Long-Term Exposure to Fine Particulate Matter, Residential Proximity to Major Roads and Measures of Brain Structure (Abstract, Elissa H. Wilker, Sarah R. Preis, Alexa S. Beiser, Philip A. Wolf, Rhoda Au, Itai Kloog, Wenyuan Li, Joel Schwartz, Petros Koutrakis, Charles DeCarli, Sudha Seshadri, Murray A. Mittleman, Strole, American Heart Association, Apr. 23, 20-15)
Also discussed here: Long-term exposure to air pollution may pose risk to brain structure, cognitive functions (ScienceDaily, Apr. 23, 2015)
And here: Air pollution could increase risk of dementia (Laura Donnelly, The Telegraph, Apr. 23, 2015)
And here: Smog may be harming your brain (Health24, Apr. 24, 2015)
Today we review research on heath impacts on the brain from long term exposure to vehicle emissions from nearby traffic. A slight increase in PM 2.5 (by 2 μg/m3) was associated with a decrease in cerebral brain volume equivalent to an extra year of aging. This suggests the air pollution is associated with structural brain aging, even in dementia, and with a 50% greater risk of having a silent stroke which results from a blockage in the blood vessels supplying the brain.. The mechanism that links the brain to air pollution is unclear but the authors suggest that inflammation from fine particles in the lungs is likely important.
“the study found that an increase of only 2µg per cubic meter in PM2.5, a range commonly observed across metropolitan regions in New England and New York, was associated with being more likely to have covert brain infarcts and smaller cerebral brain volume, equivalent to approximately one year of brain aging.”
"The mechanisms through which air pollution may affect brain aging remain unclear, but systemic inflammation resulting from the deposit of fine particles in the lungs is likely important."
“This study shows that for a 2 microgram per cubic meter of air (μg/m3) increase in PM2.5, a range commonly observed across major US cities, on average participants who lived in more polluted areas had the brain volume of someone a year older than participants who lived in less polluted areas. They also had a 46 percent higher risk of silent strokes on MRI,"
“A 2-μg/m3 increase in PM2.5 was associated with −0.32%...smaller total cerebral brain volume and 1.46 …higher odds of covert brain infarcts. Living further away from a major roadway was associated with 0.10 greater log-transformed white matter hyperintensity volume for an interquartile range difference in distance”
“researchers who studied more than 900 participants of the Framingham Heart Study found evidence of smaller brain structure and of covert brain infarcts, a type of "silent" ischemic stroke resulting from a blockage in the blood vessels supplying the brain.”
“Exposure to elevated levels of PM2.5 was associated with smaller total cerebral brain volume, a marker of age-associated brain atrophy, and with higher odds of covert brain infarcts. These findings suggest that air pollution is associated with insidious effects on structural brain aging even in dementia- and stroke-free persons.”
"Our findings suggest that air pollution is associated with insidious effects on structural brain aging, even in dementia- and stroke-free individuals."