If you’ve ever been overwhelmed by the aroma of freshly ground coffee upon walking into a café, or the particular bouquet of a hotel lobby, you know firsthand that scent marketing is real. But while some businesses strategically pump smells into the air, others strive to counteract ones that naturally exist on their premises—a subject to which Dr. Michael Bull, one of the leading air quality and odor experts in the United Kingdom, has dedicated more than three decades of his career. The former director of global engineering company Arup’s environmental consulting arm in the U.K., he established his own firm earlier this year.

Dr. Bull applies his knowledge of assessing and managing smells to an array of industries, including farms, restaurants, airports, highways, wastewater treatment plants, and manufacturing facilities, making recommendations for how to plan infrastructure around the scents a venture emits or encounters, conducting odor assessment reports, and combating air pollutants. He has also presented expert evidence on air quality matters to committees at British Parliament and in court, where he regularly works with clients on statutory nuisance cases, in which a scent or air quality affects a person’s health or property. We recently spoke with Dr. Bull about his line of work, and the central olfactory issues he encounters today.

What led you to choose a career in assessing odors and their relationship to architecture?

Smell is the forgotten sense. People often create a design around a given appearance or tactility, but we rarely [think about] designing based on how an environment smells. Generally, smell has much less perceived value than our other senses—insurance claim payouts are much higher for loss of sight, for example. Still, I find it fascinating.

You seem to deal with a lot of infrastructure issues that, like smells, are largely invisible but have serious implications. What are some of the scent-related situations you’ve encountered lately?

A lot of my work is concerned with where to put residential housing, because most land near potentially odorous activities is quite cheap. There are many people who are keen to build new developments near sewage works, or waste disposal sites. My team looks at those areas to see whether the odor levels are such that it affects people so much that it would be inadvisable to build there. We also do a lot of restaurant building applications, determining how those establishments can operate without causing a problem. This doesn’t just involve unpleasant smells—pleasant smells can be a nuisance, too.

How can pleasant smells be a nuisance?

A factory was making strawberry flavorings in the town I used to live next door to. Its residents got fed up going out in their gardens and smelling strawberries all the time! So there was a big action taken against the company. In fact, many restaurants have had action taken against them for causing nuisances like this. People are fussy about smells. They’re mostly fine with natural floral smells, but if it’s an artificial smell being forced on them, that’s much less liked.

But how do you stop something as pervasive as a smell?

There’s a whole industry of abatement equipment and solutions to reduce the amount of odor in the gases [a site] emits, either by using something like ozone to chemically react with odor molecules so they’re no longer odorous, or absorbing them in a carbon filter. Sewage stations often control offensive odors using biofilters [where bacteria is used to break down pollutants]. There are also odor-masking agents. I was at a landfill site today, where a scent that smelled like fabric conditioner was [periodically] sprayed to obscure its unpleasant odor.

Do these tactics typically succeed in deceiving people’s noses?

Our sense of smell is nowhere near as sensitive as many animals’ [are], but it’s much more advanced than a lot of the highly specialized analytical equipment I use. When people ask me to go out and measure a smell, I often tell them they can learn a lot by simply using their noses.