Science & Technology, Canada (Commonwealth Union) – Air pollution has long been known to have a detrimental impact on our health and in recent times research from a variety of academic institutions has focused on the impacts on specific human organs. The negative impact on the brain and cognitive function, with exposure to air pollution, especially fine particulate matter, has been linked to decreased brain function, including a lower IQ, memory, and attention issues, along with an elevated risk of neurodegenerative diseases such as Alzheimer’s and Parkinson’s. Lead exposure, commonly found in air, water, and soil pollution, has also been shown to damage the developing brain that can lead to behavioral problems, learning difficulties, and decreased IQ. Additionally, exposure to toxins such as mercury and polychlorinated biphenyls has been linked to neurodevelopmental and neurobehavioral problems, including autism and ADHD.
Recent research conducted by the University of British Columbia (UBC) and the University of Victoria has indicated that common levels of traffic pollution can impair human brain function in just a matter of hours.
The results that were published in the journal Environmental Health, demonstrate that simply 2 hours of exposure to diesel exhaust leads to a decline in the brain’s functional connectivity, this a measure of how various regions of the brain interact and communicate together. The research gives the 1st evidence in humans, from a controlled experiment, of altered brain network connectivity associated with air pollution.
“For many decades, scientists thought the brain may be protected from the harmful effects of air pollution,” says senior study author Dr. Chris Carlsten, professor and head of respiratory medicine and the Canada Research Chair in occupational and environmental lung disease from the UBC. “This study, which is the first of its kind in the world, provides fresh evidence supporting a connection between air pollution and cognition.”
The research involved briefly exposing 25 healthy adults to diesel exhaust and filtered air at various times in a laboratory. Brain activity was measured prior to and following every exposure with the application of functional magnetic resonance imaging (fMRI).
Scientists evaluated changes in the brain’s default mode network (DMN), a set of inter-connected brain regions having a significant part in memory and internal thought. The fMRI demonstrated that the participants had less functional connectivity in widespread regions of the DMN following exposure to diesel exhaust, when contrasted to filtered air.
“We know that 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,” explained University of Victoria’s Dr. Jodie Gawryluk, who is a psychology professor as well as the 1st author of the study. “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.”
It was observed that, the alterations in the brain were temporary and participants’ connectivity returned to normal following the exposure. Dr. Carlsten postulated that the impacts may be long-lasting with continuous exposure. He stated that individuals should keep in mind of the air they are inhaling and take appropriate measures to lower their exposure to possible toxic air pollutants such as car exhaust.
The study was carried out at the UBC Air Pollution Exposure Laboratory, at the Vancouver General Hospital, that has the very latest exposure booth that can mimic what it is like to inhale a variety of air pollutants. The study, which was carefully designed and approved for safety, the researchers applied freshly-generated exhaust that was diluted and aged to reflect the real-world.
The finding are likely to be of significant use to researchers evaluating neurodegenerative conditions.
