macrophages 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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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. Together, we can make things right for our communities, our planet, and our future.

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

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New study gives clues on why exercise helps with inflammation

egamulin — Thu, 15 Jun 2023 16:30:43 +0000

Moderate exercise changes function of macrophage cells in bone marrow, new mouse-model research out of 91��ɫ finds

TORONTO, June 15, 2023 - Researchers have long known that moderate exercise has a beneficial impact on the body’s response to inflammation, but what’s been less understood is why. done on a mouse model suggests that the answers may lie at the production level of macrophages — white blood cells responsible for killing off infections, healing injury and otherwise acting as first responders in the body.

“Much like if you train your muscles through exercise, we showed that exercise of moderate intensity ended up training the precursors of those macrophages in the bone marrow,” says Faculty of Health Associate Professor and 91��ɫ Research Chair with the School of Kinesiology and Health Science. “The way that exercise is doing this is by changing the way those cells breathe, essentially, how they use oxygen to generate energy and then changing the way they access their DNA.”

Associate Professor and 91��ɫ Research Chair Ali Abdul-Sater

While many studies look at temporary boosts to the immune system immediately after exercise, this study, published in the journal AJP-Cell, found these changes occurred even a week later, suggesting that the changes were long term.

We often hear about inflammation in the body in the context of its negative effects, but inflammation is the body’s response to infection and other stressors, and some level of inflammation is necessary and desirable.

“Inflammation is amazing, it's a very important part of our normal immune response,” says Abdul-Sater. “What we’re concerned about is excessive inflammation. Heart disease, diabetes, many cancers and autoimmune diseases, all essentially begin because there was an inappropriate inflammatory response.”

He says it is around the six-to-eight-week mark into the exercise regimen where changes really became apparent, compared with sedentary mice. “There's a lot of rewiring that's taking place in the circuitry of how the cells breathe, how the cells metabolize glucose, how the cells then access DNA. So all that just takes time.”

Abdul-Sater says that because the inflammatory response is a very ancient one, this aspect of the immune system is generally very similar across mammals, and he expects the research would translate well to humans. In the next phase, Abdul-Sater and collaborators from the university will collect immune cells from human volunteers who will do exercises of various intensities to see which workout routines are most beneficial to balance the inflammatory response. They will also look at inflammation in mice in more complex infectious diseases similar to COVID-19 and autoimmune disease, where overactive inflammatory responses lead to poor outcomes.

“People that got seriously ill from COVID-19, went into what is called a cytokine storm essentially, they released this massive number of cytokines, those mediators that are produced by inflammatory cells, which then cause that accumulation of fluid in lungs.”

While the findings that exercise is beneficial will not come as a surprise, Abdul-Sater says he hopes that by finding the underlying mechanisms of the beneficial impact, this knowledge can be put to good use.

“The thing with humans is there's no intervention that will work on everyone. We know that, but what this study suggests is that moderate and persistent exercise not only improves metabolic health, but also will improve immune health in the long run.”

About 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 success. 91��ɫ’s fully bilingual Glendon Campus is home to Southern Ontario’s Centre of Excellence for French Language and Bilingual Postsecondary Education. 91��ɫ’s campuses in Costa Rica and India offer students exceptional transnational learning opportunities and innovative programs. Together, we can make things right for our communities, our planet, and our future.

Media Contacts: Emina Gamulin, 91��ɫ Media Relations and External Communications, 437-217-6362, egamulin@yorku.ca

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