Olfactory Remains

The picture seen here is taken from a local Arizona news source circa 2014, attached to an article citing the decrease in “migrant deaths” in the Arizona desert at that time. That data was given by Border Patrol. They say most of the deaths are caused by the heat.

But this post isn’t about migrant deaths; it’s about olfactory forensics, using one’s sense of smell to find decomposing bodies.

On the other side of the United States/Mexico border, deaths aren’t from heat, and the bodies are not of migrants. They’re people suspected to have been kidnapped by drug cartels, either for ransom, recruitment, or rivalry. Then there’s the women, who are abducted for trafficking. For whatever tragic fate befell them, their bodies are buried in a clandestine grave.

When farmers and cowboys find bones in the brush, they notify The Searchers of El Fuerte, who investigate suspected burial areas. They dig the earth, and then sniff the air. If they find bodily remains, they take them and send them for DNA testing. If a match is found, they try to inform their relatives.

It may sound primitive, but this is common practice. The human nose is the most powerful device we know of for detecting things that smell. It’s hard to believe, but it does explain why actual humans are hired to smell the fish at large industrial operations to make sure they’re fit for human consumption. It’s also why the fragrance industry employs noses. Shoot, Firmenich, who in 2017 was making 95% of the world’s supply of Hedione (which is in 95% of fragranced products) employ their own truck drivers, custodians, and administrative assistants to assure the quality of their Hedione batches. (This is because so many people have a hard time smelling it; if you’re good at detecting Hedione, no matter what your actual job, you will be asked to sniff batches.)

Back to the bodies. As flesh breaks down, it produces a molecule called Cadaverine, which smells like rotten flesh. (If you’re not sure what that smells like, try driving past exit 14 on the New Jersey Turnpike sometime around August; that should do it.)

Eventually, the cadaverine subsides, leaving other equally offensive odors. There will come a time when a deterred body no longer produces a smell at all. Until then, it is a recognizable indicator.

Image source

Notes:

The Searchers - Mexican women who look for the dead

Dec 2018, BBC

Cadaverine has the sickly-sweet smell of rotting flesh

You Are Never Gonna Bereave This

Limbic Signal, 2017

What Exit - The Smells of the New Jersey Turnpike

Limbic Signal, 2016

Sensory Psychologist Avery Gilbert features the “I Smell Dead People” installments on his blog First Nerve

Post Script:

Body Farms are places where bodies are buried under all kinds of different conditions, to be examined at various stages of decomposition, for the purpose of aiding forensic anthropology. The information learned on these body farms could be useful for solving potential crimes or missing persons cases.

The Body Farm at the University of Tennessee’s Forensic Anthropology Center

You Are Never Gonna Bereave This

‘the sickly sweet smell of rotting flesh’-scented bodywash

Researchers isolate the ‘human smell of death’

Clarification: Scientists are not looking for the “smell of death”, but for the unique profile of molecules specific to decomposing humans when compared to other similar animals.

First of all – who cares? Forensic anthropologists care, because they want to help find dead human bodies in places populated by so many other dead critters. The wildfires in California are an example. With so many dead things there, how do we find the humans? Dogs can be trained (just like people, let Avery Gilbert give you a mouthful on that note) to recognize trace amounts of one particular chemical, or a signature profile, regardless of whether it is part of a much larger bouquet. If we could find the difference between dead human bodies and others, we could better inform our search.

Second thing – what’s the difference between “the smell of death” and the ‘human smell of death’ used in the headline above? Not much. This is certain because we already know “the smell of death”, and it’s called Cadaverine.

It’s got a lot to do with Putrescine, which is another part of “the smell of death” (as well as the smell of semen). Unfortunately, or fortunately, I cannot smell it; I’m anosmic; so I can’t be trusted. I’ll continue nonetheless. Cadaverine is described as the sickly sweet smell of rotting flesh, and you probably smell it more than you think (Exit 14 on the New Jersey Turnpike anyone?). How I wonder what dead bodies “really” smell like, because I am noseblind to one of its major constituents, but I will tell you this: On a midsummer afternoon, at a formal event like a wedding or church, where everyone is freshly-showered yet wafting personal microbiome clouds in competition with their carefully-crafted fragrance-enhancing products, Cadaverine trickles through the air.

Yes, a sheen of it covers these warm bodies, a fine layer of pulverized, rotting flesh, spread to every square inch by perhaps day-, perhaps week-old washcloths. I call it “dirty washcloth”, but I’d rather not. Sometimes, or in a strange animalistic way, it can actually smells good.

Oh, would you look at that, the Bvlgari Soir that’s been sitting on a test-strip on my desk for the past six days has been almost all dissipated, through the stages from complex aroma, to base notes, to one particular note, something musky, to this now lone Cadaverine. Even your cologne smells like dead people.

Post Script:

The Search for a Volatile Human Specific Marker in the Decomposition Process

Abstract

In this study, a validated method using a thermal desorber combined with a gas chromatograph coupled to mass spectrometry was used to identify the volatile organic compounds released during decomposition of 6 human and 26 animal remains in a laboratory environment during a period of 6 months. 452 compounds were identified. Among them a human specific marker was sought using principle component analysis. We found a combination of 8 compounds (ethyl propionate, propyl propionate, propyl butyrate, ethyl pentanoate, pyridine, diethyl disulfide, methyl(methylthio)ethyl disulfide and 3-methylthio-1-propanol) that led to the distinction of human and pig remains from other animal remains. Furthermore, it was possible to separate the pig remains from human remains based on 5 esters (3-methylbutyl pentanoate, 3-methylbutyl 3-methylbutyrate, 3-methylbutyl 2-methylbutyrate, butyl pentanoate and propyl hexanoate). Further research in the field with full bodies has to corroborate these results and search for one or more human specific markers. These markers would allow a more efficiently training of cadaver dogs or portable detection devices could be developed.

Rosier E, Loix S, Develter W, Van de Voorde W, Tytgat J, Cuypers E (2015) The Search for a Volatile Human Specific Marker in the Decomposition Process. PLoS ONE 10(9): e0137341. DOI: 10.1371/journal.pone.0137341

Post Post Script:

Sensory Psychologist Avery Gilbert features the “I Smell Dead People” installments on his blog First Nerve.