The Future of Smelling

Coming on the heels of a grant proposal, I am starting to think about my upcoming paper for the American Association for the Advancement of Science meetings in Boston in February. My talk will focus on the future of human smelling in a panel called ‘How We Came To Our Senses: Ecology, Evolution, and Future of Human Sensation’ The panel also features my colleagues Dr. Nathaniel Dominy (Dartmouth College), Dr. Amanda Melin (University of Calgary), and Dr. Paul Breslin (Monell Chemical Senses). This panel is a lovely step forward for my research which has focused on the evolution of our sense of smell and modern human variation in ability to detect specific odors (as limited by the small number of receptor-ligand knowns). I have written before about our early efforts to rebuild ancient noses which was picked up in several media outlets. I hope to get the final results of the Old Noses out in early 2018 along with the human variation data (stay tuned for some sneak-peak blog posts). For now, though, I want to focus on the next steps.

While visiting Durham University in the UK this fall, I have been thinking about modern cities and smellscapes–a contrast to where I would normally be, rural Alaska. Namely, I have been thinking about how a thread of anthropological research on environmental inequities is highly relevant to modern smellscapes. Specifically, sensory environments in cities are not equal and some people bear the burden of negative sensory input on a regular basis–garbage, noise, greater concentrations of pollution (e.g., bus routes), urban decay. The higher your socio-economic status, the more you can afford to elevate your place of living out of the sensory fray and surround yourself with positive sensory landscapes. The access to positive sensory landscapes is only going to become more polarized: urban population density projections show an increase from 54% to 66% by 2050 (UN)–in Europe 73% of the population lives in urban areas and 82% in the US. Africa and Asia are not as urbanized but projections show great increases in those areas in the few decades.

We are already very mismatched to the modern urban smellscape–our evolutionary sensory tuning took place in lush environments in Africa, rich with natural odors of plants and animals and other humans. We were in deep and regular contact with the environment–actively engaged (and anyone who has engage in any kind of smell training–perfume and wine mainly–knows how important that regular exposure is. In fact, some research has shown that hunter-gatherers can detect odors in more more dilute forms. Now, we find ourselves in built environments with manufactured odors (think Lush, Subway, and any number of modern chains with bespoke smells) and pollutants (which also diminish our capacity to smell well as seen here and here). This is true of urban areas but also true of rural areas with high activity in farming, mining, and manufacturing–all of which produce anthropogenic waste.

What does that mean for us? We are at greater risk of reduced capacity to smell (smell-ability) and increasingly find ourselves in environments with unnatural odors, high concentrations of harmful odors, and an inequitable distribution of positive sensory input. Smell loss and exposure to negative smellscapes (e.g., living near a piggery, manufacturing plant, or landfill–to name a few) increases risk for depression as well as reduces quality of life. No one has yet looked at impacts of artificial smells. An impaired sense of smell can result in eating issues as well as exposure to danger (not smelling rotten foods, toxins). Urban futures must focus on equitable in the sensory landscape, reduction in artificial sensory stimuli, and mitigation of negative sensory input across the urban setting. These efforts should be paramount to protect a sense that most people don’t think about but that performs vital day to day functions. I plan to launch several projects in the coming year that will address many of these unknowns and advance awareness of sensory inequities–this work will be embedded in my current work establishing the general architecture of human smelling in the distant evolutionary past and modern distribution of variation So, stay tuned!!