Naked Science Forum
General Science => General Science => Topic started by: paul.fr on 21/08/2007 10:45:52
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i hear that we shed lots of skin whilst in bed, then some friendly bed bugs come along and eat it up. say i put a fresh sheet on my bed, after a week would it weigh more than it did to start with?
if so, would the dead skin or the bugs be the majority of the weight?
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Assuming you put the sheet on the bed dry, then yes it would weigh more. Even 1 speck of dust would increase the weight.
As for what proportion would be dead skin & bugs... (https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2Fbestsmileys.com%2Fclueless%2F7.gif&hash=d5e7b0c86f070976c8926e13a2b350d0)
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I'm just itching to know the real answer to this one.
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I think there is some confusion between bed bugs and dust mites.
Bed bugs feed on human blood, not skin; and are occasional parasites that are usually exterminated when they are detected.
Dust mites will feed on skin (depending on the exact species), and are fairly ubiquitous. They exist in beds, in carpets, and pretty much everywhere (human skin detritus is one of the major components of house dust).
The major problem with dust mites tends to be an allergic reaction to their faeces.
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Couple of things to clear up here; first, bed bugs don't eat dead skin - they actually drink your blood!
Bed bugs are becoming a serious scourge - to the point of being called an epidemic - worldwide. Historically always a problem, they were suppressed to very low levels in the 40s by an intensive global insecticidal spraying effort. However, they are now making a comeback and many are now resistant to the insecticides in common usage.
Small, maybe a few millimetres across, they hide in crevices close to where people sleep. At night time they venture out and follow their noses, or rather antennae, which are endowed with heat and chemical receptors, to find where a person is sleeping. They then pierce the skin with a sharp mouthpart and drink blood. When they are full they creep off to digest their "meal". Giveaways that this is happening are usually itchy "bites" on the body as well as unexplained spots of blood on the sheets and little black blotches on the bed frame; these dark dots are small blobs of bed bug faeces, the dark colouration coming from the oxidised iron in the blood they consumed.
The things that eat our dead skin are house dust mites. Unlike bed bugs, these are actually microscopic and also don't prey on humans directly. Their excrement contains a protein that provokes asthma in sensitised individuals.
Returning to the original question, which asked if the bed sheets increase in mass as they become soiled, the answer is almost certainly yes. Soiled sheets will contain large numbers of dead skin cells as well as the residues of other substances shed from the body in various secretions including sweat and saliva. One estimate I read was that the body loses 40,000 skin cells per minute, totalling 1.5 stones in dead skin mass over a lifetime! Since we spend a third of our lives in bed, one can reasonably expect a fair proportion of those shed cells to be deposited in the bed and hence glued to the sheets!
Hence, I'd argue, that the bedsheets gain weight with use!
Chris
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I understand that soiled sheets weigh more than clean sheets, but what I don't understand is all the talk about bed bugs lately. What's up with that? [?]