Human methane? Come on Dave, use your words. Farts, passed gas, broken wind, cut cheese, trumps (for Brits). I am sure the Brits have another 10 words for it. The second point is "are farts delicate?" I am a mother of a teenager ( a boy), and human methane is never delicate. I think people have measured the C and maybe the H isotopes of farts, but if they haven't I am sure you could do a good job with a structured study on the subject. I can truthfully say we have not attempted the measurement at the Carnegie, although it has been discussed. Marilyn, A lady, and we do not emit human methane or anything else similar to it. > A delicate question here. Does anybody know of data for 13c compositions > of > methane from human emissions? I am writing up data for CO2 and methane > isotopes of cave air and I am seeking alternative explanations for one or > two 'anomalous' data points with methane d13C as light as -53 permil. > Cave > air methane is otherwise significantly heavier than background atmosphere > due to microbial oxidation. Methane emitted from mammals is normally > around > 30 permil lighter than food intake but wondered if any data existed for > specifically for the human species.... > > Thanks > > dave > > > -- > David Mattey > Geology Department, > Royal Holloway College, > University of London > Egham, > Surrey TW20 0EX > > Telephone 01780 443582 (Secretary) > 443587 (Direct line) > 443629 (Stable Isotope Laboratories) > 07780 697564 (Mobile) > > www.gl.rhul.ac.uk/silab >