Two new studies examine how particulate matter pollution affects the brain

Pollution is a global problem and affects us all. Two new studies shed light on how fine dust pollution in the air, for exampleof cars and power plants, affects our brain.

Particulate matter pollution affects brain development in children

The first study, published in Environment International, found that the particulate matter known as PM2.5 can change the size of a child's developing brain, ultimately increasing the risk of cognitive and emotional problems later in life adolescence can increase.

At this young age, the neurons in children's brains are expanding at incredible speeds. “As your brain develops, it wants to create efficient networks,” said lead author Megan Herting, an assistant professor at the Keck School of Medicine of USC. “When these networks are altered by particulate matter pollution, different parts of the brain can mature and make connections at different rates. This could trigger individual differences later.”

Herting's team used MRI scans of nearly 11,000 children ages nine and 10 from 21 cities in the United States and compared each scan with annual pollution data for each child's place of residence. This is the first study of its kind to show that particulate matter pollution, even at relatively low levels, may be an important environmental factor affecting the patterns of brain development in American children.

When they compared highly exposed children with those less exposed to PM2.5, they saw differences. For example, areas associated with emotions were larger in highly exposed children, while other areas associated with cognitive functions were smaller.

Herting plans to track the children's progress as part of the ABCD Study - the largest long-term study of brain health and child development in the United States.

Eating fish could protect the brain from fine dust pollution

The second study, published in the journal Neurology, found that omega-3 fatty acids may protect older women from brain shrinkage.

Previous research showed that women in their 70s and 80s who were exposed to higher levels of air pollution experienced greater memory loss and Alzheimer's-like brain atrophy than their peers who breathed cleaner air.

For this study, researchers examined the brain MRIs of 1,315 women ages 65 to 80 and the results of blood tests to determine the levels of healthy omega-3 fatty acids in their blood.

"We found that women with higher omega-3 blood levels had larger amounts of brain white matter compared to those who lived in places with higher levels of PM2.5 in the air," said author Jiu-Chiuan Chen, a professor at the Keck School of Medicine of USC.

The white matter, in contrast to the gray, makes up the largest part of the brain volume. It is the vast, intertwined system of neural connections that unites different regions of the brain where various mental processes take place. Loss of white matter can be a sign of Alzheimer's disease.

Weitere Informationen: Dora Cserbik et al. Fine particulate matter exposure during childhood relates to hemispheric-specific differences in brain structure, Environment International (2020).DOI: 10.1016/j.envint.2020.105933
Cheng Chen et al. Erythrocyte omega-3 index, ambient fine particle exposure and brain aging, Neurology (2020).DOI: 10.1212 / WNL.0000000000010074