The Hidden World of Scents Outside Your Door

Part of the allure of going on a smell walk is how challenging it feels to engage such an underused sense.

Images of a sidewalk, a flower, and a person walking
Getty; Redux; Joanne Imperio / The Atlantic

This article was featured in One Story to Read Today, a newsletter in which our editors recommend a single must-read from The Atlantic, Monday through Friday. Sign up for it here.      

When I leave my house, I’m first struck by the scent of a dry lawn, its soil desiccated by the heat waves of this past summer. I admire a neighbor’s roses (honey, jam, cloves) and make a right at the pho restaurant (garlic, cinnamon, emulsified bones). The pungent mothballs used by a produce market to deter pests remind me of halitosis. That odor is soon overtaken by the smell of imported guava, so fragrant that it pierces right through the plastic wrap. This high-octane perfume follows me down the block.

I am on a smell walk, a habit formed during the coronavirus pandemic: I stroll around my tree-lined neighborhood in Toronto’s east end, focusing not on the city’s more obvious sights and sounds, but on its subtler scented stimuli. I started these walks for my mental health—walking provided me with daily physical activity, and smelling enabled a much-needed sense of cognitive stillness. These days, it’s become a scavenger hunt for my curiosity, an opportunity to encounter new odors that might teach me something about the place and time I inhabit.

Part of the allure of a smell walk, I’ll admit, is how challenging and clumsy it feels to engage such an underused sense. Moving through the world nose-first feels antithetical to how I—and maybe most of us—grew up within it. Ours is a culture dominated by the audiovisual; filtering our experience by olfaction doesn’t come as easily as noticing the changing of seasons in the trees, say, or recognizing a melody from a passing vehicle. It requires deliberate attention and an unnatural-seeming amount of mental effort, like maintaining a firm grasp on something that is used to being free.

It also feels a little like rooting for the underdog. If the five senses were a boy band, smell would certainly be the least popular member. This is not news: Some of the most influential philosophers in Western history turned up their noses at olfaction. “Man can smell things only poorly,” Aristotle declared, deeming our noses inaccurate sense organs. Immanuel Kant called smell “the most dispensable” of our senses, citing its fleeting nature as the reason “it does not pay to cultivate it or refine it.” Centuries later, a study conducted by the marketing company McCann Worldgroup would reveal that more than half of the 16-to-22-year-olds they interviewed would rather give up their sense of smell than technology. My friends agree, putting smell on the chopping block before all other senses, even when I, a lifelong fragrance nerd, tell them—with some indignation—that the senses are inextricable, and that about 80 percent of our experience of taste is actually olfactory in nature.

The pandemic changed this indifference to scent. Loss of smell became a telltale sign of COVID infection. People around me started reporting a temporary loss of olfaction. Some experienced ghost smells, also known as phantosmia, such as a sudden waft of cigarette smoke out of nowhere. Others experienced parosmia—distortions in their perception of familiar smells. An epicurean friend (who, for a period, found her favorite dishes ruined by this condition) admitted to me that she’d never attributed much importance to her sense of smell—until it was gone.

Elsewhere, stories about smell proliferated. TikToks extolling the benefits of smell training (the practice of repeatedly smelling the same handful of fragrances to rehabilitate the nose) hit my For You page. Mask wearers talked about missing the smells of the outside world. Scent had entered the chat. I felt a strange sense of camaraderie with these smell observers, who were newly attentive to its wonders; my obsession was finally being recognized.

When I got COVID two years into the pandemic, I documented changes in my olfaction with a mix of trepidation and inquisitiveness. Reading about someone else’s parosmia is one thing, but the only way to truly understand a scent is to experience it firsthand. My sense of smell shape-shifted for weeks. Water tasted alarmingly metallic. Cilantro, mysteriously stripped of its floral soapiness, was palatable again. Perfumes I knew by heart smelled like they were riddled with holes—entire spectrums of scent that I could no longer detect. Smell walks gained another purpose, a chance to put my nose to the test: Would I be able to smell the grass at the park? What about the roasted coffee from the Starbucks on the corner? Would my sense of smell return—in its entirety—in time for the lilacs?

Thankfully, it did, allowing me to indulge in some of my most cherished seasonal smells: clothes hung out to dry in the sun, the coconutty bouquet of drugstore sunscreens, a waft of charred meat from a distant grill. Soon, it’ll be the cool mineral air on a fall night, the must of wet leaves underfoot. The smell walks are a reminder that seasonal transitions happen in the atmosphere too, not just in the color of leaves overhead.

What is a recreational practice for me draws on the extensive work of artists and academics who study how smell informs our understanding of public space. One of them is Kate McLean, the director of the graphic-design program at the University of Kent, who leads smell walks in cities worldwide to track how scents operate in particular environments. She translates the resulting data into “smellscape mappings”—vibrant renderings consisting of colored dots, which represent different smell sources, and radiating concentric blobs that show their decreasing intensity and drift. Summer of 2012 in Newport, Rhode Island, smelled like beer bars, beach roses, the ocean. Summer of 2017 around Astor Place, New York City: construction, wet garbage bins, cigarette smoke. We frequently remember our cities through photographs and archives, but how do we remember their smells? McLean’s cartography for the ephemeral becomes a shared memory to be passed on—and an invitation to capture, through a less common lens, the times and spaces we exist in.

Smell awareness can also reveal sociocultural information that tends to be eclipsed by the other senses. The Berlin-based olfactory artist Sissel Tolaas, who has been logging scents since the 1990s, sees all smells as units of data, which she organizes in different ways. In Talking Nose, odors that Tolaas collected in Mexico City became a scratch-and-sniff map that called attention to the city’s dense air pollution; in the installation Eau D’You Who Am I, visitors were invited to touch the walls to release smells that represented different facets of Singaporean youth identity. Today, Tolaas’s personal scent archive consists of more than 7,000 smells, each numbered and preserved in its own aluminum can, and linked to a story about the context of that scent. “Every smell in the archive,” she writes, “has a story to tell.”

I think that’s true of all smells. On my walks, the aim is to notice scents without judging their origins, as one might treat intruding thoughts during meditation. Tuning in can feel like discovering a secret radio station, one that communicates clues about the kaleidoscopic world we live in—who was here, what they consumed, how they spent their days. And if you keep up the smell walks, they become documents of change, in seasons as in culture. I live in fear that my favorite pho shop will one day close down and be replaced by a trendy cannabis shop, echoing the fate of so many other businesses in the area. What I’d miss most would be the immediate comfort of its smell.

Kant deemed olfaction unworthy of study because of its ephemerality. His loss. For me, scent’s impermanence is precisely why it is so vital. It’s in many ways a mirror of life itself: here, then gone, made richer when we pay attention along the way.