Air pollution affects children’s brain structure
Exposure to fine particulate matter (PM2.5) in childhood can change the architecture of the brain, according to an NIEHS-funded study. This study was the first to document links between exposure to air pollution at levels below regulatory standards and white matter connectivity in children across the U.S. White matter connectivity is critical for communication between cognitive and emotional regions of the brain.
Researchers used data from nearly 8,000 nine- and 10-year-old children across the U.S. They estimated exposure to PM2.5 by integrating advanced machine learning models and each child’s address of residence. They examined brain white matter architecture using magnetic resonance imaging, advanced diffusion weighted imaging, and biophysical modeling, and analyzed associations with air pollution exposure.
There were strong associations between PM2.5 levels and differences in white matter structure and diffusivity. Diffusivity is used to examine structural integrity and variations in the space between cells and cerebrospinal fluid. PM2.5 increased a type of diffusion that indicates changes in the cellular composition of white matter tracts in brain regions important in attention, emotional processing, and memory. Some regions were affected only in the left side of the brain, which controls language and logic, and others were affected in both sides of the brain.
Because most of the study population had PM2.5 exposures below regulatory levels set by the U.S. Environmental Protection Agency, the team suggested further improvements in air quality are needed to protect the developing brain.
Citation: Burnor E, Cserbik D, Cotter DL, Palmer CE, Ahmadi H, Eckel SP, Berhane K, McConnell R, Chen JC, Schwartz J, Jackson R, Herting MM. 2021. Association of outdoor ambient fine particulate matter with intracellular white matter microstructural properties among children. JAMA Netw Open 4(12):e2138300.