Scientists on scent of death-detecting electronic nose

An electronic nose that can detect the "smell of death," helping searchers recover bodies from disaster areas and aiding crime scene investigators to determine the exact time of death, is one step closer to wafting from the pages of science-fiction into real life.

Scientists have found that specific chemicals are released at incremental times after death, a breakthrough that bolsters the idea imagined in Ray Bradbury's classic 1953 novel, Fahrenheit 451, of a mechanical hound that hunts its prey by following their scent. Bradbury describes the hound as having "sensitive capillary hairs in the nylon-brushed nostrils."

The author's idea doesn't seem far from what Pennsylvania State University forensic scientists envision in the future.

Dan Sykes, director of analytical instructional laboratories at the university and the project leader, said the goal is to match the abilities of cadaver dogs that help find and recover bodies buried after earthquakes, tornadoes, hurricanes and other natural disasters.

"These dogs are highly effective, but it takes a lot of time, money and manpower to train them," said Sykes. "A device that is as effective as dogs, but is a fraction of the cost, would be something worth pursuing."

The research was presented Sunday at the National Meeting of the American Chemical Society in Washington.

RCMP spokeswoman Julie Gagnon said police use dogs in all kinds of situations, including searching for bodies, sniffing out drugs and explosives, and tracking suspects.

"The RCMP would be interested in anything that would help in the recovery of human remains," she said. "The dogs are pretty amazing in what they can do, but (our own) research is always ongoing to try to figure out how they do it and to try to mimic what they do with instruments."

Still, Sykes said developing a portable death nose remains elusive, but results so far have been encouraging.

Sarah Jones, a forensic science graduate student who's collaborating on the project, said a nose for death could also help crime scene investigators by pinpointing the exact time of demise quickly and at the scene. "Every step we take is towards that," she said.

Researchers euthanized pigs, then placed them in specially designed "odour-collecting units" to study which chemical compounds were released. They found they can already determine time of death as accurately as investigators do by analyzing bugs on bodies.

"Pigs are good models for this research," said Jones. "They go through the same phases of decomposition as humans, as well as the same number of stages. Those stages last about as long in pigs as they do in humans before complete decomposition occurs and only the bones remain."

After studying the week's worth of odour data, a clear chemical profile emerged, said Jones.

"In days one through three, we found precursors to a compound called endol. On Day 3, we found endol and putrascine, the main compounds that we were trying to detect," she said.

The scientists are now trying to capture scents in different weather conditions, including snow — which may help them to determine if it's possible to create a death nose that could sniff out avalanche victims.

This is the most comprehensive research on the topic to date.

No comments: