For many decades, scientists thought the brain may be protected from the harmful effects of air pollution.
But in a study from the University of British Columbia and elsewhere, scientists found that common levels of traffic pollution can impair human brain function in only a matter of hours.
The findings show that just two hours of exposure to diesel exhaust causes a decrease in the brain’s functional connectivity.
The study provides the first evidence in humans of altered brain network connectivity induced by air pollution.
In the study, the researchers briefly exposed 25 healthy adults to diesel exhaust and filtered air at different times in a laboratory setting.
Brain activity was measured before and after each exposure using functional magnetic resonance imaging (fMRI).
The researchers analyzed changes in the brain’s default mode network (DMN), a set of inter-connected brain regions that play an important role in memory and internal thought.
They found that participants had decreased functional connectivity in widespread regions of the DMN after exposure to diesel exhaust, compared to filtered air.
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.
The team says 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.
Notably, the changes in the brain were temporary and participants’ connectivity returned to normal after the exposure.
The team speculated that the effects could be long-lasting where exposure is continuous.
People should be mindful of the air they’re breathing and take appropriate steps to minimize their exposure to potentially harmful air pollutants like car exhaust.
If you care about brain health, please read studies about high vitamin D level linked to lower dementia risk in diabetes and findings of coffee may help lower your risk of stroke, dementia.
For more information about brain health, please see recent studies about antioxidants that could help reduce the risk of dementia, and Omega-3 supplements could improve memory functions in older people.
The study was conducted by Dr. Chris Carlsten et al and published in the journal Environmental Health.
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