Two hours of exposure to traffic pollution can affect the brain

In the first work of its kind in the world, researchers from the University of British Columbia and the University of Victoria provided evidence establishing a connection between environmental pollution and cognition.

Well known are the effects of environmental pollution in the air, water, as well as the consequences it generates in climate change. But little is said about the consequences that the phenomenon causes in people’s health.

However, according to the World Health Organization (WHO), it is estimated that each year exposure to air pollution causes seven million premature deaths and causes the loss of millions of years of healthy life.

Now, a recent study by researchers at the University of British Columbia and the University of Victoria has shown that ordinary levels of traffic pollution can affect human brain function in a matter of hours.

The findings of the peer-reviewed work, and whose results were published in the journal Environmental Health, show that just two hours of exposure to diesel exhaust causes a decrease in the functional connectivity of the brain, an example of how brain function is altered by air pollution.

“While traffic-related air pollution exposure is known to cause enormous global harm to human health, the neurobiological underpinnings remain elusive. This study addresses this gap in knowledge”, the researchers began by arguing what motivated them to carry out the work.

And regarding their findings they expanded: “We observed decreases attributable to short-term contamination in the functional connectivity of the network in default mode. Decreases in brain connectivity cause many detrimental effects to the human body, so this finding should guide policy change in regulating exposure to air pollution.”

For the study, which was conducted at the UBC Air Pollution Exposure Laboratory, located at Vancouver General Hospital, the researchers briefly exposed 25 healthy adults to diesel exhaust and filtered air at different times in a laboratory environment. Brain activity was measured before and after each exposure using functional magnetic resonance imaging (fMRI).

Dr Chris Carlsten is Professor and Director of Respiratory Medicine and Canada Research Chair in Occupational and Environmental Lung Diseases at UBC, as well as the lead author of the study, noting: “For many decades, scientists thought that the brain might be protected from the harmful effects of air pollution. This study, which is the first of its kind in the world, provides new evidence supporting a connection between air pollution and cognition.”

The researchers looked at changes in the brain’s default mode network (DMN), a set of interconnected brain regions that play an important role in memory and internal thinking. The fMRI revealed that the participants had decreased functional connectivity over large regions of the DMN after exposure to diesel exhaust, compared to filtered air.

“Several years ago, a study very similar to this was carried out in which people were made to breathe from diesel exhaust pipes for two hours, with rest intervals of two hours, and it was seen that during inspiration the systolic pressure increased significantly. and diastolic of individuals”, added this to the current evidence.

For him, “this confirms that changes in pollution are not only cumulative over the years, producing all the vascular and pulmonary disease already described, but are also immediate.”