Keith Kelsen’s Narrative of Scent Biomarkers

Biomarkers and the Ability to Counteract Body Odors in Autonomous  & Rideshare vehicles

Our work with biomarkers, has brought up interesting facts.  Biomarkers are the “measurable substance in an organism whose presence is indicative of some phenomenon” and its smell. Biomarkers play a vital role in the development of therapies, the diagnosis and personalized treatment of diseases.

Scientists who study volatile organic compounds (VOCs) have long known that every person has a distinct odor, just like fingerprints. This is called your “odorprint” and is the way that dogs track certain people. The smells emanating from various parts of the body are unique to the individual, varying based on age, diet, sex, and critically, health.

“Some diseases result in a characteristic odor emanating from different sources on the body of a sick individual,” Dr. Mats Olsson, Karolinska Institute, Sweden

But finding and validating novel biomarkers remains challenging. The work that we are doing in this area is to define Scent biomarkers and then eliminate the odor.  This work faces three significant challenges. First, understanding what causes human body odor. Next, identifying those odors that are unpleasant. This is especially true in shared spaces like subways, elevators and the new phenomenon of shared cars. Finally, assessing what can be done to eliminate these odors for a more pleasant passenger experience.

Understanding Biomarkers & Bad Body Odor

According to YouBeauty, “as humans, we can generate as much as a gallon of sweat in two hours. Sweating developed as our body’s natural way to release toxins through our skin”. There’s sweat that smells good and bad.  The attractive sweat from your workouts, is composed mostly of water and electrolytes, that smell better. All of these are parts of the biomarkers of scent.


Realities of modern life cause stress.  Stress causes many reactions, most importantly, sweat.  Chemically, to most humans the most negative smelling sweat of all is stress sweat. The product of the aprocrine glands, it’s very condensed and stinky. Aprocrine glands produce a less-watery sweat. The odor is caused by hyperactive bacteria that love the fats and proteins in the mix. According to the Mayo Clinic, that is what releases the odor.


WebMD reports a diet heavy in garlic, broccoli, brussels sprouts or onion can stink. Smelly foods are broken down into smelly compounds that circulate in the blood stream and come out through the breath, sweat and urine. Many of the vegetables in the cruciferous family especially include smelly compounds, most typically, sulfur.


A genetic disorder called Trimethylaminuria causes the body to be unable to break down a chemical compound called trimethylamine. Trimethylamine is what gives fish its fishy smell. Trimethylamine has been described as smelling like rotting fish, rotting eggs, garbage, or urine. As this compound builds up in the body, it causes affected people to give off a strong odor in their sweat.


When people consume alcohol, the body treats it like a toxin and attempts to break it down into acetic acid. It manages to metabolize almost 90% of alcohol this way.  The rest gets excreted through the pores as a stinky, alcohol sweat. As alcohol courses through your blood and around your body, some seeps out through the pores. That creates the distinctive alcohol sweat Scent. It doesn’t matter what type of alcohol; once the body begins to break it down it all smells the same.

Prescription Drugs

Prescription drugs like anti-depressants and even over the counter ones like acetaminophen, can cause an increase in sweat and carry unprocessed proteins.  As we learned with stress, this increases bacteria and the bad odor.

Trends that Make this Important

Sharing spaces and smells has long been a problem of public transit.  Some people have often remarked it is why they drive their own cars.  Even the comedy Seinfeld did an entire episode where the odorprint of the valet left behind caused Jerry Seinfeld to sell his car!  General Motors’ Maven car-sharing service expanded to Toronto just this past week. The small operation’s mission is teaching GM important lessons about surviving in the future, where owning a personal car could be downright uncool. One of the questions to be answered is how to remove an odorprint and make the shared use of the car more pleasant.


Our sense of smell is arguably the primary human sense and key to our survival. In public places, what are “disgusting Scents” cause all sorts of negative reactions and rejection behavioral patterns.  This could prove untenable to the automobile industry as they bet on car sharing services like Über and Maven.  The solution is in detecting these objectionable odors and masking or counter act them with a pleasant Scent. Applying this technology to autonomous and/or shared vehicles (Uber, Lyft, Chariot, Maven) will change the journey.

The Electronic Nose[i]

We can hear over 300 tones, we can see 16 million colors, and  we can smell over 10 Billion scents. Using biomarkers of scent, there are sensors that, like a super-sensitive human nose, can “smell” and identify the chemical composition of an odor.  Currently, this is experimental technology  is used primarily for diagnosis of up to 17 potential diseases, as we have profiled in previous Scent Narratives. According to the scientists who developed it, can identify Parkinson’s disease, various cancers, kidney failure, multiple sclerosis and Crohn’s disease with 86% accuracy. This technology has other lifestyle applications as well, as people cannot survive just by “holding your breath”!  We sample both good and bad Scents in our environment with each inhalation.

“Without breathing, you’re dead. You can live without looking, and hearing, and whatever, but the moment you stop breathing, you’re dead. Humans take over 23,000 breaths in 24 hours —that’s nearly 1000 breaths each hour, or around 16 inhalations a minute. Every breath you take, you inhale smell molecules.” – Sissel Tolaas, Norwegian Smell Artist

The Importance of A Clean Air Scent

“I wish people knew much more that the human nose is more sensitive than most people think it is. Even though we are certainly not as good as rodents or dogs, simply because we don’t have as many receptors in our nose, we are still pretty darn sensitive.” Pamela Dalton, Professor at Monell Chemical Senses

Smart Fart

The unfortunately embarrassing name is only the beginning for a novel technology.  Smart Fart™, is a pill supplement that perfumes and masks the odor of gas. It is currently using crowd sourcing currently to raise money for production and launch of the pill.  Smart Fart’s inventor, Attila Csensk, thought of the idea after an embarrassing public event. Once the money is raised, Smart Fart will create over 150 different fragrances by cooperating with perfume manufact­urers.  However, the person prone to making the smell would have to “plan” to literally have, forgive me, “perfumed farts”.

This solution does not consider that many humans are reluctant to be responsible for their odor. Some and perversely like to make others experience their unique odorprint.  There needs to be a technological solution for various spaces, especially in transportation.


The Metro Stinks

Finding a solution for fresh air scent is as close as the Paris Metro.  In the intriguing blog, “Why does Paris smell like Pee? The “Flashpacker family” travels the world and writes about it.  Their conclusion?  “Little dogs + lack of public toilets + homeless folk sleeping in the Metro station = aroma d’urine”. Even  National Geographic addressed the concerns in an article by Daniel Stone in the November 2017 issue:

“Since before the days of Napoleon, the city of love has battled the odorous scourge of les pipis sauvages, or wild peeing. The widespread practice of public urination is technically illegal. But that hasn’t seemed to stanch the streams that pour into the streets, into planter boxes, and onto lampposts.” Daniel Stone

After pumping over 350Mn Euros over the last 5years into cleaning the stations and trains, the failure to make a change in Scent caused a change in administration last August. Catherine Guillouard is now president and chief executive of RATP (the group that runs the Metro) is committed to changing the Scent of the Metro once and for all.

The Metro Can Smell Like Paris Should

There is hope to replace the scourge of Paris with a Scent more pleasant, like the Scent of freshly baked baguettes.  The City of Paris and RATP are doing a joint experiment with a French company to 1) Sense the presence of an unpleasant odor, 2) Diffuse a more pleasant Scent, 3) Measure the impact, 4) Change the experience.  The successful conclusion of this experiment holds great promise for suffering noses around the world.

The technology used to solve this globally hated smell can be adopted to all forms of transportation, including the shared car phenomenon that is rapidly replacing car ownership.  Now, that shared car doesn’t have to have that shared odor.

The Most Intriguing Mystery

“Understanding the sense of smell may not seem a profound enough problem to dominate all the life sciences, but it contains, piece by piece, all the mysteries.” Dr. Lewis Thomas

The sense of smell is a mystery—and a particularly inscrutable one. While poets and authors have described it in countless ways, it was only in the last 25 years have scientists identified the molecules in our noses responsible for detecting odors. This breakthrough, along with the discovery of biomarkers, is a new frontier for technology. The three scientists who made the discovery won a Nobel Prize for their efforts in 1998. The intricacies of the human brain combined with motivation and human disparity the complexity of what is disgusting and what is good is both perplexing and intriguing.



[i] Technion-Israel Institute of Technology, Dr. Hossam Haick, “Na-Nose”, See also Cyranose

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