A recent study from McGill University has found a link between air pollution and immune system changes that may precede autoimmune diseases. Researchers focused on fine particulate matter in air pollution and its association with higher levels of a biomarker connected to autoimmune conditions, such as systemic lupus.
"These results point us in a new direction for understanding how air pollution might trigger immune system changes that are associated with autoimmune disease," said Dr. Sasha Bernatsky, James McGill Professor of Medicine and member of the McGill Centre for Climate Change and Health, the Division of Rheumatology and the Centre for Outcome Research and Evaluation. "We know some genetic factors play a role in autoimmune disease, but they don't tell the whole story."
The study adds to existing evidence that air pollution impacts more than just heart and lung health. "These fine particles in air pollution are small enough to reach the bloodstream, potentially affecting the whole body," Bernatsky added.
Researchers analyzed blood samples from over 3,500 participants enrolled in CanPath, a national registry that includes more than 400,000 Canadians from various provinces. They discovered that individuals living in areas with higher levels of fine particulate matter (PM2.5) were more likely to have elevated anti-nuclear antibodies (ANA), which are linked to autoimmune diseases.
Bernatsky, who also serves as Senior Scientist at the Research Institute of the McGill University Health Centre, emphasized that poor air quality is not limited to urban environments. "Air pollution is often seen as an urban problem caused by traffic, but rural and suburban areas experience poor air quality too," she said, highlighting wildfire smoke as another contributing factor.
Canada maintains national standards for PM2.5 exposure. According to the researchers, awareness among policymakers about limiting exposure is increasing. "Even though air quality is overall better in Canada than in many other countries, research suggests there is no safe level, which is why Canadian policymakers need research like ours" said Bernatsky.
Not all communities face equal risks from air pollution. Lower-income neighborhoods are sometimes located near industrial sources or major roads. Additionally, autoimmune diseases such as lupus tend to affect women and non-white populations—including Indigenous peoples—at higher rates.
In previous research led by Bernatsky in Quebec in 2017, proximity to industrial sources of fine particles was linked with increased blood markers associated with rheumatoid arthritis. The team plans to extend their work using data from British Columbia.
