Publication Type : Scientific Paper
Thematic Areas : Medical Sciences
Publisher : Police Res D
Source : Police Res D, Volume 4, p.13 - 15 (1986)
Campus : Kochi
School : School of Medicine
Department : Forensic Medicine
Year : 1986
Abstract : Lisa Leone. A STUDY OF DECOMPOSITION RATES IN EASTERN NORTH
CAROLINA (Under the direction of Dr. Megan A. Perry) Department of Anthropology,
Estimating the time since death (or postmortem interval) via postmortem changes is
crucial in forensic cases involving decomposed human corpses. Several factors can
influence the rate of decomposition, such as ambient temperature, rainfall, and humidity.
Decomposition rates thus can vary drastically between two locations because many
factors are environment specific. Taphonomic and entomological information need to be
studied at the local level. The present study observed the decomposition of two domestic
pigs (Sus scrofa) of 103 and 158 pounds in weight. After being humanely killed, these
specimens were placed on the soil surface in two contrasting environments on East
Carolina University's West Research Campus. One specimen was placed in a cooler,
shaded area, while the other was placed in direct sunlight. From August 2005 to January
2006, data were gathered on the temperature, rainfall, and humidity experienced at each
site. The weight (biomass) loss, girth, and insect activity occurring with each pig
specimen was also recorded.
The purpose of this case study was to investigate decomposition rates in eastern North
Carolina and to determine which environmental factor(s) most influenced this process.
First, subjects placed in different environments were expected to decay at different rates.
Second, the shaded and exposed subjects additionally were expected to follow the same
basic decomposition patterns as those seen in Shean et al.’s (1993) meaning that the
exposed subject would reach maximum bloat before the shaded subject and also
decompose at a more rapid rate. First, ambient temperatures profoundly influenced insect
activity, the primary mode of biomass loss, as did the amount of sunlight exposure and
the direct relationship between exposure to sunlight and moisture. Second, the exposed
subject did achieve maximum bloat before the shaded subject (49.0 inches by day 2
versus 41.0 inches on day 3). However, the exposed pig did not decompose before the
shaded pig. The exposed pig first lost a higher percentage of biomass per day than the
shaded pig (43% versus 17.5 %) primarily as a result of warmer temperatures
experienced at the exposed site. Prolonged exposure to high temperatures and direct
sunlight however caused the soft tissues of the exposed subject to dehydrate and become
unsuitable for insect use and decomposition thus slowed as fewer and fewer insects
frequented the exposed carcass.
Cite this Research Publication : Pillay V. V. and VK, K., “Cadaver fauna as indicator of time of deaths: A few case studies”, Police Res D, vol. 4, pp. 13 - 15, 1986.