Air pollution is back in the spotlight because of more frequent wildfires and also efforts to roll back air quality regulations in the U.S. and around the world. At University of Rochester Medicine, researchers are helping to show why this matters not only for your lungs but also for your brain.
“Air pollution is a global threat,” said Marissa Sobolewski, PhD, associate professor of Environmental Medicine and Neuroscience. “Its effects are broader than many people realize.”
How Air Pollution Affects the Brain
Air pollution has mainly been viewed as a lung and heart problem, but new research shows it can also affect brain health. It may contribute to problems ranging from learning difficulties to dementia.
URochester Medicine researchers have long been part of the foundational work showing that very small airborne particles can reach the brain. These tiny particles, called ultrafine particles, are so small that they can move from the nose or lungs into the brain and other parts of the body.
Experts say the danger is not tied to just one disease. Instead, air pollution appears to act as a broad risk factor that can worsen both developmental and degenerative brain disorders.
“In many ways, there’s a shared trigger,” said URochester Medicine researcher Alison Elder, PhD. “Inflammation and oxidative stress may be part of the reason that pollution has such broad effects.”
What Are Ultrafine Particles?
Air pollution contains particles of different sizes, including coarse particles, fine particles (like PM2.5), and ultrafine particles. Ultrafine particles are so small that thousands could fit across the width of a single grain of salt, and some are similar in size to viruses.
These ultrafine particles are especially concerning because they can:
Children and Air Pollution Risk
Children may be especially vulnerable because their brains are still developing. Brain growth depends on carefully timed stages, including cell development, migration, synapse formation, and the process of myelination as nerve cells grow.
“Childhood is a window of unique sensitivity,” said Sobolewski. “Timing matters.”
Research suggests that exposure during pregnancy and early life may affect impulsivity, learning, cognitive flexibility, and social development.
Studies in animals and humans also support the idea that exposure during early development can lead to lasting changes in brain structure and function.
Why Children Are at Higher Risk
Children may face greater harm because:
These early-life exposures can have lasting effects that show up later in life. Sobolewski and colleagues are especially interested in how these effects may differ by sex and developmental stage.
Air Pollution and Neurodegenerative Disease
Air pollution has also been linked to neurodegenerative disorders such as Alzheimer’s and Parkinson’s disease.
Studies link air pollution exposure to:
Researchers are also studying how air pollution may affect the brain’s waste-clearing systems, including the glymphatic system, which helps move fluid and remove toxins. If this system does not work well, harmful substances may linger in the brain longer.
“Cleaner environmental standards can make a real difference.”
URochester Medicine scientists continue to study these links, including how high-exposure settings such as wildfires, burn pits, subways, and welding environments may affect brain aging and disease risk.
How to Protect Your Brain
While no one can avoid air pollution entirely, there are practical steps people and families can take to reduce exposure.
On High-Pollution Days (Including During Wildfires):
Check the Air Quality Before Heading Out
Check the Air Quality Index (AQI) on your phone weather app or through AirNow.gov. Green on the index is generally safe, but people with asthma, COPD, or other conditions may need to be more cautious even at moderate levels.
“Pay attention to AQI,” said URochester Medicine pulmonologist Dan Croft, MD. “It can help guide safer choices.”
Support Overall Brain Health
Good sleep, a balanced diet, and regular physical activity can help the body better handle environmental stressors. Croft noted that these basics matter: “Sleep, nutrition, and movement all help build resilience.”
The Bigger Picture
Air pollution is not just an environmental issue. It is also a brain health issue.
As URochester Medicine researchers continue to study how pollution affects children, adults, and aging brains, their work is helping build the case for stronger protections and smarter prevention.
“Better air quality standards mean better health,” said Sobolewski. “That includes brain health.”
Local Research, Global Impact
Founded in 1975, the Rochester Environmental Health Sciences Center focuses on preventing and reducing diseases linked to environmental factors. Through translational research and partnerships, we work to turn discoveries into real-world strategies that help prevent disease and improve human health.