As Aerox, we offer our customers sustainable solutions for reducing industrial odor emissions. In the conversations we have with our contacts, we often get questions about exactly how this works, what smell really is, why something smells and why we are actually in this market.
So it’s interesting to reflect on what odor and odor nuisance mean now. In this article, therefore, I would like to address the questions: What is smell? Why do you smell this? And when does smell become a stench?
Smelling is done with your nose, or rather with your olfactory epithelium. The olfactory epithelium is a piece of tissue at the top of the nasal cavity. In the epithelium are offshoots of nerves, the olfactory receptors. When you smell something, these are volatile and water- and fat-soluble substances in the air, detected in the nasal cavity by binding to an olfactory receptor. This sends a signal to the brain by which the smell is perceived.
Smell is used by humans more than we think. A human has about 400 scent receptors, which can pick up different odors. Whereas it was initially believed that humans can smell about 10,000 different odors, recent publications cite calculations indicating numbers of more than a trillion (Science, March 2014, Humans Can Discriminate More than 1 Trillion Olfactory Stimuli). The olfactory receptors are directly connected through holes in the skull to the olfactory bulb, also called olfactory bulb(Lat: bulbus olfactorus), in the limbic system in the brain.
Smell is our only sense with such a direct connection. The limbic system is evolutionarily an older part of the brain, involved in emotions and emotional memory, as well as primary defense responses, among other things. Certain odors immediately evoke an immune response, and that’s a good thing. After all, it may be an odor associated with something that poses an immediate danger.
Other scents do the opposite and evoke positive reactions. However, the perception of the vast majority of all smells depends on what one has been taught and how something is labeled. This is why scents sometimes bring out such strong memories or reactions. These in turn affect our mood and thus our well-being.
Natural scents are almost always composed of several different scent molecules, sometimes even hundreds. With artificial fragrances, this is often not the case and involves 1 single or a mixture of only a few substances. Artificial fragrances are added to products to approximate a certain smell, but because of our sophisticated registration in our brains, we are almost always able to properly recognize the difference between natural and artificial products.
Natural or artificial odors that bother us give us a negative perception. This is called smell and this can be very personal in nature. What is a smell to one person may be stench to another. Of course, there are odors, such as sewage smell, that everyone experiences as a stench. However, pleasant odors, such as those from coffee, can also be perceived as smells. This happens when they are very strong: not from a single fresh cup of coffee but from a factory chimney. Thus, odor is “a negative perception of smell.”
As Aerox, we have been active in this specific and very interesting market for many years. The reason why can be guessed: the social importance of industrial odor reduction. The ever-increasing urbanization now produces a tension between industry and residential areas. Both are and will continue to be needed, and thus all parties must cooperate and take responsibility for this.
With our specific knowledge that we have in house for this, we have very good relationships with all of our clients that endorse this approach. Of course, we continue this work unabated knowing that the end result of our efforts ensures fresh air for our customers’ environments worldwide.
Erik C. Versteeg, Managing Director, Aerox B.V., April 11, 2017