This study involved brain scans of 25 healthy adults taken before and after exposure to traffic fumes. Alarmingly, researchers have found that exposure to the fumes has an immediate effect on the brain, reducing connectivity between brain networks and impairing overall cognitive function.

While the effects of pollution on humans have long been studied, this study is the first to look at its acute effects on brain activity.

Chris Carlsten, MD, senior author of the study, said in a statement: “For decades, scientists believed that the brain could 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 link between air pollution and cognitive function.”

One significant limitation of the study was that it compared filtered air to diesel-polluted air, and diesel vehicles are less common than gasoline vehicles on American roads and highways. Additional studies involving more types of transport pairs will help us understand the global significance of these findings.

It will also be interesting to see what long-term studies find in addition to these acute side effects.

Recent findings on cognitive decline are yet another reason to avoid breathing polluted air whenever possible (and to encourage local legislatures to help encourage the transition to electric cars). The push for cleaner air is easier said than done, especially for racial minorities lower income groups which bear the brunt of air pollution in the US2

“Air pollution is now recognized as the biggest environmental threat to human health, and we’re increasingly seeing effects on all major organ systems,” says Carlsten. “I expect we will see similar effects on the brain from exposure to other air pollutants, such as wildfire smoke. Given the increasing incidence of neurocognitive disorders, this is an important issue for health officials and policymakers.”

Taken together, these findings point to a growing public health crisis that will require collective action. As cleaner energy, transportation and household power options are discussed as green and sustainable options, positive health outcomes must be considered as part of the equation.