University of British Columbia researchers launch app to map Metro Vancouver’s ‘smellscape’

When something fails to pass the ‘sniff test’ – whether it’s a plan of action or the milk in the back of the fridge – it’s often best to leave it be. But when it comes to unpleasant odours in the air, we don’t have much choice. We have to breathe.

Which is why two University of British Columbia researchers are studying the smells of Metro Vancouver through a new tracking app called SmellVan. They’re hoping residents will help map the city’s ‘smellscape.’ The goal is to better understand the relationship among odours, potentially harmful pollutants, and health.

Odour is typically treated as a nuisance as opposed to something that directly affects health,” says Naomi Zimmerman, a mechanical engineer who studies air quality. “But experience of odour can be pretty intense – headaches, nausea.”

Smell Vancouver, or SmellVan, is a web-based app, available at Zimmerman and fellow mechanical engineer Amanda Giang, whose work focuses on environmental policy, launched the app late last year to encourage members of the public to log odours and report any health effects they are experiencing. The pair plan to identify odour “hotspots” in the region and sample these areas for the potential presence of air pollutants.

With the help of a $250,000 grant from Ottawa’s New Frontiers in Research Fund, they have hired grad students to help analyze results, which they will share with municipal officials and collaborators with the BC Centre for Disease Control.

“Vancouver has a range of interesting smells that people encounter that might be related to health – we have agriculture, industry, marine traffic, waste disposal,” says Zimmerman. “We will look seriously at anything where people report severe health impacts.”

A similar smell tracking app launched by Carnegie Mellon University researchers in 2016 in Pittsburgh, Ohio found rotten egg smells were the most commonly reported odour. Researchers in that city linked the smell to hydrogen sulfide, which can cause headaches, dizziness, cough, nausea, and shortness of breath.

Portland, Oregon and Louisville, Kentucky are among a handful of American cities that also offer residents smell apps. Zimmerman, who did a post-doc at Pittsburgh’s Carnegie Mellon University, was inspired by that city’s experience to create the first smell app for a Canadian city.

It’s not just about emissions

Giang says she’s learning to appreciate Metro Vancouver in a whole new way through residents’ smell reports. The app allows users to characterize smells, such as ‘chemical, decaying animal, smoky’ and rate how offensive they find the odour – from mildly to extremely.

“As air quality scientists, we are often focused on the emissions side. But people’s experience in terms of quality of life is important,” says Giang. “Some smells can indicate the presence of health-harming air pollutants—either because they’re emitted by the same sources, or because it’s reacting with the atmosphere or something that is co-emitted.”

While it’s early days for the app, the pair have already noticed reports from areas with meat processing plants, sewage line issues, and neighbourhoods experiencing a lot of wood smoke. They hope to launch a ‘Sniff of the Month’ appeal on Twitter to highlight significant odours and gather more users.

Giang and Zimmerman will keep the app going for at least two years so they can track seasonal differences in Vancouver’s smellscape. They want to capture the ways in which atmospheric chemicals oxidize or otherwise change, depending on sunlight, temperature, and humidity.

They will also use the smell reports and air quality measurements to help ground-truth their air quality computer models and estimates of odour and air contaminant emissions.

“We hope it will offer residents a sense of validation and a source of information if they want to self-mobilize,” says Zimmerman. “It’s a way to get the community engaged.”