A new study has shed light on the shocking effects long-term exposure to fine particle air pollution may cause – such as subtle structural changes in the brain that increase risks of poor cognitive function and dementia.
Fine particle air pollution – smaller than 2.5 micrometers in diameter (PM 2.5) may be the most common and hazardous type of air pollution, the study shows. These fine particles comes from burning wood or coal, car exhaust and other sources.
“Long-term exposure to air pollution showed harmful effects on the brain in this study, even at low levels, particularly with older people and even those who are relatively healthy,” said lead study author Elissa Wilker, instructor of medicine at the Harvard Medical School.
Researchers analyzed 943 adults who were healthy and free of dementia and stroke. The pool of participants lived in the greater Boston area and throughout New England and New York – regions where air pollution levels are low compared to other parts of the nation and world.
During a 10-year timeframe from 1995-2005, researchers used magnetic resonance imaging (MRI) to determine the effect of long-term exposure to air pollution on markers of brain structure.
They found a two microgram per cubic meter of air increase in particulate matter (PM) 2.5 was associated with a 0.32 percent smaller total cerebral brain volume and 46 percent higher risk of covert brain infarcts, a type of silent stroke the Times of India reported.
“The magnitude of association that we observed for brain volume was similar to approximately one year of brain ageing,” Wilker said.
Fundamental changes in the structure of the cerebral brain volume and smaller brain size are markers of age-associated brain atrophy, the study wrote.
The small infarcts, typically located in deep regions of the brain, have been associated with neurological abnormalities, poor cognitive function, dementia, and are thought to reflect small vessel disease, the researchers concluded.
The findings were published in the journal Stroke.