The burial of humans in Central Europe takes place mainly in the soil. The interest in the study of post-mortem decomposition has a long tradition. Investigations on this subject were preferably carried out from a forensic point of view, e.g. to determine the time of death and the cause of death of corpses from burials. However, almost exclusively casuistic reports predominate without characterizing the medium in which the decomposition took place in more detail. This, however, would be important for an exact statement regarding the time of death, especially in the case of variations of corpse decomposition despite comparable lying times in the soil.
In this context, we are particularly interested in the influence of site-specific characteristics on the decomposition of buried human remains. The post-mortem transformation, which proceeds via the phases and processes of autolysis, hemolysis, putrefaction and decomposition, which cannot be strictly delimited in time, ends with the skeletonization of the corpse. The period between the time of death and skeletonization is 3-12 years in the burial ground under favorable conditions. During postmortem changes, decomposition products enter the surrounding soil, where they are enriched, possibly chemically altered, or translocated with the leachate. These compounds can be used as biomarkers that should have a low concentration in unamended soil, exhibit a long residence time, and remain in their original chemical structure. Recent studies on pig carcasses show that some degradation products (e.g., fatty acids) are detectable in soil even after a short residence time. Detection of these compounds in soil samples from vacated burrows, can identify them as sites of temporary decomposition. A major focus of our research is the investigation of typical biomarkers of decomposition, development of analytical methods to quantify them, and interpretation of the interactions between decomposition products and soils.
However, decomposition can also be considerably delayed or come to an apparent standstill if site-related process disturbances occur in the early stages of decay. The most important special form of late cadaveric decomposition is the formation of cadaveric lipid (adipocere, so-called fat wax) by transformation of the soft tissues into an 'armor-like' solid and persistent mass. If this decomposition inhibition occurs, reconstruction of the time of death is virtually impossible. While the processes of lipid formation are considered to be elucidated, there is uncertainty as to which external factors control the formation of adipocere. It is often stated that, in addition to cadaver-specific characteristics and mode of burial, the soil in particular controls the rate of decomposition through its properties (e.g., anaerobic environment, presence of Ca2+ and Mg2+), although the actual decomposition process is primarily independent of the soil. Our studies will contribute to a better understanding of the formation as well as the decomposition of adipocere in the context of varying soil properties.
Earth grave with the formation of adipocere (Photo: B. von der Lühe)
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Management: Prof. Dr. Sabine Fiedler
Staff: Barbara von der Lühe
Cooperations:
Prof. Dr. Lorna Dawson and Dr. Robert Mayes (James Hutton Institute, Aberdeen, United Kingdom)
Prof. Dr. Mathias Graw (Institute of Forensic Medicine, Technical University of Munich)
Prof. Dr. Shari Forbes (University of Technology, Sydney, Australia)
Selected publications:
Fiedler, S., Breuer, J., Pusch, C. M., Holley, S., Wahl, J., Ingwersen, J., Graw, M. (2012): Graveyards – Special landfills. The Science of the Total Environment 419: 90-97. https://doi.org/10.1016/j.scitotenv.2011.12.007
Fiedler, S., Berger, J., Stahr, K., Graw. M. (2009): Localisation of a mass grave from the Nazi Era – a case study. In: Criminal and Environmental Soil Forensics. Edited by K. Ritz, L. Dawson, D. Miller. Springer-Verlag, Berlin, New York, pp. 303-314. ISBN 978-1-4020-9204-6
Fiedler, S., Berger, J., Illich, B., Graw, M. (2009): The effectiveness of ground-penetrating radar survey to locate unmarked burial sites on modern cemeteries. Journal of Applied Geophysics 68: 380-385. https://doi.org/10.1016/j.jappgeo.2009.03.003
Fiedler, S., Buegger, F., Klaubert, B., Zipp, K., Dohrmann, R., Witteyer, M., Zarei, M., Graw, M. (2009). Adipocere withstands 1,600 years of fluctuating groundwater levels in soil. Journal of Archaeological Science 36: 1328-1333. https://doi.org/10.1016/j.jas.2009.01.017
Fiedler, S., Schneckenberger, K., Graw, M. (2004): Characterization of soils containing adipocere. Archives of Environmental Contamination and Toxicology 47(4): 561-568. https://doi.org/10.1007/s00244-004-3237-4
Fiedler, S., Graw, M. (2003): Decomposition of buried corpses, with special references to the formation of adipocere. Naturwissenschaften 90: 291-300. https://doi.org/10.1007/s00114-003-0437-0