I generally agree with the previous comments, but
point out that there is a lot more work that
needs to be done on modern mammals to unravel the
complexities of oxygen. Much of the thinking
about oxygen is based on mass balance models and
has yet to be confirmed empirically. For
example, body size should be negatively
correlated to d18O values if larger mammals drink
more water (e.g., Bryant and Froelich 1995), but
oxygen does not appear to be correlated with body
size in many faunas (e.g., Cerling et al. 2004),
possibly because folivores also tend to be
large-bodied. Papers that come to mind include:
Kohn (1996), Sponheimer and Lee-Thorp (2001),
Iacumin and Longinelli (2002), Balasse et al. (2003), and Levin et al. (2006).
Balasse, M., A. B. Smith, S. H. Ambrose, and S.
R. Leigh. 2003. Determining sheep birth
seasonality by analysis of tooth enamel oxygen
isotope ratios: the Late Stone Age site of
Kasteelberg (South Africa). Journal of Archaeological Science 30:205-215.
Bryant, J. D., and P. N. Froelich. 1995. A model
of oxygen isotope fractionation in body water of
large mammals. Geochimica et Cosmochimica Acta 59:4523-4537.
Cerling, T. E., J. A. Hart, and T. B. Hart. 2004.
Stable isotope ecology in the Ituri Forest. Oecologia 138:5-12.
Iacumin, P., and A. Longinelli. 2002.
Relationship between d18O values for skeletal
apatite from reindeer and foxes and yearly mean
d18O values of environmental water. Earth and
Planetary Science Letters 201:213-219.
Kohn, M. J. 1996. Predicting animal d18O:
accounting for diet and physiological adaptation.
Geochimica et Cosmochimica Acta 60:4811-4829.
Levin, N. E., T. E. Cerling, B. H. Passey, J. M.
Harris, and J. R. Ehleringer. 2006. A stable
isotope aridity index for terrestrial environments. PNAS 103:11201-11205.
Sponheimer, M., and J. A. Lee-Thorp. 2001. The
oxygen isotope composition of mammalian enamel
carbonate from Morea Estate, South Africa. Oecologia 126:153-157.
Hope this helps,
At 02:26 PM 12/14/2007, you wrote:
>Food is an important source of H and O to the
>body water, as is atmospheric O2 through
>metabolism. In general, I would expect the
>opposite of the pattern you describe
>below...body water d18O should be relatively
>heavy due to metabolic (+23.5‰) and dietary (ca.
>+10‰ and greater) contributions, whereas the d2H
>should be not too dissimilar from drinking water
>(plant and animal tissue d2H is only moderately
>2H-enriched relative to environmental water).
>There is a lot of published work on 18O in body
>water, for a good example w/ some synthesis see
>Bryant and Froelich, GCA: 59, 4523-4537, 1995.
>Podlesak and colleagues have also published some
>relevant data in the latest issue of GCA: 72, 19-35, 2008.
>From: Stable Isotope Geochemistry
>[mailto:[log in to unmask]] On Behalf Of H.A.J. Meijer
>Sent: Friday, December 14, 2007 10:53 AM
>To: [log in to unmask]
>Subject: [ISOGEOCHEM] 2H and 18O values for "blood" water and body tissue
>My estimate for the isotope values for blood (that is the water
>component) in humans and animals would be that it has to be pretty
>close to the local (drinking) water. It is possibly slightly enriched
>due to evaporation processes in the body as well as in the open water
>available in nature for animals to drink, but not by more than a few
>In the "bakground" samples we process for doubly labelled water
>studies, however, relatively high values for 2H occur regularly,
>sometimes higher than + 50 o/oo. 18O is always in the local natural
>range that I expect.
>Is this an artefact, i.e. contamination by memory effects in the lab,
>or in the field, or during sample storage (samples are being stored
>in flame-off capilaries)?. If so, why does it never happen for 18O?
>Or is it real? We know that the hydrogen in body water interacts with
>H in tissue to some extent, but can tissue be that highly enriched in
>2H? And if so, why is it so variable?
>Is there any experience with "blood water" isotopes in fields where
>people do not use enriched water as well, f.i. in forensics?
>Thanks on forehand for helping!
>Prof. dr. Harro A.J. Meijer
>Centrum voor IsotopenOnderzoek (CIO), Rijksuniversiteit Groningen
>Nijenborgh 4, 9747 AG Groningen, Netherlands
>tel +31-50-3634760 fax +31-50-3634738