Presentation Type
Oral Presentation
Category
STEM (science, technology, engineering, mathematics)
Abstract/Artist Statement
Forensic identifications may be hampered when perpetrators find unique ways of obscuring their victims’ identities, such as fire and household corrosive substances. Thermal alteration, sodium hydroxide, and hydrochloric acid are known to change both the structural integrity and composition of skeletal elements; but the patterns of these processes, nor how each may affect the potential for obtaining identifying DNA data, are well understood.
Burned bone concomitantly follows a defined color spectrum and eventually reaches calcination, consisting only of its original inorganic mineral, hydroxyapatite, which is naturally white in color and brittle.
In contrast, analyses of chemical exposure focus on total dissolution times, rather than on discrete changes. However, it is well documented that household chemicals are used to disfigure victims due to their availability and apparent effects.2 Sodium hydroxide is a corrosive base that effectively dissolves soft tissues and produces high temperatures through violent exothermic reactions but ostensibly fails to alter bone structure and color. Hydrochloric acid appears to be among the most destructive chemicals with all tissue dissolving within 24 hours.
This study compares and analyzes the micro- and macroscopic changes occurring in fully skeletonized remains over the course of a maximum of two hours and assesses the viability of DNA analysis. Furthermore, this study tests how bone shape and volume to surface area ratios may affect the degree of alteration.
In the fire treatment, elements were placed over an open-air fire pit for 1 hour. The chemical alteration protocol consisted of four 30-minute intervals in their respective solutions (total: 2 hours).
Pre- and post-treatment dimension data were recorded using a 3D scanner and weight was measured to the closest ±0.01g. Photographs were captured using whole-specimen and inverted microscopes. Furthermore, DNA was extracted using a silica-based method and quantified through a human-specific qPCR methodology.
Mentor Name
Meradeth Snow
Assessing the Micro- and Macroscopic Changes of Taphonomically Altered Bone
UC 332
Forensic identifications may be hampered when perpetrators find unique ways of obscuring their victims’ identities, such as fire and household corrosive substances. Thermal alteration, sodium hydroxide, and hydrochloric acid are known to change both the structural integrity and composition of skeletal elements; but the patterns of these processes, nor how each may affect the potential for obtaining identifying DNA data, are well understood.
Burned bone concomitantly follows a defined color spectrum and eventually reaches calcination, consisting only of its original inorganic mineral, hydroxyapatite, which is naturally white in color and brittle.
In contrast, analyses of chemical exposure focus on total dissolution times, rather than on discrete changes. However, it is well documented that household chemicals are used to disfigure victims due to their availability and apparent effects.2 Sodium hydroxide is a corrosive base that effectively dissolves soft tissues and produces high temperatures through violent exothermic reactions but ostensibly fails to alter bone structure and color. Hydrochloric acid appears to be among the most destructive chemicals with all tissue dissolving within 24 hours.
This study compares and analyzes the micro- and macroscopic changes occurring in fully skeletonized remains over the course of a maximum of two hours and assesses the viability of DNA analysis. Furthermore, this study tests how bone shape and volume to surface area ratios may affect the degree of alteration.
In the fire treatment, elements were placed over an open-air fire pit for 1 hour. The chemical alteration protocol consisted of four 30-minute intervals in their respective solutions (total: 2 hours).
Pre- and post-treatment dimension data were recorded using a 3D scanner and weight was measured to the closest ±0.01g. Photographs were captured using whole-specimen and inverted microscopes. Furthermore, DNA was extracted using a silica-based method and quantified through a human-specific qPCR methodology.