Human soft-tissue decomposition in an aquatic environment and its transformation into adipocere

The problems addressed in this study are how long does it take for adipocere to form in a human body and what are the gross morphological changes that occur on and within the decomposing body. In order to determine the answers for these questions an actualistic study was constructed to test the rates of adipocere formation on human cadavers in a non- laboratory environment.

The experiment consisted of immersing three human cadavers into excavated holes in the earth for three months (or until adipocere formed). Gross morphological changes of the external tissues and body were recorded as well as the ambient and water temperatures. Fluctuations in climatological and meteorological conditions were compared to the transformation occurring in and around the cadavers. Liquid and tissue samples were extracted during the study period and analyzed for fatty acid content and microbial composition.

The analysis of recorded temperatures for both weather and water revealed that adipocere formation was most likely occurring during the warmer periods of the study. The interpretation of the fatty acid profiles showed inconclusive results but suggested the expected increase in palmitic fatty acid as the rate of oleic fatty acid decreased. The polar lipid fatty acid profile suggested corroborative evidence of Clostridium perfringens (welchii), the primary bacteria responsible for adipocere formation, still present after a three month interval.

Conclusions suggest that temperature is a major variable in underwater decomposition. The "Goldilocks Phenomenon" indicates there is a certain range for temperatures to be operative in the formation of adipocere. The optimum growth temperature for the primary bacteria involved in the formation, Clostridium perfringens (welchii), would be from about 70° to 113° F. (21° to 45° C.). The literature on this topic states that a warm, moist, virtually anaerobic environment with adequate bacterial action is suitable for adipocere formation to occur. This study concurs with these criteria. In two of the three cadavers, characteristic tissue resembling that found on adipociferous bodies was present after a time period of three months. The two cases with this phenomenon were the ones that floated the entire time of the study. The gross morphological changes that occurred in/on the cadaver in Hole 2 provided data for a progressional stage analysis to be made. The development of adipocere formed on the cadaver in the following stages: float, bloat, insect activity, hatching, mummification/maceration, fungal growth, color loss, cutis anserina, adipocere. The limited sample size (i.e., three cadavers) for this research does not allow for accurate predictions to be made on adipocere formation. However, it is possible to say that complete immersion in an aquatic environment may not be necessary for this decompositional process to occur. Also, an individual who is deceased prior to immersion will tend to float but is still susceptible to adipocere formation.