Researchers from the University of British Columbia (UBC) and the University of Victoria have shown that breathing air pollution can alter the connection of the brain within two hours. This suggests that breathing air pollution may have an effect on how your brain is wired.
The results come from a randomized, double-blind experiment in which 25 healthy persons were exposed to vehicle pollution in a testing environment. Participants were further exposed to clean, filtered air at a different stage.
Before and after each situation, brain scans were performed. The default mode network (DMN), a collection of interconnected brain areas that are most active when we are thinking internally, such as reflecting on the past and remembering, exhibited decreased connectivity in the brains of individuals after they had been exposed to air pollution.
While the present study did not examine the potential consequences on brain capacity, other studies have, and these findings have never been seen in people.
For instance, previous research has connected disrupted brain connection to worse working memory and productivity.
According to neuropsychologist Jodie Gawryluk from the University of Victoria, it is alarming to see road pollution disrupting these similar networks.
It's likely that these alterations might make it harder for people to think clearly or operate at their jobs, however additional study is needed to fully understand the functional consequences of these changes.
The study's findings are transient, and as fresh air started entering the lungs, they went back to normal. This is excellent news.
The results do, however, point to a potential mechanism through which long-term exposure to air pollution may harm the brain.
The ramifications to public health might be severe with up to 99 percent of the world's population breathing unhealthy levels of air pollution.
Recent research in China has connected air pollution to worse language and arithmetic exam results, which, on average, erases one year's worth of schooling.
According to respiratory specialist Chris Carlsten from UBC, "for many decades, experts believed the brain may be insulated from the detrimental effects of air pollution."
This study, the first of its sort anywhere in the world, offers new proof in favor of the link between air pollution and cognition.
In 2020, researchers found signs of Alzheimer's disease in the brains of adolescents, kids, and even babies who resided in Mexico City, a heavily polluted metropolitan center. (Recent data reveals that during COVID-19 lockdown times, when vehicle movements and, consequently, exhaust gases, were curtailed, the air quality significantly improved.)
Another study conducted in the same city identified metal nanoparticles found in many residents' brains as a potential cause of that harm.
Scientists proved in 2022 that these particles, once breathed in, can occasionally escape the brain's protective barrier, which was previously believed to keep dangerous stuff out.
The current study only considered automobile exhaust emissions, but there may be other types of air pollution that operate even more quickly and have more detrimental consequences.
For instance, experts project that before leaded gas was outlawed in the United States, at least 170 million Americans inhaled the harmful vapors, causing a total IQ score loss of 824 million points (nearly 3 points per person).
The fact that gas today may not contain lead does not guarantee that it is safe for your lungs or your brain.
Carlsten cautions, "People might want to think carefully the next time they're trapped in traffic with the windows down."
Make sure your car's air filter is functioning properly, and if you're bicycling or walking down a busy street, think about choosing a different route.
The study was published in Environmental Health.
