Donated bodies are left exposed to the elements at the University of Tennessee's "Body Farm," so researchers can study decomposition's four stages, starting with the "fresh" state (shown). Image: Grant Delin
- After death, the human body decomposes through four stages.
- The final, skeleton stage may be reached as quickly as two weeks or as slowly as two years, depending on temperature, humidity and other environmental conditions where the body lies.
- Dead bodies emit a surprising array of chemicals, from benzene to freon, which can help forensic scientists find clandestine graves.
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Welcome or not, dying is a natural part of the circle of life. Death initiates a complex process by which the human body gradually reverts back to dust, as it were. In the language of forensics, decomposition transforms our biological structures into simple organic and inorganic building blocks that plants and animals can use.
Four main factors affect the pace and completeness of decay. The most important is temperature: the rate of chemical reactions in a cadaver doubles with each 10 degree Celsius rise. Humidity or water from the environment buffers those reactions, slowing their effects. Extreme acidity or alkalinity hastens how quickly enzymes degrade biological molecules—although again, the presence of ample water can mediate the effects. Finally, anything that blocks exposure to oxygen, such as burial, submersion or high altitude, will slow decomposition. Depending on the interplay of these four factors, the body can turn into a skeleton as rapidly as two weeks or take more than two years.
This article was originally published with the title Dust to Dust.