Hi Harro,
Sorry for the human focus of my posting. I've picked up the thread reading most recent postings first, which all seemed to revolve around human blood and urine.
You are right, with animals (unless frequent flyers / frequent switchers of food source) the link should be even more direct.
Best,
Wolfram
________________________________________
From: Stable Isotope Geochemistry [[log in to unmask]] On Behalf Of H.A.J. Meijer [[log in to unmask]]
Sent: 19 December 2007 11:19
To: [log in to unmask]
Subject: Re: [ISOGEOCHEM] 2H and 18O values for "blood" water and body tissue
Some comments from me added:
>
>Many thanks for highlighting these very
>important points. This is exactly what I reply
>to those clever people who ask the "bottled
>water" question completely ignoring water intake
>from preparing meals and beverages. In most
>parts of the world even Coke is "local" since
>only the concentrate is shipped and made up with
>water at a local bottling plant.
>
>As you rightly say, water intake is more than
>what we physically drink; most food has a
>weight% water content no too dissimilar to that
>of the human body if not higher. So in regions /
>populations where consumer choice (for whatever
>reason) favours locally / regionally grown food
>there is a strong and more direct correlation
>between isotopic signature of local water and
>isotopic signature of blood (and urine) and
>compared to regions/ populations where food may
>still be sourced from within the same country
>but from isotopically diverse locations (e.g.
>North America).
My original question was about (wild) animals,
thus certainly regional food sources.
>
>This strong correlation has been exploited for
>years by scientists interested in total body
>water and energy expenditure using the labelled
>(2H) or doubly-labelled (2H and 18O) water
>method, respectively.
>
>In other words, any erratic or unexpected
>deviation between isotopic signatures of
>ingested water and blood (or urine) should
>prompt one to interogate every step in one's
>study for potential artefact formation caused by
>composite isotope abundance values (water plus
>dissolved organics) or by isotopic fractionation.
>
>As at least one correspondent has already
>pointed out, water stress (dehydration) and
>environmental conditions favouring loss of body
>water can account for this.
>
>In the absence of the above the more likely
>explanation sadly is fractionation caused by
>sample storage and sample manipulation, which
>again has already been mentioned by other list
>member but cannot be stressed enough.
In the mean time, I am convined my findings must
be an artefact. Causes can be long storage,
leaking capillaries, memory effects in our
disitllation system,... Only: Why does it only
affect 2H, and not 18O? This finding excludes all
"normal" effects I can think of...
I am afraid we have to organise a storage test,
in which we organise capillaries with blood from
animals that never have been in toch with
labelled water, and then : analyse part of the
capilaries directly - analyse part of them much
later, of which part again a part will be stored
separately, and aprt together with capillaries
that conatain blood samples from DLW studies with
elavated 2H and 18O levels.
Easier said than doen, though...
Thanks once more, everybody.
Harro
>
>
>Best,
>
>Wolfram
>
>
>________________________________________
>From: Stable Isotope Geochemistry
>[[log in to unmask]] On Behalf Of Thomas L.
>Millican [[log in to unmask]]
>Sent: 18 December 2007 21:19
>To: [log in to unmask]
>Subject: Re: [ISOGEOCHEM] 2H and 18O values for "blood" water and body tissue
>
>I'd expect a lot of variability between
>individuals, but there are still a number of
>water intake sources that are localized besides
>just drinking water and beer.
>As a personal example, every day is started with
>a cup of coffee made with water from the tap. A
>bowl of oatmeal or rice is made with water from
>the tap. Tea is made with water from the tap.
>For dinner, pasta is made with water from the
>tap. Even the beer and mead are home-made with
>water from the tap. I expect that the fruits and
>vegetables from the local farmer's market are
>grown with local rainfall similar to the water
>from the tap. Even if I were to drink bottled
>water throughout the day when I want just water,
>there's still a lot of water from the local
>water supply that I'm taking in.
>In places around the world where the local water
>supply may not be as safe to drink, this may be
>different to some degree. For example, while
>living in Bavaria, I found that the tap water
>would result in undesirable events, so I bought
>bottled water for drinking and coffee. It would
>have been nice to be able to see if there was a
>shift in O and D in my blood from the moves
>relative to the local water supplies'.
>
>
>----- Original Message -----
>From: Pier de Groot <[log in to unmask]>
>Date: Tuesday, December 18, 2007 2:29 pm
>Subject: Re: [ISOGEOCHEM] 2H and 18O values for "blood" water and body tissue
>To: [log in to unmask]
>
>> Hi Harro and others,
>>
>> A lot of good things were mentioned already about the 18O and D
>> compositionof human blood. One factor was not mentioned yet, I
>> think (or did I overlook
>> it?). Some people drink mostly mineral water. If that water
>> originates from
>> a source different in isotopic composition from the local tap water
>> it will
>> influence the blood composition too.
>> For the Netherlands that would be mostly isotopic compositions as
>> found in
>> the Belgian Ardennes, or in less cases French or German sources. If
>> theinfluence will be significant I am not certain, but maybe good
>> to think
>> about it.
>>
>> My two eurocents.
>>
>> Bets wishes,
>> Pier.
>>
>>
>> ****************************************************************
>> Delta Isotopes Consultancy
>>
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>> Pastoor Moorkensstraat 16
>> 2400 Mol - Achterbos
>> Belgium
>> Tel. +32 (0)14 326 205
>> e-mail: [log in to unmask] or [log in to unmask]
>>
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>>
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>> PSESSID=1ad86b0d1b35d7bf9aee006f1e2f5cf4
>>
>> Organization Committee member of BASIS (Benelux Association of Stable
>> Isotope Scientists).
>> http://www.basis-online.eu/
>>
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>> (marked:‘Order Now1):
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>> last update: August 15, 2005
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>> 2008.
>> ****************************************************************
>>
>>
>> > From: "H.A.J. Meijer" <[log in to unmask]>
>> > Reply-To: Stable Isotope Geochemistry <[log in to unmask]>
>> > Date: Tue, 18 Dec 2007 16:32:51 +0100
>> > To: <[log in to unmask]>
>> > Subject: Re: [ISOGEOCHEM] 2H and 18O values for "blood" water and
>> body tissue
>> >
>> > Thanks colleagues, foor all your reactions and advice.
>> >
>> > There is a lot to discuss about this subject, that is clear. I am no
>> > specialist in this matter, but my intuition that the local water
>> must> be key player, is kind of supported through several of the
>> comments.> After all, it needs not be water that is directly
>> consumed, but water
>> > that is conatained in the food (grass, vegetables, even grain
>> > contains a large fraction of water that is close to the local
>> > Meteoric water). Only under real arid conditions the water produced
>> > in the food "combustion" process may play a dominant role.
>> >
>> > But let me just be more specific about my data.
>> >
>> > The last two cases I had at hand were wild Cape gannets (South
>> > African West Coast and Namibia) and Dutch laboratory mice. First the
>> > gannets.
>> >
>> > I expect their body water to be pretty close to sea water. After
>> all,> they eat fish, and fish have no way to escape a VSMOW-like
>> imprint on
>> > their body water and tissue (seems to me, at least!). And indeed, as
>> > far as 18O is concerned, a total of 20 background values of a total
>> > of 16 individuals show a de18O of close to zero, with a spread of
>> > about +/- 1 per mil. de2H, however, shows about half of the values
>> > close to zero, and half considerably above zero (the highest
>> being up
>> > to almost 100o/oo !). Looking closer (after the suggestions on
>> > Isogeochem) I saw that some of the duplicate mm show one de2H close
>> > to zero, and one off by 20-50 per mil.
>> > The laboratory mice samples show a similar behaviour: de18O at about
>> > -4 per mil (Dutch tap water is around -6 per mil, as well as all the
>> > regional vegetation their food is supposedly coming from), de2H at
> > > about -25, but with some large excursions to more positive values.
>> >
>> > So after all, I think Dachun Zhang's observation of some kind of
>> > H-exchange in stored blood might be the answer. The samples we
>> > process are taken in the field, stored in flame-off glass capilaries
>> > and sometimes take many months before they are analysed. The
>> analysis> starts with microdistillation, but if exchange has been
>> going on
>> > before that time, the damage has been done. As it is so variable, it
>> > might have something to do with the leaktightness of the capilary?
>> > It is something to worry about in the field of Doubly labelled water
>> > for energy expenditure, though, since it can just as well affect the
>> > labelled samples.
>> >
>> > Marilyn, as for your nice series of background values on humans, I
>> > suggest you contact Klaas Westerterp (university of Maastricht,
>> > Netherlands, <[log in to unmask]>), who has an impressive
>> > track record of using DLW techniques on humans. My guess is he is
>> > interested, and he can tell you in how far your series contains
>> > unique material.
>> >
>> > Thanks once more, and if anyone has a concrete idea about a possible
>> > exchange process, I'll be eager to know.
>> >
>> > Harro
>> >
>>
--
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
http://www.rug.nl/cio
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