A recent paper published on 2015 February by the American Heart Association have suggested that long term exposure to air pollutions can shrink brain sizes.
It have long being known that brain diseases and reduction in cognitive capabilities have been linked to air pollutions. However the exact mechanism of air pollutants causing these diseases were poorly understood. And in their recent studies, neuroscientists have attempted to examine the brain using Magnetic Resonance Imaging.
In their studies, they used participants were at least 60 years old and not suffering from any brain diseases. The research took note of the proximity of their home to major highways and the total volume of various parts of their brain.
What researchers have found were that an increase of 2 micro grams of air pollutants per meter cubic were found to cause a decrease in volume of various brain regions. While participants who lived far away from major roadways were found to have a much larger brain.
Researchers concluded that air pollutants play a significant role in causing structural changes in humans and these structural changes would eventually manifest itself as brain diseases like stroke and dementia.