Environment and Climate Change Canada Archives - News@91��ɫ

New study shows atmospheric compounds formed from tire wear may pose human health risk

egamulin — Wed, 27 May 2026 17:43:58 +0000

Researchers from 91��ɫ U, Environment and Climate Change Canada found chemical compounds trigger inflammatory, toxic responses in human lung immune cells

TORONTO, May 27, 2026 – A published today in the journal Environment International reports that chemicals released from tires can transform into complex mixtures in the atmosphere that may pose previously unrecognized risks to human respiratory health.

Tire rubber contains antioxidant chemicals, most notably 6PPD and DPPD, that are released into the air as tiny particles during normal driving. A single compound formed from 6PPD, known as 6PPD-quinone was previously shown to be implicated in the death of coho salmon in urban waterways, but the broader atmospheric chemistry and potential human health impacts of these compounds have remained largely unexplored until now.

“The striking finding was that the mixtures were far more toxic than the original tire chemicals themselves and are far more toxic than the one compound previously implicated in environmental studies,” says 91��ɫ Associate Professor Ali Abdul-Sater, who co-lead the study with researchers from Environment and Climate Change Canada. “This suggests that focusing on a single compound may substantially underestimate the real health risks associated with tire-derived air pollution.”

Abdul-Sater, with the School of Kinesiology and Health Science in the Faculty of Health at 91��ɫ and director of the Psoriatic Arthritis (PsA) CARE Hub, connected with research scientists John Liggio and Samar Moussa from Environment and Climate Change Canada. The federal government agency has a “library” of archived ambient samples on hand from across the country and the researchers used some of these samples from near Highway 401, and close to 91��ɫ, for the study.

“When you oxidize one chemical from a tire, it probably makes hundreds of chemicals in the mixture, and you don't know which one of those, or all of them are causing the toxic effect that we're seeing,” explains Liggio. “Even though we can identify what they are chemically, you can't go out and buy that chemical and test only that chemical.”

Prof. Ali Abdul-Sater

In this study, they identified at least 150 chemicals and found 88 of them to be present in the roadside samples. They then recreated the mixture of tire derived chemicals in their laboratory and handed them off to Abdul-Sater.

At his lab at 91��ɫ, Abdul-Sater exposed human macrophage cells to this chemical mixture. Macrophages are immune cells that serve as the lungs’ first line of defense against inhaled particles. Surprisingly, while the fish-killing 6PPD-quinone was not found to be particularly toxic, the chemical mixture overall was.

“The results showed rapid cell death, substantial mitochondrial damage, and strong activation of inflammatory pathways,” says Abdul-Sater. “These effects were far more severe than those caused by the parent chemicals alone or by 6PPD-quinone, the single product that has received the most attention. Importantly, the concentrations that triggered these responses are comparable to estimated levels in human lung fluid based on real-world air quality measurements near busy roads.”

Moussa adds: “The original motivation for the project was to assess the toxicity of this one compound, but what we discovered was a potentially more complex issue that we aim to disentangle in future studies. When you breath in air, you take it all in, you are not selectively breathing this molecule or that molecule.”

The researchers say the results are preliminary and not cause for alarm, pointing out that these exposures have existed for half a century or more, but they may be one more environmental exposure that is contributing to the rise of chronic inflammation and related disease. Previous studies have shown negative health effects being correlated with living near major roadways.

“We have to think about this from a chronic exposure angle,” says Abdul-Sater. “These compounds may be increasing our proclivity to develop certain kinds of diseases.”

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Media Contact: Emina Gamulin, 91��ɫ Media Relations, 437-217-6362, egamulin@yorku.ca

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91��ɫ grad students take the measure of Toronto’s winter urban air

sandramc — Tue, 21 Jan 2025 19:23:15 +0000

Several students are participating in SWAPIT, a large winter air quality study, run by Environment and Climate Change Canada

Who would imagine a bright, sunny winter day could have higher concentrations of some air pollutants than a hazy summer day?

Not only is it uncommon for people to consider air quality during the coldest months of the year, but scientists rarely conduct winter air quality testing, says chemistry PhD student Daniel Persaud of 91��ɫ’s Faculty of Science. This is likely especially true during a polar vortex like Toronto, and the rest of Canada, is currently experiencing.

Even more unusual, though, is the possibility that Toronto’s cold winter air could be worse than in summertime, adds 91��ɫ’s Lassonde School of Engineering master’s degree student Samir Singh.

Daniel Persaud tending to High Park instruments

Researchers won’t know for sure which pollutants are worse until all measurements and analysis are done for the (SWAPIT), led by (ECCC). That data analysis is currently underway for last year’s campaign and SWAPIT scientists plan to meet next week to share initial results with each other to generate new insights and plan the release of the findings publicly.

“The unique thing about this study is that it's occurring during the winter months when there are different sources of pollutants from indoor heating to the de-icing of highways, which could have impacts. It is now evident that the levels of some pollutants are elevated in the winter months,” says Persaud. “Most of the other studies focused on smog, which normally occurs during the summer months.”

Persaud and Singh are two of several 91��ɫ grad students taking part in the SWAPIT study to better understand the mix of pollutants in Toronto’s urban winter air and why known pollutants haven’t declined as expected over the years. Persaud is under the supervision of Professor with Associate Professor , both atmospheric chemists in the Faculty of Science, while Singh is supervised by Associate Professor , director of the Graduate Program in Earth and Space Science at Lassonde and the Air Pollution Lab.

Elisabeth Galarneau

, air quality research scientist at ECCC, is leading the study, with 91��ɫ as one of the collaborators. “Studies like this can lead to improved tools for testing air quality and provide better information about our urban cities across the country,” she says.

ECCC calls it the largest urban study of its kind in Canada with more than 90 scientific and technical experts with some 44 sub-projects. The winter phase of the study took place over an intensive six-week field measurement campaign last winter.

“There is a need to understand what pollutants are most prevalent in the air in the winter as different sources of contaminants become more prevalent during that time compared to the summer, things like high particulate matter from forest fires which is unlikely during winter,” says Young.

It’s not the first time 91��ɫ has been a partner in large atmospheric projects. A couple of summers ago, Young and VandenBoer led (Toronto Halogens, Emissions, Contaminants and Inorganics Experiment) in collaboration with the (AEROMMA) project organized by NASA and the National Oceanic and Atmospheric Administration.

SWAPIT, like THE CIX, uses 91��ɫ’s rooftop Air Quality Research Station to monitor air quality, but this time it also included another 91��ɫ research station perched on the east edge of the Keele Campus, plus several other non-91��ɫ stations spread out across the GTA.

Cora Young

“In both of these studies, we are looking at the mix of pollutants and their source. It’s one thing to know there is a particular level of a toxic gas in the atmosphere, but how that might combine with another pollutant to create a whole new contaminant is one of the things we’re working on,” says VandenBoer.

As part of the instrumentation used to gather air quality data for this study, Singh and Gordon installed a spectrometer on the roof of one of 91��ɫ’s administrative buildings to measure the distribution of particle sizes, along with a particulate matter sensor, an anemometer to measure wind speed and direction, and two cameras to measure the amount of traffic. In addition to particulate matter, some of the pollutants measured are per- and polyfluorinated substances (PFAS), ozone and , such as benzene, as well as trace contaminants like flame retardants and plasticizers. Given the sheer number of pollutants to be measured, it is considered the largest study of its kind globally.

Trevor VandenBoer

“It will be interesting to see the variation over time, spatially, as well as how the pollutants vary throughout the city, from one testing site to another,” says Singh, who routinely checks on the 91��ɫ sites and collects initial raw data along the way to gauge how things are progressing or if there is anything significant.

“Until we investigate what kind of pollutants and in what amounts are circulating at various times throughout the year and where they are coming from, whether that’s vehicle emissions in the country’s major cities or emissions from the oil sands facilities in the west, we don’t know what effect they may be having,” says Gordon. “This type of information has not been readily available, which makes combating air quality issues difficult.”

Mark Gordon

The 91��ɫ students involved in the study also worked with ECCC scientists at additional locations, including Pearson International Airport, High Park, and the Evergreen Brickworks. Both Singh and Persaud say they appreciate the opportunity to be involved in this study and to collaborate with external partners.

“It’s a unique opportunity to use our skills, resources and data with various groups, not only here at 91��ɫ, but with Environmental Canada, and hopefully we get some good data out and it can lead to changes that would benefit human health and air quality,” says Persaud, who adds it gives him the opportunity to gain hands on experience in environmental monitoring and data analysis.

The goal, he adds, is to hopefully influence policy in the end, but for now they need to identify what’s responsible for pushing up the air quality index whether that’s in the winter or summer months. In addition to human health, it’s also important for the health of the environment, including the Great Lakes.

Daniel Persaud checking on the equipment at the Brick Works location

As Singh points out, the data they collect can help understand what pollutants are in the air and the direction they’re coming from, which the wind sensor they installed will help to do. The results will hopefully illuminate some of the impacts these pollutants might have on people’s health during the winter. They can be also be an indicator of the influence of a changing climate and be compared to similar research to give them a bigger picture of the issues.

Persaud not only helped deploy custom built wet deposition samplers for this study, but also went on to co-author a paper, , with VandenBoer, Young and others, about the instrument in the peer-reviewed journal Atmospheric Measurement Techniques. (See the .)

Wet deposition includes rain, sleet and snow, which can all carry contaminants. He will collect and analyze those samples for things like PFAS, which don’t break down in the environment and can travel thousands of kilometres away from their source and accumulate in soil, water and snow. Traces can even be found in wildlife, including fish, and even people.

Equipment to measure air pollutants on top of 91��ɫ's chemistry building

“We hope to understand, to get an idea of the concentration and spatial distribution of these compounds,” says Persaud, who has been studying atmospheric deposition for the past six years. “We look for trends, we correlate them with atmospheric tracers, and we hope that we can compare our measurements to measurements that other groups are making in the study so we can truly understand the big picture with atmospheric transport and deposition.”

A different project Persaud participated in with Young was investigating the presence of these compounds in ice cores, which were collected and analyzed from Ellesmere Island, Nunavut in Canada’s High Arctic – – published in the peer-reviewed journal Environmental Science: Processes and Implications. They were able to date perfluoroalkyl acids going back to about 1967.

“We could see a gradual increase as more industrial revolution happened,” says Persaud, who has always been interested in chemistry and interactions with the environment.

Persaud realized during his undergrad that he wanted to pursue a career investigating contaminants in the environment. That passion led him to 91��ɫ where he is now part of the group run by Young, one of the few research groups that use and develop analytical techniques to understand environmental issues, he says. “I'm fortunate to be a part of Dr. Young’s group. We use and develop analytical techniques to solve environmental issues. PFAS is a hot topic in environmental chemistry.”

For Singh, he saw 91��ɫ as having the best professors and programs in atmospheric science, which made the decision to move to this University for his graduate work easy. As part of Gordon’s Air Pollution Lab, students like Singh can study emissions and the mixing of pollutants caused by city and highway traffic, emissions from oil sands production facilities, and how pollutants interact with forest environments and mix within the forest canopy.

It's the kind of academic work both students are excited about and eager to apply their new knowledge to the real world, such as participating in the SWAPIT project, toward making a difference in the health of people and the environment.

“This can generate meaningful insights and develop evidence-based solutions for improving air quality,” says Persaud.

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Some 500 high school students to learn how to change their world at 91��ɫ

sandramc — Tue, 20 Feb 2024 12:30:00 +0000

TORONTO, Feb. 20, 2024 – Some 500 Ontario high school students from more than 25 high schools are coming to 91��ɫ next week to learn how they can change the world through understanding the risks of fast fashion, the importance of wetlands, the dangers of storm water runoff and much more.

Toronto-based singer-songwriter and musician Brighid Fry will perform at the Change Your World conference

The annual Faculty of Environmental and Urban Change student conference, Change Your World, is partnering with environmental and youth organizations to offer students hands-on workshops to inspire and learn how they can make a sustainable and equitable difference. Included in the day’s line up is a workshop on how to build resiliency in the face of anxiety about the future.

Media are invited to the event and its workshops on Thursday, Feb. 22.

The workshops will run in both the morning and afternoon sessions and include:

The Cost of Fast Fashion by 91��ɫ’s Environmental Arts and Justice
Shaping Sustainable Cities for a Resilient Future
Exploring the World of Wetlands by Ontario Nature
The Game of Nations: Power, Peace, and the Planet, a giant immersive board game, by ALPHA Education
Climate Change and Renewables by Relay Education, students are hands on with wind turbine models and solar panels in second half of workshop
Rain to Runoff: A Stormwater Story by Toronto and Region Conservation Authority
Ready, Set, Build: Green Infrastructure and Climate Futurism by Toronto Youth Environmental Council
Nature in the City: Understanding Toronto's Urban Forest by City of Toronto – Urban Forestry which includes a tree identification walk (weather permitting)

For a full list of workshops, visit the website.

There will also be a special guest performance by award-winning musician and climate activist Brighid Fry, who has released five EPs on her own and with bands Kingdom of Birds and Housewife (formerly Moscow Apartment).

Keynote speakers for the event:

Mike Layton, 91��ɫ’s chief sustainability officer in the Office of Sustainability, a former Toronto city councillor, 91��ɫ alumus and long-time champion of sustainability.

Alicia Richins, a sustainable impact strategist director of strategy and governance for Leading Change Canada, an organization focused on activating youth sustainability leadership for the transition to a low carbon economy within a generation.
Joanne Huy, a community engagement professional with a passion for transforming lives and communities through transformative learning experiences and meaningful engagement.

WHAT: Change Your World conference

WHEN: Opening Ceremonies from 9:45 to 10:45 a.m.; morning workshops from 11 a.m. to noon; performance by Brighid Fry from 12:30 to 1 p.m.; afternoon workshops from 1 to 2 p.m.

WHERE: Vari Hall and various classrooms, Keele Campus, 91��ɫ

91��ɫ is a modern, multi-campus, urban university located in Toronto, Ontario. Backed by a diverse group of students, faculty, staff, alumni and partners, we bring a uniquely global perspective to help solve societal challenges, drive positive change, and prepare our students for meaningful life and career paths. 91��ɫ's Glendon Campus is home to Southern Ontario's Centre of Excellence for French Language and Bilingual Postsecondary Education. 91��ɫ’s campus in Costa Rica offers students exceptional transnational learning opportunities and innovative programs, while at the Markham Campus, innovation, technology, entrepreneurship and industry collaboration are built into every program. 91��ɫ’s new School of Medicine, the first Canadian medical school to focus on community-based primary health-care education, will welcome its first cohort in September 2028 (subject to accreditation). 91��ɫ was recently named one of Canada’s Greenest Employers for the 14th consecutive year. Together, we can make things right for our communities, our planet, and our future.

Media Contact: Sandra McLean, 91��ɫ Media Relations,  sandramc@yorku.ca

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Ozone-depleting chemical alternatives getting into our food and water

roshanp — Thu, 14 May 2020 14:23:46 +0000

Ices cores the team drilled in the Arctic ready for shipping. Photo credit: Ali Criscitiello, University of Alberta

TORONTO, May 14, 2020 – An international environmental agreement to regulate the use of chemicals depleting the ozone layer may have inadvertently allowed higher levels of other harmful chemicals to flourish, new research co-led by 91��ɫ and Environment and Climate Change Canada has found.

The 1987 Montreal Protocol on Substances that Deplete the Ozone Layer was designed to phase out ozone-depleting chemicals, chlorofluorocarbons (CFCs), such as freon used in older air conditioners.

But these replacement compounds, thought to be a better alternative, degrade into products that do not break down in the environment and have instead continually increased in the Arctic since about 1990.

“Our results suggest that global regulation and replacement of other environmentally harmful chemicals contributed to the increase of these compounds in the Arctic, illustrating that regulations can have important unanticipated consequences,” says Assistant Professor of the Faculty of Science and the paper’s corresponding author.

It is important to study these products of CFC replacement compounds, short-chain perfluoroalkyl carboxylic acids (scPFCAs), before more of them are phased in over the next few years as they can adversely impact human health and the environment. They are part of the perfluoroalkyl substances (PFAS) class of man-made chem icals used in commercial products and industrial processes that are currently receiving a lot of attention.

These scPFCAs are products of chemicals used in the fluoropolymer industry in automotive, electrical and electronic applications, industrial processing and construction.

Team members prepare ice cores in the Arctic. Photo credit: Ali Criscitiello, University of Alberta

“Our measurements provide the first long-term record of these chemicals, which have all increased dramatically over the past few decades,” says Young. “Our work also showed how these industrial sources contribute to the levels in the ice caps.”

They can travel long distances in the atmosphere and often end up in lakes, rivers and wetlands causing irreversible contamination and affecting the health of freshwater invertebrates, including insects, crustaceans and worms.

Current drinking water treatment technology is unable to remove them, and they have already been found accumulating in human blood as well as in the fruits, vegetables and other crops we eat.

The researchers measured all three known scPFCA compounds over several decades in two locations of the high Arctic and found all of them have steadily increased in the Arctic, particularly trifluoroacetic acid.

The researchers acknowledge the importance of the Montreal Protocol’s positive impact on the ozone and climate but point out that even the best regulations can have unintended negative impacts on the environment.

The research is published in the journal .

PHOTOS:

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91��ɫ champions new ways of thinking that drive teaching and research excellence. Our students receive the education they need to create big ideas that make an impact on the world. Meaningful and sometimes unexpected careers result from cross-disciplinary programming, innovative course design and diverse experiential learning opportunities. 91��ɫ students and graduates push limits, achieve goals and find solutions to the world’s most pressing social challenges, empowered by a strong community that opens minds. 91��ɫ U is an internationally recognized research university – our 11 faculties and 25 research centres have partnerships with 200+ leading universities worldwide. Located in Toronto, 91��ɫ is the third largest university in Canada, with a strong community of 53,000 students, 7,000 faculty and administrative staff, and more than 300,000 alumni. 91��ɫ U's fully bilingual Glendon Campus is home to Southern Ontario's Centre of Excellence for French Language and Bilingual Postsecondary Education.

Media Contact:

Sandra McLean, 91��ɫ Media Relations, 416-272-6317, sandramc@yorku.ca

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