The investigation of decomposition rates and lipid degradation of victims in disaster events.

Mass disasters are a frequently occurring phenomenon that are increasing worldwide. The rise in natural and man-made catastrophes has increased the demand for better understanding of these unique environments, including understanding the best procedures for recovering and identifying human remains. At present, little data exist on the decomposition rates in these complex environments. In cases of commingling (i.e., multiple victims in close proximity), recovery and identification attempts are complicated due to the unique micro-environment created. Knowing the potential state of a victim, particularly when both commingled and independent victims are present, can assist with management of the recovery efforts. There is currently very limited work comparing commingled victim decomposition to the more traditionally individually placed surface victims. Previous research has shown that lipids are suitable as a soft tissue biomarker for human decomposition and can potentially be used to investigate the postmortem state of victims. This paper studies the decomposition rates, with an additional focus on commingled remains, on the lipid profiles of human remains in disaster events. A total of 10 donors were used across two simulated disasters, where the deceased were placed under rubble in various configurations (i.e., alone or commingled) to simulate a building collapse. This study reports the successful development of a gas chromatography coupled with tandem mass spectrometry (GC-MS/MS) multiple reaction monitoring (MRM) method, to evaluate decomposition patterns of victims of disaster events. Fatty acids showed an increase over time, with the commingled donors showing higher abundance of lipids two weeks post-placement. These results, in combination with the visual decomposition, show that there are significant differences in the decomposition states between victim configurations. The findings of this research can help rescue operations worldwide. Knowledge about the state of decomposition of the victim(s) will assist in determining the most suitable method for identification purposes, appropriate handling requirements for victims based on predicted decomposition state, and steer more precise rescue operations.