Research uncovers the specific smell of human death

Death has a specific smell: a cocktail of chemicals that the ingredients which have been uncovered by a new study. Researchers have been able to isolate the cause of the particular scent of human death, which may lead to exciting possibilities in the future.

The findings could be incredibly useful in the field of forensics, as a synthetic smell could be used to train dogs to be able to more accurately find human bodies, or even to develop electronic devices to seek out the scent for use in police work.

This is the first time that researchers have been able to scientifically distinguish between the smell of dead human bodies and dead animal bodies. This discovery could be especially useful in natural disasters to help recover the dead quickly and help families grieve.

Six dead human bodies and 26 animal bodies were studied over six months as they decayed, and researchers studied the exact chemicals emitted from each one. They were able to distinguish specific chemical markers from the human bodies that were not found from the decaying bodies of mice, moles, rabbits, turtles or even pigs, which are often used in decomposition experiments for their similarity to humans. Never before have pig bodies been studied alongside human bodies in the same conditions and even though they have the same microbes in their guts, the same percentage of body fat, and similar hair as people, there were still several distinct differences.

However, there was one problem with the study – they examined individual isolated body parts rather than whole bodies, meaning that the chemical make-up of a whole body decaying could be different.

The team noted in their paper “further research in the field with full bodies has to corroborate these results and search for one or more human specific markers.”

You may think that the smell of death is a slightly weird topic to focus your research on, but there has been a lot of new findings surrounding the topic in recent news. For example, a paper co-authored by researchers from the University of Kent and Arkansas Tech University found evidence that both humans and animals perceive the scent given off by dead bodies as threatening, triggering a fight-or-flight response.

“It is hard to think of a scent as frightening,” said co-authors Dr. Arnaud Wisman and Dr. Ilan Shrira. They found that the smell given off by decaying tissue acts as a “chemosensory warning signal” that “mobilises protective responses to deal with relevant threats.”

A series of four experiments were conducted where participants were exposed, either knowingly or unknowingly to the smell, and their reactions were compared to when they were smelling other scents such as ammonia and water.

Research regarding dead bodies, both human and animal, is ongoing as forensic science aims to improve and get more accurate. There are projects such as the Body Farm in Tennessee, where donated bodies are left in different conditions and studied to see how they decompose, allowing us to gain an ever-more useful understanding of how tissue breaks down.