We have all heard of the many dangers of traffic pollution. We know how it affects our lungs and respiratory health. But research shows it can also impair brain function in just a matter of hours.
A new study conducted by researchers at the University of British Columbia and the University of Victoria shows that just two hours of exposure to diesel exhaust can decrease the brain’s functional connectivity. It offers the first evidence of altered brain network connectivity induced by air pollution in humans.
“For many decades, scientists thought the brain may be protected from the harmful effects of air pollution. This study, which is the first of its kind in the world, provides fresh evidence supporting a connection between air pollution and cognition,” said senior study author Dr. Chris Carlsten, professor and head of respiratory medicine and the Canada Research Chair in occupational and environmental lung disease at UBC.
The study involved exposing 25 healthy adults to diesel exhaust and filtered air at different times in a lab setting. Brain activity was measured with functional magnetic resonance imaging (fMRI) after each exposure.
The researchers then analyzed changes in the brain’s default mode network (DMN). Results revealed that participants had decreased connectivity in various regions of the DMN after exposure to diesel exhaust as compared to filtered air.
“We know that altered functional connectivity in the DMN has been associated with reduced cognitive performance and symptoms of depression, so it’s concerning to see traffic pollution interrupting these same networks. While more research is needed to fully understand the functional impacts of these changes, it’s possible that they may impair people’s thinking or ability to work,” said Jodie Gawryluk, study author and psychology professor at the University of Victoria.
How to Prevent Traffic Pollution-Related Impairment
People can minimize traffic pollution-related impairment by rolling up their windows when stuck in traffic. They can also make sure their car filter is in good working order. If you are walking or biking, consider taking a less busy route.
It should also be noted that the impairment noted in the study was short-term. Participants’ brain function returned to normal after the exposure ceased. However, researchers speculate that damage could be permanent if exposure is continuous.
It is also suspected that traffic-related air pollution is not the only kind of pollution that can have negative cognitive effects. Other products of combustion, such as forest fire smoke, are also a concern.
“With an increasing incidence of neurocognitive disorders, it’s an important consideration for public health officials and policymakers,” said Carlsten.