Naked Science Forum
Life Sciences => Physiology & Medicine => Topic started by: logcabiny on 09/05/2008 09:03:26
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For some years I have been struggling with the question of whether, in a strictly life or death survival situation, the human body can survive longer by drinking sea water or by not drinking any water. I know that the kidneys are able to concentrate urine considerably in dire circumstances. There is an example of a person who survived something in the range of 90 days at sea and did purposefully drink sea water, but I also found out that he supplemented the sea water with rain water when available. As I understand it you have to make the decision immediately upon finding oneself in the situation since waiting 2-3 days without drinking puts the body in a state of dehydration. At that point drinking sea water has clearly been shown to be quickly deadly. The question is whether one might survive longer by beginning to drink sea water while in a fully hydrated state.
Our blood is said to contain 130 mMol/liter of sodium. Of course, that's not all it contains, but sodium is the primary difficulty encountered when drinking sea water. I'm still not sure of even the average salinity of sea water to compare. Also, how much can the kidneys concentrate the urine and still function? What I am seeking is to know the maximum salinity input that can be sustained in equilibrium and how that compares to sea water. If it is better to consume sea water from the beginning of the survival mode onset, then how much sea water should be consumed daily?
Any definitive help will be greatly appreciated. I've had lots of opinions over the years, but nothing really scientific or experimentally based. Any improvement in survival by even a few days could potentially save lives. Besides, we really need to know whether the standard procedure of "don't drink any sea water" is actually correct or not.
Thanks for reading.
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I am guessing excess sodium is far more toxic than dehydration.