In her co-op building a few blocks from Toronto’s Billy Bishop Airport, Joan Prowse counts her neighbours who are sick.
“There’s respiratory problems, there are cancers for sure, there are cases of dementia,” she says, pointing down the hall.
Her neighbour Brenda Roman, 87, has emphysema, a type of progressive chronic obstructive pulmonary disease (COPD).
“What it does is limit my ability to breathe,” Roman told CBC News in a 2024 interview. At that time, she had to take a breath between each word, and needed an oxygen mask to move around.
Now Roman says she’s too weak for an interview, but said in an email she still thinks the poor air quality in her neighbourhood, sandwiched between the Gardiner Expressway and Billy Bishop Airport, could be contributing to her illness.
“I’m not a scientist, but I do know that the one thing that I did very wrong was to live here for 38 years,” she said in the interview.
While scientists can’t connect individual health conditions to the local pollution, monitoring studies make it clear their Bathurst Quay neighbourhood in southwest Toronto has high levels of what are known as ultrafine particles — pollution far smaller than PM2.5, that can get deep in the lungs and are linked to many health problems.
Now, members of the community are concerned it’s about to get worse.
Last month, Ontario Premier Doug Ford says he wants to expand the city airport — just 350 metres from Prowse and Roman’s building — and bring in larger jets.
Breathing in ultrafine particles
Prowse, who is also the chair of the Bathurst Quay Neighbourhood Association, says with many residents in her building suffering from respiratory illnesses, she went looking for answers.
In 2019, she shared her concerns about the air quality in her area with Marianne Hatzopoulou, transport and air pollution researcher at University of Toronto.
“I was immediately very intrigued because you’ve got the proximity to the Gardiner [Expressway] … then at the same time you have the airport which is another large major transportation infrastructure,” said Hatzopoulou.
Hatzopoulou and her team installed air quality monitors on rooftops in different locations in the area, tracking a number of pollutants over the period from 2019 to 2022.
One thing they were looking for was ultrafine particles (UFPs) — a type of pollution that’s a thousand times smaller than a human hair, smaller than 0.1 micrometres, and typically comes from types of combustion like busy roads, highways, planes and trains.
They’re so light they can’t be measured by weight like fine particulate matter, known as PM2.5; instead, they’re counted using specialized equipment that tallies how many are found in a cubic centimetre of air.
The neighbourhood study found that there were high concentrations of UFPs coming from the Gardiner Expressway, and Billy Bishop Airport was an even larger source of the pollution.
When the airport was operating, especially during aircraft landing and take off under southerly winds, UFP levels would spike, to upwards of 100,000 particles/cu. cm.
For comparison, that far exceeds what the World Health Organization considers “high” for UFPs, which is 20,000 particles/cu. cm for a one-hour average.
The WHO level isn’t a guideline, only a “good practice statement,” something the organization provides when there is evidence of risk but not enough information to set specific guidelines.
But air quality researchers who spoke to CBC News say limits should be set.
“There’s more than enough evidence now to be looking into creating either standards or at least guidelines for Canada so that people who live in neighbourhoods like this one have some type of recourse,” said Greg Evans, a professor of chemical engineering at the University of Toronto and co-author of the neighbourhood study.
Health impacts of ultrafine particles
That neighbourhood study is part of a bigger body of research on the risks of ultrafine particles, — and how prevalent they are in some Canadian cities.
“These particles are very small so when they’re released into the air, we breathe them into our lungs, and they reach down into the very deep locations of our lungs and our very small airways,” said Scott Weichenthal, an environmental epidemiologist professor at Montreal’s McGill University.
“And once they’re there, they can actually move from our lungs into our bloodstream. And from our bloodstream, they really can reach anywhere in our body, including our brains.”
In 2023, a study of 11 million people in the Netherlands found a significant association between annual average UFP exposure and premature deaths, along with deaths from lung cancer and respiratory illnesses, separate from other regulated pollutants.
In response, the Netherlands set up long-term monitoring of UFP exposure throughout the country.
“The evidence around ultrafine [particles] began in the 90s and then sort of accelerated in Canada from the 2010s until now,” said Weichenthal.
“Canada is really a leader in this kind of research,” he said, because of a database from Statistics Canada and Health Canada that lets researchers link population trends to environmental exposure.
“So we can follow people where they live over time.”
In 2024, Weichental and Hatzopoulou, in collaboration with McGill University and the University of Toronto, found that ultrafine particles contributed to about 1,100 premature deaths a year in Montreal and Toronto. It was hailed as the first study to look at UFPs and mortality in Canada.
While both the Dutch and Canadian studies looked at road and air traffic, other UFP studies have looked specifically at airports like Paris’s Charles de Gaulle and Amsterdam’s Airport Schiphol. Both found high concentrations of ultrafine particles.
The body of research, Weichenthal says, points to serious health risks from chronic ultrafine particle exposure, even if we can’t be certain the role it played in an individual’s health issue.
“For people who are experiencing things like asthma or COPD or dementia, those things are certainly consistent with what we know about the health effects of these particles,” he said.
“But we certainly can’t say that definitively that’s why they got these things.”
Bigger jets on their way?
With the pollution already documented in their neighbourhood, Bathurst Quay residents are concerned about Ontario Premier Doug Ford’s plans for the airport next door.
Last month, he announced plans to bring jets to Billy Bishop Airport — despite opposition from the City of Toronto — by declaring the urban airport a special economic zone using Bill 5, a law passed in Ontario last year. This would allow the province to override planning and environmental regulations.
The airport is governed by a three-party agreement between the City of Toronto, Toronto Port Authority and Transport Canada.
Norm Di Pasquale, the chair of NoJetsTO, fought and petitioned to stop the airport’s expansion over 10 years ago. He recently restarted the organization in the wake of Ford’s announcement.
He says the expansion will mean more car traffic and more jet fuel.
“People are struggling to make the status quo work in this neighborhood. I don’t know how jets to the island airport are going to work for the health of the people in Bathurst Quay.”
A recent statement from the federal government said any changes to the airport will require agreement from all members of the tripartite agreement.
Hatzopoulou, the U of T air quality researcher, says that larger jets will mean more pollution including ultrafine particles.
“I can’t see a world in which this proposed expansion is not going to increase ultrafine particle concentrations.”
Prowse says this proposed expansion is the first time she’s thought about leaving the community that she’s lived in since 1989.
“We need to make sure that it becomes a regulated substance,” said Prowse. “Not just in my neighbourhood, but everywhere across the country.”
No regulations
Despite a growing amount of evidence to suggest that ultrafine particles could have an impact on our health, they aren’t yet regulated around the world like PM2.5.
“What’s interesting is that the evidence base we now have for ultrafine particles is actually greater than what we had for PM2.5 at the time when the first health guidelines were released for PM2.5,” said Weichenthal.
Health Canada said in an email that “air quality management is a shared responsibility across all levels of government.
“The science on UFPs is evolving, and it remains challenging to draw firm conclusions about UFP-specific health effects separate from PM2.5 more broadly.”
CBC News also reached out to Environment and Climate Change Canada, which is responsible for the Canadian Ambient Air Quality Standards. In an email, it said current regulations “reduce direct PM2.5 emissions as well as emissions of other pollutants that can form particulates in the air.”
“Ultrafine particles are a recognized subset of particulate matter,” it said, but it did not state that there are regulations for ultrafine particles specifically.
It’s challenging to pin down evidence on environmental pollutants; determining cause-and-effect experimentally would require exposing humans to dangerous substances on purpose, which is obviously unethical.
But both Hatzopolou and Weichenthal agree it’s getting harder to see what the argument is for doing nothing.
“We don’t need causal evidence. We know enough to say, ‘Let’s start looking at ways to reduce UFPs, what can governments do, what can the private sector do, what can the public do,’” said Hazopoulou.
”These are harmful pollutants, not just in Canada, but in different parts of the world,” adds Weichental. “And so the time really has come to look carefully at doing something.”
