Sniffing cities: Researcher uses ‘smell walks’ to map the world’s scents

University of Kent researcher Kate McLean-Mackenzie leads “smell walks” through different cities.

On a smell walk, she says, all the information about your environment has to come through your nose. Participants are invited to concentrate on what they can smell both at a distance and up close. 

While it might sound strange to some — deliberately sniffing your way through a downtown stroll — McLean-Mackenzie thinks places shouldn’t only be experienced through our eyes, but our noses as well.  

“You refocus how you experience the world,” McLean-Mackenzie told As It Happens guest host, Paul Hunter. “It does change the way that you think about places. It makes you slow down and you kind of see places in a new light when you smell them.”

McLean-Mackenzie has spent the last 15 years analyzing and recording the smells of 40 towns and cities across the world for her upcoming book, Atlas of Scents and Smells.

What is a ‘smellscape’?

McLean-Mackenzie says she maps out these “smellscapes” using the data she and the other participants gather from their smell walks in different places around the world.

A smellscape, she describes, is “the olfactory equivalent of a visual landscape.”

“So, if you think when you’re actually looking outside, you can see everything that’s in your immediate sight line, you can scan from left to right, you look over a horizon line, you look down and you see whatever’s in those vistas. The smellscape is a similar thing,” she said. “It’s what comes to your nose in the vicinity that you’re in.”

Ever wonder what Antarctica smells like? In McLean-Mackenzie’s atlas, it’s the leathery tang of a dead seal mingled with the scent of the heavy machinery used at the Rothera Research Station where the data was collected. 

Then there’s Kyiv, Ukraine, where she took her research nine years ago. At the time, she says, the city smelled like its own history — the pine forest it was built in, blended with the river and “moments of summer in the middle of winter” marked by “odd bits of moss and greenery.” 

Nearly four years after Russia’s invasion of Ukraine, McLean-Mackenzie knows Kyiv likely smells very different now. That, she says, is exactly why preserving these scent records matters.

“As times change, as places change, as industries change, then the smellscapes will also change,” said McLean-Mackenzie. “And I just think it’s a great thing to have a record, both a visual one and one in words, of what those cities smelled like.”

The map also captures the ephemeral nature of smells.

McLean-Mackenzie recalls a smell walk through Montreal at 5:30 on a cold and wet morning. She recorded the “early odours” of trees, leaves on the ground, damp earth and coffee “that really punctuated” the air. 

As the morning went on and the group moved deeper into the city, those scents gave way to more “traditional urban smells”– the warm notes of “coffees, bagels, food coming out of different places.”

More than just scent

McLean-Mackenzie says she knows scent is subjective and that not everyone on a smell walk will agree on the whiffs they pick up at a certain location. But when they do agree, she says, that’s when the real magic happens.

“When somebody says, ‘I smelled this,’ and then somebody goes, ‘Oh, I did too,’ you start to see this amazing connection and how we very often smell very similar things,” she said.

Beyond the novelty of identifying and cataloguing the heady bouquets of urban life, McLean-Mackenzie says the work is also about capturing how scents make people feel. 

And that is what keeps her smelling, she says, after 15 years.

“The stories that come from it are just magical,” she said. “Everybody has a smell story that is something that is very poignant to them and so there’s an emotion attached to it and there’s the idea of special locations and there is this beautiful idea about the complexity of a smellscape that means no one place smells of one thing.”

Asked to name her favourite scent, McLean-Mackenzie did not hesitate. 

“Garden shed,” she said firmly. “Ahhh, inside a garden shed, it’s amazing. It’s lawn mower, it’s cut grass, it’s possibly a bit of creosote, it’s the warmth of the asphalt on the roof and a little bit of the wood itself that the garden shed is made of.”