OHSU researchers report that common air pollutants—particulate matter, nitrogen dioxide and ozone—are associated with changes in cortical thickness in adolescents, especially in frontal and temporal brain regions. The analysis of nearly 11,000 ABCD study participants found associations for baseline exposure around ages nine to ten. Effects were strongest in urban areas but were also observed below current EPA safety thresholds, prompting calls for cleaner transportation, more green space and stricter air-quality rules.
OHSU Study: Common Air Pollutants Linked to Structural Changes in Adolescent Brains
OHSU finds air pollution can deter adolescent brain development
A new study from Oregon Health & Science University (OHSU) finds that common air pollutants — including particulate matter, nitrogen dioxide and ozone — are associated with measurable structural changes in adolescent brains.
Published in the January 2026 issue of Environmental Research, the study analyzed nearly 11,000 participants from the Adolescent Brain Cognitive Development (ABCD) study, the largest longitudinal investigation of brain development in U.S. youth. Researchers focused on baseline exposure during the early phase of adolescence, roughly around the onset of puberty at ages nine to ten.
The team reported that exposure to these pollutants was linked with alterations in cortical thickness, particularly in the frontal and temporal lobes — regions that support executive function, language, mood regulation and socioemotional processing. Atypical cortical thinning can signal atypical maturation and may be associated with later cognitive and emotional difficulties.
"What we’re discovering is that chronic exposure to common, low-level air pollutants may act like a slow, subtle pressure on the developing brain," said Calvin Jara, M.D., the study’s lead author and an otolaryngology/head and neck surgery resident at OHSU. "It may not cause symptoms right away, but over time it appears capable of nudging brain development off its typical course."
While effects were strongest in urban areas with higher pollution levels, the researchers also observed similar brain-structure changes in children exposed to pollution concentrations below current U.S. Environmental Protection Agency (EPA) safety thresholds. This raises concerns that even “low-level”, chronic exposure could have widespread developmental consequences.
Researchers warn that structural changes in frontal and temporal regions could undermine attention, memory and emotional regulation. The authors emphasize the need for follow-up studies to determine long-term outcomes and to explore the biological mechanisms linking air pollution with brain development.
"Environmental factors have a huge impact on how healthy children can be, and ultimately how healthy they’ll be over their lifetime," said Bonnie Nagel, Ph.D., OHSU’s interim chief research officer and a co-author of the study. "This work adds to the growing evidence that pollution is not just an environmental issue, but a significant public-health concern for our youngest and most vulnerable."
The study authors call for public-policy actions to reduce pollution exposure, such as cleaner transportation and infrastructure, expanded access to green space, and stricter air-quality standards, alongside continued research into long-term neurodevelopmental effects.
Study source: OHSU; published in Environmental Research, January 2026. Analysis based on the ABCD study dataset (nearly 11,000 participants).
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