A group of scientists in the US are suggesting that a profile of the chemicals released from decomposing bodies may lead to a portable device capable enough to detect people buried in disasters and at crime scenes.
Speaking at the 238th National Meeting of the American Chemical Society (ACS) in Washington on Sunday, they said that such an electronic device might he helpful in determining the time elapsed since death quickly, accurately and onsite.
Presently, investigators rely upon dogs to detect and recover bodies in earthquakes, tornadoes, hurricanes, and other natural disasters.
"These dogs are highly effective, but it takes lots of time, expense and manpower to train them. If there was a device that was as effective for a fraction of the cost, that would be something worth pursuing," said Dr. Dan Sykes, a researcher involved in the study.
Graduate student Sarah A. Jones, collaborating on the research with Sykes, said that such devices could be developed by identifying which gases are released when bodies decompose under a variety of natural environmental conditions.
She further said that scientists must also detail the time sequence in which such odorant chemicals are released in the hours and days after death.
"What we're looking for is the profile of what gases are released when we die, as well as how the environment and the manner in which we die affects this profile," Jones says.
Jones and Sykes revealed that they euthanized pigs under humane conditions to study decomposition immediately after death.
"Pigs are good models for this research. They go through the same phases of decomposition as humans, as well as the same number of stages. And those stages last about as long in pigs as they do in humans before complete decomposition occurs and only the bones remain," Jones says.
During the study, the researchers placed dead pigs in specially designed odour-collecting units under a variety of environmental conditions.
Above each specimen, they affixed special sensors known as solid phase micro extraction (SPME) fibres to capture the gases.
They revealed that the specially-coated fibres were the same that are widely used to sample chemical composition of air.
Jones and Sykes collected odour data every six to 12 hours over the course of a week.
Studying the week's worth of odour data, they said, a clear chemical profile emerged.
"In days one through three, we found precursors to indole, which is a really good sign. On day three, we found indole and putrescine, the main compounds that we were trying to detect," Jones says.
They now are capturing gases released in a variety of other scenarios to re-construct the different ways human bodies could decompose, creating a more complete picture of decomposition.