The Effects of Sun and Shade on the Early Stages of Human Decomposition

Existing literature on human decomposition has noted the importance of sun versus shade locations. To date, no study has focused on this variable exclusively. While the affects of temperature are becoming well recognized, there is conflicting information surrounding direct sunlight or lack thereof. Some researchers note that decomposition progresses faster in the sun, while others note that it is faster in the shade. The only existing study of such information was performed in the state of Washington using two pigs. Therefore, the goal of this study is to bridge the gap between animal and human decomposition and to note the differences that result from sun expo sure and shaded locations. From this information, anthropologists will be able to estimate a more accurate postmortem interval based on human as well as animal decomposition studies. This was accomplished by documenting weather data and changes in the bodies of nude subjects as they decomposed in both sun exposed and shaded areas. The individual results were compared to each other using weather data that had been calculated into accumulated degree days.

Over the summer months, the cadavers of five unembalmed, unautopsied individuals were placed at the Anthropology Research Facility to decompose. Subjects were studied and all pertinent information, including all kinds of weather data, was recorded on a daily basis over the course of three months. Accumulated degree days were calculated for each location and compared to each other and the local weather service information. Exposed bodies progressed faster then the shaded bodies through the early stages of decomposition. In addition, they began to dessicate earlier due to extreme heat and sun, and thereafter became stalled to future progression of decomposition. This study demonstrates that location of decomposition must be appreciated and examined when estimating the time since death.

Bound copy includes a CD of 160 additional photos. Attached below is a PDF of those photos (although only 62 of the 160 converted correctly).