According to Science Daily, researchers from the University of British Columbia and the University of Victoria have performed a study that demonstrates that even small amounts of traffic pollution can affect human brain function in as little as a few hours. The findings, published in Environmental Health, reveal that even two hours of exposure to diesel pollution might reduce functional connections in the brain.
Dr. Chris Carlsten, the senior author of the study and chief of respiratory medicine at UBC, also holds a Canada Research Chair in occupational and environmental lung disease. “For long, scientists believed that the brain would be impervious to the damaging effects of air pollution.” The authors of the research state that their findings provide “new evidence” linking air pollution to cognitive deterioration.
In this study, 25 healthy people were exposed to diesel exhaust and filtered air for varying amounts of time in a lab environment. Functional magnetic resonance imaging was used to evaluate brain activity before and after each dosing (fMRI).
The researchers examined behavioral changes in terms of the brain’s default mode network (DMN), which is a collection of related areas critical for memory and reflection. Compared to filtered air, exposure to diesel exhaust impairs functional connectivity in the DMN in multiple locations, as measured by fMRI.
Concerningly, “altered functional connectivity in the DMN has been associated with lower cognitive performance and symptoms of sadness,” according to Dr. Jodie Gawryluk, the study’s first author and a professor of psychology at the University of Victoria. Although further study is needed to confirm it, these alterations will likely hurt human cognitive or occupational performance.
The brain modifications were only transitory, and as the exposure ended, the connections between brain cells returned to normal. Dr. Carlsten hypothesized that with continuous exposure, long-term impacts might be envisaged. He urged people to be mindful of the air quality and to safeguard against dangerous pollutants such as automobile exhaust.
He also recommends drivers think twice before pulling down their windows in congested areas. While Dr. Carlsten’s team focused on the mental effects of traffic-related pollution, they warned that other combustion products are also likely to be a problem.
“Air pollution is becoming considered the largest environmental concern to human health,” says Dr. Carlsten, “and we are gradually detecting the repercussions across all major organ systems.”
“Exposure to other air contaminants, such as forest fire smoke, is expected to have a similar impact on the brain. Because neurocognitive diseases are rising, governments and public health experts must address this issue.”