Researchers from the University of Victoria and the University of British Columbia recently published a research demonstrating how regular traffic pollution levels can harm human brain function in just a few hours.
According to peer-reviewed study findings published in the journal Environmental Health, just two hours of exposure to diesel exhaust impairs functional connectivity, which is a measure of how efficiently the brain interacts. The study provides the first scientific evidence of altered brain network connections caused by air pollution in humans in a controlled setting.
For many decades, specialists assumed the brain may be protected from the detrimental effects of air pollution, says lead researcher Dr. Chris Carlsten, professor and director of respiratory medicine at UBC and holder of the Canada Research Chair in occupational and environmental lung disease. This study, the first of its kind anywhere in the world, adds to the body of evidence supporting the relationship between air pollution and cognition.
For the study, 25 healthy people were exposed to diesel exhaust and filtered air for short periods of time in a lab setting. Brain activity was measured before and after each dosage using functional magnetic resonance imaging (fMRI).
The researchers examined the default mode network (DMN), a set of linked brain structures important for memory and internal processing. Individuals’ functional connectivity in various regions of the DMN decreased after exposure to diesel exhaust compared to filtered air, according to the fMRI data.
Dr. Jodie Gawryluk, a psychology professor at the University of Victoria and the study’s lead author, said, “It’s concerning to see traffic pollution disrupting the same networks that have been linked to decreased cognitive performance and depressive symptoms.” People may find it harder to think clearly or do their jobs because of these changes, but more research is needed to fully understand the functional effects of these changes.