imperial refinery edmonton houses

On Edmonton’s fringe, refineries are just one part of a larger air pollution puzzle

The city, like many, deals with a complex blend of pollutants, but science is just starting to unravel what that means for our health

Urban areas throughout the world are plagued by the issue of air pollution. Cars, home heating, fires and industry send a toxic slew of chemicals into the air to mix, mingle and enter our bodies. 

Edmonton is no different, including the industrial fringe on its eastern edge. 

Snug between Edmonton and Sherwood Park — in a region with a population of around one million people — the industrial area houses everything from an aluminum facility to refineries, all of which pump their own emissions to an airshed that sometimes ranks worse than much larger cities. 

The reasons are many. The combination of sources, the direction of the wind and the way it sometimes gets trapped over the city in the winter. The refineries, one owned by Imperial Oil and the other by Suncor, are small contributors in the overall picture, but they do pump out a daunting list of chemicals known to cause harm to humans — from benzene to sulphur dioxide. 

What is rarely known is how often and in what doses those substances are released, and just what that means for those living nearby. Emissions monitoring in the immediate area is mostly handled by industry and it only continuously monitors a handful of substances. In the rest of the Edmonton area, monitoring is done by a non-profit called the Alberta Capital Airshed.

Industry compiles and submits more detailed inventories of the pollutants they release to both the provincial and federal governments, however, these inventories are estimates averaged over the course of a year.

Even with those estimates, the science behind health impacts from the combination of particles and pollutants in the air is largely unknown, according to Dr. Alvaro Osornio-Vargas, a pediatrician and professor at the University of Alberta who studies the health impacts of air pollution. But he has no doubt air pollution is harmful to human health. 

“So the conclusion is, yes, industry is releasing toxicants that could impact the health of the neighbours. That would be the short answer,” he says. 

“The [issue] is we don’t have solid evidence. The reason behind that is because we don’t monitor all the chemicals emitted by industry — not in Canada, nor around the world. So we rely on information that industry provides to government.”

The known knowns and the known unknowns of refineries

The information from industry appears robust, breaking down how many tonnes of dozens of substances are released by specific facilities over the years. But the sheer volume of numbers masks the reality that it provides little in the way of clarity.

“They say in this last year, we emitted this many tonnes of benzene coming specifically out of these refineries. But again, it’s an estimate,” says Osornio-Vargas. “And when you say we put it out there through the year, we don’t know if they put out more in the winter, or in the summer, or night or in the middle of the day.” 

A stack from the Imperial Oil refinery near Edmonton. Pollutants can travel long distances, impacting Edmonton's air quality.
A stack from the Imperial Oil refinery near Edmonton juts into the sky. Pollutants from refinery stacks can travel long distances, mixing with other substances in the air.

He says that lack of detail means his research into things like asthma rates among children and the impact of industrial emissions lacks certainty. 

“That’s why I am hesitant to say, yes, industry is causing health problems in the population,” he says. 

Isolating the impacts of industry, or one industry, on the overall health of nearby residents is difficult despite the harmful effects of chemicals like benzene — a known carcinogen — or fine particulate matter — a mix of toxic materials that can find their way into lungs and cause breathing difficulties.

Distance plays a role in exposures, so too do the cumulative effects of pollution.

Dr. Elaine MacDonald, program director of healthy communities with Ecojustice, says the way volatile organic compounds — gases emitted from solids and liquids in places like refineries — are released, changes how they ultimately settle. Emissions from sources closer to the ground can “easily” be found within a kilometre of a refinery, while emissions from stacks that are sent higher into the atmosphere take longer to fall, and have a wider dispersion. Those emissions would also be less concentrated.

Like Osornio-Vargas, she would like to see more detailed information on when there are spikes of emissions.

A full view of Imperial Oil refinery, with oil rail cars in the foreground. Refineries are among the facilities that are impacting the Edmonton air quality.
A full view of the Imperial Oil refinery, with oil rail cars in the foreground. There is no doubt that air pollution is a major health concern, accounting for an estimated 15,300 premature deaths in Canada each year, but quantifying the contribution of specific industry emissions is difficult.

In 2018, a consortium of media outlets, including Global News, the Toronto Star, and National Observer reported on how Canadian refineries were producing substantially more pollution than their counterparts in the United States.

“When you’re talking about pollutants that are respiratory toxins that are going to impact your ability to breathe, it is the short-term exposure that is of concern, it’s not your annual average,” says MacDonald, who analyzed the data comparing emissions from facilities on both sides of the border. “If you’re talking about a carcinogen, then it might be your annual average, because there’s a long latency period to develop cancer and so on.” 

The potential health impacts of air pollution from industry

Osornio-Vargas says it’s important to use the data that is available, even if it’s insufficient, in order to identify gaps and try to identify patterns that could point to a larger problem. He has done multiple studies tracking pollutants and health outcomes.

In one case, he and his colleagues used data on almost 150 different chemicals emitted around Alberta and mapped the emitting facilities. They then examined data on premature births and the births of small babies. 

“If those complexes or those industries are meeting certain combinations of chemicals, the probability of having a small baby or a preterm baby increased by 15 to 20 per cent,” Osornio-Vargas says, but he’s quick to circle back to the limitations of the data and the inability to draw stronger conclusions. 

“I will say there might be some increased risk, but the magnitude of the risk remains to be measured with more precision.”

Other health risks are more difficult to link to air pollution. Osornio-Vargas says childhood cancers, for example, aren’t common enough to do a proper study. 

Air pollution has been linked to asthma attacks in those already diagnosed, but a recent study out of Ontario found there could be a link between the onset of asthma and increased exposure to air pollutants in children from chemical factories and refineries in the Sarnia region.

Another recent study out of Edmonton linked exposure to carbon monoxide, particulate matter and nitrogen dioxide with hospitalizations for substance abuse. The paper argues there is growing evidence that exposure to air pollution might affect human behaviour.

Health Canada estimates air pollution contributes to 15,300 premature deaths each year — 1,400 in Alberta alone. It puts the economic cost of all health impacts attributed to air pollution at $120 billion per year.

Those estimates, however, are based exclusively on exposure to fine particulates, nitrogen dioxide and ozone. The agency says that “owing to data limitations and knowledge gaps,” not all impacts from those substances can be quantified. 

Enbridge storage tanks near Edmonton.
Storage tanks at Enbridge’s Edmonton terminal near the refineries, where oil is shipped across North America and diluent, used to dilute Alberta’s heavy crude, is shipped in.

“Further, there are other air contaminants that contribute to air pollution health impacts, but they are beyond the scope of this work,” reads the 2021 report.

Alberta air quality: who is monitoring what?

Specialized air monitoring stations do pick up continuous levels of some contaminants, but that can change depending on the station. Those stations tend to monitor what’s known as criteria air contaminants — particulate matter, nitrogen oxides, ozone and sulphur dioxide — all of which contribute to poor air quality. Some stations monitor additional emissions including carbon monoxide, hydrogen sulphide and volatile organic compounds, the latter which often leaks from valves and other equipment within facilities. 

The industrial zone between Edmonton and Sherwood Park is the only area in what’s known as the capital airshed that is not actively monitored by the non-profit organization Alberta Capital Airshed, which produces real-time air quality data. One monitoring station is run by the government and four are run by industry. Two industry stations and the government station do provide their data to Alberta Capital Airshed, while two industry stations do not. 

The North Saskatchewan River flows through Edmonton and past the Imperial Oil refinery. The refinery is one of the most significant contributors of emissions in the area, but is still a relatively small part of the overall air pollution puzzle.
The Imperial Oil refinery looms in the background, just off the North Saskatchewan River that flows through Edmonton.

Across Alberta, the vast majority of monitoring is done by 10 airshed organizations, according to Garry Redmond, the executive director of the Alberta Capital Airshed. He believes it is the best model for the industrial area and would provide more transparent data for the public.

“I would just say that I think that it would be helpful if we had airshed monitoring in the area, that the data was more readily available,” he says. “And I’m looking more at industry when I say that versus government.”

The Strathcona Industrial Association, which conducts live monitoring on behalf of industry in the area, says it provides data on its own website for the substances it monitors. It says the two stations that share data with the airshed organization are the only ones that monitor for ozone — a key measurement for what’s known as the Air Quality Health Index.

“[Strathcona Industrial Association] has a solid vested interest in the local community,” Erica Thomas, executive director of the association, wrote in an email to The Narwhal. “The collective of 12 members hold each other accountable. Furthermore, we continue to be responsible to the regulator, providing monthly and annual reports.”

The office of Jason Nixon, Alberta’s minister of environment and parks, ignored requests for information and emailed questions from The Narwhal.

Imperial Oil did not respond to requests for comment and Suncor said the industrial association was the best organization to answer questions about pollutants and Suncor’s refinery emissions.

The air quality in Edmonton

Data from monitoring stations show the Edmonton area has some of the worst air quality in the province, although most of the yearly averages are well below provincial thresholds, and certain areas of the province rank far worse for some pollutants, particularly around the oilsands

Levels of fine particulates and nitrogen dioxide were high in multiple Edmonton locations, according to a 2020 report by Alberta’s airsheds. Spikes of nitrogen oxide were well beyond the Annual Alberta Ambient Air Quality objective at some stations.

Suncor's Edmonton refinery low on the horizon.
Suncor’s Edmonton refinery produces fewer emissions than the Imperial facility, but is still a significant emitter. Monitoring around the two refineries is largely conducted by industry and most substances are not continuously monitored.

Redmond says if they do see spikes in pollution at a continuous monitoring station, they can extrapolate the source using wind speed, direction temperature and relative humidity, but they can’t know for sure.

He says in general, the airshed has seen increases in fine particulates and ozone, but decreases in sulphur dioxide and some downward trends for nitrogen oxides — although it remains a concern. Hydrogen sulphide, he says, goes up and down and is heavily dependent on location.

And while not all of the Edmonton region’s air quality issues can be put at the feet of two refineries on the city’s eastern edge, there’s no doubt those refineries contribute to the mix — with most of the air travelling east over Sherwood Park. 

Data from the Alberta government shows that out of 336 facilities reporting their contributions to air pollution in 2018, the Imperial and Suncor refineries were major contributors. Imperial was the 15th worst emitter of fine particulates, while Suncor was 22nd. In terms of volatile organic compounds, Suncor ranked eighth worst, while Imperial was 19th. Across the whole province, the Imperial refinery was the second biggest emitter of carbon monoxide, and Suncor ranked 24th. 

A Suncor refinery at sunset. This facility is one of many that contribute to the poor air quality in Edmonton.
Suncor’s refinery in Edmonton is just one facility that contributes to Alberta’s overall poor air quality. The province is responsible for an outsized share of pollutants released into the environment, according to the federal government. Refineries are responsible for four per cent of all volatile organic compounds released in Alberta.

The wider picture in Alberta is even worse, with the province contributing to 45 per cent of the total Canadian pollutant releases to air, water and land in 2019, according to the National Pollutant Release Inventory. When it comes to volatile organic compounds, Alberta was responsible for 44 per cent of the national total and refineries accounted for four per cent. 

While emissions dropped for the most part across Canada between 1990 and 2019, they increased significantly in the oil and gas sector in all of the criteria air contaminants except sulphur oxides, such as sulphur dioxide. 

A toxic cocktail for Edmonton’s air quality 

Part of the problem when looking at overall air quality in Edmonton and beyond is the mix of contributing factors. A bad wildfire season will propel Alberta near the front of the pack for bad air in a given year. Wind direction, temperature and more all contribute to the peaks and valleys of pollutants. But so do accidental releases from industry through failures, shutdowns or emergencies.

In the winter, inversions can trap air over the city, contributing to thicker smog. The cold weather means there’s more wood burning and home heating contributing to the toxic mix as well.  

“So that’s a bit of a double whammy,” Redmond says. 

“The triple whammy part is that chemicals can go up and actually have reactions with one another and then they can actually fall down. So we’re seeing, some would say a chemical supercurrent. So definitely high levels of particulate matter with other pollutants involved as well.”

Osornio-Vargas says it’s not well understood how various substances interact in the air and what impact that has on our health. Past research has tended to focus on the impact of one substance, rather than what it means to breath a blend of pollutants.

Even with more robust analysis, researchers like Osornio-Vargas must also contend with new variables that could change the way pollutants behave.

“Air pollution has a direct impact on climate and now we’re creating a monster in which climate is also modifying air pollution for the worse,” he says.

“So we need to start bringing together instead of separating the problems. I think they have a common cause.”

Updated May 3, 2022, at 9:45 a.m. MT: This article was updated to include statements from the Strathcona Industrial Association regarding its air monitoring operations.

We hear it time and time again:
“These are the stories that need to be told and you are some of the only ones telling them,” John, a new member of The Narwhal, wrote in to say.

Investigating stories others aren’t. Diving deep to find solutions to the climate crisis. Sending journalists to report from remote locations for days and sometimes weeks on end. These are the core tenets of what we do here at The Narwhal. It’s also the kind of work that takes time and resources to pull off.

That might sound obvious, but it’s far from reality in many shrinking and cash-strapped Canadian newsrooms. So what’s The Narwhal’s secret sauce? Thousands of members like John who support our non-profit, ad-free journalism by giving whatever they can afford each month (or year).

But here’s the thing: just two per cent of The Narwhal’s readers step up to keep our stories free for all to read. Will you join the two per cent and become a member of The Narwhal today?
We hear it time and time again:
“These are the stories that need to be told and you are some of the only ones telling them,” John, a new member of The Narwhal, wrote in to say.

Investigating stories others aren’t. Diving deep to find solutions to the climate crisis. Sending journalists to report from remote locations for days and sometimes weeks on end. These are the core tenets of what we do here at The Narwhal. It’s also the kind of work that takes time and resources to pull off.

That might sound obvious, but it’s far from reality in many shrinking and cash-strapped Canadian newsrooms. So what’s The Narwhal’s secret sauce? Thousands of members like John who support our non-profit, ad-free journalism by giving whatever they can afford each month (or year).

But here’s the thing: just two per cent of The Narwhal’s readers step up to keep our stories free for all to read. Will you join the two per cent and become a member of The Narwhal today?

The Narwhal is only possible because a tiny fraction of readers like you donate whatever they can to keep our journalism free for all to read.
Help keep our journalism free for all to read.
We’re tripling our Prairies coverage
The Narwhal’s newly minted Prairies bureau is here to bring you stories on energy and the environment you won’t find anywhere else. Stay tapped in by signing up for a weekly dose of our ad‑free, independent journalism.
We’re tripling our Prairies coverage
The Narwhal’s newly minted Prairies bureau is here to bring you stories on energy and the environment you won’t find anywhere else. Stay tapped in by signing up for a weekly dose of our ad‑free, independent journalism.