets a lot of its O2 from the surrounding air, then that means that under some conditions the skin can stay alive after the person has died. The implications of this for ghost and zombie research is potentially mind boggling.

  8. #8 Greg Laden
    May 17, 2010

    “Skin surface respiration would be because the skin is in direct contact with O2 bearing air. ” … to finish this thought: So leaving an uncovered portion would only help the skin right at that uncovered spot.

  9. #9 Ogg
    May 17, 2010

    When you seal skin off with a bandage you eventually get dead skin.

  10. #10 daedalus2u
    May 17, 2010

    If the skin is made hypoxic, it generates NO which causes vasodilation which increases blood flow in the skin. The skin probably can be sustained from the blood in terms of oxygen. The skin does not have a high metabolic load, it can operate on glycolysis.

    Oil based make-up may not block O2. O2 has a much higher solubility in oils and hydrocarbons than it does in water. If the make-up contained flakes, and those flakes alligned with the skin surface, that may block O2 where make-up containing powder would not.

    Pilots breathing oxygen in reduced pressure do have hypoxic skin. Hypoxic skin may be part of why climbing Mount Everest is so difficult.

  11. #11 Greg Laden
    May 17, 2010

    daedalus2u: It is indeed important to note that “covering” the skin with some goo or another does not necessarily mean cutting off our atmospheric gases.

  12. #12 WMDKitty
    May 17, 2010

    If it is true that the skin gets a lot of its O2 from the surrounding air, then that means that under some conditions the skin can stay alive after the person has died. The implications of this for ghost and zombie research is potentially mind boggling.

    O_O;

    And definitely disturbing.

  13. #13 gwen
    May 17, 2010

    As a nurse, I routinely cover skin with occlusive bandages…some of which ‘breathe’ and others which do not. Other than the shedding of dead skin cells which would have flaked off naturally had the bandage not been there, there is no difference.

  14. #14 Max Kaehn
    May 17, 2010

    It’s an interesting question for hard science fiction settings: if you have a mask on to let you breathe your native atmosphere, can you safely run around clad normally while in shirtsleeve-temperature-and-pressure pure carbon dioxide? Pure carbon monoxide? Methane?

  15. #15 AK
    May 17, 2010

    As for skin “breathing”, if a covering blocks water vapor transport away the skin will usually become (somewhat) waterlogged. This may be the origin of the myth.

    I recall reading an article (to which I no longer have access) about diffusion of water through the skin of various animals (including amphibians). IIRC it was mentioned that modern amphibians absorb oxygen partly through their skins. (A quick search couldn’t find that article, but I found several other mentions.

    I’m not going to pass those along, because I found something much more interesting: The structural design of the bat wing web and its possible role in gas exchange

    The structure of the skin in the epauletted fruit bat (Epomophorus wahlbergi) wing and body trunk was studied with a view to understanding possible adaptations for gas metabolism and thermoregulation. In addition, gas exchange measurements were performed using a respirometer designed for the purpose. The body skin had an epidermis, a dermis with hair follicles and sweat glands and a fat-laden hypodermis. In contrast, the wing web skin was made up of a thin bilayered epidermis separated by a connective tissue core with collagen and elastic fibres and was devoid of hair follicles and sweat glands. The wings spanned 18–24 cm each, with about 753 cm2 of surface exposed to air. The body skin epidermis was thick (61 ± 3 µm, SEM), the stratum corneum alone taking a third of it (21 ± 3 µm). In contrast, the wing web skin epidermis was thinner at 9.8 ± 0.7 µm, with a stratum corneum measuring 4.1 ± 0.3 µm (41%). The wing capillaries in the wing web skin ran in the middle of the connective tissue core, with a resultant surface-capillary diffusion distance of 26.8 ± 3.2 µm. The rate of oxygen consumption (V˙O2) of the wings alone and of the whole animal measured under light anaesthesia at ambient temperatures of 24 ºC and 33 ºC, averaged 6% and 10% of the total, respectively. Rate of carbon dioxide production had similar values. The membrane diffusing capacity for the wing web was estimated to be 0.019 ml O2 min−1 mmHg−1. We conclude that in Epomophorus wahlbergi, the wing web has structural modifications that permit a substantial contribution to the total gas exchange.

    The article is open access but I haven’t (yet) read beyond the abstract.

  16. #16 AK
    May 17, 2010

    Oh, yeah…

    The bolding is mine.

  17. #17 Greg Laden
    May 17, 2010

    AK: I’m not sure if we want to use the term “myth” here. After all, it appears that we do breathe through our skin, a little. If the myth is that can can hold our nose and mouth closed and still respirate, that would be wrong of course.

    Bats breathing with their wings makes a lot of sense.

  18. #18 José
    May 18, 2010

    Well, I absorbe all my nutrients through my skin during sun worship. I haven’t eaten actual food in years, so the possibility that we may absorb some or most of out oxygen through our skin comes as no shock. I also only obtain water through my hair on rainy/humid days.

  19. #19 Monado, FCD
    May 18, 2010

    I thought the mechanism of the fictional murder by gilding was that the body overheated.

  20. #20 Greg Laden
    May 18, 2010

    Monando: It depends on if you use molten gold

  21. #21 Gbiz
    June 30, 2011

    what about when people go swimming then? if half our O2 is received through our skin how do we not drown while having only our heads out of water or otherwise feel oxygen deprived?

  22. #22 dr manohar bhandari , mbbbs , md
    August 19, 2011

    although my answer is not so called scientific but it is the fact that we respire though our skin .if you will cover your entire skin with thick layer of wax , you will feel your self oxygen deprived, previously in our country , BHARAT ( INDIA ) this technique was adopted by kings for slow death of criminals . i am sure death in such cases was mainly because of the lack of skin respiration . i will be thankful to you if you will do some concrete research work in this direction . thanks alot for giving opportunity to give comment , thank you again .

  23. #23 dr manohar bhandari , mbbbs , md
    August 19, 2011

    although my answer is not so called scientific but it is the fact that we respire though our skin .if you will cover your entire skin with thick layer of wax , you will feel your self oxygen deprived, previously in our country , BHARAT ( INDIA ) this technique was adopted by kings for slow death of criminals . i am sure death in such cases was mainly because of the lack of skin respiration . i will be thankful to you if you will do some concrete research work in this direction . thanks alot for giving opportunity to give comment , thank you again .

  24. #24 David Lauridsen
    September 7, 2011

    Greg,

    Thank you for addressing this issue. I have another for you that has plagued me for a long time that hopefully you would be willing to tackle. Specifically, the explanation of the source of the sound when you “crack the knuckles” of your finger joints.

    Cavitation is virtually always listed as the reason for the loud cracking sound that accompanies the “cracking” of one’s knuckles. I say…maybe! I understand that joints make several different sounds for many different reasons, but I think that the explanation of cavitation that is usually given is flat out incorrect.

    See my post at: http://www.scq.ubc.ca/a-curmudgeonly-clarification-of-cavitation-and-a-call-to-correct-all-cracking-content/

    I’d love to see what you think.

    Thanks,

    David

  25. #25 Greg Laden
    September 7, 2011

    Interesting. I agree that your description of cavitation makes sense and the other descriptions are either too vague or don’t really seem to work. Also, there other things that “crack” that are simply tissues moving against each other, most likely.

    I hope everyone goes and reads your description and chimes in!

  26. #26 Bubbles
    New Zealand
    May 5, 2013

    I would like to agree.One can ingest Oxygen in through the skin.I enjoy using the form of gentle Oxygen infusion (Hospital grade) small quantities of Ozone and Steam
    to the body …not inhalation…and the blood oxygen levels have been proven to increase.

  27. #27 Pete Olmay
    January 14, 2014

    Gee, I hate to burst the bubble of people getting their “science” from Mythbusters, but the fictional Goldfinger death was inspired by the very real hospitalization of Buddy Ebsen cast as the first Tin Man in the Wizard of Oz poisoned by the make-up.

  28. #28 Greg Laden
    January 14, 2014

    Pete: Totally. Better to get our science from the Wizard of Oz than Mythbusters! :)

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