Taking time to get out of the urban environment and relax in forest or park spaces relieves mental stress and improves emotional health, but the impact of a busy urban environment on the brain may be more significant than previously thought. Based on recent research from the University of British Columbia, the brain is extremely sensitive to not just the environment, but the level of pollution contained within its environment.
The study focused on measuring cognitive function with MRI on healthy adults and compared the differences between cognitive function when exposed to pollution (diesel exhaust fumes) or clean, filtered air for 2 hours. The participants’ brains were scanned before and after the exposures for control methods, and the experiments were carried out with a two-week washout period.
Those participants who were exposed to polluted air had impaired connectivity between brain regions in the DMN (default mode network), a network which connects various brain regions and is used in thought and memory processes. Similar effects on the DMN have been noted with poorer mental health states, but this was the first time it was noted with air quality. The effects were temporary and full recoveries were made after the exposure was removed, but the results were surprising.
With busy commutes and time spent traveling from home to work, pollution is increasingly inescapable. The reassuring fact is that the effects were short-term, but more investigations into air quality and brain health will be needed to get a fuller picture. If you’re feeling the brain fog, consider driving a little out of the way for your time in nature rather than a city park; though, even a city park will benefit you in other ways. Air filters in the urban, indoor environment may make all the difference instead.
Jodie R. Gawryluk, Daniela J. Palombo, Jason Curran, Ashleigh Parker, Chris Carlsten. Brief diesel exhaust exposure acutely impairs functional brain connectivity in humans: a randomized controlled crossover study. Environmental Health, 2023; 22 (1) DOI: 10.1186/s12940-023-00961-4