A latest study by researchers on the University of British Columbia and the University of Victoria has shown that common levels of traffic pollution can impair human brain function in just a matter of hours.

The peer-reviewed findings, published within the journal Environmental Health, show that just two hours of exposure to diesel exhaust causes a decrease within the brain’s functional connectivity – a measure of how The study provides the primary evidence in humans, from a controlled experiment, of altered brain network connectivity induced by air pollution.

“For a lot of many years, scientists thought the brain could also be shielded from the harmful effects of air pollution,” said senior study creator Dr. Chris Carlsten, professor and head of respiratory medicine and the Canada Research Chair in occupational and environmental lung disease at UBC. “This study, which is the primary of its kind on the earth, provides fresh evidence supporting a connection between air pollution and cognition.”

For 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 within the brain’s default mode network (DMN), a set of inter-connected brain regions that play a vital role in memory and internal thought. The fMRI revealed that participants had decreased functional connectivity in widespread regions of the DMN after exposure to diesel exhaust, in comparison with filtered air.

We all know that altered functional connectivity within the DMN has been related to reduced cognitive performance and symptoms of depression, so it’s concerning to see traffic pollution interrupting these same networks. While more research is required to completely understand the functional impacts of those changes, it’s possible that they might impair people’s pondering or ability to work.”

Dr. Jodie Gawryluk, psychology professor on the University of Victoria and study’s first creator

Taking steps to guard yourself

Notably, the changes within the brain were temporary and participants’ connectivity returned to normal after the exposure. Dr. Carlsten speculated that the results could possibly be long lasting where exposure is continuous. He said that individuals ought to be mindful of the air they’re respiration and take appropriate steps to attenuate their exposure to potentially harmful air pollutants like automobile exhaust.

“People will want to think twice the subsequent time they’re stuck in traffic with the windows rolled down,” said Dr. Carlsten. “It is vital to be certain that your automobile’s air filter is in good working order, and if you happen to’re walking or biking down a busy street, consider diverting to a less busy route.”

While the present study only checked out the cognitive impacts of traffic-derived pollution, Dr. Carlsten said that other products of combustion are likely a priority.

“Air pollution is now recognized as the most important environmental threat to human health and we’re increasingly seeing the impacts across all major organ systems,” says Dr. Carlsten. “I expect we’d see similar impacts on the brain from exposure to other air pollutants, like forest fire smoke. With the increasing incidence of neurocognitive disorders, it’s a vital consideration for public health officials and policymakers.”

The study was conducted at UBC’s Air Pollution Exposure Laboratory, positioned at Vancouver General Hospital, which is supplied with a state-of-the-art exposure booth that may mimic what it’s prefer to breathe quite a lot of air pollutants. On this study, which was fastidiously designed and approved for safety, the researchers used freshly-generated exhaust that was diluted and aged to reflect real-world conditions.

Source:

University of British Columbia

Journal reference:

Gawryluk, J.R., et al. (2023) Transient diesel exhaust exposure acutely impairs functional brain connectivity in humans: a randomized controlled crossover study. Environmental Health. doi.org/10.1186/s12940-023-00961-4.