GEOCHEMICAL ANALYSIS OF CREMATED HUMAN REMAINS

In 2002, people across the USA were appalled as the story of the Tri-State Crematory unfolded on national television. After a woman walking her dog discovered a skull, responding authorities begin to search the area and kept finding more bodies. Over 330 bodies were eventually recovered. Rather than performing the contracted cremations, bodies were simply dumped around the crematory property. Strangely, most bodies received prior to a certain date were properly cremated, while later on, most of the bodies were dumped on-site though some were sent to other facilities for cremation. Hundreds of families were uncertain as to the contents of the urns in their possession and regional crime laboratories were overwhelmed with questioned remains. Many families received cement dust, wood ash or other materials instead of the cremated remains of their loved ones. While this event is the most spectacular in recent memory, questions involving cremated human remains are relatively common.

Bones and teeth are a complex mixture of organic matter and mineralized tissues composed of calcium phosphate. Usually referred to as bioapatite, it most closely resembles the geologically occurring mineral hydroxylapatite, the hexagonal crystalline structure of which is quite flexible, allowing for a wide range of elemental substitutions. Trace amounts of around half the elements on the periodic table can be incorporated into geoapatite. Substitution into living organisms is much more limited. This suggests that trace element analysis can potentially be used to distinguish bioapatite from fillers. However it is vital to have a clear understanding of what a reasonable trace elemental load would be in order to make this determination. Fluoride substitutes so readily into apatite, even at body temperature, that fluorapatite quickly develops in humans that have been using fluoridated water or toothpaste. Conversely, high levels of arsenic, sulfur, vanadium or antimony are generally indicative of geoapatite. Differentiation is not always clear cut. In this study of samples of human leg bones and dentin cremated at 1010°C for 2.5 hours, XRF and XRD results clearly show distinctive differences between bone apatite, dentin apatite, and geological apatite. These results are also compared to those in the literature to provide a fuller understanding.