A National Survey of Human Body Water Variation.

O'GRADY, SHANNON P; REMIEN, CHRISTOPHER H; ENRIGHT, LINDSEY E; VALENZUELA, LUCIANO O; CHESSON, LESLEY A; PODLESAK, DAVE; CERLING, THURE E; EHLERINGER, JAMES R

Washington

Conferencia; Forensics Isotope Ratio Mass Spectrometry Conference; 2010

The hydrogen and oxygen isotopic composition of body water influences the isotopic composition of tissues commonly used to investigate the movement patterns of humans (i.e., hair). We developed a body water model that incorporates the isotope composition of drinking water, food, and O2 as well as variables such as diet composition and energy expenditure to estimate the δ-values of human body water. While this model reliably estimated δ-values of body water when compared with published values, validation of the model requires considerations of normal variation within a population that might be associated with differences in diet, level of activity, and drinking habits. We measured the actual variations in body water among 10 individuals over a 5-day period in each of 8 different cities across the USA. In addition to body water measurements, participants completed a food and activity log so that the role of dietary and activity differences could be incorporated. Measured hydrogen and oxygen stable isotope ratios were compared with predicted values to account for differences in diet and energy expenditure among participants.